/* ============================================================
   AI Nav · 样式表
   主题: 深色 + 霓虹青紫
   设计语言: 玻璃拟态 / 渐变描边 / 微动效
   ============================================================ */

:root {
  --bg-0: #070A18;
  --bg-1: #0B1020;
  --bg-2: #11172B;
  --bg-card: rgba(20, 26, 48, 0.55);
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --text-0: #F1F5FF;
  --text-1: #C7CDE6;
  --text-2: #8089A8;
  --text-3: #5B6485;

  --c-cyan: #22D3EE;
  --c-indigo: #6366F1;
  --c-purple: #A855F7;
  --grad: linear-gradient(135deg, #22D3EE 0%, #6366F1 50%, #A855F7 100%);
  --grad-soft: linear-gradient(135deg, rgba(34,211,238,0.18), rgba(168,85,247,0.18));

  --radius-s: 8px;
  --radius-m: 12px;
  --radius-l: 16px;
  --radius-xl: 20px;

  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.35);
  --shadow-glow: 0 0 24px rgba(99, 102, 241, 0.25);

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
          "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  font-family: var(--font);
  color: var(--text-0);
  background: var(--bg-0);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(99, 102, 241, 0.18), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, rgba(168, 85, 247, 0.12), transparent 60%),
    radial-gradient(1000px 800px at 50% 100%, rgba(34, 211, 238, 0.10), transparent 60%),
    var(--bg-0);
  background-attachment: fixed;
}

a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }

/* ============================================================
   背景光晕装饰
   ============================================================ */
.bg-glow {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
}
.blob {
  position: absolute;
  width: 480px;
  height: 480px;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.35;
  animation: float 18s ease-in-out infinite;
}
.blob-1 { background: #22D3EE; top: -120px; left: -120px; }
.blob-2 { background: #A855F7; top: 30%; right: -180px; animation-delay: -6s; }
.blob-3 { background: #6366F1; bottom: -160px; left: 30%; animation-delay: -12s; }

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50%      { transform: translate(40px, -30px) scale(1.08); }
}

/* ============================================================
   顶部 header
   ============================================================ */
.site-header {
  max-width: 1480px;
  margin: 0 auto;
  padding: 40px 28px 24px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 24px;
  align-items: center;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
}
.brand-logo {
  width: 48px;
  height: 48px;
  filter: drop-shadow(0 0 12px rgba(99,102,241,0.45));
}
.brand-text h1 {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.5px;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.brand-sub {
  margin: 2px 0 0;
  font-size: 12px;
  color: var(--text-2);
  letter-spacing: 0.4px;
}

/* 搜索框 */
.search-wrap {
  position: relative;
  display: flex;
  align-items: center;
  background: rgba(15, 20, 40, 0.7);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 0 16px;
  height: 52px;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
}
.search-wrap:focus-within {
  border-color: rgba(99, 102, 241, 0.6);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.12), var(--shadow-glow);
}
.search-icon {
  font-size: 16px;
  margin-right: 10px;
  opacity: 0.7;
}
#search {
  flex: 1;
  height: 100%;
  background: transparent;
  border: none;
  outline: none;
  color: var(--text-0);
  font-size: 15px;
  font-family: inherit;
}
#search::placeholder { color: var(--text-3); }
.search-kbd {
  font-family: var(--font);
  font-size: 11px;
  color: var(--text-2);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 2px 7px;
  margin-left: 8px;
}

.header-stats {
  display: flex;
  gap: 18px;
  font-size: 13px;
  color: var(--text-2);
  white-space: nowrap;
}
.header-stats b {
  font-size: 16px;
  font-weight: 700;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-right: 3px;
}

/* ============================================================
   主体 + 右侧 sidebar 两栏布局
   ============================================================ */
.layout {
  max-width: 1480px;
  margin: 0 auto;
  padding: 8px 28px 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 240px;
  gap: 28px;
  align-items: start;
}

/* ============================================================
   广告：已切换到 AdSense Auto Ads（v12），无手动 ad-slot。
   位置由 AdSense 自动选择，移动端约 7 个、桌面端约 6 个。
   ============================================================ */

/* ============================================================
   右侧分类 sidebar（sticky）
   ============================================================ */
.cat-sidebar {
  position: sticky;
  top: 16px;
  align-self: start;
  width: 100%;
  max-height: calc(100vh - 32px);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.cat-sidebar-inner {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-l);
  padding: 14px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  display: flex;
  flex-direction: column;
  min-height: 0;
}
.cat-sidebar-title {
  font-size: 12px;
  color: var(--text-2);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 10px;
  padding-left: 4px;
}

/* ============================================================
   分类导航 chips（竖排在 sidebar 内）
   ============================================================ */
.cat-nav {
  display: flex;
  flex-direction: column;
  gap: 6px;
  overflow-y: auto;
  max-height: calc(100vh - 110px);
  padding-right: 2px;
  scrollbar-width: thin;
  scrollbar-color: rgba(255, 255, 255, 0.15) transparent;
}
.cat-nav::-webkit-scrollbar { width: 4px; }
.cat-nav::-webkit-scrollbar-track { background: transparent; }
.cat-nav::-webkit-scrollbar-thumb { background: rgba(255, 255, 255, 0.15); border-radius: 2px; }

.cat-chip {
  width: 100%;
  text-align: left;
  padding: 8px 12px;
  font-size: 13px;
  color: var(--text-1);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 10px;
  transition: all 0.18s;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
}
.cat-chip:hover {
  color: var(--text-0);
  border-color: var(--border);
  background: rgba(255, 255, 255, 0.04);
}
.cat-chip.active {
  color: #fff;
  background: var(--grad);
  border-color: transparent;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

/* ============================================================
   主体内容
   ============================================================ */
.content {
  min-width: 0; /* 防止 grid 子项被内容撑爆 */
  padding: 0 0 40px;
}

.cat-section {
  margin: 36px 0 8px;
}
.cat-section:first-child { margin-top: 16px; }

.cat-title {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0 0 16px;
  font-size: 18px;
  font-weight: 600;
  color: var(--text-0);
}
.cat-title .cat-emoji {
  font-size: 22px;
}
.cat-title .cat-count {
  font-size: 12px;
  color: var(--text-3);
  font-weight: 500;
}

/* 工具卡片 grid */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 12px;
}

.tool-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-m);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all 0.2s;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
}
.tool-card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: var(--grad);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  opacity: 0;
  transition: opacity 0.2s;
  pointer-events: none;
}
.tool-card:hover {
  transform: translateY(-2px);
  border-color: transparent;
  box-shadow: var(--shadow-card), var(--shadow-glow);
  background: rgba(28, 36, 64, 0.7);
}
.tool-card:hover::before { opacity: 1; }

.tool-name {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-0);
}
.tool-name::after {
  content: "↗";
  font-size: 11px;
  opacity: 0;
  color: var(--c-cyan);
  transition: opacity 0.2s, transform 0.2s;
  margin-left: auto;
}
.tool-card:hover .tool-name::after {
  opacity: 1;
  transform: translate(2px, -2px);
}
.tool-desc {
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--text-2);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ============================================================
   空状态
   ============================================================ */
.empty {
  text-align: center;
  padding: 80px 20px;
  color: var(--text-2);
}
.empty-icon { font-size: 48px; margin-bottom: 16px; }
.empty h2 { margin: 0 0 8px; font-size: 18px; color: var(--text-1); }
.empty a { color: var(--c-cyan); text-decoration: underline; }

/* ============================================================
   底部
   ============================================================ */
.site-footer {
  max-width: 1480px;
  margin: 0 auto;
  padding: 24px 28px 40px;
  text-align: center;
  font-size: 12.5px;
  color: var(--text-2);
  border-top: 1px solid var(--border);
}
.site-footer p { margin: 4px 0; }
.site-footer .muted { color: var(--text-3); font-size: 11.5px; }
.site-footer a { color: var(--c-cyan); }
.site-footer a:hover { text-decoration: underline; }

/* ============================================================
   响应式（≤ 900px：sidebar 转成顶部横排 sticky）
   ============================================================ */
@media (max-width: 900px) {
  .site-header {
    grid-template-columns: 1fr;
    gap: 16px;
    padding: 24px 18px 16px;
  }
  .header-stats { order: 3; }
  .header-right {
    order: 4;
    justify-content: space-between;
    width: 100%;
  }
  .lang-btn { padding: 5px 10px; font-size: 11px; }

  /* layout 单列；用 order 把 sidebar 提到 main 之前 */
  .layout {
    grid-template-columns: 1fr;
    padding: 8px 18px 0;
    gap: 12px;
  }
  /* 移动端：Auto Ads 由 AdSense 智能插入，不再写手动画尺寸 */
  .cat-sidebar {
    position: sticky;
    top: 0;
    order: -1;
    max-height: none;
    z-index: 10;
  }
  .cat-sidebar-inner {
    padding: 10px 12px;
    border-radius: var(--radius-m);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.35);
  }
  .cat-sidebar-title { display: none; }
  .cat-nav {
    flex-direction: row;
    flex-wrap: nowrap;
    overflow-x: auto;
    max-height: none;
    gap: 8px;
    padding-right: 0;
    scrollbar-width: none;
  }
  .cat-nav::-webkit-scrollbar { display: none; }
  .cat-chip {
    width: auto;
    flex-shrink: 0;
    padding: 6px 12px;
    font-size: 12.5px;
  }

  .content { padding: 0 0 28px; }
  .site-footer { padding: 20px 18px 32px; }
  .tool-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 10px; }
  .tool-card { padding: 12px 14px; }
  .brand-text h1 { font-size: 20px; }
  .card { padding: 24px 20px; }
}

@media (max-width: 480px) {
  .tool-grid { grid-template-columns: 1fr 1fr; }
  .search-wrap { height: 46px; }
  #search { font-size: 14px; }
  .search-kbd { display: none; }
  .card { padding: 20px 16px; }
}

/* 滚动条美化 */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.08); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: rgba(255,255,255,0.15); }

/* 选区 */
::selection { background: rgba(99, 102, 241, 0.4); color: #fff; }

/* ============================================================
   右上角语言切换 + about/privacy 通用样式
   ============================================================ */
.header-right {
  display: flex;
  align-items: center;
  gap: 16px;
}
.lang-switch {
  display: inline-flex;
  background: rgba(15, 20, 40, 0.7);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill, 999px);
  padding: 3px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  gap: 2px;
}
.lang-btn {
  appearance: none;
  background: transparent;
  border: none;
  color: var(--text-2);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.4px;
  padding: 6px 12px;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
  font-family: inherit;
}
.lang-btn:hover { color: var(--text-0); }
.lang-btn.active {
  background: var(--grad);
  color: #0B1020;
  box-shadow: 0 2px 8px rgba(99, 102, 241, 0.25);
}

/* about / privacy 通用 card */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-l);
  padding: 32px;
  margin-top: 20px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.card h2 {
  margin-top: 0;
  font-size: 22px;
  color: var(--text-0);
}
.card h3 {
  font-size: 16px;
  color: var(--text-0);
  margin-top: 20px;
  margin-bottom: 8px;
}
.card p, .card ul {
  line-height: 1.8;
  color: var(--text-1);
}
.card ul {
  padding-left: 20px;
  line-height: 1.9;
}
.card .note {
  color: var(--text-2);
  font-size: 14px;
  background: rgba(99, 102, 241, 0.06);
  border-left: 3px solid var(--c-cyan);
  padding: 10px 14px;
  border-radius: 0 8px 8px 0;
  line-height: 1.7;
}
.card code {
  background: var(--bg-2);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
  color: var(--text-0);
}
.cyan { color: var(--c-cyan); }
.grad-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.back-home {
  text-align: center;
  margin-top: 32px;
}
.back-home a {
  color: var(--c-cyan);
  text-decoration: none;
  font-size: 15px;
}
.back-home a:hover { text-decoration: underline; }

/* about 单列 header（带语言切换的简化版） */
.about-header {
  grid-template-columns: 1fr auto;
  padding-bottom: 24px;
}
.about-header .header-right { gap: 0; }