:root {
  --bg:        #F5F6FA;
  --bg-panel:  #FFFFFF;
  --bg-hover:  #EEF1FA;
  --border:    #E3E6EF;
  --text:      #1A2233;
  --text-dim:  #6B7280;
  --accent:    #2563EB;
  --accent-dark: #1D4ED8;
  --radius:    10px;
  --font-ui:   -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "Consolas", "SFMono-Regular", Menlo, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ui);
  font-size: 16px;
  line-height: 1.5;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible, button:focus-visible, input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* header logo */
.brand-mark { display: block; border-radius: 9px; }

/* top bar */
.topbar {
  display: flex; align-items: center; gap: 20px;
  padding: 14px 24px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); flex-shrink: 0; }
.brand-title { display: block; font-weight: 700; font-size: 1.05rem; }
.brand-tagline { display: block; font-size: 0.75rem; color: var(--text-dim); }

.search-wrap { position: relative; flex: 1 1 280px; min-width: 200px; max-width: 420px; }
#siteSearch {
  width: 100%; padding: 10px 14px;
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius);
  color: var(--text); font-size: 0.95rem;
}
#siteSearch::placeholder { color: var(--text-dim); }
.search-results {
  position: absolute; top: calc(100% + 6px); left: 0; right: 0;
  background: var(--bg-panel); border: 1px solid var(--border); border-radius: var(--radius);
  max-height: 360px; overflow-y: auto; z-index: 50;
  box-shadow: 0 10px 30px rgba(20,30,60,0.12);
}
.search-results a {
  display: block; padding: 10px 14px; color: var(--text);
  border-bottom: 1px solid var(--border); font-size: 0.88rem;
}
.search-results a:last-child { border-bottom: none; }
.search-results a:hover { background: var(--bg-hover); text-decoration: none; }
.search-results .sr-file { font-family: var(--font-mono); font-size: 0.8rem; color: var(--text-dim); }
.search-results .sr-empty, .search-results .sr-more {
  padding: 10px 14px; color: var(--text-dim); font-size: 0.85rem;
}

.tier-switch { display: flex; gap: 6px; flex-shrink: 0; }
.tier-switch a {
  padding: 8px 14px; border-radius: 999px; font-size: 0.85rem; font-weight: 600;
  color: var(--text-dim); border: 1px solid var(--border); background: var(--bg-panel);
}
.tier-switch a:hover { color: var(--text); text-decoration: none; border-color: var(--accent); }
.tier-switch a.active { background: var(--accent); color: #fff; border-color: var(--accent); }

/* breadcrumbs + back button */
.subnav { display: flex; align-items: center; gap: 14px; padding: 12px 24px 0; max-width: 1160px; margin: 0 auto; flex-wrap: wrap; }
.btn-back {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 12px; border-radius: 999px; border: 1px solid var(--border);
  background: var(--bg-panel); color: var(--text); font-size: 0.82rem; font-weight: 600;
  cursor: pointer;
}
.btn-back:hover { border-color: var(--accent); color: var(--accent); }
.breadcrumbs { padding: 0; max-width: none; }
.breadcrumbs ol {
  list-style: none; display: flex; flex-wrap: wrap; gap: 6px; margin: 0; padding: 0;
  font-size: 0.85rem; color: var(--text-dim);
}
.breadcrumbs li:not(:last-child)::after { content: "/"; margin-left: 6px; color: var(--border); }

/* layout */
.content { max-width: 1160px; margin: 0 auto; padding: 24px; }
.page-h1 { font-size: 1.5rem; margin: 4px 0 4px; }
.page-h2 { font-size: 1.15rem; margin: 32px 0 12px; color: var(--text-dim); }
.page-sub { color: var(--text-dim); margin: 0 0 20px; }

/* colored hero banner on Category/Model pages */
.page-banner {
  border-radius: var(--radius); padding: 22px 26px; margin-bottom: 20px; color: #fff;
}
.page-banner h1 { margin: 0 0 4px; font-size: 1.4rem; }
.page-banner p { margin: 0; font-size: 0.85rem; opacity: 0.92; }

/* filter / search form boxes */
.filter-box, .search-form input {
  width: 100%; max-width: 360px; padding: 10px 14px; margin-bottom: 16px;
  background: var(--bg-panel); border: 1px solid var(--border); border-radius: var(--radius);
  color: var(--text); font-size: 0.95rem;
}
.search-form { display: flex; gap: 10px; margin-bottom: 24px; }
.search-form input { margin-bottom: 0; flex: 1; max-width: 480px; }
.search-form button {
  padding: 10px 20px; border-radius: var(--radius); border: none;
  background: var(--accent); color: #fff; font-weight: 700; cursor: pointer;
}
.search-form button:hover { background: var(--accent-dark); }

/* ---------- category browser: left sidebar + right preview ---------- */
.browse-layout { display: flex; gap: 22px; align-items: flex-start; }

.category-sidebar {
  flex: 0 0 270px; display: flex; flex-direction: column; gap: 6px;
  position: sticky; top: 90px; max-height: calc(100vh - 110px); overflow-y: auto;
}
.cat-item {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 14px; background: var(--bg-panel);
  border: 1px solid var(--border); border-left: 5px solid var(--cat-color, var(--accent));
  border-radius: 8px; color: var(--text); font-weight: 600; font-size: 0.92rem;
  transition: background 0.12s ease, transform 0.12s ease;
}
.cat-item:hover, .cat-item.active { background: var(--bg-hover); text-decoration: none; transform: translateX(2px); }
.cat-item .dot { width: 10px; height: 10px; border-radius: 50%; background: var(--cat-color, var(--accent)); flex-shrink: 0; }
.cat-item .cat-name { flex: 1; font-family: var(--font-mono); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.cat-item .count { font-size: 0.72rem; color: var(--text-dim); font-weight: 400; }

.category-preview { flex: 1; min-width: 0; }
.preview-panel.hidden { display: none; }
.preview-banner {
  border-radius: var(--radius); padding: 18px 22px; margin-bottom: 14px; color: #fff;
}
.preview-banner h2 { margin: 0 0 4px; font-size: 1.2rem; }
.preview-banner span { font-size: 0.82rem; opacity: 0.92; }

.preview-models {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 10px;
}
.preview-model {
  display: flex; flex-direction: column; gap: 4px;
  padding: 12px 14px; background: var(--bg-panel); border: 1px solid var(--border);
  border-radius: 8px; color: var(--text);
}
.preview-model:hover { border-color: var(--accent); text-decoration: none; transform: translateY(-1px); }
.pm-name { font-weight: 600; font-family: var(--font-mono); font-size: 0.88rem; }
.pm-meta { font-size: 0.72rem; color: var(--text-dim); }

/* listing tables (category direct page, search, model files) */
.listing {
  width: 100%; border-collapse: collapse;
  background: var(--bg-panel); border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden;
}
.listing th, .listing td { padding: 12px 14px; text-align: left; border-bottom: 1px solid var(--border); font-size: 0.92rem; }
.listing th {
  background: var(--bg); color: var(--text-dim); font-weight: 600;
  font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em;
}
.listing tbody tr:last-child td { border-bottom: none; }
.listing tbody tr.row-link { cursor: pointer; }
.listing tbody tr.row-link:hover { background: var(--bg-hover); }
.listing td.filename, .listing td:nth-child(3), .listing td:nth-child(4) { font-family: var(--font-mono); font-size: 0.85rem; }
.tier-tag { font-size: 0.72rem; color: var(--text-dim); margin-left: 6px; }

.ext-badge {
  display: inline-block; padding: 2px 8px; border-radius: 6px;
  background: #FFF3E0; color: #B45309;
  font-family: var(--font-mono); font-size: 0.72rem; font-weight: 700;
}
.btn-download {
  display: inline-block; padding: 7px 14px; border-radius: 8px;
  background: var(--accent); color: #fff; font-weight: 700; font-size: 0.85rem;
}
.btn-download:hover { background: var(--accent-dark); text-decoration: none; }

.empty-state { padding: 40px 20px; text-align: center; color: var(--text-dim); }

/* ad slots - visually separated from content, labeled, never touching download buttons */
.ad-slot {
  max-width: 1160px; margin: 24px auto 0; padding: 14px 24px;
}
.ad-slot::before {
  content: "Advertisement"; display: block; text-align: center;
  font-size: 0.68rem; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--text-dim); margin-bottom: 6px;
}
.ad-slot-inline { margin: 24px 0; padding: 14px 0; }

.sitefooter {
  border-top: 1px solid var(--border); padding: 20px 24px; margin-top: 20px;
  text-align: center; color: var(--text-dim); font-size: 0.78rem; max-width: 900px; margin-left: auto; margin-right: auto;
}
.sitefooter .copyright { margin-top: 10px; font-size: 0.8rem; }

@media (max-width: 900px) {
  .browse-layout { flex-direction: column; }
  .category-sidebar {
    position: static; flex-direction: row; overflow-x: auto; overflow-y: hidden;
    max-height: none; width: 100%; padding-bottom: 6px;
  }
  .cat-item { flex: 0 0 auto; white-space: nowrap; }
  .cat-item .cat-name { white-space: nowrap; }
}

@media (max-width: 640px) {
  .topbar { padding: 12px 16px; }
  .content { padding: 16px; }
  .listing th:nth-child(3), .listing td:nth-child(3) { display: none; }
  .tier-switch a { padding: 7px 10px; font-size: 0.8rem; }
}

@media (prefers-reduced-motion: reduce) {
  .cat-item, .preview-model { transition: none; }
}