/* ================================================================
   现代导航 - Linear/Vercel 风格
   基调：柔和克制 · 层次分明 · 呼吸感
   ================================================================ */
:root {
  --bg: #fafafa;
  --bg-2: #ffffff;
  --surface: #ffffff;
  --sidebar-bg: #ffffff;
  --text: #0a0a0a;
  --text-secondary: #52525b;
  --text-muted: #a1a1aa;
  --border: #e4e4e7;
  --border-hover: #d4d4d8;

  --brand: #0a0a0a;
  --brand-soft: #f4f4f5;

  --accent-1: #f97316;   /* 橘 */
  --accent-2: #a855f7;   /* 紫 */
  --accent-3: #06b6d4;   /* 青 */
  --accent-4: #10b981;   /* 绿 */

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.03);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.08), 0 4px 12px rgba(0, 0, 0, 0.04);

  --radius-lg: 14px;
  --radius: 10px;
  --radius-sm: 6px;
}

[data-theme="dark"] {
  --bg: #0a0a0a;
  --bg-2: #111111;
  --surface: #141414;
  --sidebar-bg: #0f0f0f;
  --text: #fafafa;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --border: #262626;
  --border-hover: #3f3f46;

  --brand: #fafafa;
  --brand-soft: #1c1c1c;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 20px 50px rgba(0, 0, 0, 0.5), 0 4px 12px rgba(0, 0, 0, 0.3);
}

/* ================================================================
   基础
   ================================================================ */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  letter-spacing: -0.01em;
}

.app { display: flex; min-height: 100vh; }

/* ================================================================
   侧边栏
   ================================================================ */
.sidebar {
  width: 240px;
  flex-shrink: 0;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  padding: 20px 12px;
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  z-index: 20;
  transition: transform 0.25s;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 600;
  padding: 8px 12px 20px;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}
.logo-icon {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  flex-shrink: 0;
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.25),
    0 2px 8px rgba(99, 102, 241, 0.35);
}
.logo-icon svg { width: 16px; height: 16px; }
[data-theme="dark"] .logo-icon {
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.2),
    0 2px 12px rgba(139, 92, 246, 0.4);
}
.logo-text { color: var(--text); }

.nav {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 1px;
  padding: 4px 0;
}

.nav a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 7px 12px;
  border-radius: 6px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 13.5px;
  font-weight: 500;
  transition: background-color 0.12s, color 0.12s;
}
.nav a:hover {
  background: var(--brand-soft);
  color: var(--text);
}
.nav a.active {
  background: var(--brand-soft);
  color: var(--text);
  font-weight: 600;
}
.nav-icon {
  width: 18px;
  height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  opacity: 0.75;
  flex-shrink: 0;
}
.nav-icon svg { width: 16px; height: 16px; }
.nav a.active .nav-icon { opacity: 1; }

.sidebar-footer {
  padding: 12px 8px 0;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}
.theme-toggle {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  cursor: pointer;
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 13px;
  transition: all 0.12s;
  display: flex;
  align-items: center;
  gap: 6px;
}
.theme-toggle:hover {
  background: var(--brand-soft);
  border-color: var(--border-hover);
  color: var(--text);
}
[data-theme="dark"] .icon-light,
:root:not([data-theme="dark"]) .icon-dark { display: none; }
.version {
  font-size: 11px;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

/* ================================================================
   主内容
   ================================================================ */
.main { flex: 1; min-width: 0; }

/* Hero */
.hero {
  padding: 80px 32px 48px;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 400px;
  background:
    radial-gradient(circle at 30% 50%, rgba(249, 115, 22, 0.08), transparent 50%),
    radial-gradient(circle at 70% 50%, rgba(168, 85, 247, 0.08), transparent 50%);
  filter: blur(40px);
  pointer-events: none;
  z-index: 0;
}
[data-theme="dark"] .hero::before {
  background:
    radial-gradient(circle at 30% 50%, rgba(249, 115, 22, 0.12), transparent 50%),
    radial-gradient(circle at 70% 50%, rgba(168, 85, 247, 0.12), transparent 50%);
}

.hero-inner {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
  position: relative;
  z-index: 1;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 5px 12px;
  border: 1px solid var(--border);
  border-radius: 20px;
  margin-bottom: 20px;
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}
.hero-tag::before {
  content: "";
  width: 6px;
  height: 6px;
  background: #10b981;
  border-radius: 50%;
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.15);
}

.hero-title {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 14px;
  color: var(--text);
  line-height: 1.1;
}
.hero-subtitle {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 32px;
  letter-spacing: -0.01em;
}

.search-box {
  display: flex;
  align-items: stretch;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  max-width: 620px;
  margin: 0 auto;
  box-shadow: var(--shadow-md);
  transition: all 0.15s;
}
.search-box:hover { border-color: var(--border-hover); }
.search-box:focus-within {
  border-color: var(--text);
  box-shadow: 0 0 0 4px var(--brand-soft), var(--shadow-md);
}
.engine-select {
  border: 0;
  padding: 0 14px;
  background: transparent;
  color: var(--text);
  font-size: 13px;
  border-right: 1px solid var(--border);
  outline: none;
  cursor: pointer;
  font-weight: 500;
}
#searchInput {
  flex: 1;
  border: 0;
  padding: 14px 16px;
  font-size: 14.5px;
  outline: none;
  color: var(--text);
  background: transparent;
  font-family: inherit;
}
#searchInput::placeholder { color: var(--text-muted); }
.search-btn {
  border: 0;
  padding: 0 22px;
  background: var(--brand);
  color: var(--bg);
  font-weight: 600;
  font-size: 13.5px;
  cursor: pointer;
  transition: opacity 0.12s;
  letter-spacing: -0.01em;
}
.search-btn:hover { opacity: 0.85; }

.menu-btn {
  display: none;
  position: absolute;
  top: 20px;
  left: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 18px;
  width: 40px;
  height: 40px;
  border-radius: 8px;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  z-index: 5;
}

/* Content */
.content {
  max-width: 1180px;
  margin: 0 auto;
  padding: 8px 32px 60px;
  position: relative;
}

.category { margin-bottom: 40px; scroll-margin-top: 20px; }
.category-header {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 16px;
  padding: 0 2px;
}
.category-icon {
  width: 20px;
  height: 20px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
}
.category-icon svg { width: 18px; height: 18px; }
.category-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.01em;
}
.category-count {
  font-size: 12px;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  margin-left: auto;
  font-weight: 500;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 8px;
}

/* 卡片 */
.card {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  text-decoration: none;
  color: var(--text);
  transition: all 0.15s ease;
  min-height: 68px;
  position: relative;
  overflow: hidden;
}
.card:hover {
  transform: translateY(-1px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
}

.card-icon {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--brand-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  transition: transform 0.2s;
}
.card:hover .card-icon { transform: scale(1.05); }

.card-body { flex: 1; min-width: 0; }
.card-name {
  font-size: 13.5px;
  font-weight: 600;
  margin-bottom: 3px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: var(--text);
  letter-spacing: -0.01em;
}
.card-desc {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.4;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.card.hidden { display: none; }

.empty {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-muted);
  font-size: 14px;
}

/* Footer */
.footer {
  text-align: center;
  padding: 32px 20px;
  color: var(--text-muted);
  font-size: 13px;
  border-top: 1px solid var(--border);
}
.footer p { letter-spacing: -0.01em; }

/* ================================================================
   滚动条
   ================================================================ */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover { background: var(--border-hover); }

::selection { background: rgba(249, 115, 22, 0.15); color: var(--text); }

/* ================================================================
   响应式
   ================================================================ */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    transform: translateX(-100%);
    box-shadow: var(--shadow-lg);
  }
  .sidebar.open { transform: translateX(0); }
  .menu-btn { display: flex; align-items: center; justify-content: center; }
  .hero { padding: 80px 20px 40px; }
  .hero-title { font-size: 32px; }
  .hero-subtitle { font-size: 14px; }
  .content { padding: 0 16px 40px; }
  .search-box { flex-wrap: wrap; }
  .engine-select { flex: 1 0 40%; }
  .search-btn { flex: 1 0 40%; padding: 12px; }
  #searchInput { flex: 1 0 100%; order: -1; border-bottom: 1px solid var(--border); }
}