/* ============================================================
   AIGEO 导航 · Design Contract
   Style: tech-dark | Stack: plain HTML/CSS/JS | Pure static
   ============================================================ */
:root {
  --bg: #070b14;
  --bg-soft: #0b1120;
  --surface: rgba(255, 255, 255, 0.03);
  --surface-hover: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.14);
  --primary: #22d3ee;
  --accent: #818cf8;
  --grad: linear-gradient(135deg, #22d3ee 0%, #818cf8 100%);
  --text: #e6eaf2;
  --muted: #8b94a7;
  --faint: #5b6478;
  --tag-bg: rgba(34, 211, 238, 0.08);
  --tag-text: #7dd3e8;
  --china: #f59e0b;
  --radius: 14px;
  --radius-sm: 8px;
  --maxw: 1200px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Consolas, monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 128px; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

::selection { background: rgba(34, 211, 238, 0.3); }

::-webkit-scrollbar { width: 10px; height: 8px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: #1e293b; border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: #334155; }

a { color: inherit; text-decoration: none; }
img { display: block; }

/* ===== Hero ===== */
.hero {
  position: relative;
  padding: 72px 20px 56px;
  text-align: center;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(600px 300px at 20% 0%, rgba(34, 211, 238, 0.12), transparent 70%),
    radial-gradient(600px 300px at 80% 10%, rgba(129, 140, 248, 0.12), transparent 70%),
    radial-gradient(rgba(255, 255, 255, 0.045) 1px, transparent 1px);
  background-size: auto, auto, 28px 28px;
}

.hero-inner {
  position: relative;
  max-width: 720px;
  margin: 0 auto;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 36px;
  text-align: left;
}

.brand-logo {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: var(--grad);
  display: grid;
  place-items: center;
  color: #06121f;
  box-shadow: 0 4px 24px rgba(34, 211, 238, 0.35);
}

.brand-logo svg { width: 22px; height: 22px; }
.brand-logo.small { width: 30px; height: 30px; border-radius: 9px; }
.brand-logo.small svg { width: 16px; height: 16px; }

.brand-text { display: flex; flex-direction: column; }
.brand-name { font-size: 17px; font-weight: 700; letter-spacing: 0.5px; }
.brand-sub { font-size: 11px; color: var(--faint); font-family: var(--mono); letter-spacing: 0.3px; }

.hero-title {
  font-size: clamp(30px, 5vw, 44px);
  font-weight: 800;
  letter-spacing: -0.5px;
  line-height: 1.25;
  margin-bottom: 14px;
}

.grad {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-sub {
  color: var(--muted);
  font-size: 15px;
  max-width: 560px;
  margin: 0 auto 32px;
}

/* ===== Search ===== */
.search-box {
  position: relative;
  max-width: 560px;
  margin: 0 auto 28px;
}

.search-icon {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  color: var(--faint);
  pointer-events: none;
}

.search-icon svg { display: block; width: 100%; height: 100%; }

.search-box input {
  width: 100%;
  padding: 14px 52px 14px 46px;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: rgba(255, 255, 255, 0.04);
  backdrop-filter: blur(12px);
  color: var(--text);
  font-family: var(--font);
  font-size: 14px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-box input::placeholder { color: var(--faint); }

.search-box input:focus {
  border-color: rgba(34, 211, 238, 0.5);
  box-shadow: 0 0 0 4px rgba(34, 211, 238, 0.12);
}

.search-box kbd {
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--mono);
  font-size: 11px;
  color: var(--faint);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 2px 7px;
  background: var(--surface);
}

/* ===== Hero stats ===== */
.hero-stats {
  display: flex;
  justify-content: center;
  gap: 14px;
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 10px 26px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  min-width: 120px;
}

.stat-num { font-family: var(--mono); font-size: 20px; font-weight: 700; color: var(--text); }
.stat-label { font-size: 12px; color: var(--muted); }

/* ===== Toolbar ===== */
.toolbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(7, 11, 20, 0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.toolbar-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  gap: 14px;
}

.chips {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: none;
  flex: 1;
  padding: 2px 0;
}

.chips::-webkit-scrollbar { display: none; }

.chip {
  flex-shrink: 0;
  border: 1px solid transparent;
  background: var(--surface);
  color: var(--muted);
  font-family: var(--font);
  font-size: 13px;
  padding: 6px 14px;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.18s;
  white-space: nowrap;
}

.chip:hover { color: var(--text); background: var(--surface-hover); }

.chip.active {
  background: var(--grad);
  color: #06121f;
  font-weight: 600;
}

/* ===== Content ===== */
.content {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 40px 20px 80px;
}

.category {
  margin-bottom: 56px;
  scroll-margin-top: 128px;
}

.section-head {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  margin-bottom: 22px;
}

.section-icon {
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  border-radius: 12px;
  border: 1px solid var(--border-strong);
  background: linear-gradient(160deg, rgba(34, 211, 238, 0.14), rgba(129, 140, 248, 0.10));
  display: grid;
  place-items: center;
  color: var(--primary);
}

.section-icon svg { width: 20px; height: 20px; }

.section-title {
  font-size: 21px;
  font-weight: 700;
  letter-spacing: -0.2px;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.count {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--tag-text);
  background: var(--tag-bg);
  border: 1px solid rgba(34, 211, 238, 0.18);
  padding: 2px 10px;
  border-radius: 999px;
}

.section-en {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--faint);
  letter-spacing: 0.5px;
  margin-top: 2px;
}

.section-desc {
  color: var(--muted);
  font-size: 13.5px;
  margin-top: 8px;
  max-width: 720px;
}

.section-note {
  margin-top: 10px;
  padding: 10px 14px;
  border-left: 2px solid rgba(245, 158, 11, 0.5);
  background: rgba(245, 158, 11, 0.05);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: #cbb28a;
  font-size: 12.5px;
  max-width: 720px;
}

/* ===== Card grid ===== */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 14px;
}

.card {
  position: relative;
  border: 1px solid var(--border);
  background: var(--surface);
  border-radius: var(--radius);
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: transform 0.18s, border-color 0.18s, background 0.18s, box-shadow 0.18s;
}

.card:hover {
  transform: translateY(-3px);
  border-color: rgba(34, 211, 238, 0.35);
  background: var(--surface-hover);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.35);
}

.card[hidden] { display: none; }

.card-top {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  position: relative;
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  border-radius: 10px;
  display: grid;
  place-items: center;
  overflow: hidden;
}

.logo-letter {
  font-weight: 800;
  font-size: 17px;
  color: rgba(255, 255, 255, 0.92);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.logo-favicon {
  position: absolute;
  inset: 4px;
  width: calc(100% - 8px);
  height: calc(100% - 8px);
  object-fit: contain;
  border-radius: 6px;
  background: #f8fafc;
  opacity: 0;
  transition: opacity 0.25s;
  padding: 2px;
}

.logo-favicon.ok { opacity: 1; }

.card-title {
  font-size: 15.5px;
  font-weight: 650;
  color: var(--text);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: color 0.18s;
  word-break: break-word;
}

.card-title svg { width: 13px; height: 13px; color: var(--faint); flex-shrink: 0; transition: color 0.18s; }
.card:hover .card-title { color: var(--primary); }
.card:hover .card-title svg { color: var(--primary); }

.card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 8px;
  min-width: 0;
}

.card-desc {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.55;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: auto;
}

.tag {
  font-size: 11.5px;
  font-family: var(--mono);
  color: var(--faint);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  padding: 2px 8px;
  border-radius: 6px;
}

/* ===== Empty state ===== */
.empty-state {
  text-align: center;
  padding: 80px 20px;
  color: var(--faint);
}

.empty-state svg { width: 40px; height: 40px; margin: 0 auto 14px; display: block; }
.empty-state p { font-size: 14px; }

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border);
  background: var(--bg-soft);
  padding: 36px 20px 44px;
}

.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
  align-items: flex-start;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 15px;
}

.footer-note {
  color: var(--muted);
  font-size: 12.5px;
  max-width: 720px;
  line-height: 1.7;
}

.footer-meta {
  color: var(--faint);
  font-size: 11.5px;
  font-family: var(--mono);
  letter-spacing: 0.5px;
}

/* ===== Back to top ===== */
.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  border: 1px solid var(--border-strong);
  background: rgba(11, 17, 32, 0.9);
  backdrop-filter: blur(10px);
  color: var(--muted);
  display: grid;
  place-items: center;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: all 0.25s;
  z-index: 60;
}

.back-top svg { width: 18px; height: 18px; }
.back-top.show { opacity: 1; pointer-events: auto; transform: translateY(0); }
.back-top:hover { color: var(--primary); border-color: rgba(34, 211, 238, 0.4); }

/* ===== Responsive ===== */
@media (max-width: 720px) {
  .hero { padding: 48px 16px 40px; }
  .toolbar-inner { padding: 8px 14px; gap: 10px; }
  .content { padding: 28px 16px 60px; }
  .grid { grid-template-columns: 1fr; }
  .hero-stats { flex-wrap: wrap; }
  .stat { min-width: 100px; padding: 8px 16px; }
  html { scroll-padding-top: 108px; }
  .category { scroll-margin-top: 108px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}