refactor: Optimize sidebar data loading, update font to ExtraBold, and adjust blur effects for category cards and header.

hdyc-svelte/src/app.css

@@ -343,9 +343,14 @@ a:focus-visible {
   justify-content: space-between;
   padding: 0 1.5rem;
   background: var(--header-bg);
+  border-bottom: 1px solid var(--border);
+}
+
+@media (min-width: 1025px) {
+  .site-header {
     backdrop-filter: blur(16px);
     -webkit-backdrop-filter: blur(16px);
-  border-bottom: 1px solid var(--border);
+  }
 }
 
 .header-left {

hdyc-svelte/src/app.html

@@ -12,7 +12,7 @@
 		/>
 		<link
 			rel="preload"
-			href="/fonts/inter/Inter-Bold.woff2"
+			href="/fonts/inter/Inter-ExtraBold.woff2"
 			as="font"
 			type="font/woff2"
 			crossorigin

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/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 type { CalculatorDef } from '$lib/data/calculators';
+
+  let allCalculators: CalculatorDef[] = [];
+  let isLoaded = false;
+
+  async function loadData() {
+    if (isLoaded || !browser) return;
+    const module = await import('$lib/data/calculators');
+    allCalculators = module.calculators;
+    isLoaded = true;
+  }
 
   let expandedCategory = '';
   let expandedUnits: Record<string, string> = {};
@@ -76,7 +87,12 @@
 
   $: 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 => {
@@ -161,6 +177,11 @@
   }
 
   export let open = false;
+
+  $: if (browser && (isDesktop || open)) {
+    loadData();
+  }
+
   $: isSidebarHidden = !isDesktop && !open;
 
   function closeSidebar() {