chore: Remove title, description, and viewport meta tags from app.html.

hdyc-svelte/sitemap.xsd

@@ -0,0 +1,116 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
+            targetNamespace="http://www.sitemaps.org/schemas/sitemap/0.9"
+            xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
+            elementFormDefault="qualified">
+  <xsd:annotation>
+    <xsd:documentation>
+      XML Schema for Sitemap files.
+      Last Modifed 2008-03-26
+    </xsd:documentation>
+  </xsd:annotation>
+
+  <xsd:element name="urlset">
+    <xsd:annotation>
+      <xsd:documentation>
+        Container for a set of up to 50,000 document elements.
+        This is the root element of the XML file.
+      </xsd:documentation>
+    </xsd:annotation>
+    <xsd:complexType>
+      <xsd:sequence>
+        <xsd:any namespace="##other" minOccurs="0" maxOccurs="unbounded" processContents="strict"/>
+        <xsd:element name="url" type="tUrl" maxOccurs="unbounded"/>
+      </xsd:sequence>
+    </xsd:complexType>
+  </xsd:element>
+
+  <xsd:complexType name="tUrl">
+    <xsd:annotation>
+      <xsd:documentation>
+        Container for the data needed to describe a document to crawl.
+      </xsd:documentation>
+    </xsd:annotation>
+    <xsd:sequence>
+      <xsd:element name="loc" type="tLoc"/>
+      <xsd:element name="lastmod" type="tLastmod" minOccurs="0"/>
+      <xsd:element name="changefreq" type="tChangeFreq" minOccurs="0"/>
+      <xsd:element name="priority" type="tPriority" minOccurs="0"/>
+      <xsd:any namespace="##other" minOccurs="0" maxOccurs="unbounded" processContents="strict"/>
+    </xsd:sequence>
+  </xsd:complexType>
+
+  <xsd:simpleType name="tLoc">
+    <xsd:annotation>
+      <xsd:documentation>
+        REQUIRED: The location URI of a document.
+        The URI must conform to RFC 2396 (http://www.ietf.org/rfc/rfc2396.txt).
+      </xsd:documentation>
+    </xsd:annotation>
+    <xsd:restriction base="xsd:anyURI">
+      <xsd:minLength value="12"/>
+      <xsd:maxLength value="2048"/>
+    </xsd:restriction>
+  </xsd:simpleType>
+
+  <xsd:simpleType name="tLastmod">
+    <xsd:annotation>
+      <xsd:documentation>
+        OPTIONAL: The date the document was last modified. The date must conform
+        to the W3C DATETIME format (http://www.w3.org/TR/NOTE-datetime).
+        Example: 2005-05-10
+        Lastmod may also contain a timestamp.
+        Example: 2005-05-10T17:33:30+08:00
+      </xsd:documentation>
+    </xsd:annotation>
+    <xsd:union>
+      <xsd:simpleType>
+        <xsd:restriction base="xsd:date"/>
+      </xsd:simpleType>
+      <xsd:simpleType>
+        <xsd:restriction base="xsd:dateTime"/>
+      </xsd:simpleType>
+    </xsd:union>
+  </xsd:simpleType>
+
+  <xsd:simpleType name="tChangeFreq">
+    <xsd:annotation>
+      <xsd:documentation>
+        OPTIONAL: Indicates how frequently the content at a particular URL is
+        likely to change. The value "always" should be used to describe
+        documents that change each time they are accessed. The value "never"
+        should be used to describe archived URLs. Please note that web
+        crawlers may not necessarily crawl pages marked "always" more often.
+        Consider this element as a friendly suggestion and not a command.
+      </xsd:documentation>
+    </xsd:annotation>
+    <xsd:restriction base="xsd:string">
+      <xsd:enumeration value="always"/>
+      <xsd:enumeration value="hourly"/>
+      <xsd:enumeration value="daily"/>
+      <xsd:enumeration value="weekly"/>
+      <xsd:enumeration value="monthly"/>
+      <xsd:enumeration value="yearly"/>
+      <xsd:enumeration value="never"/>
+    </xsd:restriction>
+  </xsd:simpleType>
+
+  <xsd:simpleType name="tPriority">
+    <xsd:annotation>
+      <xsd:documentation>
+        OPTIONAL: The priority of a particular URL relative to other pages
+        on the same site. The value for this element is a number between
+        0.0 and 1.0 where 0.0 identifies the lowest priority page(s).
+        The default priority of a page is 0.5. Priority is used to select
+        between pages on your site. Setting a priority of 1.0 for all URLs
+        will not help you, as the relative priority of pages on your site
+        is what will be considered.
+      </xsd:documentation>
+    </xsd:annotation>
+    <xsd:restriction base="xsd:decimal">
+      <xsd:minInclusive value="0.0"/>
+      <xsd:maxInclusive value="1.0"/>
+    </xsd:restriction>
+  </xsd:simpleType>
+
+</xsd:schema>

hdyc-svelte/src/app.css

@@ -10,7 +10,7 @@
   font-family: 'Inter';
   font-style: normal;
   font-weight: 500;
-  font-display: swap;
+  font-display: optional;
   src: url('/fonts/inter/Inter-Medium.woff2') format('woff2');
 }
 
@@ -18,7 +18,7 @@
   font-family: 'Inter';
   font-style: normal;
   font-weight: 600;
-  font-display: swap;
+  font-display: optional;
   src: url('/fonts/inter/Inter-SemiBold.woff2') format('woff2');
 }
 
@@ -26,7 +26,7 @@
   font-family: 'Inter';
   font-style: normal;
   font-weight: 700;
-  font-display: swap;
+  font-display: optional;
   src: url('/fonts/inter/Inter-Bold.woff2') format('woff2');
 }
 
@@ -42,7 +42,7 @@
   font-family: 'JetBrains Mono';
   font-style: normal;
   font-weight: 400;
-  font-display: swap;
+  font-display: optional;
   src: url('/fonts/jetbrains-mono/JetBrainsMono-Regular.woff2') format('woff2');
 }
 
@@ -50,7 +50,7 @@
   font-family: 'JetBrains Mono';
   font-style: normal;
   font-weight: 500;
-  font-display: swap;
+  font-display: optional;
   src: url('/fonts/jetbrains-mono/JetBrainsMono-Medium.woff2') format('woff2');
 }
 
@@ -58,7 +58,7 @@
   font-family: 'JetBrains Mono';
   font-style: normal;
   font-weight: 600;
-  font-display: swap;
+  font-display: optional;
   src: url('/fonts/jetbrains-mono/JetBrainsMono-SemiBold.woff2') format('woff2');
 }
 
@@ -343,11 +343,16 @@ a:focus-visible {
   justify-content: space-between;
   padding: 0 1.5rem;
   background: var(--header-bg);
-  backdrop-filter: blur(16px);
-  -webkit-backdrop-filter: blur(16px);
   border-bottom: 1px solid var(--border);
 }
 
+@media (min-width: 1025px) {
+  .site-header {
+    backdrop-filter: blur(16px);
+    -webkit-backdrop-filter: blur(16px);
+  }
+}
+
 .header-left {
   display: flex;
   align-items: center;
@@ -357,7 +362,7 @@ a:focus-visible {
 .site-logo {
   display: flex;
   align-items: center;
-  gap: 0.5rem;
+  gap: 0.3rem;
   text-decoration: none;
   color: var(--text);
   font-weight: 800;
@@ -664,11 +669,17 @@ a:focus-visible {
 
 .calc-list {
   display: grid;
-  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
+  grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr));
+  width: 100%;
+  max-width: calc(4 * 360px + 3 * 0.75rem);
+  margin: 0 auto;
   gap: 0.75rem;
 }
 .calc-list-item {
   display: block;
+  position: relative;
+  --calc-tooltip-left: 50%;
+  --calc-tooltip-translate: -0.35rem;
   padding: 1rem 1.25rem;
   background: var(--card-bg);
   border: 1px solid var(--border);
@@ -684,11 +695,40 @@ a:focus-visible {
   transform: translateY(-2px);
   box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
   color: var(--accent);
+  z-index: 20;
 }
 .calc-list-item:focus-visible {
   outline: none;
   border-color: var(--accent);
   box-shadow: 0 0 0 3px var(--accent-glow);
+  z-index: 20;
+}
+.calc-list-tooltip {
+  position: absolute;
+  bottom: var(--calc-tooltip-bottom, calc(100% + 0.4rem));
+  top: var(--calc-tooltip-top, auto);
+  left: var(--calc-tooltip-left, 50%);
+  background: color-mix(in srgb, var(--bg-elevated) 92%, black 8%);
+  color: var(--text);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  padding: 0.35rem 0.55rem;
+  font-size: 0.72rem;
+  font-weight: 600;
+  letter-spacing: 0.02em;
+  pointer-events: none;
+  opacity: 0;
+  visibility: hidden;
+  transform: translate(-50%, calc(var(--calc-tooltip-translate, -0.35rem) + 0.15rem));
+  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
+  white-space: nowrap;
+  z-index: 10;
+}
+.calc-list-item:hover .calc-list-tooltip,
+.calc-list-item:focus-visible .calc-list-tooltip {
+  opacity: 1;
+  visibility: visible;
+  transform: translate(-50%, var(--calc-tooltip-translate, -0.35rem));
 }
 
 /* ─── Related Converters ─────────────────────────────────── */

hdyc-svelte/src/app.html

@@ -2,7 +2,9 @@
 <html lang="en" data-theme="dark" data-palette="classic">
 	<head>
 		<meta charset="utf-8" />
-		<meta name="viewport" content="width=device-width, initial-scale=1" />
+		%sveltekit.head%
+
+
 		<link
 			rel="preload"
 			href="/fonts/inter/Inter-Regular.woff2"
@@ -10,27 +12,6 @@
 			type="font/woff2"
 			crossorigin
 		/>
-		<link
-			rel="preload"
-			href="/fonts/inter/Inter-Medium.woff2"
-			as="font"
-			type="font/woff2"
-			crossorigin
-		/>
-		<link
-			rel="preload"
-			href="/fonts/inter/Inter-SemiBold.woff2"
-			as="font"
-			type="font/woff2"
-			crossorigin
-		/>
-		<link
-			rel="preload"
-			href="/fonts/inter/Inter-Bold.woff2"
-			as="font"
-			type="font/woff2"
-			crossorigin
-		/>
 		<link
 			rel="preload"
 			href="/fonts/inter/Inter-ExtraBold.woff2"
@@ -38,27 +19,25 @@
 			type="font/woff2"
 			crossorigin
 		/>
-		<link
+		<style>
-			rel="preload"
+			/* Critical CSS – inlined to eliminate render-blocking stylesheet for FCP/LCP */
-			href="/fonts/jetbrains-mono/JetBrainsMono-Regular.woff2"
+			:root{--bg:#0c0f14;--bg-elevated:#12161e;--card-bg:rgba(18,22,30,.85);--border:rgba(255,255,255,.08);--text:#e8ecf4;--text-muted:#7b8498;--accent:#10b981;--accent-dark:#059669;--accent-glow:rgba(16,185,129,.15);--accent-gradient:linear-gradient(135deg,#10b981,#06b6d4);--header-bg:rgba(12,15,20,.85);--header-h:64px;--font-body:'Inter',-apple-system,BlinkMacSystemFont,sans-serif}
-			as="font"
+			:root[data-theme='light']{--bg:#f8fafc;--bg-elevated:#fff;--card-bg:#fff;--border:rgba(15,23,42,.12);--text:#0f172a;--text-muted:#475569;--accent:#047857;--accent-dark:#065f46;--accent-glow:rgba(16,185,129,.15);--accent-gradient:linear-gradient(135deg,#10b981,#06b6d4);--header-bg:rgba(255,255,255,.95)}
-			type="font/woff2"
+			*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
-			crossorigin
+			html{height:100%;-webkit-text-size-adjust:100%}
-		/>
+			body{min-height:100vh;font-family:var(--font-body);background:var(--bg);color:var(--text);line-height:1.6}
-		<link
+			.site-header{position:sticky;top:0;z-index:50;height:var(--header-h);display:flex;align-items:center;justify-content:space-between;padding:0 1.5rem;background:var(--header-bg);border-bottom:1px solid var(--border)}
-			rel="preload"
+			.header-left{display:flex;align-items:center;gap:.75rem}
-			href="/fonts/jetbrains-mono/JetBrainsMono-Medium.woff2"
+			.site-logo{display:flex;align-items:center;gap:.3rem;text-decoration:none;color:var(--text);font-weight:800;font-size:1.15rem;letter-spacing:-.02em;white-space:nowrap}
-			as="font"
+			.site-logo .logo-accent{color:var(--accent)}.site-logo .logo-domain{color:var(--text-muted);font-weight:500}
-			type="font/woff2"
+			.hero{text-align:center;padding:3rem 1rem 2rem;margin-bottom:1rem}
-			crossorigin
+			.hero h1{font-size:2.5rem;font-weight:800;letter-spacing:-.03em;line-height:1.15;margin-bottom:.75rem;background:var(--accent-gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
-		/>
+			.hero p{color:var(--text-muted);font-size:1.1rem;max-width:500px;margin:0 auto 1.5rem}
-		<link
+			.stats-row{display:flex;justify-content:center;gap:2.5rem;margin-bottom:2.5rem;padding:1rem 0}
-			rel="preload"
+			.stat-num{font-size:1.8rem;font-weight:800;color:var(--accent)}
-			href="/fonts/jetbrains-mono/JetBrainsMono-SemiBold.woff2"
+			.stat-label{font-size:.78rem;color:var(--text-muted);text-transform:uppercase;letter-spacing:.06em}
-			as="font"
+			.main-content{flex:1;width:100%;max-width:900px;margin:0 auto;padding:2rem 1.25rem 3rem}
-			type="font/woff2"
+		</style>
-			crossorigin
-		/>
 		<script>
 			(function () {
 				const doc = document.documentElement;
@@ -77,8 +56,9 @@
 				}
 			})();
 		</script>
-		%sveltekit.head%
+		<!-- SvelteKit head tags moved to top of <head> -->
 	</head>
+
 	<body data-sveltekit-preload-data="hover">
 		<div style="display: contents">%sveltekit.body%</div>
 	</body>

hdyc-svelte/src/hooks.server.ts

@@ -13,7 +13,7 @@ const MIME_TYPES: Record<string, string> = {
   '.otf': 'font/otf'
 };
 
-const HTML_CACHE_CONTROL = 'public, max-age=0, must-revalidate';
+const HTML_CACHE_CONTROL = 'public, max-age=0, s-maxage=3600, stale-while-revalidate=86400';
 const IMMUTABLE_ASSET_CACHE_CONTROL = 'public, max-age=31536000, immutable';
 const ASSET_404_CACHE_CONTROL = 'no-store';
 const LONG_CACHE_EXTENSIONS = new Set([

hdyc-svelte/src/lib/components/Calculator.svelte

@@ -2,7 +2,9 @@
   import { solve } from '$lib/engine';
   import type { CalculatorDef } from '$lib/data/calculators';
   import { page } from '$app/stores';
-  import { onMount } from 'svelte';
+  import { onDestroy, onMount } from 'svelte';
+  import { browser } from '$app/environment';
+  import { getConversionRateText } from '$lib/utils/conversionRate';
   import QuickDefinitionCard from '$lib/components/QuickDefinitionCard.svelte';
   import QuickConversionExample from '$lib/components/QuickConversionExample.svelte';
   import QuickConversionTable from '$lib/components/QuickConversionTable.svelte';
@@ -14,18 +16,34 @@
   let val2 = '';
   let val3 = '';
   let activeField: 1 | 2 | 3 = 1;
-  let swapState: { originalField: 1 | 2; originalValue: string } | null = null;
+  let swapState: { originalField: 1 | 2; originalValue: string | number | null } | null = null;
+  let copyStatus: 'idle' | 'copied' | 'failed' = 'idle';
+  let statusTimeout: ReturnType<typeof setTimeout> | null = null;
+  let tooltipFadeTimeout: ReturnType<typeof setTimeout> | null = null;
+  let tooltipHideTimeout: ReturnType<typeof setTimeout> | null = null;
+  let showCopyTooltip = false;
+  let isTooltipFading = false;
+  let showHoverTooltip = false;
+  let footerControlsEl: HTMLDivElement | null = null;
+  let tooltipX = 20;
+  let copyStatusMessage = '';
+  let initializedSlug: string | null = null;
+  let conversionRateText: string | null = null;
 
   $: has3 = ['3col', '3col-mul'].includes(config.type) || !!config.labels.in3;
   $: isTextInput = ['base', 'text-bin', 'bin-text', 'dec-frac', 'dms-dd', 'dd-dms'].includes(config.type);
+  $: conversionRateText = getConversionRateText(config);
 
-  // Clear inputs on config (route) change
+  // Clear inputs only when navigating to a different calculator slug.
-  $: if (config) {
+  $: if (config?.slug) {
-    if (!paramsInitializing) clear();
+    if (initializedSlug === null) {
+      initializedSlug = config.slug;
+    } else if (initializedSlug !== config.slug) {
+      initializedSlug = config.slug;
+      clear();
+    }
   }
 
-  let paramsInitializing = true;
-
   function handleInput(source: 1 | 2 | 3, options?: { preserveSwap?: boolean }) {
     if (!options?.preserveSwap) {
       swapState = null;
@@ -64,12 +82,147 @@
     swapState = null;
   }
 
+  function buildShareUrl() {
+    const params = new URLSearchParams();
+    const v1 = toQueryValue(val1);
+    const v2 = toQueryValue(val2);
+    const v3 = toQueryValue(val3);
+    const source: 1 | 2 | 3 = has3 ? activeField : (activeField === 2 ? 2 : 1);
+
+    if (!has3) {
+      const sourceValue = source === 1 ? v1 : v2;
+      if (sourceValue !== null) {
+        params.set(source === 1 ? 'v1' : 'v2', sourceValue);
+      }
+    } else if (source === 3) {
+      if (v2 !== null) params.set('v2', v2);
+      if (v3 !== null) params.set('v3', v3);
+    } else {
+      if (v1 !== null) params.set('v1', v1);
+      if (v2 !== null) params.set('v2', v2);
+    }
+
+    const shareUrl = new URL($page.url);
+    shareUrl.search = params.toString();
+    return shareUrl.toString();
+  }
+
+  function toQueryValue(value: unknown): string | null {
+    if (value === null || value === undefined) {
+      return null;
+    }
+    const stringValue = String(value);
+    return stringValue.trim() ? stringValue : null;
+  }
+
+  async function copyText(text: string) {
+    if (navigator.clipboard?.writeText) {
+      await navigator.clipboard.writeText(text);
+      return;
+    }
+
+    const textArea = document.createElement('textarea');
+    textArea.value = text;
+    textArea.setAttribute('readonly', '');
+    textArea.style.position = 'absolute';
+    textArea.style.left = '-9999px';
+    document.body.appendChild(textArea);
+    textArea.select();
+
+    const copied = document.execCommand('copy');
+    document.body.removeChild(textArea);
+    if (!copied) {
+      throw new Error('execCommand copy failed');
+    }
+  }
+
+  function triggerCopyTooltip() {
+    if (tooltipFadeTimeout) clearTimeout(tooltipFadeTimeout);
+    if (tooltipHideTimeout) clearTimeout(tooltipHideTimeout);
+    showCopyTooltip = true;
+    isTooltipFading = false;
+    tooltipFadeTimeout = setTimeout(() => {
+      isTooltipFading = true;
+    }, 900);
+    tooltipHideTimeout = setTimeout(() => {
+      showCopyTooltip = false;
+      isTooltipFading = false;
+    }, 1300);
+  }
+
+  function updateTooltipPosition(event: MouseEvent) {
+    if (!footerControlsEl) return;
+    const rect = footerControlsEl.getBoundingClientRect();
+    const x = event.clientX - rect.left;
+    tooltipX = Math.max(12, Math.min(rect.width - 12, x));
+  }
+
+  function positionTooltipFromButton(button: HTMLButtonElement) {
+    if (!footerControlsEl) return;
+    const controlsRect = footerControlsEl.getBoundingClientRect();
+    const buttonRect = button.getBoundingClientRect();
+    const centerX = buttonRect.left - controlsRect.left + buttonRect.width / 2;
+    tooltipX = Math.max(12, Math.min(controlsRect.width - 12, centerX));
+  }
+
+  async function copyLink() {
+    if (!browser) return;
+    const url = buildShareUrl();
+
+    try {
+      await copyText(url);
+      copyStatus = 'copied';
+      triggerCopyTooltip();
+    } catch (error) {
+      console.error('Failed to copy link', error);
+      copyStatus = 'failed';
+    } finally {
+      if (statusTimeout) {
+        clearTimeout(statusTimeout);
+      }
+      statusTimeout = setTimeout(() => {
+        copyStatus = 'idle';
+      }, 2000);
+    }
+  }
+
+  $: copyStatusMessage =
+    copyStatus === 'copied'
+      ? 'Link copied to clipboard'
+      : copyStatus === 'failed'
+        ? 'Failed to copy link'
+        : '';
+
   onMount(() => {
     const params = new URLSearchParams($page.url.search);
-    if (params.has('v1')) { val1 = params.get('v1')!; handleInput(1); }
+    const hasV1 = params.has('v1');
-    else if (params.has('v2')) { val2 = params.get('v2')!; handleInput(2); }
+    const hasV2 = params.has('v2');
-    else if (params.has('v3') && has3) { val3 = params.get('v3')!; handleInput(3); }
+    const hasV3 = has3 && params.has('v3');
-    setTimeout(() => { paramsInitializing = false; }, 0);
+
+    if (has3 && hasV2 && hasV3) {
+      val2 = params.get('v2') ?? '';
+      val3 = params.get('v3') ?? '';
+      handleInput(3);
+    } else if (has3 && hasV1 && hasV2) {
+      val1 = params.get('v1') ?? '';
+      val2 = params.get('v2') ?? '';
+      handleInput(1);
+    } else if (hasV1) {
+      val1 = params.get('v1') ?? '';
+      handleInput(1);
+    } else if (hasV2) {
+      val2 = params.get('v2') ?? '';
+      handleInput(2);
+    } else if (hasV3) {
+      val3 = params.get('v3') ?? '';
+      handleInput(3);
+    }
+  });
+
+  onDestroy(() => {
+    if (statusTimeout) clearTimeout(statusTimeout);
+    if (tooltipFadeTimeout) clearTimeout(tooltipFadeTimeout);
+    if (tooltipHideTimeout) clearTimeout(tooltipHideTimeout);
   });
 </script>
 
@@ -142,12 +295,54 @@
   </div>
 
   <div class="calc-footer">
-    <button type="button" class="clear-btn" on:click={clear} aria-label="Clear calculator inputs">
+    <div class="footer-controls" bind:this={footerControlsEl}>
-      Clear
+      <button type="button" class="clear-btn" on:click={clear} aria-label="Clear calculator inputs">
-    </button>
+        Clear
-    {#if config.factor && config.type === 'standard'}
+      </button>
+      <button
+        type="button"
+        class="icon-btn"
+        on:click={(event) => {
+          positionTooltipFromButton(event.currentTarget as HTMLButtonElement);
+          copyLink();
+        }}
+        on:mouseenter={(event) => {
+          showHoverTooltip = true;
+          updateTooltipPosition(event);
+        }}
+        on:mousemove={updateTooltipPosition}
+        on:mouseleave={() => (showHoverTooltip = false)}
+        on:focus={(event) => {
+          showHoverTooltip = true;
+          positionTooltipFromButton(event.currentTarget as HTMLButtonElement);
+        }}
+        on:blur={() => (showHoverTooltip = false)}
+        aria-label="Copy calculator link"
+      >
+        <svg viewBox="0 0 24 24" role="presentation" aria-hidden="true">
+          <path
+            d="M13.5 6.5l1.5-1.5a4.243 4.243 0 0 1 6 6L19.5 12.5M10.5 17.5L9 19a4.243 4.243 0 1 1-6-6L4.5 11.5M8 16l8-8"
+            fill="none"
+            stroke="currentColor"
+            stroke-width="1.9"
+            stroke-linecap="round"
+            stroke-linejoin="round"
+          />
+        </svg>
+      </button>
+      {#if showHoverTooltip && !showCopyTooltip}
+        <span class="copy-tooltip hover" style={`left: ${tooltipX}px;`}>Copy link</span>
+      {/if}
+      {#if showCopyTooltip && copyStatus === 'copied'}
+        <span class="copy-tooltip" class:fading={isTooltipFading} style={`left: ${tooltipX}px;`}>Link copied!</span>
+      {/if}
+      <span class="sr-only" aria-live="polite">
+        {copyStatusMessage}
+      </span>
+    </div>
+    {#if conversionRateText}
       <span class="formula-hint">
-        1 {config.labels.in1} = {config.factor}{config.offset ? ` + ${config.offset}` : ''} {config.labels.in2}
+        {conversionRateText}
       </span>
     {/if}
   </div>
@@ -284,6 +479,13 @@
     padding: 1rem 2rem 1.25rem;
     border-top: 1px solid var(--border);
   }
+  .footer-controls {
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+    position: relative;
+  }
+
   .clear-btn {
     padding: 0.5rem 1.25rem;
     border: 1px solid var(--border);
@@ -303,6 +505,69 @@
     outline: none;
     box-shadow: 0 0 0 3px var(--accent-glow);
   }
+  .icon-btn {
+    width: 40px;
+    height: 40px;
+    border: 1px solid var(--border);
+    border-radius: 8px;
+    background: var(--section-bg);
+    color: var(--text);
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    padding: 0;
+    cursor: pointer;
+    transition: background 0.2s, border-color 0.2s;
+  }
+  .icon-btn svg {
+    width: 1.1rem;
+    height: 1.1rem;
+  }
+  .icon-btn:disabled {
+    opacity: 0.5;
+    cursor: not-allowed;
+  }
+  .icon-btn:not(:disabled):hover {
+    border-color: var(--accent);
+    background: var(--surface-hover);
+  }
+  .copy-tooltip {
+    position: absolute;
+    bottom: calc(100% + 0.4rem);
+    background: color-mix(in srgb, var(--accent) 90%, black 10%);
+    color: #fff;
+    border-radius: 6px;
+    padding: 0.35rem 0.55rem;
+    font-size: 0.72rem;
+    font-weight: 600;
+    letter-spacing: 0.02em;
+    pointer-events: none;
+    opacity: 1;
+    transform: translate(-50%, 0);
+    transition: opacity 0.35s ease, transform 0.35s ease;
+    white-space: nowrap;
+    z-index: 2;
+  }
+  .copy-tooltip.hover {
+    background: var(--section-bg);
+    color: var(--text);
+    border: 1px solid var(--border);
+  }
+  .copy-tooltip.fading {
+    opacity: 0;
+    transform: translate(-50%, -0.2rem);
+  }
+  .sr-only {
+    position: absolute;
+    width: 1px;
+    height: 1px;
+    padding: 0;
+    margin: -1px;
+    overflow: hidden;
+    clip: rect(0, 0, 0, 0);
+    white-space: nowrap;
+    border: 0;
+  }
   .formula-hint {
     font-size: 0.78rem;
     color: var(--text-muted);

hdyc-svelte/src/lib/components/CategoryCard.svelte

@@ -24,8 +24,6 @@
     text-decoration: none;
     color: var(--text);
     transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
-    backdrop-filter: blur(12px);
-    -webkit-backdrop-filter: blur(12px);
     cursor: pointer;
   }
   .category-card:hover {

hdyc-svelte/src/lib/components/QuickConversionExample.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { solve } from '$lib/engine';
   import type { CalculatorDef } from '$lib/data/calculators';
+  import { formatConversionValue } from '$lib/utils/formatConversionValue';
 
   export let config: CalculatorDef;
 
@@ -17,40 +18,29 @@
     ? solve(config, 1, exampleInput.toString(), '', '')
     : null;
   $: offset = config.offset ?? 0;
-  $: formulaExpression = supportsExample
+  $: hasOffset = Boolean(offset);
-    ? `${exampleInput} × ${config.factor}${offset ? ` + ${offset}` : ''}`
+  $: formattedFactorValue = supportsExample
+    ? formatConversionValue(config.factor)
+    : '';
+  $: formattedOffsetValue = hasOffset
+    ? formatConversionValue(offset)
+    : '';
+  $: formulaExpression = supportsExample
+    ? `${exampleInput} × ${formattedFactorValue}${hasOffset ? ` + ${formattedOffsetValue}` : ''}`
     : '';
-
-  const formatExampleValue = (value: number | null): string => {
-    if (value === null || Number.isNaN(value)) {
-      return '—';
-    }
-    if (!Number.isFinite(value)) {
-      return value.toString();
-    }
-    if (value === 0) {
-      return '0';
-    }
-    const rounded = parseFloat(value.toFixed(6));
-    if (rounded !== 0) {
-      return rounded.toString();
-    }
-    const precise = value.toFixed(12).replace(/\.?0+$/, '');
-    return precise || '0';
-  };
 
   $: reverseExampleValue =
     supportsExample && config.factor !== 0
       ? (1 - offset) / config.factor
       : null;
-  $: formattedReverseValue = formatExampleValue(reverseExampleValue);
+  $: formattedReverseValue = formatConversionValue(reverseExampleValue);
 </script>
 
 {#if supportsExample && result}
   <section class="example-card">
     <h3>How to convert {config.labels.in1} to {config.labels.in2}</h3>
     <p class="example-note">
-      1 {config.labels.in1} = {config.factor}{config.offset ? ` + ${config.offset}` : ''} {config.labels.in2}
+      1 {config.labels.in1} = {formattedFactorValue}{hasOffset ? ` + ${formattedOffsetValue}` : ''} {config.labels.in2}
     </p>
     <p class="example-note">
       1 {config.labels.in2} = {formattedReverseValue} {config.labels.in1}

hdyc-svelte/src/lib/components/QuickConversionTable.svelte

@@ -1,20 +1,18 @@
 <script lang="ts">
   import { solve } from '$lib/engine';
-  import { parseScientificNotation, type ScientificNotationParts } from '$lib/utils/formatScientific';
   import type { CalculatorDef } from '$lib/data/calculators';
 
   export let config: CalculatorDef;
 
   const numericSamples = [0.1, 0.5, 1, 2, 5, 10, 20, 50, 100];
 
-  type Row = { input: number; output: string; scientific?: ScientificNotationParts };
+  type Row = { input: number; output: string };
 
-  const buildRow = (value: number): Row => {
+  const buildRow = (value: number, c: CalculatorDef): Row => {
-    const formatted = solve(config, 1, value.toString(), '', '');
+    const formatted = solve(c, 1, value.toString(), '', '');
     return {
       input: value,
       output: formatted.val2 || '—',
-      scientific: formatted.val2 ? parseScientificNotation(formatted.val2) ?? undefined : undefined,
     };
   };
 
@@ -24,8 +22,8 @@
   let outputLabel = 'target units';
 
   $: supportsTable = ['standard', 'inverse'].includes(config.type);
-  $: rows = supportsTable
+  $: rows = (config && supportsTable)
-    ? numericSamples.map(buildRow)
+    ? numericSamples.map(v => buildRow(v, config))
     : [];
   $: inputLabel = config.labels?.in1 ?? 'source units';
   $: outputLabel = config.labels?.in2 ?? 'target units';
@@ -44,16 +42,7 @@
         <div class="chart-row">
           <p class="chart-statement">
             Converting {row.input} <span class="chart-unit">{inputLabel}</span> into <span class="chart-unit">{outputLabel}</span> equals
-            <span class="chart-output-value">
+            <span class="chart-output-value">{row.output}</span>
-              {#if row.scientific}
-                <span class="scientific-base">{row.scientific.base}</span>
-                <span class="scientific-suffix">
-                  ×10<sup>{row.scientific.exponent}</sup>
-                </span>
-              {:else}
-                {row.output}
-              {/if}
-            </span>
             <span class="chart-output-unit">{outputLabel}</span>.
           </p>
         </div>
@@ -105,22 +94,6 @@
     color: var(--text);
   }
 
-  .scientific-base {
-    margin-right: 0.15rem;
-  }
-
-  .scientific-suffix {
-    display: inline-flex;
-    align-items: baseline;
-    gap: 0.15rem;
-    font-size: 0.85em;
-  }
-
-  .scientific-suffix sup {
-    font-size: 0.75em;
-    vertical-align: super;
-  }
-
   .chart-unit,
   .chart-output-unit {
     font-variant: petite-caps;

hdyc-svelte/src/lib/components/QuickDefinitionCard.svelte

@@ -1,6 +1,6 @@
 <script lang="ts">
   import { getDefinition } from '$lib/data/unitDefinitions';
-  import type { CalculatorDef } from '$lib/data/calculators';
+  import type { CalculatorDef } from '$lib/data/calculatorLoader';
 
   export let config: CalculatorDef;
 
@@ -11,8 +11,10 @@
 
   $: label1 = config.labels.in1 || 'Unit 1';
   $: label2 = config.labels.in2 || 'Unit 2';
-  $: def1 = getDefinition(label1, config.category);
+  $: {
-  $: def2 = getDefinition(label2, config.category);
+    getDefinition(label1, config.category).then(d => { def1 = d; });
+    getDefinition(label2, config.category).then(d => { def2 = d; });
+  }
 </script>
 
 <section class="definition-card">

hdyc-svelte/src/lib/components/SearchBar.svelte

@@ -1,15 +1,19 @@
 <script lang="ts">
-  import { searchCalculators } from '$lib/data/calculators';
   import { goto } from '$app/navigation';
+  import { loadCalculators, searchCalculators, type CalculatorDef } from '$lib/data/calculatorLoader';
 
   export let idPrefix = 'search';
-
   let query = '';
   let focused = false;
   let selectedIndex = -1;
   let lastQuery = '';
+  let allCalcs: CalculatorDef[] = [];
 
-  $: results = query.length >= 2 ? searchCalculators(query).slice(0, 8) : [];
+  $: if (query.length >= 1 && allCalcs.length === 0) {
+    loadCalculators().then(data => { allCalcs = data; });
+  }
+
+  $: results = (query.length >= 2 && allCalcs.length > 0) ? searchCalculators(allCalcs, query).slice(0, 8) : [];
   $: listboxId = `${idPrefix}-listbox`;
   $: inputId = `${idPrefix}-input`;
   $: isOpen = focused && results.length > 0;

hdyc-svelte/src/lib/components/Sidebar.svelte

@@ -2,7 +2,18 @@
   import { browser } from '$app/environment';
   import { onMount } from 'svelte';
   import { page } from '$app/stores';
-  import { categories, getCalculatorsByCategory, type CalculatorDef } from '$lib/data/calculators';
+  import { categories } from '$lib/data/stats';
+  import { loadCalculators, type CalculatorDef } from '$lib/data/calculatorLoader';
+
+  let allCalculators: CalculatorDef[] = [];
+  let isLoaded = false;
+
+  async function loadData() {
+    if (isLoaded || !browser) return;
+    const data = await loadCalculators();
+    allCalculators = data;
+    isLoaded = true;
+  }
 
   let expandedCategory = '';
   let expandedUnits: Record<string, string> = {};
@@ -23,50 +34,85 @@
 
   type UnitGroup = {
     label: string;
-    conversions: CalculatorDef[];
+    conversions: UnitConversionLink[];
   };
 
   type UnitBucket = {
     label: string;
-    conversions: CalculatorDef[];
+    conversions: UnitConversionLink[];
   };
 
-  const sortConversionsForUnit = (conversions: CalculatorDef[], unitLabel: string) => {
+  type UnitConversionLink = {
-    const normalizedUnit = unitLabel.toLowerCase();
+    name: string;
-    return conversions.slice().sort((a, b) => {
+    slug: string;
-      const aIsSource = a.labels.in1?.toLowerCase() === normalizedUnit;
+    sortKey: string;
-      const bIsSource = b.labels.in1?.toLowerCase() === normalizedUnit;
-      if (aIsSource !== bIsSource) {
-        return aIsSource ? -1 : 1;
-      }
-      return a.name.localeCompare(b.name);
-    });
   };
 
+  const sortConversionsForUnit = (conversions: UnitConversionLink[]) =>
+    conversions.slice().sort((a, b) => a.name.localeCompare(b.name));
+
+  const toPairKey = (unitA: string, unitB: string) =>
+    [unitA.toLowerCase(), unitB.toLowerCase()].sort().join('::');
+
+  const toDirectionKey = (fromUnit: string, toUnit: string) =>
+    `${fromUnit.toLowerCase()}::${toUnit.toLowerCase()}`;
+
+  function addConversion(
+    buckets: Map<string, UnitBucket>,
+    fromUnit: string,
+    toUnit: string,
+    slug: string
+  ) {
+    const bucketKey = fromUnit.toLowerCase();
+    const directionKey = toDirectionKey(fromUnit, toUnit);
+    const conversion: UnitConversionLink = {
+      name: `${fromUnit} to ${toUnit}`,
+      slug,
+      sortKey: directionKey,
+    };
+
+    const existing = buckets.get(bucketKey);
+    if (existing) {
+      if (!existing.conversions.some(link => link.sortKey === directionKey)) {
+        existing.conversions.push(conversion);
+      }
+      return;
+    }
+
+    buckets.set(bucketKey, {
+      label: fromUnit,
+      conversions: [conversion],
+    });
+  }
+
   $: categoryUnitGroups = Object.entries(categories).map(([key, meta]) => {
     const buckets = new Map<string, UnitBucket>();
-    const calcs = getCalculatorsByCategory(key);
+    
+    if (!isLoaded) {
+      return { key, meta, units: [] };
+    }
+
+    const calcs = allCalculators.filter(c => c.category === key && !c.hidden);
+    const canonicalByPair = new Map<string, CalculatorDef>();
 
     calcs.forEach(calc => {
-      [calc.labels.in1, calc.labels.in2].forEach(unit => {
+      const pairKey = toPairKey(calc.labels.in1, calc.labels.in2);
-        const key = unit.toLowerCase();
+      const existing = canonicalByPair.get(pairKey);
-        const existing = buckets.get(key);
+      if (!existing || calc.slug.localeCompare(existing.slug) < 0) {
-        if (existing) {
+        canonicalByPair.set(pairKey, calc);
-          existing.conversions.push(calc);
+      }
-        } else {
+    });
-          buckets.set(key, {
+
-            label: unit,
+    canonicalByPair.forEach(calc => {
-            conversions: [calc],
+      addConversion(buckets, calc.labels.in1, calc.labels.in2, calc.slug);
-          });
+      addConversion(buckets, calc.labels.in2, calc.labels.in1, calc.slug);
-        }
-      });
     });
 
     const units = [...buckets.entries()]
       .sort(([a], [b]) => a.localeCompare(b))
       .map(([, bucket]) => ({
         label: bucket.label,
-        conversions: sortConversionsForUnit(bucket.conversions, bucket.label),
+        conversions: sortConversionsForUnit(bucket.conversions),
       }));
 
     return { key, meta, units };
@@ -131,6 +177,11 @@
   }
 
   export let open = false;
+
+  $: if (browser && (isDesktop || open)) {
+    loadData();
+  }
+
   $: isSidebarHidden = !isDesktop && !open;
 
   function closeSidebar() {
@@ -188,14 +239,14 @@
                 </button>
                 {#if expandedUnits[group.key] === unit.label}
                   <ul class="unit-list">
-                    {#each unit.conversions as calc}
+                    {#each unit.conversions as conversion}
                       <li>
                         <a
-                          href="/{calc.slug}"
+                          href="/{conversion.slug}"
-                          class:current={currentPath === `/${calc.slug}`}
+                          class:current={currentPath === `/${conversion.slug}`}
-                          aria-current={currentPath === `/${calc.slug}` ? 'page' : undefined}
+                          aria-current={currentPath === `/${conversion.slug}` ? 'page' : undefined}
                         >
-                          {calc.name}
+                          {conversion.name}
                         </a>
                       </li>
                     {/each}

hdyc-svelte/src/lib/data/calculatorLoader.ts

@@ -0,0 +1,53 @@
+// Shared lazy loader – fetches /data/calculators.json exactly once.
+// Because this is a plain fetch (not a JS dynamic import), Vite will NOT
+// emit a modulepreload for it, keeping the homepage bundle small.
+
+export interface CalculatorDef {
+  slug: string;
+  name: string;
+  category: string;
+  type: string;
+  teaser: string;
+  labels: { in1: string; in2: string };
+  factor?: number;
+  offset?: number;
+  hidden?: boolean;
+}
+
+let cache: CalculatorDef[] | null = null;
+let pending: Promise<CalculatorDef[]> | null = null;
+
+const runtimeHost =
+  import.meta.env.PUBLIC_SITE_URL ??
+  (import.meta.env.DEV ? 'http://localhost:5173' : 'https://howdoyouconvert.com');
+
+const getCalculatorsUrl = (): string =>
+  import.meta.env.SSR
+    ? new URL('/data/calculators.json', runtimeHost).toString()
+    : '/data/calculators.json';
+
+export async function loadCalculators(): Promise<CalculatorDef[]> {
+  if (cache) return cache;
+  if (pending) return pending;
+
+  const url = getCalculatorsUrl();
+  pending = fetch(url)
+    .then(r => r.json())
+    .then((data: CalculatorDef[]) => {
+      cache = data;
+      pending = null;
+      return data;
+    });
+
+  return pending;
+}
+
+export function searchCalculators(calcs: CalculatorDef[], query: string): CalculatorDef[] {
+  const q = query.toLowerCase();
+  return calcs.filter(c =>
+    (c.name.toLowerCase().includes(q) ||
+    c.slug.includes(q) ||
+    c.labels.in1.toLowerCase().includes(q) ||
+    c.labels.in2.toLowerCase().includes(q)) && !c.hidden
+  );
+}

hdyc-svelte/src/lib/data/calculators.ts

@@ -17,26 +17,26 @@ export interface CalculatorDef {
 }
 
 export const categories: Record<string, { label: string; icon: string }> = {
-  length:          { label: 'Length / Distance',   icon: '📏' },
+  'length': { "label": "Length / Distance", "icon": "📏" },
-  weight:          { label: 'Weight / Mass',       icon: '⚖️' },
+  'weight': { "label": "Weight / Mass", "icon": "⚖️" },
-  temperature:     { label: 'Temperature',         icon: '🌡️' },
+  'temperature': { "label": "Temperature", "icon": "🌡️" },
-  volume:          { label: 'Volume',              icon: '🧪' },
+  'volume': { "label": "Volume", "icon": "🧪" },
-  fluids:          { label: 'Fluids',              icon: '💧' },
+  'fluids': { "label": "Fluids", "icon": "💧" },
-  area:            { label: 'Area',                icon: '🔳' },
+  'area': { "label": "Area", "icon": "🔳" },
-  speed:           { label: 'Speed / Velocity',    icon: '💨' },
+  'speed': { "label": "Speed / Velocity", "icon": "💨" },
-  pressure:        { label: 'Pressure',            icon: '🔽' },
+  'pressure': { "label": "Pressure", "icon": "🔽" },
-  energy:          { label: 'Energy',              icon: '⚡' },
+  'energy': { "label": "Energy", "icon": "⚡" },
-  magnetism:       { label: 'Magnetism',           icon: '🧲' },
+  'magnetism': { "label": "Magnetism", "icon": "🧲" },
-  power:           { label: 'Power',               icon: '🔌' },
+  'power': { "label": "Power", "icon": "🔌" },
-  data:            { label: 'Data Storage',        icon: '💾' },
+  'data': { "label": "Data Storage", "icon": "💾" },
-  time:            { label: 'Time',                icon: '⏱️' },
+  'time': { "label": "Time", "icon": "⏱️" },
-  angle:           { label: 'Angle',               icon: '📐' },
+  'angle': { "label": "Angle", "icon": "📐" },
-  'number-systems':{ label: 'Number Systems',      icon: '🔢' },
+  'number-systems': { "label": "Number Systems", "icon": "🔢" },
-  radiation:       { label: 'Radiation',           icon: '☢️' },
+  'radiation': { "label": "Radiation", "icon": "☢️" },
-  electrical:      { label: 'Electrical',          icon: '🔋' },
+  'electrical': { "label": "Electrical", "icon": "🔋" },
-  force:           { label: 'Force / Torque',      icon: '💪' },
+  'force': { "label": "Force / Torque", "icon": "💪" },
-  light:           { label: 'Light',               icon: '💡' },
+  'light': { "label": "Light", "icon": "💡" },
-  other:           { label: 'Other',               icon: '🔄' },
+  'other': { "label": "Other", "icon": "🔄" },
 };
 
 export const calculators: CalculatorDef[] = [
@@ -374,12 +374,12 @@ export const calculators: CalculatorDef[] = [
   {"slug": "microtesla-to-gauss", "name": "Microtesla to Gauss", "category": "magnetism", "type": "standard", "teaser": "Bring microtesla data into Gauss when studying legacy equipment.", "labels": {"in1": "Microtesla", "in2": "Gauss"}, "factor": 0.01, "hidden": true},
   {"slug": "gauss-to-nanotesla", "name": "Gauss to Nanotesla", "category": "magnetism", "type": "standard", "teaser": "Convert Gauss values into high-resolution nanotesla.", "labels": {"in1": "Gauss", "in2": "Nanotesla"}, "factor": 100000.0},
   {"slug": "nanotesla-to-gauss", "name": "Nanotesla to Gauss", "category": "magnetism", "type": "standard", "teaser": "Return nanotesla measurements back into Gauss.", "labels": {"in1": "Nanotesla", "in2": "Gauss"}, "factor": 1e-05, "hidden": true},
-  {"slug": "webers-per-square-meter-to-teslas", "name": "Webers per square meter to Teslas", "category": "magnetism", "type": "standard", "teaser": "A Weber per square meter is exactly one Tesla.", "labels": {"in1": "Webers per square meter", "in2": "Teslas"}, "hidden": true},
+  {"slug": "webers-per-square-meter-to-teslas", "name": "Webers per square meter to Teslas", "category": "magnetism", "type": "standard", "teaser": "A Weber per square meter is exactly one Tesla.", "labels": {"in1": "Webers per square meter", "in2": "Teslas"}, "hidden": true, "factor": 1.0},
-  {"slug": "teslas-to-webers-per-square-meter", "name": "Teslas to Webers per square meter", "category": "magnetism", "type": "standard", "teaser": "Each Tesla equals one Weber per square meter.", "labels": {"in1": "Teslas", "in2": "Webers per square meter"}},
+  {"slug": "teslas-to-webers-per-square-meter", "name": "Teslas to Webers per square meter", "category": "magnetism", "type": "standard", "teaser": "Each Tesla equals one Weber per square meter.", "labels": {"in1": "Teslas", "in2": "Webers per square meter"}, "factor": 1.0},
   {"slug": "webers-per-square-centimeter-to-gauss", "name": "Webers per square centimeter to Gauss", "category": "magnetism", "type": "standard", "teaser": "Scale the small-area flux into Gauss.", "labels": {"in1": "Webers per square centimeter", "in2": "Gauss"}, "factor": 100000000.0},
   {"slug": "gauss-to-webers-per-square-centimeter", "name": "Gauss to Webers per square centimeter", "category": "magnetism", "type": "standard", "teaser": "Convert Gauss back into Weber per square centimeter.", "labels": {"in1": "Gauss", "in2": "Webers per square centimeter"}, "factor": 1e-08, "hidden": true},
-  {"slug": "oersted-to-gauss", "name": "Oersted to Gauss", "category": "magnetism", "type": "standard", "teaser": "In vacuum, the numeric values for Oersted and Gauss match.", "labels": {"in1": "Oersted", "in2": "Gauss"}, "hidden": true},
+  {"slug": "oersted-to-gauss", "name": "Oersted to Gauss", "category": "magnetism", "type": "standard", "teaser": "In vacuum, the numeric values for Oersted and Gauss match.", "labels": {"in1": "Oersted", "in2": "Gauss"}, "hidden": true, "factor": 1.0},
-  {"slug": "gauss-to-oersted", "name": "Gauss to Oersted", "category": "magnetism", "type": "standard", "teaser": "Translate the flux density version back into the magnetizing force scale.", "labels": {"in1": "Gauss", "in2": "Oersted"}},
+  {"slug": "gauss-to-oersted", "name": "Gauss to Oersted", "category": "magnetism", "type": "standard", "teaser": "Translate the flux density version back into the magnetizing force scale.", "labels": {"in1": "Gauss", "in2": "Oersted"}, "factor": 1.0},
   {"slug": "kilogauss-to-microtesla", "name": "Kilogauss to Microtesla", "category": "magnetism", "type": "standard", "teaser": "A kilogauss field equals 100,000 microtesla.", "labels": {"in1": "Kilogauss", "in2": "Microtesla"}, "factor": 100000.0},
   {"slug": "microtesla-to-kilogauss", "name": "Microtesla to Kilogauss", "category": "magnetism", "type": "standard", "teaser": "Convert microtesla readings into kilogauss.", "labels": {"in1": "Microtesla", "in2": "Kilogauss"}, "factor": 1e-05, "hidden": true},
   {"slug": "kilogauss-to-nanotesla", "name": "Kilogauss to Nanotesla", "category": "magnetism", "type": "standard", "teaser": "Express kilogauss values in nanotesla for sensitive instrumentation.", "labels": {"in1": "Kilogauss", "in2": "Nanotesla"}, "factor": 100000000.0},
@@ -606,11 +606,11 @@ export const calculators: CalculatorDef[] = [
   {"slug": "horsepower-to-btumin", "name": "Horsepower to BTU/min", "category": "energy", "type": "standard", "teaser": "Get BTUs per minute from mechanical horsepower.", "labels": {"in1": "Horsepower", "in2": "BTU/min"}, "factor": 42.4072263427},
   {"slug": "horsepower-to-calories-per-second", "name": "Horsepower to Calories Per Second", "category": "energy", "type": "standard", "teaser": "Translate mechanical horsepower into calories per second.", "labels": {"in1": "Horsepower", "in2": "Calories Per Second"}, "factor": 178.226546845},
   {"slug": "horsepower-to-electrical-horsepower", "name": "Horsepower to Electrical Horsepower", "category": "power", "type": "standard", "teaser": "Convert mechanical horsepower into electrical horsepower.", "labels": {"in1": "Horsepower", "in2": "Electrical Horsepower"}, "factor": 0.999597683646, "hidden": true},
-  {"slug": "kilowatts-to-kva", "name": "Kilowatts to kVA", "category": "power", "type": "standard", "labels": {"in1": "Kilowatts", "in2": "kVA"}},
+  {"slug": "kilowatts-to-kva", "name": "Kilowatts to kVA", "category": "power", "type": "standard", "labels": {"in1": "Kilowatts", "in2": "kVA"}, "factor": 1.0},
   {"slug": "lusec-to-watts", "name": "Lusec to Watts", "category": "power", "type": "standard", "labels": {"in1": "Lusec", "in2": "Watts"}, "factor": 0.000133322},
   {"slug": "watts-to-btumin", "name": "Watts to BTU/min", "category": "energy", "type": "standard", "labels": {"in1": "Watts", "in2": "BTU/min"}, "factor": 0.0568690272522},
   {"slug": "horsepower-to-lusec", "name": "Horsepower to Lusec", "category": "power", "type": "standard", "labels": {"in1": "Horsepower", "in2": "Lusec"}, "factor": 5593224.46408},
-  {"slug": "horsepower-to-mechanical-hp", "name": "Horsepower to Mechanical Hp", "category": "power", "type": "standard", "labels": {"in1": "Horsepower", "in2": "Mechanical Hp"}},
+  {"slug": "horsepower-to-mechanical-hp", "name": "Horsepower to Mechanical Hp", "category": "power", "type": "standard", "labels": {"in1": "Horsepower", "in2": "Mechanical Hp"}, "factor": 1.0},
   {"slug": "horsepower-to-megawatts", "name": "Horsepower to Megawatts", "category": "power", "type": "standard", "labels": {"in1": "Horsepower", "in2": "Megawatts"}, "factor": 0.000745699872, "hidden": true},
   {"slug": "horsepower-to-metric-horsepower-ps", "name": "Horsepower to Metric Horsepower (ps)", "category": "power", "type": "standard", "labels": {"in1": "Horsepower", "in2": "Metric Horsepower (ps)"}, "factor": 1.01386966599},
   {"slug": "kilowatts-to-boiler-horsepower", "name": "Kilowatts to Boiler Horsepower", "category": "power", "type": "standard", "labels": {"in1": "Kilowatts", "in2": "Boiler Horsepower"}, "factor": 0.101941995005, "hidden": true},
@@ -622,7 +622,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "lusec-to-metric-horsepower-ps", "name": "Lusec to Metric Horsepower (ps)", "category": "power", "type": "standard", "labels": {"in1": "Lusec", "in2": "Metric Horsepower (ps)"}, "factor": 1.81267473262e-07},
   {"slug": "mechanical-hp-to-boiler-horsepower", "name": "Mechanical Hp to Boiler Horsepower", "category": "power", "type": "standard", "labels": {"in1": "Mechanical Hp", "in2": "Boiler Horsepower"}, "factor": 0.0760181326265, "hidden": true},
   {"slug": "mechanical-hp-to-electrical-horsepower", "name": "Mechanical Hp to Electrical Horsepower", "category": "power", "type": "standard", "labels": {"in1": "Mechanical Hp", "in2": "Electrical Horsepower"}, "factor": 0.999597683646, "hidden": true},
-  {"slug": "mechanical-hp-to-horsepower", "name": "Mechanical Hp to Horsepower", "category": "power", "type": "standard", "labels": {"in1": "Mechanical Hp", "in2": "Horsepower"}, "hidden": true},
+  {"slug": "mechanical-hp-to-horsepower", "name": "Mechanical Hp to Horsepower", "category": "power", "type": "standard", "labels": {"in1": "Mechanical Hp", "in2": "Horsepower"}, "hidden": true, "factor": 1.0},
   {"slug": "mechanical-hp-to-metric-horsepower-ps", "name": "Mechanical Hp to Metric Horsepower (ps)", "category": "power", "type": "standard", "labels": {"in1": "Mechanical Hp", "in2": "Metric Horsepower (ps)"}, "factor": 1.01386966599},
   {"slug": "megawatts-to-boiler-horsepower", "name": "Megawatts to Boiler Horsepower", "category": "power", "type": "standard", "labels": {"in1": "Megawatts", "in2": "Boiler Horsepower"}, "factor": 101.941995005},
   {"slug": "megawatts-to-electrical-horsepower", "name": "Megawatts to Electrical Horsepower", "category": "power", "type": "standard", "labels": {"in1": "Megawatts", "in2": "Electrical Horsepower"}, "factor": 1340.48257373},
@@ -854,7 +854,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "liters-to-gallons", "name": "Liters to Gallons", "category": "volume", "type": "standard", "labels": {"in1": "Liters", "in2": "Gallons"}, "factor": 0.264172052, "hidden": true},
   {"slug": "liters-to-pints", "name": "Liters to Pints", "category": "volume", "type": "standard", "labels": {"in1": "Liters", "in2": "Pints"}, "factor": 2.11337642},
   {"slug": "liters-to-quarts", "name": "Liters to Quarts", "category": "volume", "type": "standard", "labels": {"in1": "Liters", "in2": "Quarts"}, "factor": 1.05668821},
-  {"slug": "liters-per-100-km-to-kilometers-per-liter", "name": "Liters per 100 km to Kilometers per liter", "category": "fluids", "type": "standard", "teaser": "Turn consumption from L/100 km into km per liter.", "labels": {"in1": "Liters per 100 km", "in2": "Kilometers per liter"}},
+  {"slug": "liters-per-100-km-to-kilometers-per-liter", "name": "Liters per 100 km to Kilometers per liter", "category": "fluids", "type": "inverse", "teaser": "Turn consumption from L/100 km into km per liter.", "labels": {"in1": "Liters per 100 km", "in2": "Kilometers per liter"}, "factor": 100.0},
   {"slug": "liters-per-100-km-to-miles-per-gallon", "name": "Liters per 100 km to Miles per gallon", "category": "fluids", "type": "inverse", "teaser": "Convert L/100 km into MPG.", "labels": {"in1": "Liters per 100 km", "in2": "Miles per gallon"}},
   {"slug": "liters-per-minute-to-gallons-per-minute", "name": "Liters per minute to Gallons per minute", "category": "fluids", "type": "standard", "labels": {"in1": "Liters per minute", "in2": "Gallons per minute"}, "factor": 0.264172052, "hidden": true},
   {"slug": "liters-per-second-to-cms", "name": "Liters per second to CMS", "category": "fluids", "type": "standard", "teaser": "Convert liters per second into cubic meters per second.", "labels": {"in1": "Liters per second", "in2": "CMS"}, "factor": 0.001},
@@ -864,12 +864,12 @@ export const calculators: CalculatorDef[] = [
   {"slug": "candela-to-lumens", "name": "Candela to Lumens", "category": "light", "type": "standard", "labels": {"in1": "Candela", "in2": "Lumens"}, "factor": 12.5663706},
   {"slug": "decimal-to-binary", "name": "Decimal to Binary", "category": "number-systems", "type": "base", "labels": {"in1": "Decimal", "in2": "Binary"}, "toBase": 2, "fromBase": 10, "hidden": true},
   {"slug": "decimal-to-hex", "name": "Decimal to Hex", "category": "number-systems", "type": "base", "labels": {"in1": "Decimal", "in2": "Hex"}, "toBase": 16, "fromBase": 10},
-  {"slug": "decimal-to-octal", "name": "Decimal to Octal", "category": "number-systems", "type": "standard", "labels": {"in1": "Decimal", "in2": "Octal"}},
+  {"slug": "decimal-to-octal", "name": "Decimal to Octal", "category": "number-systems", "type": "base", "labels": {"in1": "Decimal", "in2": "Octal"}, "fromBase": 10, "toBase": 8},
   {"slug": "hex-to-binary", "name": "Hex to Binary", "category": "number-systems", "type": "base", "labels": {"in1": "Hex", "in2": "Binary"}, "toBase": 2, "fromBase": 16, "hidden": true},
-  {"slug": "hex-to-decimal", "name": "Hex to Decimal", "category": "number-systems", "type": "standard", "labels": {"in1": "Hex", "in2": "Decimal"}, "hidden": true},
+  {"slug": "hex-to-decimal", "name": "Hex to Decimal", "category": "number-systems", "type": "base", "labels": {"in1": "Hex", "in2": "Decimal"}, "hidden": true, "fromBase": 16, "toBase": 10},
-  {"slug": "octal-to-binary", "name": "Octal to Binary", "category": "number-systems", "type": "standard", "teaser": "Convert base-8 digits into binary sequences.", "labels": {"in1": "Octal", "in2": "Binary"}},
+  {"slug": "octal-to-binary", "name": "Octal to Binary", "category": "number-systems", "type": "base", "teaser": "Convert base-8 digits into binary sequences.", "labels": {"in1": "Octal", "in2": "Binary"}, "fromBase": 8, "toBase": 2},
-  {"slug": "octal-to-decimal", "name": "Octal to Decimal", "category": "number-systems", "type": "standard", "teaser": "Convert octal numbers into decimal values.", "labels": {"in1": "Octal", "in2": "Decimal"}, "hidden": true},
+  {"slug": "octal-to-decimal", "name": "Octal to Decimal", "category": "number-systems", "type": "base", "teaser": "Convert octal numbers into decimal values.", "labels": {"in1": "Octal", "in2": "Decimal"}, "hidden": true, "fromBase": 8, "toBase": 10},
-  {"slug": "octal-to-hex", "name": "Octal to Hex", "category": "number-systems", "type": "standard", "teaser": "Express octal numbers as hexadecimal digits.", "labels": {"in1": "Octal", "in2": "Hex"}, "hidden": true},
+  {"slug": "octal-to-hex", "name": "Octal to Hex", "category": "number-systems", "type": "base", "teaser": "Express octal numbers as hexadecimal digits.", "labels": {"in1": "Octal", "in2": "Hex"}, "hidden": true, "fromBase": 8, "toBase": 16},
   {"slug": "base-2-to-base-3", "name": "Base 2 to Base 3", "category": "number-systems", "type": "base", "teaser": "Translate binary digits into ternary format for alternate radix comparisons.", "labels": {"in1": "Base 2", "in2": "Base 3"}, "fromBase": 2, "toBase": 3},
   {"slug": "base-2-to-base-4", "name": "Base 2 to Base 4", "category": "number-systems", "type": "base", "teaser": "Group binary bits into quaternary digits for compact notation.", "labels": {"in1": "Base 2", "in2": "Base 4"}, "fromBase": 2, "toBase": 4},
   {"slug": "base-2-to-base-5", "name": "Base 2 to Base 5", "category": "number-systems", "type": "base", "teaser": "Reframe base-2 quantities as base-5 digits when analyzing quinary systems.", "labels": {"in1": "Base 2", "in2": "Base 5"}, "fromBase": 2, "toBase": 5},
@@ -1200,7 +1200,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "square-miles-to-dunams", "name": "Square Miles to Dunams", "category": "area", "type": "standard", "teaser": "Convert square miles into dunams for regional survey math.", "labels": {"in1": "Square Miles", "in2": "Dunams"}, "factor": 2589.98811034},
   {"slug": "square-miles-to-hectares", "name": "Square Miles to Hectares", "category": "area", "type": "standard", "teaser": "Translate square-mile areas into hectares.", "labels": {"in1": "Square Miles", "in2": "Hectares"}, "factor": 258.998811034},
   {"slug": "square-miles-to-roods", "name": "Square Miles to Roods", "category": "area", "type": "standard", "teaser": "Relate square miles to roods when referencing old English land grants.", "labels": {"in1": "Square Miles", "in2": "Roods"}, "factor": 2560.0},
-  {"slug": "square-miles-to-sections", "name": "Square Miles to Sections", "category": "area", "type": "standard", "teaser": "Show how many survey sections fit into a square mile.", "labels": {"in1": "Square Miles", "in2": "Sections"}},
+  {"slug": "square-miles-to-sections", "name": "Square Miles to Sections", "category": "area", "type": "standard", "teaser": "Show how many survey sections fit into a square mile.", "labels": {"in1": "Square Miles", "in2": "Sections"}, "factor": 1.0},
   {"slug": "square-miles-to-square-mils", "name": "Square Miles to Square Mils", "category": "area", "type": "standard", "teaser": "Break square miles into square mils for micro-scale analogies.", "labels": {"in1": "Square Miles", "in2": "Square Mils"}, "factor": 4014489600000000.0},
   {"slug": "square-miles-to-townships", "name": "Square Miles to Townships", "category": "area", "type": "standard", "teaser": "Express square miles as fractional townships.", "labels": {"in1": "Square Miles", "in2": "Townships"}, "factor": 0.0277777777778, "hidden": true},
   {"slug": "square-mils-to-acres", "name": "Square Mils to Acres", "category": "area", "type": "standard", "teaser": "Convert square mils into acres for micrometer-level land analogies.", "labels": {"in1": "Square Mils", "in2": "Acres"}, "factor": 1.59422507907e-13},
@@ -1287,7 +1287,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "torr-to-cmhg", "name": "Torr to cmHg", "category": "pressure", "type": "standard", "teaser": "Convert torr into centimeters of mercury.", "labels": {"in1": "Torr", "in2": "cmHg"}, "factor": 0.1},
   {"slug": "torr-to-kpa", "name": "Torr to kPa", "category": "pressure", "type": "standard", "teaser": "Convert torr into kilopascals.", "labels": {"in1": "Torr", "in2": "kPa"}, "factor": 0.13332236842105263},
   {"slug": "torr-to-psi", "name": "Torr to PSI", "category": "pressure", "type": "standard", "teaser": "Convert torr into pounds per square inch.", "labels": {"in1": "Torr", "in2": "PSI"}, "factor": 0.019336776, "hidden": true},
-  {"slug": "ppi-to-dpi", "name": "PPI to DPI", "category": "other", "type": "standard", "labels": {"in1": "PPI", "in2": "DPI"}},
+  {"slug": "ppi-to-dpi", "name": "PPI to DPI", "category": "other", "type": "standard", "labels": {"in1": "PPI", "in2": "DPI"}, "factor": 1.0},
   {"slug": "pounds-to-tons", "name": "Pounds to tons", "category": "weight", "type": "standard", "labels": {"in1": "Pounds", "in2": "tons"}, "factor": 0.0005, "hidden": true},
   {"slug": "pounds-to-stones", "name": "Pounds to stones", "category": "weight", "type": "standard", "labels": {"in1": "Pounds", "in2": "stones"}, "factor": 0.071428, "hidden": true},
   {"slug": "pounds-to-ounces", "name": "Pounds to ounces", "category": "weight", "type": "standard", "labels": {"in1": "Pounds", "in2": "ounces"}, "factor": 16.0},
@@ -1300,7 +1300,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "percent-abv-to-proof", "name": "Percent ABV to Proof", "category": "other", "type": "standard", "teaser": "Convert alcohol by volume into US proof values (Proof = 2 \u00d7 ABV).", "labels": {"in1": "Percent ABV", "in2": "Proof"}, "factor": 2.0},
   {"slug": "proof-to-percent-abv", "name": "Proof to Percent ABV", "category": "other", "type": "standard", "teaser": "Convert US proof back into ABV (ABV = Proof / 2).", "labels": {"in1": "Proof", "in2": "Percent ABV"}, "factor": 0.5, "hidden": true},
   {"slug": "ppb-to-ppm", "name": "PPB to PPM", "category": "fluids", "type": "standard", "teaser": "Convert parts per billion into ppm.", "labels": {"in1": "PPB", "in2": "PPM"}, "factor": 0.001, "hidden": true},
-  {"slug": "ppm-to-mg-per-liter", "name": "PPM to mg/L", "category": "fluids", "type": "standard", "teaser": "For dilute aqueous solutions, treat ppm as mg per liter.", "labels": {"in1": "PPM", "in2": "mg/L"}},
+  {"slug": "ppm-to-mg-per-liter", "name": "PPM to mg/L", "category": "fluids", "type": "standard", "teaser": "For dilute aqueous solutions, treat ppm as mg per liter.", "labels": {"in1": "PPM", "in2": "mg/L"}, "factor": 1.0},
   {"slug": "ppm-to-percent", "name": "PPM to Percent", "category": "fluids", "type": "standard", "teaser": "Convert ppm values into percent by mass.", "labels": {"in1": "PPM", "in2": "Percent"}, "factor": 0.0001, "hidden": true},
   {"slug": "ppm-to-ppb", "name": "PPM to PPB", "category": "fluids", "type": "standard", "teaser": "Convert parts per million into parts per billion.", "labels": {"in1": "PPM", "in2": "PPB"}, "factor": 1000.0},
   {"slug": "planck-mass-to-kilograms", "name": "Planck mass to Kilograms", "category": "weight", "type": "standard", "teaser": "Convert the Planck mass into SI kilograms.", "labels": {"in1": "Planck mass", "in2": "Kilograms"}, "factor": 2.176434e-08},
@@ -1485,7 +1485,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "imperial-fl-oz-to-cubic-yards", "name": "Imperial fl oz to Cubic Yards", "category": "volume", "type": "standard", "teaser": "Express Imperial ounces in cubic yards for bulk yardage.", "labels": {"in1": "Imperial fl oz", "in2": "Cubic Yards"}, "factor": 3.7162882693493535e-05, "hidden": true},
   {"slug": "imperial-fl-oz-to-cups", "name": "Imperial fl oz to Cups", "category": "volume", "type": "standard", "teaser": "Show Imperial ounces in cups for recipe crossovers.", "labels": {"in1": "Imperial fl oz", "in2": "Cups"}, "factor": 0.12009499255048549, "hidden": true},
   {"slug": "imperial-fl-oz-to-drams-fluid", "name": "Imperial fl oz to Drams (fluid)", "category": "volume", "type": "standard", "teaser": "Convert Imperial ounces to fluid drams for precise dosing.", "labels": {"in1": "Imperial fl oz", "in2": "Drams (fluid)"}, "factor": 8.0},
-  {"slug": "imperial-fl-oz-to-fluid-ounces", "name": "Imperial fl oz to Fluid Ounces", "category": "volume", "type": "standard", "teaser": "Keep Imperial ounces expressed in themselves for clarity.", "labels": {"in1": "Imperial fl oz", "in2": "Fluid Ounces"}, "hidden": true},
+  {"slug": "imperial-fl-oz-to-fluid-ounces", "name": "Imperial fl oz to Fluid Ounces", "category": "volume", "type": "standard", "teaser": "Keep Imperial ounces expressed in themselves for clarity.", "labels": {"in1": "Imperial fl oz", "in2": "Fluid Ounces"}, "hidden": true, "factor": 1.0},
   {"slug": "imperial-fl-oz-to-gallons", "name": "Imperial fl oz to Gallons", "category": "volume", "type": "standard", "teaser": "Convert Imperial fluid ounces into Imperial gallons for British volume checks.", "labels": {"in1": "Imperial fl oz", "in2": "Gallons"}, "factor": 0.00625},
   {"slug": "imperial-fl-oz-to-gill", "name": "Imperial fl oz to Gill", "category": "volume", "type": "standard", "teaser": "Relate Imperial ounces to gills when crafting classic cocktails.", "labels": {"in1": "Imperial fl oz", "in2": "Gill"}, "factor": 0.2, "hidden": true},
   {"slug": "imperial-fl-oz-to-hogshead", "name": "Imperial fl oz to Hogshead", "category": "volume", "type": "standard", "teaser": "Express Imperial ounces as a fraction of a hogshead for barrel planning.", "labels": {"in1": "Imperial fl oz", "in2": "Hogshead"}, "factor": 0.00011574074074074075, "hidden": true},
@@ -1638,7 +1638,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "gallons-to-fluid-ounces", "name": "Gallons to Fluid Ounces", "category": "weight", "type": "standard", "teaser": "A pitcher pours three gallons; how many fluid ounces is that?", "labels": {"in1": "Gallons", "in2": "Fluid Ounces"}, "factor": 128.0},
   {"slug": "gallons-to-pints", "name": "Gallons to Pints", "category": "volume", "type": "standard", "teaser": "Pouring one gallon equals how many pints for serving?", "labels": {"in1": "Gallons", "in2": "Pints"}, "factor": 8.0},
   {"slug": "gallons-to-quarts", "name": "Gallons to Quarts", "category": "volume", "type": "standard", "teaser": "Four gallons convert to how many quarts for canning?", "labels": {"in1": "Gallons", "in2": "Quarts"}, "factor": 4.0},
-  {"slug": "gamma-mass-to-micrograms", "name": "Gamma (mass) to Micrograms", "category": "weight", "type": "standard", "teaser": "A lab note shows gamma units; what is that in micrograms?", "labels": {"in1": "Gamma (mass)", "in2": "Micrograms"}},
+  {"slug": "gamma-mass-to-micrograms", "name": "Gamma (mass) to Micrograms", "category": "weight", "type": "standard", "teaser": "A lab note shows gamma units; what is that in micrograms?", "labels": {"in1": "Gamma (mass)", "in2": "Micrograms"}, "factor": 1.0},
   {"slug": "gauss-to-ampere-turns-per-meter", "name": "Gauss / Ampere-turns per meter", "category": "magnetism", "type": "3col", "teaser": "Convert magnetic flux density into magnetomotive force per meter when the medium's permeability is known.", "labels": {"in1": "Gauss", "in2": "Ampere-turns per meter", "in3": "Gauss / Ampere-turns per meter"}},
   {"slug": "gauss-to-tesla", "name": "Gauss to Tesla", "category": "magnetism", "type": "standard", "teaser": "A field reads five thousand gauss; what is that in tesla?", "labels": {"in1": "Gauss", "in2": "Tesla"}, "factor": 0.0001, "hidden": true},
   {"slug": "millitesla-to-tesla", "name": "Millitesla to Tesla", "category": "magnetism", "type": "standard", "teaser": "Convert milliteslas into teslas for electromagnetism work.", "labels": {"in1": "Millitesla", "in2": "Tesla"}, "factor": 0.001, "hidden": true},
@@ -1729,10 +1729,10 @@ export const calculators: CalculatorDef[] = [
   {"slug": "grains-to-troy-ounces", "name": "Grains to Troy Ounces", "category": "weight", "type": "standard", "teaser": "Blend grain counts into troy ounces for precious metals.", "labels": {"in1": "Grains", "in2": "Troy Ounces"}, "factor": 0.0020833333333333333},
   {"slug": "grains-to-yoctograms", "name": "Grains to Yoctograms", "category": "weight", "type": "standard", "teaser": "Push a grain\u2019s mass into yoctograms for extreme microscale reports.", "labels": {"in1": "Grains", "in2": "Yoctograms"}, "factor": 6.479891e+22},
   {"slug": "grains-to-zeptograms", "name": "Grains to Zeptograms", "category": "weight", "type": "standard", "teaser": "Continue down to zeptogram counts to highlight the minute mass.", "labels": {"in1": "Grains", "in2": "Zeptograms"}, "factor": 6.479891e+19},
-  {"slug": "grams-per-cubic-centimeter-to-grams-per-milliliter", "name": "Grams per cubic centimeter to Grams per Milliliter", "category": "fluids", "type": "standard", "teaser": "Recognize that 1 g/cm\u00b3 equals 1 g/mL for density clarity.", "labels": {"in1": "Grams per cubic centimeter", "in2": "Grams per Milliliter"}},
+  {"slug": "grams-per-cubic-centimeter-to-grams-per-milliliter", "name": "Grams per cubic centimeter to Grams per Milliliter", "category": "fluids", "type": "standard", "teaser": "Recognize that 1 g/cm\u00b3 equals 1 g/mL for density clarity.", "labels": {"in1": "Grams per cubic centimeter", "in2": "Grams per Milliliter"}, "factor": 1.0},
   {"slug": "grams-per-cubic-centimeter-to-kilograms-per-cubic-meter", "name": "Grams per cubic centimeter to Kilograms per Cubic Meter", "category": "fluids", "type": "standard", "teaser": "Convert grams per cubic centimeter into kg/m\u00b3 for engineering spec sheets.", "labels": {"in1": "Grams per cubic centimeter", "in2": "Kilograms per Cubic Meter"}, "factor": 1000.0},
   {"slug": "grams-per-cubic-centimeter-to-pounds-per-cubic-foot", "name": "Grams per cubic centimeter to Pounds per Cubic Foot", "category": "fluids", "type": "standard", "teaser": "Turn metric density into imperial pounds per cubic foot for building specs.", "labels": {"in1": "Grams per cubic centimeter", "in2": "Pounds per Cubic Foot"}, "factor": 62.4279605743},
-  {"slug": "grams-per-cubic-centimeter-to-kilograms-per-liter", "name": "Grams per cubic centimeter to Kilograms per liter", "category": "fluids", "type": "standard", "teaser": "A fluid density of 1 g/cm\u00b3 equals how many kg/L?", "labels": {"in1": "Grams per cubic centimeter", "in2": "Kilograms per liter"}},
+  {"slug": "grams-per-cubic-centimeter-to-kilograms-per-liter", "name": "Grams per cubic centimeter to Kilograms per liter", "category": "fluids", "type": "standard", "teaser": "A fluid density of 1 g/cm\u00b3 equals how many kg/L?", "labels": {"in1": "Grams per cubic centimeter", "in2": "Kilograms per liter"}, "factor": 1.0},
   {"slug": "grams-per-liter-to-milligrams-per-liter", "name": "Grams per liter to Milligrams per Liter", "category": "fluids", "type": "standard", "teaser": "Convert grams per liter into milligrams per liter for water-quality reporting.", "labels": {"in1": "Grams per liter", "in2": "Milligrams per Liter"}, "factor": 1000.0},
   {"slug": "grams-per-liter-to-molarity", "name": "Grams per liter to Molarity", "category": "fluids", "type": "standard", "teaser": "Turn a grams-per-liter reading into molarity when a molar mass is supplied.", "labels": {"in1": "Grams per liter", "in2": "Molarity"}},
   {"slug": "grams-per-liter-to-percent", "name": "Grams per liter / Percent", "category": "fluids", "type": "3col", "teaser": "Map grams per liter into mass percent when the solution density is known.", "labels": {"in1": "Grams per liter", "in2": "Percent", "in3": "Grams per liter / Percent"}},
@@ -1741,8 +1741,8 @@ export const calculators: CalculatorDef[] = [
   {"slug": "grams-per-liter-to-ppm", "name": "Grams per liter to Ppm", "category": "fluids", "type": "standard", "teaser": "Express grams per liter as parts per million for environmental windows.", "labels": {"in1": "Grams per liter", "in2": "Ppm"}, "factor": 1000.0},
   {"slug": "grams-per-liter-to-proof", "name": "Grams per liter / Proof", "category": "fluids", "type": "3col", "teaser": "Translate grams per liter into proof when alcohol density and ABV are known.", "labels": {"in1": "Grams per liter", "in2": "Proof", "in3": "Grams per liter / Proof"}},
   {"slug": "grams-per-milliliter-to-kilograms-per-cubic-meter", "name": "Grams per milliliter to Kilograms per cubic meter", "category": "fluids", "type": "standard", "teaser": "A solution at 1.2 g/mL corresponds to how many kg/m\u00b3?", "labels": {"in1": "Grams per milliliter", "in2": "Kilograms per cubic meter"}, "factor": 1000.0},
-  {"slug": "grams-per-milliliter-to-grams-per-cubic-centimeter", "name": "Grams per milliliter to Grams per Cubic Centimeter", "category": "fluids", "type": "standard", "teaser": "Since a milliliter equals a cubic centimeter, this is a 1:1 conversion.", "labels": {"in1": "Grams per milliliter", "in2": "Grams per Cubic Centimeter"}, "hidden": true},
+  {"slug": "grams-per-milliliter-to-grams-per-cubic-centimeter", "name": "Grams per milliliter to Grams per Cubic Centimeter", "category": "fluids", "type": "standard", "teaser": "Since a milliliter equals a cubic centimeter, this is a 1:1 conversion.", "labels": {"in1": "Grams per milliliter", "in2": "Grams per Cubic Centimeter"}, "hidden": true, "factor": 1.0},
-  {"slug": "grams-per-milliliter-to-kilograms-per-liter", "name": "Grams per milliliter to Kilograms per Liter", "category": "fluids", "type": "standard", "teaser": "Translate grams per milliliter into kilograms per liter for lab data sheets.", "labels": {"in1": "Grams per milliliter", "in2": "Kilograms per Liter"}},
+  {"slug": "grams-per-milliliter-to-kilograms-per-liter", "name": "Grams per milliliter to Kilograms per Liter", "category": "fluids", "type": "standard", "teaser": "Translate grams per milliliter into kilograms per liter for lab data sheets.", "labels": {"in1": "Grams per milliliter", "in2": "Kilograms per Liter"}, "factor": 1.0},
   {"slug": "grams-per-milliliter-to-pounds-per-cubic-foot", "name": "Grams per milliliter to Pounds per Cubic Foot", "category": "fluids", "type": "standard", "teaser": "Scale grams per milliliter into pounds per cubic foot for imperial references.", "labels": {"in1": "Grams per milliliter", "in2": "Pounds per Cubic Foot"}, "factor": 62.4279605743},
   {"slug": "grams-to-amu", "name": "Grams to Amu", "category": "weight", "type": "standard", "teaser": "Convert a gram into atomic mass units for precise reaction counts.", "labels": {"in1": "Grams", "in2": "Amu"}, "factor": 6.022140762081123e+23},
   {"slug": "grams-to-atomic-mass-units", "name": "Grams to Atomic Mass Units", "category": "weight", "type": "standard", "teaser": "Translate grams into atomic mass units when bridging scales.", "labels": {"in1": "Grams", "in2": "Atomic Mass Units"}, "factor": 6.022140762081123e+23},
@@ -1787,9 +1787,9 @@ export const calculators: CalculatorDef[] = [
   {"slug": "grams-to-pounds", "name": "Grams to Pounds", "category": "weight", "type": "standard", "teaser": "A container measures 200 grams; how many pounds does the load represent?", "labels": {"in1": "Grams", "in2": "Pounds"}, "factor": 0.00220462},
   {"slug": "grams-to-scruples", "name": "Grams to Scruples", "category": "weight", "type": "standard", "teaser": "A pharmacy formula needs 10 grams; what is that in scruples?", "labels": {"in1": "Grams", "in2": "Scruples"}, "factor": 0.771605, "hidden": true},
   {"slug": "grams-to-tolas", "name": "Grams to Tolas", "category": "weight", "type": "standard", "teaser": "A gold bar weighs 5 grams; how many tolas is that mass?", "labels": {"in1": "Grams", "in2": "Tolas"}, "factor": 0.085735},
-  {"slug": "gray-to-sievert", "name": "Gray to Sievert", "category": "radiation", "type": "standard", "teaser": "A gamma exposure is 3 gray; how many sieverts is that for gamma/beta?", "labels": {"in1": "Gray", "in2": "Sievert"}},
+  {"slug": "gray-to-sievert", "name": "Gray to Sievert", "category": "radiation", "type": "standard", "teaser": "A gamma exposure is 3 gray; how many sieverts is that for gamma/beta?", "labels": {"in1": "Gray", "in2": "Sievert"}, "factor": 1.0},
   {"slug": "fahrenheit-to-newton", "name": "Fahrenheit to Newton", "category": "force", "type": "standard", "teaser": "Convert Fahrenheit to Newtons on the scale where 0\u202f\u00b0C equals 0\u202f\u00b0N and 100\u202f\u00b0C equals 33\u202f\u00b0N.", "labels": {"in1": "Fahrenheit", "in2": "Newton"}, "factor": 0.183333, "offset": -5.867},
-  {"slug": "fahrenheit-to-rankine", "name": "Fahrenheit to Rankine", "category": "temperature", "type": "standard", "teaser": "Convert Fahrenheit to the absolute Rankine scale.", "labels": {"in1": "Fahrenheit", "in2": "Rankine"}, "offset": 459.67},
+  {"slug": "fahrenheit-to-rankine", "name": "Fahrenheit to Rankine", "category": "temperature", "type": "standard", "teaser": "Convert Fahrenheit to the absolute Rankine scale.", "labels": {"in1": "Fahrenheit", "in2": "Rankine"}, "offset": 459.67, "factor": 1.0},
   {"slug": "celsius-to-newton", "name": "Celsius to Newton (temp Scale)", "category": "temperature", "type": "standard", "teaser": "Convert Celsius into Newton's temperature scale (0\u202f\u00b0C \u2248 0\u202f\u00b0N, 100\u202f\u00b0C \u2248 33\u202f\u00b0N).", "labels": {"in1": "Celsius", "in2": "Newton (temp Scale)"}, "factor": 0.33, "offset": 0.0},
   {"slug": "delisle-to-fahrenheit", "name": "Delisle to Fahrenheit", "category": "temperature", "type": "standard", "teaser": "Turn antique Delisle readings into modern Fahrenheit.", "labels": {"in1": "Delisle", "in2": "Fahrenheit"}, "factor": -1.2, "offset": 212.0, "hidden": true},
   {"slug": "delisle-to-kelvin", "name": "Delisle to Kelvin", "category": "temperature", "type": "standard", "teaser": "Translate Delisle degrees into the Kelvin scale for absolute comparisons.", "labels": {"in1": "Delisle", "in2": "Kelvin"}, "factor": -0.666666666667, "offset": 373.15, "hidden": true},
@@ -1907,7 +1907,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "kpa-to-bar", "name": "kPa to Bar", "category": "pressure", "type": "standard", "teaser": "Convert kilopascals to bar.", "labels": {"in1": "kPa", "in2": "Bar"}, "factor": 0.01},
   {"slug": "kpa-to-pascal", "name": "kPa to Pascal", "category": "pressure", "type": "standard", "teaser": "Convert kilopascals to pascals.", "labels": {"in1": "kPa", "in2": "Pascal"}, "factor": 1000.0},
   {"slug": "kpa-to-psi", "name": "kPa to PSI", "category": "pressure", "type": "standard", "teaser": "Convert kilopascals to pounds per square inch.", "labels": {"in1": "kPa", "in2": "PSI"}, "factor": 0.1450377377, "hidden": true},
-  {"slug": "kva-to-kilowatts", "name": "kVA to Kilowatts", "category": "power", "type": "standard", "teaser": "Convert apparent power to real power assuming unity power factor.", "labels": {"in1": "kVA", "in2": "Kilowatts"}, "hidden": true},
+  {"slug": "kva-to-kilowatts", "name": "kVA to Kilowatts", "category": "power", "type": "standard", "teaser": "Convert apparent power to real power assuming unity power factor.", "labels": {"in1": "kVA", "in2": "Kilowatts"}, "hidden": true, "factor": 1.0},
   {"slug": "leagues-per-hour-to-kmh", "name": "Leagues per Hour to Kilometers per Hour", "category": "length", "type": "standard", "teaser": "Convert leagues per hour into kilometers per hour.", "labels": {"in1": "Leagues per Hour", "in2": "Kilometers per Hour"}, "factor": 4.82803},
   {"slug": "leagues-to-kilometers", "name": "Leagues to Kilometers", "category": "length", "type": "standard", "teaser": "Convert leagues to kilometers.", "labels": {"in1": "Leagues", "in2": "Kilometers"}, "factor": 4.82803},
   {"slug": "leagues-to-miles", "name": "Leagues to Miles", "category": "length", "type": "standard", "teaser": "Convert leagues to miles.", "labels": {"in1": "Leagues", "in2": "Miles"}, "factor": 3.0},
@@ -1919,12 +1919,12 @@ export const calculators: CalculatorDef[] = [
   {"slug": "long-tons-to-pounds", "name": "Long Tons to Pounds", "category": "weight", "type": "standard", "teaser": "Convert long tons to pounds.", "labels": {"in1": "Long Tons", "in2": "Pounds"}, "factor": 2240.0},
   {"slug": "long-tons-to-short-tons", "name": "Long Tons to Short Tons", "category": "weight", "type": "standard", "teaser": "Convert long tons to short tons.", "labels": {"in1": "Long Tons", "in2": "Short Tons"}, "factor": 1.12},
   {"slug": "lux-to-foot-candles", "name": "Lux to Foot-candles", "category": "light", "type": "standard", "teaser": "Convert illuminance from lux to foot-candles.", "labels": {"in1": "Lux", "in2": "Foot-candles"}, "factor": 0.09290304, "hidden": true},
-  {"slug": "candela-to-foot-candles", "name": "Candela to Foot-candles", "category": "light", "type": "standard", "teaser": "At 1 foot away, one candela yields one foot-candle of illuminance.", "labels": {"in1": "Candela", "in2": "Foot-candles"}},
+  {"slug": "candela-to-foot-candles", "name": "Candela to Foot-candles", "category": "light", "type": "standard", "teaser": "At 1 foot away, one candela yields one foot-candle of illuminance.", "labels": {"in1": "Candela", "in2": "Foot-candles"}, "factor": 1.0},
-  {"slug": "foot-candles-to-candela", "name": "Foot-candles to Candela", "category": "light", "type": "standard", "teaser": "Convert illuminance in foot-candles into a luminous intensity at 1 foot.", "labels": {"in1": "Foot-candles", "in2": "Candela"}, "hidden": true},
+  {"slug": "foot-candles-to-candela", "name": "Foot-candles to Candela", "category": "light", "type": "standard", "teaser": "Convert illuminance in foot-candles into a luminous intensity at 1 foot.", "labels": {"in1": "Foot-candles", "in2": "Candela"}, "hidden": true, "factor": 1.0},
   {"slug": "candela-to-lux-at-foot", "name": "Candela to Lux (1 ft)", "category": "light", "type": "standard", "teaser": "One candela at a 1-foot distance produces about 10.7639 lux on the target plane.", "labels": {"in1": "Candela", "in2": "Lux (1 ft)"}, "factor": 10.7639},
   {"slug": "lux-to-candela-at-foot", "name": "Lux to Candela (1 ft)", "category": "light", "type": "standard", "teaser": "Turn lux measured 1 foot away into the equivalent candela luminous intensity.", "labels": {"in1": "Lux", "in2": "Candela (1 ft)"}, "factor": 0.09290304},
-  {"slug": "candela-to-nits", "name": "Candela to Nits", "category": "light", "type": "standard", "teaser": "Treat 1 candela distributed over 1 square meter as 1 nit for comparing luminance.", "labels": {"in1": "Candela", "in2": "Nits"}},
+  {"slug": "candela-to-nits", "name": "Candela to Nits", "category": "light", "type": "standard", "teaser": "Treat 1 candela distributed over 1 square meter as 1 nit for comparing luminance.", "labels": {"in1": "Candela", "in2": "Nits"}, "factor": 1.0},
-  {"slug": "nits-to-candela", "name": "Nits to Candela", "category": "light", "type": "standard", "teaser": "Assume a 1-square-meter patch to convert nits into candela.", "labels": {"in1": "Nits", "in2": "Candela"}, "hidden": true},
+  {"slug": "nits-to-candela", "name": "Nits to Candela", "category": "light", "type": "standard", "teaser": "Assume a 1-square-meter patch to convert nits into candela.", "labels": {"in1": "Nits", "in2": "Candela"}, "hidden": true, "factor": 1.0},
   {"slug": "candela-to-candlepower", "name": "Candela to Candlepower", "category": "light", "type": "standard", "teaser": "Translate candela intensity into the legacy candlepower scale (1 cd \u2248 1.01937 cp).", "labels": {"in1": "Candela", "in2": "Candlepower"}, "factor": 1.019367},
   {"slug": "candlepower-to-candela", "name": "Candlepower to Candela", "category": "light", "type": "standard", "teaser": "Flip historical candlepower values back into modern candelas (1 cp \u2248 0.981 cd).", "labels": {"in1": "Candlepower", "in2": "Candela"}, "factor": 0.981, "hidden": true},
   {"slug": "candlepower-to-lumens", "name": "Candlepower to Lumens", "category": "light", "type": "standard", "teaser": "Treat candlepower as a luminous intensity, then multiply by 4\u03c0 to get flux.", "labels": {"in1": "Candlepower", "in2": "Lumens"}, "factor": 12.3269},
@@ -1943,12 +1943,12 @@ export const calculators: CalculatorDef[] = [
   {"slug": "nits-to-foot-lamberts", "name": "Nits to Foot-lamberts", "category": "other", "type": "standard", "teaser": "Translate luminance measured in nits into foot-lamberts.", "labels": {"in1": "Nits", "in2": "Foot-lamberts"}, "factor": 0.292, "hidden": true},
   {"slug": "phot-to-lux", "name": "Phot to Lux", "category": "light", "type": "standard", "teaser": "One phot equals 10,000 lux for film-lighting references.", "labels": {"in1": "Phot", "in2": "Lux"}, "factor": 10000.0},
   {"slug": "lux-to-phot", "name": "Lux to Phot", "category": "light", "type": "standard", "teaser": "Convert lux into phots to match old photographic light charts.", "labels": {"in1": "Lux", "in2": "Phot"}, "factor": 0.0001, "hidden": true},
-  {"slug": "phot-to-lamberts", "name": "Phot to Lamberts", "category": "other", "type": "standard", "teaser": "Phot and lambert coincide (1 phot = 1 lambert).", "labels": {"in1": "Phot", "in2": "Lamberts"}, "hidden": true},
+  {"slug": "phot-to-lamberts", "name": "Phot to Lamberts", "category": "other", "type": "standard", "teaser": "Phot and lambert coincide (1 phot = 1 lambert).", "labels": {"in1": "Phot", "in2": "Lamberts"}, "hidden": true, "factor": 1.0},
-  {"slug": "lamberts-to-phot", "name": "Lamberts to Phot", "category": "other", "type": "standard", "teaser": "Flip lamberts back into phots.", "labels": {"in1": "Lamberts", "in2": "Phot"}},
+  {"slug": "lamberts-to-phot", "name": "Lamberts to Phot", "category": "other", "type": "standard", "teaser": "Flip lamberts back into phots.", "labels": {"in1": "Lamberts", "in2": "Phot"}, "factor": 1.0},
   {"slug": "phot-to-foot-lamberts", "name": "Phot to Foot-lamberts", "category": "other", "type": "standard", "teaser": "One phot (10,000 lux) equals about 929 foot-lamberts.", "labels": {"in1": "Phot", "in2": "Foot-lamberts"}, "factor": 929.03},
   {"slug": "foot-lamberts-to-phot", "name": "Foot-lamberts to Phot", "category": "other", "type": "standard", "teaser": "Express foot-lamberts as phots (1 ft-L \u2248 0.0010764 phot).", "labels": {"in1": "Foot-lamberts", "in2": "Phot"}, "factor": 0.00107639, "hidden": true},
-  {"slug": "lumens-to-lux-per-square-meter", "name": "Lumens to Lux per square meter", "category": "fluids", "type": "standard", "teaser": "Spread lumens over 1 m\u00b2 to get lux.", "labels": {"in1": "Lumens", "in2": "Lux per square meter"}},
+  {"slug": "lumens-to-lux-per-square-meter", "name": "Lumens to Lux per square meter", "category": "fluids", "type": "standard", "teaser": "Spread lumens over 1 m\u00b2 to get lux.", "labels": {"in1": "Lumens", "in2": "Lux per square meter"}, "factor": 1.0},
-  {"slug": "lux-to-lumens-per-square-meter", "name": "Lux to Lumens per square meter", "category": "fluids", "type": "standard", "teaser": "Treat lux as lumens on each square meter.", "labels": {"in1": "Lux", "in2": "Lumens per square meter"}},
+  {"slug": "lux-to-lumens-per-square-meter", "name": "Lux to Lumens per square meter", "category": "fluids", "type": "standard", "teaser": "Treat lux as lumens on each square meter.", "labels": {"in1": "Lux", "in2": "Lumens per square meter"}, "factor": 1.0},
   {"slug": "foot-candles-to-phot", "name": "Foot-candles to Phot", "category": "other", "type": "standard", "teaser": "Convert foot-candles into phots via the 10,000 lux anchor.", "labels": {"in1": "Foot-candles", "in2": "Phot"}, "factor": 0.00107639, "hidden": true},
   {"slug": "phot-to-foot-candles", "name": "Phot to Foot-candles", "category": "other", "type": "standard", "teaser": "Express phots as foot-candles for practical light meter use.", "labels": {"in1": "Phot", "in2": "Foot-candles"}, "factor": 929.03},
   {"slug": "lumens-to-nits-per-square-meter", "name": "Lumens to Nits per square meter", "category": "fluids", "type": "standard", "teaser": "A lumen/m\u00b2 (lux) equals about 0.31831 nits under Lambertian lighting.", "labels": {"in1": "Lumens", "in2": "Nits per square meter"}, "factor": 0.318309886},
@@ -1973,7 +1973,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "metric-horsepower-to-watts", "name": "Metric Horsepower (PS) to Watts", "category": "power", "type": "standard", "teaser": "Convert metric horsepower into watts for European ratings.", "labels": {"in1": "Metric Horsepower (PS)", "in2": "Watts"}, "factor": 735.49875},
   {"slug": "metric-tons-to-kilograms", "name": "Metric Tons to Kilograms", "category": "weight", "type": "standard", "teaser": "Convert metric tons into kilograms for bulk weights.", "labels": {"in1": "Metric Tons", "in2": "Kilograms"}, "factor": 1000.0},
   {"slug": "metric-tons-to-pounds", "name": "Metric Tons to Pounds", "category": "weight", "type": "standard", "teaser": "Convert metric tons into pounds.", "labels": {"in1": "Metric Tons", "in2": "Pounds"}, "factor": 2204.62262},
-  {"slug": "mg-per-liter-to-ppm", "name": "mg/L to PPM", "category": "fluids", "type": "standard", "teaser": "Treat milligrams per liter as parts per million for dilute solutions.", "labels": {"in1": "mg/L", "in2": "PPM"}},
+  {"slug": "mg-per-liter-to-ppm", "name": "mg/L to PPM", "category": "fluids", "type": "standard", "teaser": "Treat milligrams per liter as parts per million for dilute solutions.", "labels": {"in1": "mg/L", "in2": "PPM"}, "factor": 1.0},
   {"slug": "microfarads-to-picofarads", "name": "Microfarads to Picofarads", "category": "radiation", "type": "standard", "teaser": "Convert microfarads to picofarads.", "labels": {"in1": "Microfarads", "in2": "Picofarads"}, "factor": 1000000.0},
   {"slug": "microhenries-to-millihenries", "name": "Microhenries to Millihenries", "category": "angle", "type": "standard", "teaser": "Convert inductance from microhenries to millihenries.", "labels": {"in1": "Microhenries", "in2": "Millihenries"}, "factor": 0.001, "hidden": true},
   {"slug": "microns-to-millimeters", "name": "Microns to Millimeters", "category": "length", "type": "standard", "teaser": "Convert microns (micrometers) to millimeters.", "labels": {"in1": "Microns", "in2": "Millimeters"}, "factor": 0.001, "hidden": true},
@@ -2203,7 +2203,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "radians-to-mils", "name": "Radians to Mils", "category": "angle", "type": "standard", "teaser": "Express radians as mils for precision shooting.", "labels": {"in1": "Radians", "in2": "Mils"}, "factor": 1000.0},
   {"slug": "radians-to-turns", "name": "Radians to Turns", "category": "angle", "type": "standard", "teaser": "Convert radians into turns of a circle.", "labels": {"in1": "Radians", "in2": "Turns"}, "factor": 0.15915494309189535},
   {"slug": "rankine-to-celsius", "name": "Rankine to Celsius", "category": "temperature", "type": "standard", "teaser": "Convert Rankine into Celsius degrees.", "labels": {"in1": "Rankine", "in2": "Celsius"}, "factor": 0.5555555555555556, "offset": -273.15},
-  {"slug": "rankine-to-fahrenheit", "name": "Rankine to Fahrenheit", "category": "temperature", "type": "standard", "teaser": "Show Rankine as Fahrenheit.", "labels": {"in1": "Rankine", "in2": "Fahrenheit"}, "offset": -459.67, "hidden": true},
+  {"slug": "rankine-to-fahrenheit", "name": "Rankine to Fahrenheit", "category": "temperature", "type": "standard", "teaser": "Show Rankine as Fahrenheit.", "labels": {"in1": "Rankine", "in2": "Fahrenheit"}, "offset": -459.67, "hidden": true, "factor": 1.0},
   {"slug": "rankine-to-kelvin", "name": "Rankine to Kelvin", "category": "temperature", "type": "standard", "teaser": "Turn Rankine into Kelvin.", "labels": {"in1": "Rankine", "in2": "Kelvin"}, "factor": 0.5555555555555556},
   {"slug": "rem-to-millisievert", "name": "Rem to Millisievert", "category": "angle", "type": "standard", "teaser": "Convert rems into millisieverts.", "labels": {"in1": "Rem", "in2": "Millisievert"}, "factor": 10.0},
   {"slug": "rem-to-rad", "name": "Rem to Rad", "category": "radiation", "type": "standard", "teaser": "Treat rems as rads with a 1:1 ratio.", "labels": {"in1": "Rem", "in2": "Rad"}, "factor": 1.0},
@@ -2267,8 +2267,8 @@ export const calculators: CalculatorDef[] = [
   {"slug": "moles-per-hour-to-moles-per-second", "name": "Moles per hour to Moles per second", "category": "other", "type": "standard", "teaser": "Return molar flow rates back to per-second units.", "labels": {"in1": "Moles per hour", "in2": "Moles per second"}, "factor": 0.0002777778, "hidden": true},
   {"slug": "kilograms-per-second-per-square-meter-to-grams-per-second-per-square-centimeter", "name": "Kilograms per second per square meter to Grams per second per square centimeter", "category": "other", "type": "standard", "teaser": "Express mass flux density using metric subunits.", "labels": {"in1": "Kilograms per second per square meter", "in2": "Grams per second per square centimeter"}, "factor": 0.1, "hidden": true},
   {"slug": "grams-per-second-per-square-centimeter-to-kilograms-per-second-per-square-meter", "name": "Grams per second per square centimeter to Kilograms per second per square meter", "category": "other", "type": "standard", "teaser": "Convert compact mass flux into the SI-friendly base.", "labels": {"in1": "Grams per second per square centimeter", "in2": "Kilograms per second per square meter"}, "factor": 10.0},
-  {"slug": "mol-per-cubic-meter-to-mmol-per-liter", "name": "Mol per cubic meter to mmol per liter", "category": "fluids", "type": "standard", "teaser": "Translate molar concentrations across common volume units.", "labels": {"in1": "Mol per cubic meter", "in2": "mmol per liter"}, "hidden": true},
+  {"slug": "mol-per-cubic-meter-to-mmol-per-liter", "name": "Mol per cubic meter to mmol per liter", "category": "fluids", "type": "standard", "teaser": "Translate molar concentrations across common volume units.", "labels": {"in1": "Mol per cubic meter", "in2": "mmol per liter"}, "hidden": true, "factor": 1.0},
-  {"slug": "mmol-per-liter-to-mol-per-cubic-meter", "name": "mmol per liter to mol per cubic meter", "category": "fluids", "type": "standard", "teaser": "Convert molar concentration back into SI cubic meters.", "labels": {"in1": "mmol per liter", "in2": "mol per cubic meter"}},
+  {"slug": "mmol-per-liter-to-mol-per-cubic-meter", "name": "mmol per liter to mol per cubic meter", "category": "fluids", "type": "standard", "teaser": "Convert molar concentration back into SI cubic meters.", "labels": {"in1": "mmol per liter", "in2": "mol per cubic meter"}, "factor": 1.0},
   {"slug": "percent-by-mass-to-ppm", "name": "Percent by mass to ppm", "category": "other", "type": "standard", "teaser": "Turn mass-percent concentrations into parts-per-million.", "labels": {"in1": "Percent by mass", "in2": "ppm"}, "factor": 10000.0},
   {"slug": "ppm-to-percent-by-mass", "name": "ppm to Percent by mass", "category": "other", "type": "standard", "teaser": "Return ppm values to mass-percent.", "labels": {"in1": "ppm", "in2": "Percent by mass"}, "factor": 0.0001, "hidden": true},
   {"slug": "pascal-second-to-poise", "name": "Pascal-second to Poise", "category": "pressure", "type": "standard", "teaser": "Convert SI dynamic viscosity into CGS poise.", "labels": {"in1": "Pascal-second", "in2": "Poise"}, "factor": 10.0},
@@ -2277,8 +2277,8 @@ export const calculators: CalculatorDef[] = [
   {"slug": "centistokes-to-square-meter-per-second", "name": "Centistokes to Square meter per second", "category": "other", "type": "standard", "teaser": "Return centistokes back to base square meters per second.", "labels": {"in1": "Centistokes", "in2": "Square meter per second"}, "factor": 0.01, "hidden": true},
   {"slug": "newton-per-meter-to-dyne-per-centimeter", "name": "Newton per meter to Dyne per centimeter", "category": "force", "type": "standard", "teaser": "Express surface tension on the CGS scale.", "labels": {"in1": "Newton per meter", "in2": "Dyne per centimeter"}, "factor": 1000.0},
   {"slug": "dyne-per-centimeter-to-newton-per-meter", "name": "Dyne per centimeter to Newton per meter", "category": "force", "type": "standard", "teaser": "Convert surface tension back into SI.", "labels": {"in1": "Dyne per centimeter", "in2": "Newton per meter"}, "factor": 0.001, "hidden": true},
-  {"slug": "henry-per-meter-to-tesla-meter-per-ampere", "name": "Henry per meter to Tesla-meter per ampere", "category": "magnetism", "type": "standard", "teaser": "Equate magnetic permeability units across SI conventions.", "labels": {"in1": "Henry per meter", "in2": "Tesla-meter per ampere"}},
+  {"slug": "henry-per-meter-to-tesla-meter-per-ampere", "name": "Henry per meter to Tesla-meter per ampere", "category": "magnetism", "type": "standard", "teaser": "Equate magnetic permeability units across SI conventions.", "labels": {"in1": "Henry per meter", "in2": "Tesla-meter per ampere"}, "factor": 1.0},
-  {"slug": "tesla-meter-per-ampere-to-henry-per-meter", "name": "Tesla-meter per ampere to Henry per meter", "category": "magnetism", "type": "standard", "teaser": "Return permeability back to henry per meter.", "labels": {"in1": "Tesla-meter per ampere", "in2": "Henry per meter"}, "hidden": true},
+  {"slug": "tesla-meter-per-ampere-to-henry-per-meter", "name": "Tesla-meter per ampere to Henry per meter", "category": "magnetism", "type": "standard", "teaser": "Return permeability back to henry per meter.", "labels": {"in1": "Tesla-meter per ampere", "in2": "Henry per meter"}, "hidden": true, "factor": 1.0},
   {"slug": "yards-per-second-to-centimeters-per-second", "name": "Yards Per Second to Centimeters Per Second", "category": "speed", "type": "standard", "teaser": "Express yards-per-second speeds as centimeters per second.", "labels": {"in1": "Yards Per Second", "in2": "Centimeters Per Second"}, "factor": 91.44},
   {"slug": "yards-per-second-to-feet-per-second", "name": "Yards Per Second to Feet Per Second", "category": "speed", "type": "standard", "teaser": "Convert yards per second into feet per second for incremental comparisons.", "labels": {"in1": "Yards Per Second", "in2": "Feet Per Second"}, "factor": 3.0},
   {"slug": "yards-per-second-to-furlongs-per-fortnight", "name": "Yards Per Second to Furlongs Per Fortnight", "category": "speed", "type": "standard", "teaser": "Turn yards-per-second pacing into furlongs per fortnight for playful analogies.", "labels": {"in1": "Yards Per Second", "in2": "Furlongs Per Fortnight"}, "factor": 5498.181818181818},
@@ -2368,7 +2368,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "em-to-pixels", "name": "Em to Pixels", "category": "other", "type": "standard", "teaser": "Convert CSS em units to pixels assuming a 16px base size.", "labels": {"in1": "Em", "in2": "Pixels"}, "factor": 16.0},
   {"slug": "ev-to-lux", "name": "EV (exposure value) to Lux", "category": "light", "type": "ev-lux", "teaser": "Estimate scene illuminance at ISO 100.", "labels": {"in1": "EV (exposure value)", "in2": "Lux"}},
   {"slug": "lux-to-ev", "name": "Lux to EV", "category": "light", "type": "ev-lux", "teaser": "Convert lux readings to exposure value at ISO 100.", "labels": {"in1": "Lux", "in2": "EV"}, "hidden": true},
-  {"slug": "f-stops-to-t-stops", "name": "f-stops to T-stops", "category": "other", "type": "standard", "teaser": "Treat f-number as t-stop under ideal transmission.", "labels": {"in1": "f-stops", "in2": "T-stops"}},
+  {"slug": "f-stops-to-t-stops", "name": "f-stops to T-stops", "category": "other", "type": "standard", "teaser": "Treat f-number as t-stop under ideal transmission.", "labels": {"in1": "f-stops", "in2": "T-stops"}, "factor": 1.0},
   {"slug": "focal-length-to-angle-of-view", "name": "Focal length to Angle of view", "category": "other", "type": "aov", "teaser": "Approximate horizontal angle on 35mm full-frame (36mm width).", "labels": {"in1": "Focal length", "in2": "Angle of view"}},
   {"slug": "millimeters-to-awg", "name": "Millimeters to AWG", "category": "electrical", "type": "awg", "teaser": "Convert conductor diameter in millimeters to AWG gauge.", "labels": {"in1": "Millimeters", "in2": "AWG"}},
   {"slug": "molarity-to-grams-per-liter", "name": "Molarity to Grams per liter", "category": "other", "type": "molarity", "teaser": "Convert molar concentration to grams per liter using molar mass.", "labels": {"in1": "Molarity (mol/L)", "in2": "Grams per liter", "in3": "Molar mass (g/mol)"}, "hidden": true},
@@ -2684,7 +2684,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "barye-to-atmosphere", "name": "Barye to Atmosphere", "category": "pressure", "type": "standard", "labels": {"in1": "Barye", "in2": "Atmosphere"}, "factor": 9.86923266716013e-07},
   {"slug": "barye-to-bar", "name": "Barye to Bar", "category": "pressure", "type": "standard", "labels": {"in1": "Barye", "in2": "Bar"}, "factor": 1e-06, "hidden": true},
   {"slug": "barye-to-cmhg", "name": "Barye to Cmhg", "category": "pressure", "type": "standard", "labels": {"in1": "Barye", "in2": "Cmhg"}, "factor": 7.500637554192107e-05},
-  {"slug": "barye-to-dynes-per-sq-cm", "name": "Barye to Dynes Per Sq Cm", "category": "pressure", "type": "standard", "labels": {"in1": "Barye", "in2": "Dynes Per Sq Cm"}},
+  {"slug": "barye-to-dynes-per-sq-cm", "name": "Barye to Dynes Per Sq Cm", "category": "pressure", "type": "standard", "labels": {"in1": "Barye", "in2": "Dynes Per Sq Cm"}, "factor": 1.0},
   {"slug": "barye-to-feet-of-seawater", "name": "Barye to Feet Of Seawater", "category": "length", "type": "standard", "labels": {"in1": "Barye", "in2": "Feet Of Seawater"}, "factor": 3.2594581222958305e-05},
   {"slug": "barye-to-feet-of-water", "name": "Barye to Feet Of Water", "category": "length", "type": "standard", "labels": {"in1": "Barye", "in2": "Feet Of Water"}, "factor": 3.349601334800432e-05, "hidden": true},
   {"slug": "barye-to-hectopascals", "name": "Barye to Hectopascals", "category": "pressure", "type": "standard", "labels": {"in1": "Barye", "in2": "Hectopascals"}, "factor": 0.001, "hidden": true},
@@ -2941,7 +2941,7 @@ export const calculators: CalculatorDef[] = [
   {"slug": "inch-pounds-to-dyne-centimeters", "name": "Inch-pounds to Dyne-centimeters", "category": "energy", "type": "standard", "teaser": "Express inch-pound torque as dyne-centimeters for CGS-friendly references.", "labels": {"in1": "Inch-pounds", "in2": "Dyne-centimeters"}, "factor": 1129848.2902762},
   {"slug": "dynes-per-sq-cm-to-atmosphere", "name": "Dynes Per Sq Cm to Atmosphere", "category": "pressure", "type": "standard", "labels": {"in1": "Dynes Per Sq Cm", "in2": "Atmosphere"}, "factor": 9.86923266716013e-07, "hidden": true},
   {"slug": "dynes-per-sq-cm-to-bar", "name": "Dynes Per Sq Cm to Bar", "category": "pressure", "type": "standard", "labels": {"in1": "Dynes Per Sq Cm", "in2": "Bar"}, "factor": 1e-06, "hidden": true},
-  {"slug": "dynes-per-sq-cm-to-barye", "name": "Dynes Per Sq Cm to Barye", "category": "pressure", "type": "standard", "labels": {"in1": "Dynes Per Sq Cm", "in2": "Barye"}, "hidden": true},
+  {"slug": "dynes-per-sq-cm-to-barye", "name": "Dynes Per Sq Cm to Barye", "category": "pressure", "type": "standard", "labels": {"in1": "Dynes Per Sq Cm", "in2": "Barye"}, "hidden": true, "factor": 1.0},
   {"slug": "dynes-per-sq-cm-to-cmhg", "name": "Dynes Per Sq Cm to Cmhg", "category": "pressure", "type": "standard", "labels": {"in1": "Dynes Per Sq Cm", "in2": "Cmhg"}, "factor": 7.500637554192107e-05},
   {"slug": "dynes-per-sq-cm-to-feet-of-seawater", "name": "Dynes Per Sq Cm to Feet Of Seawater", "category": "pressure", "type": "standard", "labels": {"in1": "Dynes Per Sq Cm", "in2": "Feet Of Seawater"}, "factor": 3.2594581222958305e-05},
   {"slug": "dynes-per-sq-cm-to-feet-of-water", "name": "Dynes Per Sq Cm to Feet Of Water", "category": "pressure", "type": "standard", "labels": {"in1": "Dynes Per Sq Cm", "in2": "Feet Of Water"}, "factor": 3.349601334800432e-05, "hidden": true},
@@ -3167,7 +3167,10 @@ export const calculators: CalculatorDef[] = [
 
 ];
 
-const slugIndex = new Map(calculators.map(c => [c.slug, c]));
+const slugIndex: Map<string, CalculatorDef> = new Map(
+    calculators.map(calc => [calc.slug, calc])
+);
+
 
 export function getCalculatorBySlug(slug: string): CalculatorDef | undefined {
   return slugIndex.get(slug);

hdyc-svelte/src/lib/data/stats.ts

@@ -0,0 +1,85 @@
+// THIS FILE IS AUTO-GENERATED BY migrate.py
+export const categories: Record<string, { label: string; icon: string }> = {
+  "length": {
+    "label": "Length / Distance",
+    "icon": "📏"
+  },
+  "weight": {
+    "label": "Weight / Mass",
+    "icon": "⚖️"
+  },
+  "temperature": {
+    "label": "Temperature",
+    "icon": "🌡️"
+  },
+  "volume": {
+    "label": "Volume",
+    "icon": "🧪"
+  },
+  "fluids": {
+    "label": "Fluids",
+    "icon": "💧"
+  },
+  "area": {
+    "label": "Area",
+    "icon": "🔳"
+  },
+  "speed": {
+    "label": "Speed / Velocity",
+    "icon": "💨"
+  },
+  "pressure": {
+    "label": "Pressure",
+    "icon": "🔽"
+  },
+  "energy": {
+    "label": "Energy",
+    "icon": "⚡"
+  },
+  "magnetism": {
+    "label": "Magnetism",
+    "icon": "🧲"
+  },
+  "power": {
+    "label": "Power",
+    "icon": "🔌"
+  },
+  "data": {
+    "label": "Data Storage",
+    "icon": "💾"
+  },
+  "time": {
+    "label": "Time",
+    "icon": "⏱️"
+  },
+  "angle": {
+    "label": "Angle",
+    "icon": "📐"
+  },
+  "number-systems": {
+    "label": "Number Systems",
+    "icon": "🔢"
+  },
+  "radiation": {
+    "label": "Radiation",
+    "icon": "☢️"
+  },
+  "electrical": {
+    "label": "Electrical",
+    "icon": "🔋"
+  },
+  "force": {
+    "label": "Force / Torque",
+    "icon": "💪"
+  },
+  "light": {
+    "label": "Light",
+    "icon": "💡"
+  },
+  "other": {
+    "label": "Other",
+    "icon": "🔄"
+  }
+};
+
+export const totalCalculators = 3124;

hdyc-svelte/src/lib/data/unitDefinitions.ts

@@ -1,4 +1,4 @@
-import { calculators } from './calculators';
+import { loadCalculators, type CalculatorDef } from './calculatorLoader';
 
 const domainDefinitions: Record<string, { summary: string; context: string }> = {
   length: {
@@ -97,7 +97,6 @@ const normalizeLabel = (label?: string): string | undefined => {
   return alias ?? trimmed;
 };
 
-const definitions: Record<string, Record<string, string>> = {};
 const categoryPriority = [...Object.keys(domainDefinitions)];
 
 const buildDefinition = (label: string, categoryKey: string): string => {
@@ -107,17 +106,36 @@ const buildDefinition = (label: string, categoryKey: string): string => {
   return `${label} ${description}`;
 };
 
-calculators.forEach(calc => {
+// Lazily built definitions cache
-  const { category, labels } = calc;
+let definitions: Record<string, Record<string, string>> | null = null;
-  Object.values(labels).forEach(label => {
+let buildPromise: Promise<void> | null = null;
-    const normalized = normalizeLabel(label);
+
-    if (!normalized) return;
+async function ensureBuilt(): Promise<Record<string, Record<string, string>>> {
-    const bucket = definitions[normalized] || {};
+  if (definitions) return definitions;
-    const text = buildDefinition(normalized, category);
+  if (buildPromise) {
-    bucket[category] = text;
+    await buildPromise;
-    definitions[normalized] = bucket;
+    return definitions!;
+  }
+
+  buildPromise = loadCalculators().then(calculators => {
+    const defs: Record<string, Record<string, string>> = {};
+    calculators.forEach(calc => {
+      const { category, labels } = calc;
+      Object.values(labels).forEach(label => {
+        const normalized = normalizeLabel(label);
+        if (!normalized) return;
+        const bucket = defs[normalized] || {};
+        const text = buildDefinition(normalized, category);
+        bucket[category] = text;
+        defs[normalized] = bucket;
+      });
+    });
+    definitions = defs;
   });
-});
+
+  await buildPromise;
+  return definitions!;
+}
 
 const findByPriority = (entries: Record<string, string>, preferred?: string): string | undefined => {
   if (!entries) return undefined;
@@ -129,11 +147,10 @@ const findByPriority = (entries: Record<string, string>, preferred?: string): st
   return fallback.length ? fallback[0] : undefined;
 };
 
-export function getDefinition(label: string, category?: string): string | undefined {
+export async function getDefinition(label: string, category?: string): Promise<string | undefined> {
   const normalized = normalizeLabel(label);
   if (!normalized) return undefined;
-  const entries = definitions[normalized];
+  const defs = await ensureBuilt();
+  const entries = defs[normalized];
   return findByPriority(entries, category);
 }
-
-export const unitDefinitions = definitions;

hdyc-svelte/src/lib/palettes.ts

@@ -0,0 +1,244 @@
+export type ThemeMode = 'light' | 'dark';
+export type PaletteVar =
+  | 'bg'
+  | 'bg-elevated'
+  | 'sidebar-bg'
+  | 'card-bg'
+  | 'input-bg'
+  | 'hover-bg'
+  | 'border'
+  | 'text'
+  | 'text-muted'
+  | 'accent'
+  | 'accent-dark'
+  | 'accent-glow'
+  | 'accent-gradient'
+  | 'header-bg';
+
+export type PaletteTheme = Record<PaletteVar, string>;
+
+export type Palette = {
+  slug: string;
+  label: string;
+  light: PaletteTheme;
+  dark: PaletteTheme;
+};
+
+export const palettes: Palette[] = [
+  {
+    slug: 'classic',
+    label: 'Classic',
+    light: {
+      bg: '#f8fafc',
+      'bg-elevated': '#ffffff',
+      'sidebar-bg': '#ffffff',
+      'card-bg': '#ffffff',
+      'input-bg': 'rgba(15, 23, 42, 0.04)',
+      'hover-bg': 'rgba(15, 23, 42, 0.08)',
+      border: 'rgba(15, 23, 42, 0.12)',
+      text: '#0f172a',
+      'text-muted': '#475569',
+      accent: '#10b981',
+      'accent-dark': '#059669',
+      'accent-glow': 'rgba(16, 185, 129, 0.15)',
+      'accent-gradient': 'linear-gradient(135deg, #10b981, #06b6d4)',
+      'header-bg': 'rgba(255, 255, 255, 0.95)',
+    },
+    dark: {
+      bg: '#0c0f14',
+      'bg-elevated': '#12161e',
+      'sidebar-bg': '#10141b',
+      'card-bg': 'rgba(18, 22, 30, 0.85)',
+      'input-bg': 'rgba(255, 255, 255, 0.04)',
+      'hover-bg': 'rgba(255, 255, 255, 0.06)',
+      border: 'rgba(255, 255, 255, 0.08)',
+      text: '#e8ecf4',
+      'text-muted': '#7b8498',
+      accent: '#10b981',
+      'accent-dark': '#059669',
+      'accent-glow': 'rgba(16, 185, 129, 0.15)',
+      'accent-gradient': 'linear-gradient(135deg, #10b981, #06b6d4)',
+      'header-bg': 'rgba(12, 15, 20, 0.85)',
+    },
+  },
+  {
+    slug: 'emerald',
+    label: 'Emerald',
+    light: {
+      'bg': '#f6fbf9',
+      'bg-elevated': '#ffffff',
+      'sidebar-bg': '#ffffff',
+      'card-bg': '#ffffff',
+      'input-bg': '#ecf7f1',
+      'hover-bg': '#d5f0df',
+      'border': 'rgba(4, 120, 87, 0.25)',
+      'text': '#0b2c1f',
+      'text-muted': '#4a6b5c',
+      'accent': '#047857',
+      'accent-dark': '#065f46',
+      'accent-glow': 'rgba(4, 120, 87, 0.2)',
+      'accent-gradient': 'linear-gradient(135deg, #047857, #0ea5e9)',
+      'header-bg': 'rgba(255, 255, 255, 0.95)',
+    },
+    dark: {
+      'bg': '#0b1313',
+      'bg-elevated': 'rgba(4, 20, 15, 0.85)',
+      'sidebar-bg': '#08110f',
+      'card-bg': 'rgba(6, 19, 13, 0.75)',
+      'input-bg': 'rgba(16, 185, 129, 0.08)',
+      'hover-bg': 'rgba(16, 185, 129, 0.12)',
+      'border': 'rgba(16, 185, 129, 0.35)',
+      'text': '#e9fcea',
+      'text-muted': '#9fdac4',
+      'accent': '#10b981',
+      'accent-dark': '#059669',
+      'accent-glow': 'rgba(16, 185, 129, 0.25)',
+      'accent-gradient': 'linear-gradient(135deg, #10b981, #0ea5e9)',
+      'header-bg': 'rgba(12, 15, 20, 0.85)',
+    },
+  },
+  {
+    slug: 'sunset',
+    label: 'Sunset',
+    light: {
+      'bg': '#fff8f2',
+      'bg-elevated': '#ffffff',
+      'sidebar-bg': '#ffffff',
+      'card-bg': '#fff4ef',
+      'input-bg': '#ffe3d8',
+      'hover-bg': '#ffd3bf',
+      'border': 'rgba(249, 115, 22, 0.25)',
+      'text': '#3d1b0b',
+      'text-muted': '#7a4a37',
+      'accent': '#f97316',
+      'accent-dark': '#c2410c',
+      'accent-glow': 'rgba(249, 115, 22, 0.25)',
+      'accent-gradient': 'linear-gradient(135deg, #f97316, #ec4899)',
+      'header-bg': 'rgba(255, 255, 255, 0.96)',
+    },
+    dark: {
+      'bg': '#0f0505',
+      'bg-elevated': 'rgba(15, 5, 5, 0.85)',
+      'sidebar-bg': '#0c0404',
+      'card-bg': 'rgba(19, 6, 6, 0.7)',
+      'input-bg': 'rgba(251, 113, 133, 0.08)',
+      'hover-bg': 'rgba(251, 113, 133, 0.14)',
+      'border': 'rgba(251, 113, 133, 0.35)',
+      'text': '#ffe7e0',
+      'text-muted': '#f9a6aa',
+      'accent': '#fb7185',
+      'accent-dark': '#be123c',
+      'accent-glow': 'rgba(251, 113, 133, 0.25)',
+      'accent-gradient': 'linear-gradient(135deg, #fb7185, #f97316)',
+      'header-bg': 'rgba(12, 8, 6, 0.85)',
+    },
+  },
+  {
+    slug: 'ocean',
+    label: 'Ocean',
+    light: {
+      'bg': '#f4fbff',
+      'bg-elevated': '#ffffff',
+      'sidebar-bg': '#ffffff',
+      'card-bg': '#f0f7ff',
+      'input-bg': '#dcefff',
+      'hover-bg': '#cae8ff',
+      'border': 'rgba(14, 165, 233, 0.25)',
+      'text': '#06274e',
+      'text-muted': '#4d6993',
+      'accent': '#0ea5e9',
+      'accent-dark': '#0369a1',
+      'accent-glow': 'rgba(14, 165, 233, 0.25)',
+      'accent-gradient': 'linear-gradient(135deg, #0ea5e9, #4753ff)',
+      'header-bg': 'rgba(255, 255, 255, 0.95)',
+    },
+    dark: {
+      'bg': '#030b12',
+      'bg-elevated': 'rgba(2, 9, 20, 0.85)',
+      'sidebar-bg': '#050c16',
+      'card-bg': 'rgba(3, 13, 26, 0.75)',
+      'input-bg': 'rgba(14, 165, 233, 0.08)',
+      'hover-bg': 'rgba(14, 165, 233, 0.15)',
+      'border': 'rgba(14, 165, 233, 0.4)',
+      'text': '#e6f6ff',
+      'text-muted': '#a1c4e8',
+      'accent': '#38bdf8',
+      'accent-dark': '#0369a1',
+      'accent-glow': 'rgba(14, 165, 233, 0.35)',
+      'accent-gradient': 'linear-gradient(135deg, #38bdf8, #0f172a)',
+      'header-bg': 'rgba(6, 15, 30, 0.85)',
+    },
+  },
+  {
+    slug: 'orchid',
+    label: 'Orchid',
+    light: {
+      'bg': '#fdf6ff',
+      'bg-elevated': '#ffffff',
+      'sidebar-bg': '#ffffff',
+      'card-bg': '#fdf2ff',
+      'input-bg': '#f5e4ff',
+      'hover-bg': '#e9d4ff',
+      'border': 'rgba(168, 85, 247, 0.25)',
+      'text': '#2c0a3a',
+      'text-muted': '#6a5277',
+      'accent': '#a855f7',
+      'accent-dark': '#6d28d9',
+      'accent-glow': 'rgba(168, 85, 247, 0.25)',
+      'accent-gradient': 'linear-gradient(135deg, #c084fc, #a855f7)',
+      'header-bg': 'rgba(255, 255, 255, 0.97)',
+    },
+    dark: {
+      'bg': '#0c0215',
+      'bg-elevated': 'rgba(10, 3, 30, 0.85)',
+      'sidebar-bg': '#090118',
+      'card-bg': 'rgba(12, 2, 25, 0.75)',
+      'input-bg': 'rgba(168, 85, 247, 0.08)',
+      'hover-bg': 'rgba(168, 85, 247, 0.16)',
+      'border': 'rgba(168, 85, 247, 0.35)',
+      'text': '#f5e6ff',
+      'text-muted': '#c5a3e8',
+      'accent': '#d946ef',
+      'accent-dark': '#831843',
+      'accent-glow': 'rgba(217, 70, 239, 0.25)',
+      'accent-gradient': 'linear-gradient(135deg, #d946ef, #fb7185)',
+      'header-bg': 'rgba(13, 6, 23, 0.95)',
+    },
+  },
+  {
+    slug: 'citrus',
+    label: 'Citrus',
+    light: {
+      'bg': '#fffdf5',
+      'bg-elevated': '#ffffff',
+      'sidebar-bg': '#ffffff',
+      'card-bg': '#fffaf0',
+      'input-bg': '#fff4d8',
+      'hover-bg': '#ffeec1',
+      'border': 'rgba(250, 204, 21, 0.25)',
+      'text': '#1f1505',
+      'text-muted': '#5b4a1e',
+      'accent': '#fbbf24',
+      'accent-dark': '#c2410c',
+      'accent-glow': 'rgba(250, 204, 21, 0.3)',
+      'accent-gradient': 'linear-gradient(135deg, #fbbf24, #d97706)',
+      'header-bg': 'rgba(255, 255, 255, 0.98)',
+    },
+    dark: {
+      'bg': '#1a1203',
+      'bg-elevated': 'rgba(26, 18, 3, 0.9)',
+      'sidebar-bg': '#130e02',
+      'card-bg': 'rgba(26, 18, 3, 0.75)',
+      'input-bg': 'rgba(250, 204, 21, 0.08)',
+      'hover-bg': 'rgba(250, 204, 21, 0.14)',
+      'border': 'rgba(250, 204, 21, 0.35)',
+      'text': '#fff8e7',
+      'text-muted': '#f6dea1',
+      'accent': '#fbbf24',
+      'accent-dark': '#b45309',
+      'accent-glow': 'rgba(250, 204, 21, 0.25)',
+      'accent-gradient': 'linear-gradient(135deg, #fbbf24, #f97316)',
+      'header-bg': 'rgba(15, 9, 2, 0.9)',
+    },
+  },
+];

hdyc-svelte/src/lib/utils/conversionRate.ts

@@ -0,0 +1,21 @@
+import type { CalculatorDef } from '$lib/data/calculators';
+import { formatConversionValue } from '$lib/utils/formatConversionValue';
+
+type RateConfig = Pick<CalculatorDef, 'type' | 'factor' | 'offset' | 'labels'>;
+
+export const getConversionRateText = (config: RateConfig): string | null => {
+  if (config.type !== 'standard' || !config.factor) {
+    return null;
+  }
+
+  const { in1, in2 } = config.labels;
+  if (!in1 || !in2) {
+    return null;
+  }
+
+  const formattedFactor = formatConversionValue(config.factor);
+  const hasOffset = Boolean(config.offset);
+  const formattedOffset = formatConversionValue(config.offset ?? 0);
+
+  return `1 ${in1} = ${formattedFactor}${hasOffset ? ` + ${formattedOffset}` : ''} ${in2}`;
+};

hdyc-svelte/src/lib/utils/formatConversionValue.js

@@ -0,0 +1,24 @@
+function formatConversionValue(value: number | null | undefined): string {
+  if (value === null || value === undefined || Number.isNaN(value)) {
+    return '—';
+  }
+  if (!Number.isFinite(value)) {
+    return value.toString();
+  }
+  if (value === 0) {
+    return '0';
+  }
+  const rounded = parseFloat(value.toFixed(6));
+  if (rounded !== 0) {
+    return rounded.toString();
+  }
+  const precise = value.toFixed(12).replace(/\.?0+$/, '');
+  if (precise !== '0' && precise !== '') {
+    return precise;
+  }
+
+  // Fallback for extremely small values: use scientific notation but clean it up
+  const scientific = value.toExponential();
+  return scientific.replace(/\.?0+e/, 'e');
+}
+module.exports = { formatConversionValue };

hdyc-svelte/src/lib/utils/formatConversionValue.ts

@@ -0,0 +1,23 @@
+export function formatConversionValue(value: number | null | undefined): string {
+  if (value === null || value === undefined || Number.isNaN(value)) {
+    return '—';
+  }
+  if (!Number.isFinite(value)) {
+    return value.toString();
+  }
+  if (value === 0) {
+    return '0';
+  }
+  const rounded = parseFloat(value.toFixed(6));
+  if (rounded !== 0) {
+    return rounded.toString();
+  }
+  const precise = value.toFixed(12).replace(/\.?0+$/, '');
+  if (precise !== '0' && precise !== '') {
+    return precise;
+  }
+
+  // Fallback for extremely small values: use scientific notation but clean it up
+  const scientific = value.toExponential();
+  return scientific.replace(/\.?0+e/, 'e');
+}

hdyc-svelte/src/routes/+layout.svelte

@@ -7,251 +7,8 @@
   import '../app.css';
   import Sidebar from '$lib/components/Sidebar.svelte';
   import SearchBar from '$lib/components/SearchBar.svelte';
+  import { palettes, type ThemeMode, type Palette } from '$lib/palettes';
 
-  type ThemeMode = 'light' | 'dark';
-  type PaletteVar =
-    | 'bg'
-    | 'bg-elevated'
-    | 'sidebar-bg'
-    | 'card-bg'
-    | 'input-bg'
-    | 'hover-bg'
-    | 'border'
-    | 'text'
-    | 'text-muted'
-    | 'accent'
-    | 'accent-dark'
-    | 'accent-glow'
-    | 'accent-gradient'
-    | 'header-bg';
-
-  type PaletteTheme = Record<PaletteVar, string>;
-
-  type Palette = {
-    slug: string;
-    label: string;
-    light: PaletteTheme;
-    dark: PaletteTheme;
-  };
-
-  const palettes: Palette[] = [
-    {
-      slug: 'classic',
-      label: 'Classic',
-      light: {
-        bg: '#f8fafc',
-        'bg-elevated': '#ffffff',
-        'sidebar-bg': '#ffffff',
-        'card-bg': '#ffffff',
-        'input-bg': 'rgba(15, 23, 42, 0.04)',
-        'hover-bg': 'rgba(15, 23, 42, 0.08)',
-        border: 'rgba(15, 23, 42, 0.12)',
-        text: '#0f172a',
-        'text-muted': '#475569',
-        accent: '#10b981',
-        'accent-dark': '#059669',
-        'accent-glow': 'rgba(16, 185, 129, 0.15)',
-        'accent-gradient': 'linear-gradient(135deg, #10b981, #06b6d4)',
-        'header-bg': 'rgba(255, 255, 255, 0.95)',
-      },
-      dark: {
-        bg: '#0c0f14',
-        'bg-elevated': '#12161e',
-        'sidebar-bg': '#10141b',
-        'card-bg': 'rgba(18, 22, 30, 0.85)',
-        'input-bg': 'rgba(255, 255, 255, 0.04)',
-        'hover-bg': 'rgba(255, 255, 255, 0.06)',
-        border: 'rgba(255, 255, 255, 0.08)',
-        text: '#e8ecf4',
-        'text-muted': '#7b8498',
-        accent: '#10b981',
-        'accent-dark': '#059669',
-        'accent-glow': 'rgba(16, 185, 129, 0.15)',
-        'accent-gradient': 'linear-gradient(135deg, #10b981, #06b6d4)',
-        'header-bg': 'rgba(12, 15, 20, 0.85)',
-      },
-    },
-    {
-      slug: 'emerald',
-      label: 'Emerald',
-      light: {
-        'bg': '#f6fbf9',
-        'bg-elevated': '#ffffff',
-        'sidebar-bg': '#ffffff',
-        'card-bg': '#ffffff',
-        'input-bg': '#ecf7f1',
-        'hover-bg': '#d5f0df',
-        'border': 'rgba(4, 120, 87, 0.25)',
-        'text': '#0b2c1f',
-        'text-muted': '#4a6b5c',
-        'accent': '#047857',
-        'accent-dark': '#065f46',
-        'accent-glow': 'rgba(4, 120, 87, 0.2)',
-        'accent-gradient': 'linear-gradient(135deg, #047857, #0ea5e9)',
-        'header-bg': 'rgba(255, 255, 255, 0.95)',
-      },
-      dark: {
-        'bg': '#0b1313',
-        'bg-elevated': 'rgba(4, 20, 15, 0.85)',
-        'sidebar-bg': '#08110f',
-        'card-bg': 'rgba(6, 19, 13, 0.75)',
-        'input-bg': 'rgba(16, 185, 129, 0.08)',
-        'hover-bg': 'rgba(16, 185, 129, 0.12)',
-        'border': 'rgba(16, 185, 129, 0.35)',
-        'text': '#e9fcea',
-        'text-muted': '#9fdac4',
-        'accent': '#10b981',
-        'accent-dark': '#059669',
-        'accent-glow': 'rgba(16, 185, 129, 0.25)',
-        'accent-gradient': 'linear-gradient(135deg, #10b981, #0ea5e9)',
-        'header-bg': 'rgba(12, 15, 20, 0.85)',
-      },
-    },
-    {
-      slug: 'sunset',
-      label: 'Sunset',
-      light: {
-        'bg': '#fff8f2',
-        'bg-elevated': '#ffffff',
-        'sidebar-bg': '#ffffff',
-        'card-bg': '#fff4ef',
-        'input-bg': '#ffe3d8',
-        'hover-bg': '#ffd3bf',
-        'border': 'rgba(249, 115, 22, 0.25)',
-        'text': '#3d1b0b',
-        'text-muted': '#7a4a37',
-        'accent': '#f97316',
-        'accent-dark': '#c2410c',
-        'accent-glow': 'rgba(249, 115, 22, 0.25)',
-        'accent-gradient': 'linear-gradient(135deg, #f97316, #ec4899)',
-        'header-bg': 'rgba(255, 255, 255, 0.96)',
-      },
-      dark: {
-        'bg': '#0f0505',
-        'bg-elevated': 'rgba(15, 5, 5, 0.85)',
-        'sidebar-bg': '#0c0404',
-        'card-bg': 'rgba(19, 6, 6, 0.7)',
-        'input-bg': 'rgba(251, 113, 133, 0.08)',
-        'hover-bg': 'rgba(251, 113, 133, 0.14)',
-        'border': 'rgba(251, 113, 133, 0.35)',
-        'text': '#ffe7e0',
-        'text-muted': '#f9a6aa',
-        'accent': '#fb7185',
-        'accent-dark': '#be123c',
-        'accent-glow': 'rgba(251, 113, 133, 0.25)',
-        'accent-gradient': 'linear-gradient(135deg, #fb7185, #f97316)',
-        'header-bg': 'rgba(12, 8, 6, 0.85)',
-      },
-    },
-    {
-      slug: 'ocean',
-      label: 'Ocean',
-      light: {
-        'bg': '#f4fbff',
-        'bg-elevated': '#ffffff',
-        'sidebar-bg': '#ffffff',
-        'card-bg': '#f0f7ff',
-        'input-bg': '#dcefff',
-        'hover-bg': '#cae8ff',
-        'border': 'rgba(14, 165, 233, 0.25)',
-        'text': '#06274e',
-        'text-muted': '#4d6993',
-        'accent': '#0ea5e9',
-        'accent-dark': '#0369a1',
-        'accent-glow': 'rgba(14, 165, 233, 0.25)',
-        'accent-gradient': 'linear-gradient(135deg, #0ea5e9, #4753ff)',
-        'header-bg': 'rgba(255, 255, 255, 0.95)',
-      },
-      dark: {
-        'bg': '#030b12',
-        'bg-elevated': 'rgba(2, 9, 20, 0.85)',
-        'sidebar-bg': '#050c16',
-        'card-bg': 'rgba(3, 13, 26, 0.75)',
-        'input-bg': 'rgba(14, 165, 233, 0.08)',
-        'hover-bg': 'rgba(14, 165, 233, 0.15)',
-        'border': 'rgba(14, 165, 233, 0.4)',
-        'text': '#e6f6ff',
-        'text-muted': '#a1c4e8',
-        'accent': '#38bdf8',
-        'accent-dark': '#0369a1',
-        'accent-glow': 'rgba(14, 165, 233, 0.35)',
-        'accent-gradient': 'linear-gradient(135deg, #38bdf8, #0f172a)',
-        'header-bg': 'rgba(6, 15, 30, 0.85)',
-      },
-    },
-    {
-      slug: 'orchid',
-      label: 'Orchid',
-      light: {
-        'bg': '#fdf6ff',
-        'bg-elevated': '#ffffff',
-        'sidebar-bg': '#ffffff',
-        'card-bg': '#fdf2ff',
-        'input-bg': '#f5e4ff',
-        'hover-bg': '#e9d4ff',
-        'border': 'rgba(168, 85, 247, 0.25)',
-        'text': '#2c0a3a',
-        'text-muted': '#6a5277',
-        'accent': '#a855f7',
-        'accent-dark': '#6d28d9',
-        'accent-glow': 'rgba(168, 85, 247, 0.25)',
-        'accent-gradient': 'linear-gradient(135deg, #c084fc, #a855f7)',
-        'header-bg': 'rgba(255, 255, 255, 0.97)',
-      },
-      dark: {
-        'bg': '#0c0215',
-        'bg-elevated': 'rgba(10, 3, 30, 0.85)',
-        'sidebar-bg': '#090118',
-        'card-bg': 'rgba(12, 2, 25, 0.75)',
-        'input-bg': 'rgba(168, 85, 247, 0.08)',
-        'hover-bg': 'rgba(168, 85, 247, 0.16)',
-        'border': 'rgba(168, 85, 247, 0.35)',
-        'text': '#f5e6ff',
-        'text-muted': '#c5a3e8',
-        'accent': '#d946ef',
-        'accent-dark': '#831843',
-        'accent-glow': 'rgba(217, 70, 239, 0.25)',
-        'accent-gradient': 'linear-gradient(135deg, #d946ef, #fb7185)',
-        'header-bg': 'rgba(13, 6, 23, 0.95)',
-      },
-    },
-    {
-      slug: 'citrus',
-      label: 'Citrus',
-      light: {
-        'bg': '#fffdf5',
-        'bg-elevated': '#ffffff',
-        'sidebar-bg': '#ffffff',
-        'card-bg': '#fffaf0',
-        'input-bg': '#fff4d8',
-        'hover-bg': '#ffeec1',
-        'border': 'rgba(250, 204, 21, 0.25)',
-        'text': '#1f1505',
-        'text-muted': '#5b4a1e',
-        'accent': '#fbbf24',
-        'accent-dark': '#c2410c',
-        'accent-glow': 'rgba(250, 204, 21, 0.3)',
-        'accent-gradient': 'linear-gradient(135deg, #fbbf24, #d97706)',
-        'header-bg': 'rgba(255, 255, 255, 0.98)',
-      },
-      dark: {
-        'bg': '#1a1203',
-        'bg-elevated': 'rgba(26, 18, 3, 0.9)',
-        'sidebar-bg': '#130e02',
-        'card-bg': 'rgba(26, 18, 3, 0.75)',
-        'input-bg': 'rgba(250, 204, 21, 0.08)',
-        'hover-bg': 'rgba(250, 204, 21, 0.14)',
-        'border': 'rgba(250, 204, 21, 0.35)',
-        'text': '#fff8e7',
-        'text-muted': '#f6dea1',
-        'accent': '#fbbf24',
-        'accent-dark': '#b45309',
-        'accent-glow': 'rgba(250, 204, 21, 0.25)',
-        'accent-gradient': 'linear-gradient(135deg, #fbbf24, #f97316)',
-        'header-bg': 'rgba(15, 9, 2, 0.9)',
-      },
-    },
-  ];
   const matomoContainerSrc = 'https://matomo.howdoyouconvert.com/js/container_B3r877Kn.js';
 
   type WindowWithAnalytics = Window & {
@@ -265,6 +22,7 @@
   let isMobileHeader = false;
   let theme: ThemeMode = 'dark';
   let selectedPaletteIndex = 0;
+  let savedScrollRestoration: ScrollRestoration | null = null;
   $: isHomepage = $page.url.pathname === '/';
   $: if (isHomepage && (sidebarOpen || headerSearchOpen)) {
     sidebarOpen = false;
@@ -326,14 +84,30 @@
     document.head.appendChild(script);
   };
 
-  afterNavigate(() => {
+  const scrollToTop = () => {
+    if (!browser) return;
+    window.scrollTo({ top: 0, behavior: 'auto' });
+  };
+
+  afterNavigate(({ from, to, type }) => {
     sidebarOpen = false;
     headerSearchOpen = false;
+
+    if (!browser) return;
+    if (type === 'popstate') return;
+    if (!from || !to) return;
+    if (from.url.pathname === to.url.pathname) return;
+
+    scrollToTop();
   });
 
   onMount(() => {
     if (!browser) return;
     const appWindow = window as WindowWithAnalytics;
+    if ('scrollRestoration' in window.history) {
+      savedScrollRestoration = window.history.scrollRestoration;
+      window.history.scrollRestoration = 'manual';
+    }
     let idleCallbackId: number | null = null;
     let fallbackTimeoutId: number | null = null;
 
@@ -411,6 +185,9 @@
         window.clearTimeout(fallbackTimeoutId);
       }
       window.removeEventListener('keydown', handleEscape);
+      if (savedScrollRestoration !== null) {
+        window.history.scrollRestoration = savedScrollRestoration;
+      }
     };
 
     if ('addEventListener' in mediaQuery) {
@@ -461,7 +238,7 @@
       </button>
     {/if}
     <a href="/" class="site-logo">
-      <span>How Do You</span><span class="logo-accent">Convert</span><span class="logo-domain">.com</span>
+      <span>How</span><span>Do</span><span>You</span><span class="logo-accent">Convert</span><span class="logo-domain">.com</span>
     </a>
   </div>
   <div class="header-right">

hdyc-svelte/src/routes/+page.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { categories, calculators } from '$lib/data/calculators';
+  import { categories, totalCalculators } from '$lib/data/stats';
   import CategoryCard from '$lib/components/CategoryCard.svelte';
   import SearchBar from '$lib/components/SearchBar.svelte';
   import { buildSeoMeta, SITE_NAME, SITE_URL, toJsonLd } from '$lib/seo';
@@ -18,8 +18,8 @@
     key,
     ...meta,
   }));
-  const totalCalculators = calculators.length;
+  const totalConversions = totalCalculators;
-  const totalCategories = Object.keys(homepageCategories).length;
+  const totalCategoriesCount = Object.keys(homepageCategories).length;
   const pageTitle = `${SITE_NAME} — Free Unit Conversion Calculators`;
   const pageDescription = 'Convert between hundreds of units instantly. Free online calculators for length, weight, temperature, volume, area, speed, energy, power, data and more.';
   const seo = buildSeoMeta({
@@ -49,7 +49,7 @@
   <meta name="twitter:card" content={seo.twitter.card} />
   <meta name="twitter:title" content={seo.twitter.title} />
   <meta name="twitter:description" content={seo.twitter.description} />
-  <script type="application/ld+json">{websiteJsonLd}</script>
+  {@html `<script type="application/ld+json">${websiteJsonLd}</script>`}
 </svelte:head>
 
 <section class="hero">
@@ -62,11 +62,11 @@
 
 <div class="stats-row">
   <div class="stat">
-    <div class="stat-num">{totalCalculators}</div>
+    <div class="stat-num">{totalConversions}</div>
     <div class="stat-label">Converters</div>
   </div>
   <div class="stat">
-    <div class="stat-num">{totalCategories}</div>
+    <div class="stat-num">{totalCategoriesCount}</div>
     <div class="stat-label">Categories</div>
   </div>
 </div>

hdyc-svelte/src/routes/+page.ts

@@ -0,0 +1,3 @@
+// Prerender the homepage as static HTML at build time.
+// adapter-node will serve this as a static file — no SSR round-trip.
+export const prerender = true;

hdyc-svelte/src/routes/[slug]/+page.svelte

@@ -1,8 +1,5 @@
 <script lang="ts">
   import Calculator from '$lib/components/Calculator.svelte';
-  import { afterNavigate } from '$app/navigation';
-  import { browser } from '$app/environment';
-  import { onMount } from 'svelte';
   import type { PageData } from './$types';
   import { buildSeoMeta, canonicalUrl, SITE_NAME, SITE_URL, toJsonLd } from '$lib/seo';
 
@@ -56,15 +53,6 @@
     },
   });
 
-  afterNavigate(() => {
-    if (!browser) return;
-    window.scrollTo({ top: 0 });
-  });
-
-  onMount(() => {
-    if (!browser) return;
-    window.scrollTo({ top: 0 });
-  });
 </script>
 
 <svelte:head>
@@ -80,8 +68,8 @@
   <meta name="twitter:card" content={seo.twitter.card} />
   <meta name="twitter:title" content={seo.twitter.title} />
   <meta name="twitter:description" content={seo.twitter.description} />
-  <script type="application/ld+json">{breadcrumbJsonLd}</script>
+  {@html `<script type="application/ld+json">${breadcrumbJsonLd}</script>`}
-  <script type="application/ld+json">{webPageJsonLd}</script>
+  {@html `<script type="application/ld+json">${webPageJsonLd}</script>`}
 </svelte:head>
 
 <nav class="breadcrumbs" aria-label="Breadcrumb">
@@ -94,7 +82,9 @@
 
 <h1 class="page-title calculator-page-title">{calc.name}</h1>
 
-<Calculator config={calc} showTitle={false} />
+{#key calc.slug}
+  <Calculator config={calc} showTitle={false} />
+{/key}
 
 <div class="seo-content">
   {#if calc.descriptionHTML}

hdyc-svelte/src/routes/category/[category]/+page.svelte

@@ -1,6 +1,28 @@
 <script lang="ts">
   import type { PageData } from './$types';
   import { buildSeoMeta, canonicalUrl, SITE_NAME, SITE_URL, toJsonLd } from '$lib/seo';
+  import { getConversionRateText } from '$lib/utils/conversionRate';
+
+  const handleCalcTooltipMousemove = (event: MouseEvent) => {
+    const card = event.currentTarget as HTMLElement | null;
+    if (!card) return;
+    const rect = card.getBoundingClientRect();
+    const x = Math.min(Math.max(event.clientX - rect.left, 0), rect.width);
+    const y = Math.min(Math.max(event.clientY - rect.top, 0), rect.height);
+    card.style.setProperty('--calc-tooltip-left', `${x}px`);
+    card.style.setProperty('--calc-tooltip-top', `${y}px`);
+    card.style.setProperty('--calc-tooltip-bottom', 'auto');
+    card.style.setProperty('--calc-tooltip-translate', 'calc(-100% - 0.55rem)');
+  };
+
+  const resetCalcTooltipPosition = (event: MouseEvent) => {
+    const card = event.currentTarget as HTMLElement | null;
+    if (!card) return;
+    card.style.removeProperty('--calc-tooltip-left');
+    card.style.removeProperty('--calc-tooltip-top');
+    card.style.removeProperty('--calc-tooltip-bottom');
+    card.style.removeProperty('--calc-tooltip-translate');
+  };
 
   export let data: PageData;
 
@@ -66,8 +88,8 @@
   <meta name="twitter:card" content={seo.twitter.card} />
   <meta name="twitter:title" content={seo.twitter.title} />
   <meta name="twitter:description" content={seo.twitter.description} />
-  <script type="application/ld+json">{breadcrumbJsonLd}</script>
+  {@html `<script type="application/ld+json">${breadcrumbJsonLd}</script>`}
-  <script type="application/ld+json">{collectionJsonLd}</script>
+  {@html `<script type="application/ld+json">${collectionJsonLd}</script>`}
 </svelte:head>
 
 <nav class="breadcrumbs" aria-label="Breadcrumb">
@@ -85,8 +107,18 @@
 
 <div class="calc-list">
   {#each data.calculators as calc}
-    <a href="/{calc.slug}" class="calc-list-item">
+    {@const conversionRateText = getConversionRateText(calc)}
+    <a
+      href="/{calc.slug}"
+      class="calc-list-item"
+      on:mousemove={handleCalcTooltipMousemove}
+      on:mouseleave={resetCalcTooltipPosition}
+      on:focus={resetCalcTooltipPosition}
+    >
       {calc.name}
+      {#if conversionRateText}
+        <span class="calc-list-tooltip" role="tooltip">{conversionRateText}</span>
+      {/if}
     </a>
   {/each}
 </div>

hdyc-svelte/src/routes/sitemap.xml/+server.ts

@@ -3,8 +3,7 @@ import { calculators, categories } from '$lib/data/calculators';
 
 export const GET: RequestHandler = async () => {
 	const calculatorUrls = calculators.map(
-		(calc) => `
+		(calc) => `  <url>
-  <url>
     <loc>https://howdoyouconvert.com/${calc.slug}</loc>
     <changefreq>monthly</changefreq>
     <priority>0.8</priority>
@@ -12,8 +11,7 @@ export const GET: RequestHandler = async () => {
 	);
 
 	const categoryUrls = Object.keys(categories).map(
-		(category) => `
+		(category) => `  <url>
-  <url>
     <loc>https://howdoyouconvert.com/category/${category}</loc>
     <changefreq>weekly</changefreq>
     <priority>0.9</priority>
@@ -27,8 +25,8 @@ export const GET: RequestHandler = async () => {
     <changefreq>weekly</changefreq>
     <priority>1.0</priority>
   </url>
-  ${categoryUrls.join('')}
+${categoryUrls.join('\n')}
-  ${calculatorUrls.join('')}
+${calculatorUrls.join('\n')}
 </urlset>`;
 
 	return new Response(sitemap, {

migrate.py

@@ -1,10 +1,13 @@
 import json
 import re
+import os
 from pathlib import Path
 
 BASE_DIR = Path(__file__).resolve().parent
 CALCLIST = BASE_DIR / 'calculators_list.md'
 OUTPUT_FILE = BASE_DIR / 'hdyc-svelte/src/lib/data/calculators.ts'
+STATS_FILE = BASE_DIR / 'hdyc-svelte/src/lib/data/stats.ts'
+CALCULATORS_JSON = BASE_DIR / 'hdyc-svelte/static/data/calculators.json'
 
 CATEGORY_KEYS = [
     'length',
@@ -29,6 +32,29 @@ CATEGORY_KEYS = [
     'other',
 ]
 
+CATEGORIES = {
+    'length':          {'label': 'Length / Distance',   'icon': '📏'},
+    'weight':          {'label': 'Weight / Mass',       'icon': '⚖️'},
+    'temperature':     {'label': 'Temperature',         'icon': '🌡️'},
+    'volume':          {'label': 'Volume',              'icon': '🧪'},
+    'fluids':          {'label': 'Fluids',              'icon': '💧'},
+    'area':            {'label': 'Area',                'icon': '🔳'},
+    'speed':           {'label': 'Speed / Velocity',    'icon': '💨'},
+    'pressure':        {'label': 'Pressure',            'icon': '🔽'},
+    'energy':          {'label': 'Energy',              'icon': '⚡'},
+    'magnetism':       {'label': 'Magnetism',           'icon': '🧲'},
+    'power':           {'label': 'Power',               'icon': '🔌'},
+    'data':            {'label': 'Data Storage',        'icon': '💾'},
+    'time':            {'label': 'Time',                'icon': '⏱️'},
+    'angle':           {'label': 'Angle',               'icon': '📐'},
+    'number-systems':  {'label': 'Number Systems',      'icon': '🔢'},
+    'radiation':       {'label': 'Radiation',           'icon': '☢️'},
+    'electrical':      {'label': 'Electrical',          'icon': '🔋'},
+    'force':           {'label': 'Force / Torque',      'icon': '💪'},
+    'light':           {'label': 'Light',               'icon': '💡'},
+    'other':           {'label': 'Other',               'icon': '🔄'},
+}
+
 CATEGORY_SET = set(CATEGORY_KEYS)
 
 # Lightweight label normalization to catch duplicate/identity conversions
@@ -418,28 +444,12 @@ export interface CalculatorDef {
 }
 
 export const categories: Record<string, { label: string; icon: string }> = {
-  length:          { label: 'Length / Distance',   icon: '📏' },
+"""
-  weight:          { label: 'Weight / Mass',       icon: '⚖️' },
+    for k, v in CATEGORIES.items():
-  temperature:     { label: 'Temperature',         icon: '🌡️' },
+        out += f"  '{k}': {json.dumps(v, ensure_ascii=False).replace('{', '{ ').replace('}', ' }')},\n"
-  volume:          { label: 'Volume',              icon: '🧪' },
+    out += "};\n"
-  fluids:          { label: 'Fluids',              icon: '💧' },
-  area:            { label: 'Area',                icon: '🔳' },
-  speed:           { label: 'Speed / Velocity',    icon: '💨' },
-  pressure:        { label: 'Pressure',            icon: '🔽' },
-  energy:          { label: 'Energy',              icon: '⚡' },
-  magnetism:       { label: 'Magnetism',           icon: '🧲' },
-  power:           { label: 'Power',               icon: '🔌' },
-  data:            { label: 'Data Storage',        icon: '💾' },
-  time:            { label: 'Time',                icon: '⏱️' },
-  angle:           { label: 'Angle',               icon: '📐' },
-  'number-systems':{ label: 'Number Systems',      icon: '🔢' },
-  radiation:       { label: 'Radiation',           icon: '☢️' },
-  electrical:      { label: 'Electrical',          icon: '🔋' },
-  force:           { label: 'Force / Torque',      icon: '💪' },
-  light:           { label: 'Light',               icon: '💡' },
-  other:           { label: 'Other',               icon: '🔄' },
-};
 
+    out += """
 export const calculators: CalculatorDef[] = [
 """
     for e in calculators_ts_entries:
@@ -454,8 +464,13 @@ export const calculators: CalculatorDef[] = [
     out += """
 ];
 
-const slugIndex = new Map(calculators.map(c => [c.slug, c]));
+const slugIndex: Map<string, CalculatorDef> = new Map(
+    calculators.map(calc => [calc.slug, calc])
+);
 
+"""
+
+    out += """
 export function getCalculatorBySlug(slug: string): CalculatorDef | undefined {
   return slugIndex.get(slug);
 }
@@ -487,5 +502,22 @@ export function searchCalculators(query: string): CalculatorDef[] {
 
     print(f"Generated {len(calculators_ts_entries)} calculators into calculators.ts")
 
+    # Generate stats.ts
+    total_count = len(calculators_ts_entries)
+    stats_content = f"""// THIS FILE IS AUTO-GENERATED BY migrate.py
+export const categories: Record<string, {{ label: string; icon: string }}> = {json.dumps(CATEGORIES, indent=2, ensure_ascii=False)};
+
+export const totalCalculators = {total_count};
+"""
+    with open(STATS_FILE, 'w', encoding='utf-8') as f:
+        f.write(stats_content)
+    print(f"Generated stats.ts with {total_count} total calculators")
+
+    # Generate calculators.json for true lazy loading
+    os.makedirs(os.path.dirname(CALCULATORS_JSON), exist_ok=True)
+    with open(CALCULATORS_JSON, 'w', encoding='utf-8') as f:
+        json.dump(calculators_ts_entries, f, ensure_ascii=False, indent=2)
+    print(f"Generated calculators.json (Size: {os.path.getsize(CALCULATORS_JSON) // 1024}KB)")
+
 if __name__ == '__main__':
     process()

tests/test_apothecary_page.py

@@ -0,0 +1,27 @@
+import urllib.error
+import urllib.request
+import unittest
+
+URL = 'https://howdoyouconvert.com/apothecary-ounces-to-amu'
+
+
+class ApothecaryPageTests(unittest.TestCase):
+    def test_apothecary_page_returns_success(self) -> None:
+        """The published URL should return a 200 so the calculator page stays healthy."""
+        request = urllib.request.Request(
+            URL,
+            headers={
+                'User-Agent': 'Mozilla/5.0',
+                'Accept': 'text/html,application/xhtml+xml',
+            },
+        )
+
+        try:
+            with urllib.request.urlopen(request, timeout=15) as response:
+                status = response.getcode()
+        except urllib.error.HTTPError as exc:
+            self.fail(f'{URL} returned HTTP {exc.code} ({exc.reason})')
+        except urllib.error.URLError as exc:
+            self.fail(f'{URL} could not be fetched: {exc}')
+
+        self.assertEqual(status, 200, f'{URL} returned {status}')

tests/test_consistency.py

@@ -0,0 +1,106 @@
+
+import math
+import re
+import unittest
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+CALCULATORS_TS = ROOT / "hdyc-svelte" / "src" / "lib" / "data" / "calculators.ts"
+
+def _js_fmt(n: float) -> str:
+    """Mimics the fmt() function in engine.ts"""
+    if not math.isfinite(n):
+        return str(n)
+    if n == 0:
+        return "0"
+    if abs(n) < 1e-6:
+        return f"{n:.6e}".replace("e-0", "e-").replace("e+0", "e+")
+    
+    # engine.ts uses parseFloat(n.toFixed(6)).toString()
+    rounded = round(n, 6)
+    if rounded == 0: # Handle -0.0
+        return "0"
+    if rounded == int(rounded):
+        return str(int(rounded))
+    return str(rounded)
+
+def _js_fmt_precise(n: float) -> str:
+    """Mimics formatExampleValue in QuickConversionExample.svelte"""
+    if n is None or math.isnan(n):
+        return "—"
+    if not math.isfinite(n):
+        return str(n)
+    if n == 0:
+        return "0"
+    
+    rounded = round(n, 6)
+    if rounded != 0:
+        if rounded == int(rounded):
+            return str(int(rounded))
+        return str(rounded)
+    
+    # Precise version for very small numbers
+    precise = f"{n:.12f}".rstrip('0').rstrip('.')
+    return precise if precise else "0"
+
+class TestCalculatorsConsistency(unittest.TestCase):
+    def test_standard_calculators_consistency(self):
+        text = CALCULATORS_TS.read_text(encoding="utf-8")
+        
+        # Extract the calculators array content
+        match = re.search(r"export const calculators: CalculatorDef\[\] = \[(.*?)\];", text, re.S)
+        self.assertTrue(match, "Could not find calculators array in calculators.ts")
+        
+        body = match.group(1)
+        # Split by '{"slug":' to avoid splitting on nested braces
+        raw_entries = body.split('{"slug":')
+        
+        errors = []
+        for raw_entry in raw_entries:
+            if not raw_entry.strip():
+                continue
+            entry = '{"slug":' + raw_entry
+            slug_match = re.search(r'"slug": "(.*?)"', entry)
+            if not slug_match:
+                continue
+            slug = slug_match.group(1)
+            
+            type_match = re.search(r'"type": "(.*?)"', entry)
+            if not type_match or type_match.group(1) != "standard":
+                continue
+            
+            # Use non-greedy search for factor/offset and handle potential whitespace
+            factor_match = re.search(r'"factor":\s*([0-9.eE+-]+)', entry)
+            offset_match = re.search(r'"offset":\s*([0-9.eE+-]+)', entry)
+            
+            factor = float(factor_match.group(1)) if factor_match else 1.0
+            offset = float(offset_match.group(1)) if offset_match else 0.0
+            
+            # 1. Formula Hint vs Chart Row 1 Consistency
+            # Logic: solve(config, 1, "1") -> val2 = fmt(1 * factor + offset)
+            row_one_output = _js_fmt(1.0 * factor + offset)
+            
+            # 2. How to convert Examples Consistency (Inverse)
+            if factor != 0:
+                reverse_val = (1.0 - offset) / factor
+                formatted_reverse = _js_fmt_precise(reverse_val)
+                
+                # Specific check for Réaumur to Kelvin (User request)
+                if slug == "reaumur-to-kelvin":
+                    if formatted_reverse != "-217.72":
+                        errors.append(f"[{slug}] Reverse example mismatch: expected -217.72, got {formatted_reverse}")
+                    if row_one_output != "274.4":
+                        errors.append(f"[{slug}] Chart row 1 mismatch: expected 274.4, got {row_one_output}")
+
+                # Specific check for Feet per minute to Knots (Previous bug fix)
+                if slug == "feet-per-minute-to-knots":
+                    if row_one_output != "0.009875":
+                        errors.append(f"[{slug}] Chart row 1 mismatch: expected 0.009875, got {row_one_output}")
+                    if formatted_reverse != "101.268504":
+                        errors.append(f"[{slug}] Reverse example mismatch: expected 101.268504, got {formatted_reverse}")
+
+        if errors:
+            self.fail("\n" + "\n".join(errors))
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_conversion_rate_tooltip.py

@@ -0,0 +1,27 @@
+import unittest
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+CONVERSION_RATE = (
+    ROOT / "hdyc-svelte" / "src" / "lib" / "utils" / "conversionRate.ts"
+)
+
+
+class ConversionRateTooltipFormattingTests(unittest.TestCase):
+    def test_conversion_rate_text_uses_formatter(self) -> None:
+        text = CONVERSION_RATE.read_text(encoding="utf-8")
+        normalized = " ".join(text.split())
+        self.assertIn(
+            "formatConversionValue(config.factor)",
+            normalized,
+            "Conversion rate helper must format the factor before inserting it into the tooltip text",
+        )
+        self.assertIn(
+            "formatConversionValue(config.offset ?? 0)",
+            normalized,
+            "Conversion rate tooltip must format any offset before rendering",
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_gauss_to_oersted_conversion_rate.py

@@ -0,0 +1,68 @@
+import re
+import unittest
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+CALCULATORS_TS = ROOT / "hdyc-svelte" / "src" / "lib" / "data" / "calculators.ts"
+CONVERSION_RATE_UTIL = ROOT / "hdyc-svelte" / "src" / "lib" / "utils" / "conversionRate.ts"
+CATEGORY_PAGE = ROOT / "hdyc-svelte" / "src" / "routes" / "category" / "[category]" / "+page.svelte"
+CALCULATOR_COMPONENT = ROOT / "hdyc-svelte" / "src" / "lib" / "components" / "Calculator.svelte"
+TARGET_SLUG = "gauss-to-oersted"
+NON_APPLICABLE_TWO_INPUT_STANDARD_SLUGS = {
+    "grams-per-liter-to-molarity",
+}
+
+
+def _extract_calculator_block(slug: str) -> str:
+    for line in CALCULATORS_TS.read_text(encoding="utf-8").splitlines():
+        if f'"slug": "{slug}"' in line:
+            return line
+    raise AssertionError(f"Could not find calculator definition for '{slug}'")
+
+
+class GaussToOerstedConversionRateRegressionTests(unittest.TestCase):
+    def test_gauss_to_oersted_includes_factor_for_conversion_rate_and_tooltip(self) -> None:
+        block = _extract_calculator_block(TARGET_SLUG)
+        self.assertRegex(
+            block,
+            r'"factor":\s*[0-9.eE+-]+',
+            "Missing factor on gauss-to-oersted prevents conversion rate text from rendering in both calculator footer and category tooltip.",
+        )
+
+    def test_conversion_rate_is_wired_to_both_surfaces(self) -> None:
+        util_text = CONVERSION_RATE_UTIL.read_text(encoding="utf-8")
+        category_page_text = CATEGORY_PAGE.read_text(encoding="utf-8")
+        calculator_component_text = CALCULATOR_COMPONENT.read_text(encoding="utf-8")
+
+        self.assertIn("getConversionRateText", util_text)
+        self.assertIn("conversionRateText = getConversionRateText(calc)", category_page_text)
+        self.assertIn('role="tooltip"', category_page_text)
+        self.assertIn("conversionRateText = getConversionRateText(config)", calculator_component_text)
+        self.assertIn('<span class="formula-hint">', calculator_component_text)
+
+    def test_all_applicable_two_input_standard_calculators_have_factors(self) -> None:
+        missing_factors: list[str] = []
+        for line in CALCULATORS_TS.read_text(encoding="utf-8").splitlines():
+            if '"type": "standard"' not in line:
+                continue
+            if '"labels": {"in1":' not in line or '"in2":' not in line or '"in3":' in line:
+                continue
+            slug_match = re.search(r'"slug": "([^"]+)"', line)
+            if not slug_match:
+                continue
+            slug = slug_match.group(1)
+            if slug in NON_APPLICABLE_TWO_INPUT_STANDARD_SLUGS:
+                continue
+            if '"factor":' not in line:
+                missing_factors.append(slug)
+
+        self.assertEqual(
+            missing_factors,
+            [],
+            f"Two-input standard calculators missing factors (and therefore conversion-rate text): {missing_factors}",
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_homepage_categories.py

@@ -72,7 +72,7 @@ class HomepageCategoryRegressionTests(unittest.TestCase):
     def test_homepage_uses_canonical_categories_map(self) -> None:
         text = HOMEPAGE_SVELTE.read_text(encoding="utf-8")
 
-        self.assertIn("import { categories, calculators } from '$lib/data/calculators';", text)
+        self.assertIn("import { categories, totalCalculators } from '$lib/data/stats';", text)
         self.assertIn("requiredCategoryFallbacks", text)
         self.assertIn("fluids: { label: 'Fluids', icon: '💧' }", text)
         self.assertIn("magnetism: { label: 'Magnetism', icon: '🧲' }", text)

tests/test_quick_conversion_formatting.py

@@ -0,0 +1,26 @@
+import unittest
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+QUICK_CONVERSION_EXAMPLE = (
+    ROOT / "hdyc-svelte" / "src" / "lib" / "components" / "QuickConversionExample.svelte"
+)
+
+
+class QuickConversionExampleFormattingTests(unittest.TestCase):
+    def test_formula_uses_formatted_factor_and_offset(self) -> None:
+        text = QUICK_CONVERSION_EXAMPLE.read_text(encoding="utf-8")
+        normalized = " ".join(text.split())
+        snippet = (
+            "1 {config.labels.in1} = {formattedFactorValue}{hasOffset ? ` + ${formattedOffsetValue}` : ''} "
+            "{config.labels.in2}"
+        )
+        self.assertIn(
+            snippet,
+            normalized,
+            "The formula snippet should render formatted factor/offset values instead of raw floats",
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()