:root {
        --bg: #ffffff;
        --fg: #111111;
        --muted: #666666;
        --card: #f7f7f7;
        --border: #e5e5e5;
        --tag-bg: #efefef;
        --tag-fg: #111111;
        --badge-bg: #111111;
        --badge-fg: #ffffff;
        --shadow: 0 1px 2px rgba(0,0,0,0.06), 0 8px 24px rgba(0,0,0,0.06);
        --focus: 0 0 0 3px rgba(0,0,0,0.08);
      }
      [data-theme="dark"] {
        --bg: #0a0a0a;
        --fg: #f2f2f2;
        --muted: #a0a0a0;
        --card: #121212;
        --border: #222222;
        --tag-bg: #1a1a1a;
        --tag-fg: #f2f2f2;
        --badge-bg: #ffffff;
        --badge-fg: #000000;
        --shadow: 0 1px 2px rgba(0,0,0,0.3), 0 8px 24px rgba(0,0,0,0.25);
        --focus: 0 0 0 3px rgba(255,255,255,0.12);
      }

      * { box-sizing: border-box; }
      html, body { height: 100%; }
      body {
        margin: 0;
        background: var(--bg);
        color: var(--fg);
        font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, "Helvetica Neue", Arial, "Apple Color Emoji", "Segoe UI Emoji";
        line-height: 1.5;
      }

      /* Header */
      .site-header {
        position: sticky;
        top: 0;
        backdrop-filter: saturate(180%) blur(12px);
        background: color-mix(in oklab, var(--bg) 88%, transparent);
        border-bottom: 1px solid var(--border);
        z-index: 10;
      }
      .header-inner {
        max-width: 1200px;
        margin: 0 auto;
        padding: 18px 20px;
        display: flex;
        align-items: center;
        justify-content: space-between;
        gap: 12px;
      }
      .brand {
        display: flex;
        align-items: baseline;
        gap: 10px;
      }
      .brand h1 { font-size: 22px; margin: 0; letter-spacing: 0.3px; }
      .brand small { color: var(--muted); font-size: 13px; }

      .contact {
        display: flex;
        align-items: center;
        gap: 12px;
        font-size: 13px;
      }
      .contact a {
        color: var(--fg);
        text-decoration: none;
        display: inline-flex;
        align-items: center;
        gap: 4px;
      }
      .contact a:hover { text-decoration: underline; }

      .theme-toggle {
        display: inline-flex;
        align-items: center;
        gap: 10px;
        border: 1px solid var(--border);
        background: var(--bg);
        color: var(--fg);
        padding: 8px 12px;
        border-radius: 999px;
        cursor: pointer;
        box-shadow: var(--shadow);
      }
      .theme-toggle:focus-visible { outline: none; box-shadow: var(--focus); }
      .theme-toggle svg { width: 18px; height: 18px; }

      /* Main */
      .container { max-width: 1200px; margin: 24px auto; padding: 0 20px 60px; }

      .tabs {
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
        margin-bottom: 24px;
      }
      .tab {
        display: inline-flex;
        align-items: center;
        border: 1px solid var(--border);
        border-bottom: 2px solid transparent;
        background: var(--bg);
        color: var(--fg);
        border-radius: 6px 6px 0 0;
        padding: 8px 12px;
        font-size: 14px;
        font-weight: 600;
        letter-spacing: .2px;
        cursor: pointer;
        text-decoration: none;
        transition: border-color 0.2s ease;
      }
      .tab.active {
        background: var(--card);
        border-bottom-color: #007bff;
      }
      .tab:not(.active) { opacity: 0.5; }
      .tab:not(.active):hover { opacity: 0.8; }
      .tab-panel[hidden] { display: none; }

      .grid {
        display: grid;
        gap: 16px;
        grid-template-columns: repeat(1, minmax(0, 1fr));
      }
      @media (min-width: 640px) { .grid { grid-template-columns: repeat(2, 1fr); } }
      @media (min-width: 900px) { .grid { grid-template-columns: repeat(3, 1fr); } }
      @media (min-width: 1200px) { .grid { grid-template-columns: repeat(4, 1fr); } }

      .filters {
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
        margin-bottom: 24px;
      }
      .lang-filter {
        display: inline-flex;
        align-items: center;
        border: 1px solid var(--border);
        background: var(--bg);
        color: var(--fg);
        border-radius: 999px;
        padding: 4px 10px;
        font-size: 13px;
        font-weight: 600;
        letter-spacing: .2px;
        cursor: pointer;
        text-decoration: none;
      }
      .lang-filter[aria-pressed="false"] { opacity: 0.4; }

      .card {
        position: relative;
        border: 1px solid var(--border);
        background: var(--card);
        border-radius: 16px;
        padding: 18px 16px 16px;
        box-shadow: var(--shadow);
        display: flex;
        flex-direction: column;
        gap: 10px;
        min-height: 160px;
        text-decoration: none;
        color: var(--fg);
      }
      .card h3 {
        margin: 0 0 2px 0;
        font-size: 16px;
        letter-spacing: 0.2px;
      }
      .desc { color: var(--fg); opacity: 0.9; font-size: 14px; }
      .meta { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 12px; margin-top: 4px; }

      .badge {
        position: absolute;
        top: 12px; right: 12px;
        background: var(--badge-bg);
        color: var(--badge-fg);
        border: 1px solid var(--border);
        padding: 4px 8px;
        border-radius: 999px;
        font-size: 12px;
        font-weight: 600;
        letter-spacing: .2px;
      }

      .badge-html { background: #e34c26; color: #ffffff; }
      .badge-javascript { background: #f7df1e; color: #000000; }
      .badge-css { background: #264de4; color: #ffffff; }
      .badge-php { background: #777bb3; color: #000000; }
      .badge-java { background: #d32f2f; color: #ffffff; }

      .chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 6px; }
      .chip {
        display: inline-flex; align-items: center;
        background: var(--tag-bg);
        color: var(--tag-fg);
        border: 1px solid var(--border);
        padding: 4px 8px;
        border-radius: 999px;
        font-size: 12px;
        line-height: 1;
      }

      .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; }

      /* Timeline */
      .timeline {
        position: relative;
        margin: 0;
        padding-left: 40px;
        border-left: 2px solid var(--border);
        display: flex;
        flex-direction: column;
        gap: 24px;
      }
      .timeline-item {
        position: relative;
      }
      .timeline-item::before {
        content: '';
        position: absolute;
        left: -41px;
        top: 4px;
        width: 10px;
        height: 10px;
        background: var(--bg);
        border: 2px solid var(--border);
        border-radius: 50%;
      }
      .timeline-year {
        position: absolute;
        left: -40px;
        top: -4px;
        font-weight: 600;
        color: var(--muted);
        font-size: 14px;
      }
      .timeline-content h3 {
        margin: 0;
        font-size: 16px;
      }
      .timeline-content .meta {
        margin-top: 4px;
      }
      .timeline-content ul {
        margin: 8px 0 0 16px;
        padding: 0;
      }
      .timeline-content ul li {
        margin-bottom: 4px;
      }