feat: Initialize SvelteKit project, add tsconfig.json, and introduce a new Calculator.svelte component.

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

@@ -0,0 +1,197 @@
+<script lang="ts">
+  import { page } from '$app/stores';
+  import { categories, getCalculatorsByCategory } from '$lib/data/calculators';
+
+  let expandedCategory = '';
+
+  $: currentPath = $page.url.pathname;
+
+  function toggle(cat: string) {
+    expandedCategory = expandedCategory === cat ? '' : cat;
+  }
+
+  export let open = false;
+</script>
+
+<aside class="sidebar" class:open>
+  <div class="sidebar-header">
+    <h3>All Converters</h3>
+    <button class="close-btn" on:click={() => (open = false)} aria-label="Close sidebar">✕</button>
+  </div>
+  <nav>
+    {#each Object.entries(categories) as [key, meta]}
+      {@const calcs = getCalculatorsByCategory(key)}
+      <div class="cat-section">
+        <button
+          class="cat-toggle"
+          class:active={expandedCategory === key || currentPath.includes(`/category/${key}`)}
+          on:click={() => toggle(key)}
+        >
+          <span class="cat-icon">{meta.icon}</span>
+          <span class="cat-label">{meta.label}</span>
+          <span class="chevron" class:expanded={expandedCategory === key}>›</span>
+        </button>
+        {#if expandedCategory === key}
+          <ul class="cat-list" >
+            {#each calcs as calc}
+              <li>
+                <a
+                  href="/{calc.slug}"
+                  class:current={currentPath === `/${calc.slug}`}
+                >
+                  {calc.name}
+                </a>
+              </li>
+            {/each}
+            <li>
+              <a href="/category/{key}" class="view-all">View all {meta.label} →</a>
+            </li>
+          </ul>
+        {/if}
+      </div>
+    {/each}
+  </nav>
+</aside>
+
+{#if open}
+  <!-- svelte-ignore a11y_click_events_have_key_events -->
+  <!-- svelte-ignore a11y_no_static_element_interactions -->
+  <div class="overlay" on:click={() => (open = false)}></div>
+{/if}
+
+<style>
+  .sidebar {
+    width: 280px;
+    height: 100%;
+    overflow-y: auto;
+    background: var(--sidebar-bg);
+    border-right: 1px solid var(--border);
+    padding: 0;
+    flex-shrink: 0;
+  }
+  .sidebar-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    padding: 1.25rem 1rem;
+    border-bottom: 1px solid var(--border);
+  }
+  .sidebar-header h3 {
+    margin: 0;
+    font-size: 0.9rem;
+    font-weight: 700;
+    text-transform: uppercase;
+    letter-spacing: 0.08em;
+    color: var(--accent);
+  }
+  .close-btn {
+    display: none;
+    background: none;
+    border: none;
+    color: var(--text-muted);
+    font-size: 1.2rem;
+    cursor: pointer;
+    padding: 0.25rem;
+  }
+
+  nav {
+    padding: 0.5rem 0;
+  }
+
+  .cat-toggle {
+    display: flex;
+    align-items: center;
+    width: 100%;
+    padding: 0.6rem 1rem;
+    border: none;
+    background: none;
+    cursor: pointer;
+    font-size: 0.88rem;
+    color: var(--text);
+    gap: 0.5rem;
+    transition: background 0.15s;
+    text-align: left;
+  }
+  .cat-toggle:hover {
+    background: var(--hover-bg);
+  }
+  .cat-toggle.active {
+    color: var(--accent);
+    font-weight: 600;
+  }
+  .cat-icon {
+    font-size: 1rem;
+    flex-shrink: 0;
+    width: 1.4rem;
+    text-align: center;
+  }
+  .cat-label {
+    flex: 1;
+  }
+  .chevron {
+    font-size: 1.1rem;
+    font-weight: 700;
+    color: var(--text-muted);
+    transition: transform 0.2s;
+  }
+  .chevron.expanded {
+    transform: rotate(90deg);
+  }
+
+  .cat-list {
+    list-style: none;
+    margin: 0;
+    padding: 0 0 0.5rem;
+  }
+  .cat-list li a {
+    display: block;
+    padding: 0.35rem 1rem 0.35rem 2.8rem;
+    font-size: 0.82rem;
+    color: var(--text-muted);
+    text-decoration: none;
+    transition: color 0.15s, background 0.15s;
+    border-radius: 0;
+  }
+  .cat-list li a:hover {
+    color: var(--accent);
+    background: var(--hover-bg);
+  }
+  .cat-list li a.current {
+    color: var(--accent);
+    font-weight: 600;
+    background: var(--accent-glow);
+  }
+  .view-all {
+    font-weight: 600 !important;
+    color: var(--accent) !important;
+  }
+
+  .overlay {
+    display: none;
+  }
+
+  @media (max-width: 768px) {
+    .sidebar {
+      position: fixed;
+      top: 0;
+      left: -300px;
+      z-index: 100;
+      height: 100vh;
+      transition: left 0.3s ease;
+      box-shadow: 4px 0 24px rgba(0, 0, 0, 0.2);
+    }
+    .sidebar.open {
+      left: 0;
+    }
+    .close-btn {
+      display: block;
+    }
+    .overlay {
+      display: block;
+      position: fixed;
+      inset: 0;
+      z-index: 99;
+      background: rgba(0, 0, 0, 0.5);
+    }
+  }
+</style>