/* ============================================================
   玄天AI -- XuanTianAI.COM
   AI 从入门到应用 · 通俗版知识站点样式表
   ============================================================ */

/* ---------- 主题变量 ---------- */
:root {
  --c-bg: #0b1020;
  --c-bg-soft: #0f1730;
  --c-panel: #121a33;
  --c-panel-2: #16203f;
  --c-border: #22304f;
  --c-border-soft: #1a2440;
  --c-text: #dbe4f5;
  --c-text-dim: #8fa0c0;
  --c-text-faint: #6b7c9c;
  --c-accent: #6c8cff;
  --c-accent-2: #22d3ee;
  --c-accent-soft: rgba(108, 140, 255, .14);
  --c-accent-2-soft: rgba(34, 211, 238, .12);
  --c-warn: #ffb454;
  --c-ok: #4ade80;
  --c-danger: #ff6b81;
  --c-read: #4bb98a;          /* 已读颜色 */
  --c-mark: #ffe08a;
  --shadow: 0 8px 30px rgba(0, 0, 0, .35);
  --radius: 12px;
  --radius-sm: 8px;
  --topbar-h: 76px;           /* 顶部导航条（加高） */
  --footer-h: 44px;           /* 底部版权条 */
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Source Han Sans SC",
    "Noto Sans CJK SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", "Cascadia Code", "Fira Code", Consolas, "Courier New", monospace;
}

html[data-theme="light"] {
  --c-bg: #f4f6fb;
  --c-bg-soft: #eef1f8;
  --c-panel: #ffffff;
  --c-panel-2: #f7f9fe;
  --c-border: #dde3f0;
  --c-border-soft: #e8edf7;
  --c-text: #1c2438;
  --c-text-dim: #56637e;
  --c-text-faint: #7c88a3;
  --c-accent: #3355e0;
  --c-accent-2: #0d94a8;
  --c-accent-soft: rgba(51, 85, 224, .10);
  --c-accent-2-soft: rgba(13, 148, 168, .10);
  --c-read: #1f9c63;
  --c-mark: #b45309;
  --shadow: 0 6px 22px rgba(30, 45, 90, .10);
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; height: 100%; }

body {
  font-family: var(--font);
  background: var(--c-bg);
  color: var(--c-text);
  font-size: 16px;
  line-height: 1.9;
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
}

a { color: var(--c-accent); text-decoration: none; }
a:hover { text-decoration: underline; }

::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--c-border); border-radius: 6px; }
::-webkit-scrollbar-thumb:hover { background: var(--c-text-faint); }

/* ============================================================
   顶部栏（加高）
   ============================================================ */
.progress {
  position: fixed; top: 0; left: 0; right: 0; height: 3px;
  background: transparent; z-index: 70;
}
.progress i {
  display: block; height: 100%; width: 0%;
  background: linear-gradient(90deg, var(--c-accent), var(--c-accent-2));
  transition: width .1s linear;
}

.topbar {
  position: fixed; top: 0; left: 0; right: 0; height: var(--topbar-h);
  display: flex; align-items: center; gap: 16px;
  padding: 0 20px;
  background: color-mix(in srgb, var(--c-bg-soft) 92%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-border);
  z-index: 60;
}

.brand { display: flex; align-items: center; gap: 12px; color: var(--c-text); flex-shrink: 0; }
.brand:hover { text-decoration: none; }
.brand-mark {
  width: 44px; height: 44px; border-radius: 12px;
  display: grid; place-items: center;
  font-weight: 700; font-size: 23px; color: #fff;
  background: linear-gradient(135deg, var(--c-accent), var(--c-accent-2));
  box-shadow: 0 4px 14px var(--c-accent-soft);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-text strong { font-size: 19px; letter-spacing: .8px; }
.brand-text em {
  font-style: normal; font-size: 11.5px; color: var(--c-text-faint);
  letter-spacing: .8px; font-family: var(--mono);
}
.brand-text span.slogan { font-size: 11px; color: var(--c-accent-2); letter-spacing: .5px; }

.searchbox { position: relative; flex: 1; max-width: 480px; }
.searchbox input {
  width: 100%; height: 44px;
  padding: 0 44px 0 40px;
  border-radius: 999px;
  border: 1px solid var(--c-border);
  background: var(--c-panel);
  color: var(--c-text);
  font-family: var(--font); font-size: 15px;
  outline: none; transition: border-color .15s, box-shadow .15s;
}
.searchbox input:focus { border-color: var(--c-accent); box-shadow: 0 0 0 3px var(--c-accent-soft); }
.searchbox .s-icon {
  position: absolute; left: 15px; top: 50%; transform: translateY(-50%);
  color: var(--c-text-faint); pointer-events: none; display: flex;
}
.searchbox kbd {
  position: absolute; right: 14px; top: 50%; transform: translateY(-50%);
  font-family: var(--mono); font-size: 11px; color: var(--c-text-faint);
  border: 1px solid var(--c-border); border-radius: 5px; padding: 1px 7px;
  background: var(--c-bg-soft);
}
.searchbox input:focus + .s-icon + kbd { display: none; }

.search-results {
  position: absolute; top: 54px; left: 0; right: 0;
  max-height: 62vh; overflow-y: auto;
  background: var(--c-panel);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 6px; display: none;
}
.search-results.show { display: block; }
.search-results .sr-item {
  padding: 9px 11px; border-radius: var(--radius-sm); cursor: pointer;
  display: block; color: var(--c-text);
}
.search-results .sr-item:hover, .search-results .sr-item.active { background: var(--c-accent-soft); text-decoration: none; }
.search-results .sr-item .t { font-size: 14.5px; font-weight: 600; }
.search-results .sr-item .p {
  font-size: 11.5px; color: var(--c-text-faint); margin-top: 2px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.search-results .sr-empty { padding: 14px; color: var(--c-text-faint); font-size: 13px; text-align: center; }

.topbar-actions { margin-left: auto; display: flex; align-items: center; gap: 9px; }
.icon-btn {
  width: 42px; height: 42px; border-radius: 11px;
  border: 1px solid var(--c-border); background: var(--c-panel);
  color: var(--c-text-dim); cursor: pointer;
  display: grid; place-items: center; transition: .15s;
}
.icon-btn:hover { color: var(--c-accent); border-color: var(--c-accent); transform: translateY(-1px); }
.icon-btn.on { color: var(--c-accent); border-color: var(--c-accent); background: var(--c-accent-soft); }
#btn-menu { display: none; }

/* ---------- 顶部栏目导航 ---------- */
.mainnav {
  display: flex; align-items: center; gap: 4px; margin-left: 2px;
  overflow-x: auto; scrollbar-width: none; flex-shrink: 0;
}
.mainnav::-webkit-scrollbar { display: none; }
.nav-item {
  font-size: 14px; color: var(--c-text-dim); padding: 9px 13px;
  border-radius: 9px; white-space: nowrap; font-weight: 600;
  border: 1px solid transparent; transition: .15s;
}
.nav-item:hover { background: var(--c-panel); color: var(--c-text); text-decoration: none; }
.nav-item.on {
  background: var(--c-accent-soft); color: var(--c-accent);
  border-color: color-mix(in srgb, var(--c-accent) 45%, transparent);
}
.nav-item:first-child { color: var(--c-text); }

/* ---------- 分享面板 ---------- */
.share-panel {
  position: fixed; top: calc(var(--topbar-h) + 6px); right: 16px; width: 320px;
  background: var(--c-panel); border: 1px solid var(--c-border);
  border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 14px 15px; z-index: 80; display: none;
}
.share-panel.show { display: block; }
.sp-head {
  font-size: 14.5px; font-weight: 700; color: var(--c-text);
  display: flex; justify-content: space-between; align-items: center; margin-bottom: 11px;
}
.sp-close { cursor: pointer; color: var(--c-text-faint); font-size: 20px; line-height: 1; padding: 0 4px; }
.sp-close:hover { color: var(--c-danger); }
.sp-urlbox { display: flex; gap: 7px; margin-bottom: 11px; }
.sp-urlbox input {
  flex: 1; min-width: 0; height: 38px; padding: 0 11px;
  border: 1px solid var(--c-border); border-radius: var(--radius-sm);
  background: var(--c-panel-2); color: var(--c-text-dim); font-size: 12.5px;
  font-family: var(--mono); outline: none;
}
.sp-copy, .sp-list button {
  height: 38px; padding: 0 13px; border-radius: var(--radius-sm);
  border: 1px solid var(--c-accent); background: var(--c-accent);
  color: #fff; font-size: 13px; cursor: pointer; white-space: nowrap;
  font-family: var(--font); transition: .15s;
}
.sp-copy:hover, .sp-list button:hover { filter: brightness(1.08); }
.sp-list { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.sp-list button {
  background: var(--c-panel-2); color: var(--c-text-dim); border-color: var(--c-border);
  height: 36px; font-size: 12.5px; padding: 0 8px;
}
.sp-list button:hover { color: var(--c-accent); border-color: var(--c-accent); }
.sp-list button:last-child { grid-column: 1 / -1; }
.sp-tip { margin-top: 11px; font-size: 12px; color: var(--c-text-faint); line-height: 1.7; }

/* 轻提示 */
.toast {
  position: fixed; left: 50%; bottom: calc(var(--footer-h) + 24px); transform: translateX(-50%) translateY(10px);
  background: var(--c-text); color: var(--c-bg); font-size: 13.5px;
  padding: 9px 18px; border-radius: 999px; z-index: 90;
  opacity: 0; pointer-events: none; transition: .2s; box-shadow: var(--shadow);
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ============================================================
   底部固定版权条
   ============================================================ */
.footer-bar {
  position: fixed; left: 0; right: 0; bottom: 0; height: var(--footer-h);
  display: flex; align-items: center; justify-content: center;
  gap: 10px; flex-wrap: nowrap; overflow: hidden;
  padding: 0 16px;
  background: color-mix(in srgb, var(--c-bg-soft) 96%, transparent);
  backdrop-filter: blur(10px);
  border-top: 1px solid var(--c-border);
  font-size: 12.5px; color: var(--c-text-faint); z-index: 65;
}
.footer-bar b { color: var(--c-text-dim); font-weight: 600; }
.footer-bar .dot { opacity: .45; }
.footer-bar .warn { color: var(--c-warn); }
.footer-bar a { color: var(--c-accent); }

/* ============================================================
   布局：左(一级) | 中(二级) | 内容 | 右(三级)
   ============================================================ */
.layout {
  position: fixed; top: var(--topbar-h); left: 0; right: 0; bottom: var(--footer-h);
  display: grid;
  grid-template-columns: 272px 296px minmax(0, 1fr) 238px;
  overflow: hidden;
}
/* 大屏再放宽左右两栏，主标题不换行 */
@media (min-width: 1700px) {
  .layout { grid-template-columns: 310px 336px minmax(0, 1fr) 264px; }
}

.col { overflow-y: auto; overflow-x: hidden; }
.col-1 { background: var(--c-bg-soft); border-right: 1px solid var(--c-border); }
.col-2 { background: color-mix(in srgb, var(--c-bg-soft) 55%, var(--c-bg)); border-right: 1px solid var(--c-border); }
.col-main { background: var(--c-bg); scroll-behavior: smooth; }
.col-3 { background: var(--c-bg); border-left: 1px solid var(--c-border-soft); }

/* ---------- 一级菜单 ---------- */
.nav-title {
  font-size: 11px; letter-spacing: 1.5px; color: var(--c-text-faint);
  padding: 18px 16px 8px; font-weight: 700;
}
.l1-item {
  display: block;
  padding: 12px 14px; margin: 4px 8px; border-radius: var(--radius-sm);
  cursor: pointer; color: var(--c-text-dim); transition: .15s;
  position: relative;
}
.l1-item:hover { background: var(--c-panel); color: var(--c-text); }
.l1-item.active { background: var(--c-accent-soft); color: var(--c-text); font-weight: 600; }
.l1-item.active::before {
  content: ""; position: absolute; left: -8px; top: 8px; bottom: 8px;
  width: 3px; border-radius: 0 3px 3px 0; background: var(--c-accent);
}
.l1-head { padding: 18px 16px 10px; border-bottom: 1px solid var(--c-border-soft); margin-bottom: 6px; }
.l1-head h4 { margin: 0; font-size: 15px; color: var(--c-text); line-height: 1.5; letter-spacing: .5px; }
.l1-head p { margin: 4px 0 0; font-size: 11.5px; color: var(--c-text-faint); line-height: 1.6; }
.l1-extra {
  display: block; margin: 10px 12px 18px; padding: 10px 13px;
  border: 1px dashed var(--c-accent-2); border-radius: var(--radius-sm);
  background: var(--c-accent-2-soft); color: var(--c-accent-2);
  font-size: 13px; line-height: 1.6;
}
.l1-extra:hover { text-decoration: none; filter: brightness(1.08); }

.l1-row { display: flex; gap: 10px; align-items: flex-start; }
.l1-txt { flex: 1; min-width: 0; }
.l1-num {
  flex-shrink: 0; width: 24px; height: 24px; border-radius: 7px;
  display: grid; place-items: center; font-size: 12px; font-family: var(--mono);
  background: var(--c-panel-2); color: var(--c-text-faint);
  border: 1px solid var(--c-border); margin-top: 2px;
}
.l1-item.active .l1-num { background: var(--c-accent); color: #fff; border-color: var(--c-accent); }
.l1-name {
  display: block; font-size: 16px; line-height: 1.5;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.l1-sub { display: block; font-size: 11.5px; color: var(--c-text-faint); margin-top: 3px; line-height: 1.5; }
.l1-item.read .l1-name::after { content: " ✓"; color: var(--c-read); font-size: 11px; }

/* ---------- 二级菜单 ---------- */
.l2-head { padding: 18px 14px 12px; border-bottom: 1px solid var(--c-border-soft); margin-bottom: 6px; }
.l2-head h3 { margin: 0; font-size: 15.5px; color: var(--c-text); line-height: 1.5; }
.l2-head p { margin: 6px 0 0; font-size: 11.5px; color: var(--c-text-faint); line-height: 1.6; }
.l2-item {
  display: block; padding: 9px 14px; margin: 2px 8px;
  border-radius: var(--radius-sm); cursor: pointer;
  color: var(--c-text-dim); font-size: 14.5px; transition: .15s; line-height: 1.55;
}
.l2-item:hover { background: var(--c-panel); color: var(--c-text); }
.l2-item.active { background: var(--c-accent-2-soft); color: var(--c-accent-2); font-weight: 600; }
.l2-item .badge {
  float: right; font-size: 10px; color: var(--c-text-faint);
  font-family: var(--mono); background: var(--c-panel-2);
  border-radius: 4px; padding: 0 5px; margin-left: 6px;
}
.l2-item.read { color: var(--c-read); }
.l2-item.read .badge { color: var(--c-read); }
.l2-item.active.read { color: var(--c-accent-2); }

/* ---------- 三级目录（右侧） ---------- */
.toc-head { padding: 18px 14px 8px; font-size: 11px; letter-spacing: 1px; color: var(--c-text-faint); font-weight: 700; }
.toc-item {
  display: block; padding: 7px 12px; margin: 1px 8px;
  border-radius: 6px; font-size: 13px; color: var(--c-text-faint);
  border-left: 2px solid transparent; cursor: pointer; transition: .15s; line-height: 1.6;
}
.toc-item:hover { color: var(--c-text); background: var(--c-panel); }
.toc-item.active { color: var(--c-accent); border-left-color: var(--c-accent); background: var(--c-accent-soft); font-weight: 600; }
.toc-item.read { color: var(--c-read); }
.toc-item.active.read { color: var(--c-accent); }

/* ============================================================
   内容区（宽度自适应）
   ============================================================ */
.article {
  width: 100%;
  max-width: 1680px;
  margin: 0 auto;
  padding: 30px clamp(20px, 3.6vw, 68px) 90px;
}

.crumb { font-size: 12.5px; color: var(--c-text-faint); margin-bottom: 14px; display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.crumb span { opacity: .6; }

.chapter-hero {
  border: 1px solid var(--c-border);
  background: linear-gradient(135deg, var(--c-panel), var(--c-bg-soft));
  border-radius: var(--radius); padding: 26px 28px; margin-bottom: 28px;
  position: relative; overflow: hidden;
}
.chapter-hero::after {
  content: ""; position: absolute; right: -40px; top: -60px;
  width: 220px; height: 220px; border-radius: 50%;
  background: radial-gradient(circle, var(--c-accent-soft), transparent 70%);
}
.chapter-hero h1 { margin: 0 0 12px; font-size: clamp(22px, 2.4vw, 30px); line-height: 1.4; color: var(--c-text); }
.chapter-hero p { margin: 0; color: var(--c-text-dim); font-size: 15px; }
.chapter-hero .meta { margin-top: 14px; display: flex; gap: 8px; flex-wrap: wrap; }
.chapter-hero .meta span {
  font-size: 11.5px; color: var(--c-text-dim);
  border: 1px solid var(--c-border); border-radius: 999px;
  padding: 3px 11px; background: var(--c-panel-2);
}

/* 三级小节 */
.section { scroll-margin-top: 90px; margin-bottom: 42px; }
.section > h2 {
  font-size: clamp(18px, 1.6vw, 22px); margin: 0 0 16px; padding-bottom: 10px;
  border-bottom: 1px solid var(--c-border);
  display: flex; align-items: center; gap: 10px; color: var(--c-text); line-height: 1.5;
}
.section > h2 .idx {
  font-family: var(--mono); font-size: 12px; color: var(--c-accent);
  background: var(--c-accent-soft); border-radius: 5px; padding: 2px 8px; flex-shrink: 0;
}
.article h3 {
  font-size: 17px; margin: 26px 0 12px; color: var(--c-text);
  padding-left: 11px; border-left: 3px solid var(--c-accent); line-height: 1.6;
}
.article h4 { font-size: 15.5px; margin: 20px 0 10px; color: var(--c-text); }
.article p { margin: 0 0 13px; color: var(--c-text-dim); }
.article strong { color: var(--c-text); font-weight: 600; }
.article ul, .article ol { margin: 0 0 15px; padding-left: 24px; color: var(--c-text-dim); }
.article li { margin-bottom: 7px; }
.article li::marker { color: var(--c-accent); }
.article hr { border: none; border-top: 1px solid var(--c-border-soft); margin: 26px 0; }

.article code:not(pre code) {
  font-family: var(--mono); font-size: 13px;
  background: var(--c-panel-2); border: 1px solid var(--c-border-soft);
  border-radius: 4px; padding: 1px 6px; color: var(--c-accent-2);
}

pre {
  position: relative; margin: 0 0 16px;
  background: var(--c-panel); border: 1px solid var(--c-border);
  border-radius: var(--radius-sm); padding: 15px 17px;
  overflow-x: auto;
}
pre code {
  font-family: var(--mono); font-size: 13px; line-height: 1.8;
  color: var(--c-text); background: none; border: none; padding: 0;
}
.copy-btn {
  position: absolute; top: 8px; right: 8px;
  font-size: 11px; color: var(--c-text-faint);
  background: var(--c-panel-2); border: 1px solid var(--c-border);
  border-radius: 5px; padding: 2px 9px; cursor: pointer; opacity: 0; transition: .15s;
  font-family: var(--font);
}
pre:hover .copy-btn, .prompt-box:hover .copy-btn { opacity: 1; }
.copy-btn:hover { color: var(--c-accent); border-color: var(--c-accent); }

/* 表格：宽度随内容区自适应，太窄时可左右滑动 */
.table-wrap { width: 100%; overflow-x: auto; margin: 0 0 18px; }
table {
  width: 100%; border-collapse: collapse; margin: 0;
  font-size: 14px; table-layout: auto; min-width: 480px;
}
table th, table td { border: 1px solid var(--c-border); padding: 9px 13px; text-align: left; vertical-align: top; }
table th { background: var(--c-panel-2); color: var(--c-text); font-weight: 600; white-space: nowrap; }
table td { color: var(--c-text-dim); line-height: 1.7; word-break: break-word; }
table tr:nth-child(even) td { background: color-mix(in srgb, var(--c-panel-2) 40%, transparent); }
table a { word-break: break-all; }

.callout {
  border: 1px solid var(--c-border); border-left: 3px solid var(--c-accent);
  background: var(--c-panel); border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 13px 17px; margin: 0 0 16px; font-size: 14.5px; color: var(--c-text-dim);
}
.callout .ct { font-weight: 700; color: var(--c-accent); display: block; margin-bottom: 5px; font-size: 13.5px; }
.callout.tip { border-left-color: var(--c-ok); }
.callout.tip .ct { color: var(--c-ok); }
.callout.warn { border-left-color: var(--c-warn); }
.callout.warn .ct { color: var(--c-warn); }
.callout.danger { border-left-color: var(--c-danger); }
.callout.danger .ct { color: var(--c-danger); }
.callout p:last-child { margin-bottom: 0; }

/* 大白话解释框 */
.say {
  border: 1px dashed var(--c-accent-2);
  background: var(--c-accent-2-soft);
  border-radius: var(--radius-sm); padding: 12px 16px; margin: 0 0 16px;
  font-size: 14.5px; color: var(--c-text);
}
.say .ct { font-weight: 700; color: var(--c-accent-2); margin-right: 6px; }
.say p:last-child { margin-bottom: 0; }

/* 提示词模板框 */
.prompt-box {
  position: relative; margin: 0 0 16px;
  border: 1px solid var(--c-border); border-left: 3px solid var(--c-warn);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: var(--c-panel); padding: 14px 16px;
}
.prompt-box .pb-title {
  font-size: 12.5px; font-weight: 700; color: var(--c-warn); margin-bottom: 8px;
  display: flex; align-items: center; gap: 6px;
}
.prompt-box pre { margin: 0; background: var(--c-panel-2); border: none; padding: 12px 14px; }
.prompt-box pre code { font-family: var(--font); font-size: 14px; line-height: 1.85; white-space: pre-wrap; word-break: break-word; }

blockquote {
  margin: 0 0 16px; padding: 11px 17px;
  border-left: 3px solid var(--c-border); color: var(--c-text-faint);
  font-size: 14.5px; background: var(--c-panel-2); border-radius: 0 6px 6px 0;
}

.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 14px; margin-bottom: 18px; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 14px; margin-bottom: 18px; }
.card {
  border: 1px solid var(--c-border); background: var(--c-panel);
  border-radius: var(--radius-sm); padding: 15px 17px;
}
.card h5 { margin: 0 0 7px; font-size: 15px; color: var(--c-text); line-height: 1.5; }
.card p { margin: 0; font-size: 13.5px; color: var(--c-text-dim); line-height: 1.75; }

.tags { display: flex; flex-wrap: wrap; gap: 7px; margin: 14px 0 0; }
.tag {
  font-size: 11.5px; padding: 2px 10px; border-radius: 999px;
  background: var(--c-panel-2); border: 1px solid var(--c-border); color: var(--c-text-faint);
}

.figure { border: 1px solid var(--c-border); border-radius: var(--radius-sm); background: var(--c-panel); padding: 16px; margin: 0 0 16px; overflow-x: auto; }
.figure figcaption { font-size: 12px; color: var(--c-text-faint); text-align: center; margin-top: 8px; }
.figure svg { display: block; margin: 0 auto; max-width: 100%; height: auto; }

/* 英文词标注 */
.en {
  color: var(--c-text); font-weight: 600;
  border-bottom: 1px dotted var(--c-accent-2); padding-bottom: 1px;
}

mark { background: color-mix(in srgb, var(--c-mark) 30%, transparent); color: var(--c-mark); padding: 0 2px; border-radius: 3px; }

/* 上下篇 */
.pager {
  width: 100%; max-width: 1680px; margin: 0 auto;
  padding: 0 clamp(20px, 3.6vw, 68px) 70px;
  display: grid; grid-template-columns: 1fr 1fr; gap: 14px;
}
.pager a {
  border: 1px solid var(--c-border); background: var(--c-panel);
  border-radius: var(--radius-sm); padding: 13px 17px; display: block;
  transition: .15s; color: var(--c-text);
}
.pager a:hover { border-color: var(--c-accent); text-decoration: none; transform: translateY(-1px); }
.pager a .lab { font-size: 11.5px; color: var(--c-text-faint); display: block; }
.pager a .tt { font-size: 14.5px; font-weight: 600; line-height: 1.5; }
.pager .next { text-align: right; }

.empty { display: grid; place-items: center; height: 60vh; text-align: center; color: var(--c-text-faint); }

/* 首页工具入口按钮 */
.btn {
  display: inline-block; padding: 9px 18px; border-radius: 999px;
  background: linear-gradient(135deg, var(--c-accent), var(--c-accent-2));
  color: #fff; font-size: 14.5px; font-weight: 600; margin: 6px 8px 6px 0;
}
.btn:hover { text-decoration: none; filter: brightness(1.08); }
.btn.ghost { background: var(--c-panel); border: 1px solid var(--c-border); color: var(--c-text); }
.btn.ghost:hover { border-color: var(--c-accent); color: var(--c-accent); }

/* ============================================================
   AI 工具导航页（tools.html）
   ============================================================ */
/* ---------- 整体：左分类 + 右详情 ---------- */
.tools-layout {
  position: fixed; top: var(--topbar-h); left: 0; right: 0; bottom: var(--footer-h);
  display: grid;
  grid-template-columns: 268px minmax(0, 1fr);
  overflow: hidden;
}
.tools-side {
  border-right: 1px solid var(--c-border);
  background: var(--c-bg-soft);
  overflow-y: auto;
  padding: 18px 12px 34px;
}
.tools-main { overflow-y: auto; padding: 24px clamp(16px, 3vw, 54px) 100px; }
.ts-head {
  font-size: 15px; font-weight: 700; color: var(--c-text);
  padding: 0 6px 6px; letter-spacing: .5px;
}
.ts-sum { font-size: 12px; color: var(--c-accent-2); padding: 0 6px 12px; }
.ts-nav { display: flex; flex-direction: column; gap: 5px; }
.cat-item {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 11px; border-radius: var(--radius-sm);
  border: 1px solid transparent; color: var(--c-text-dim);
  transition: .15s;
}
.cat-item:hover { background: var(--c-panel); color: var(--c-text); text-decoration: none; }
.cat-item.on {
  background: var(--c-accent-soft); border-color: var(--c-accent);
  color: var(--c-text); font-weight: 600;
}
.ci-ico { font-size: 17px; flex: 0 0 auto; line-height: 1; }
.ci-txt { min-width: 0; }
.ci-name { display: block; font-size: 14.5px; line-height: 1.45; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.ci-num { display: block; font-size: 11.5px; color: var(--c-text-faint); margin-top: 2px; }
.ts-foot {
  margin-top: 18px; padding: 12px 12px 0; border-top: 1px solid var(--c-border-soft);
  font-size: 12px; color: var(--c-text-faint); line-height: 1.7;
}
.ts-foot p { margin: 0; }

/* ---------- 右侧：分类头部 ---------- */
.tv-head {
  display: flex; align-items: flex-start; gap: 16px;
  padding: 22px 24px; margin-bottom: 18px;
  border: 1px solid var(--c-border); border-radius: var(--radius);
  background: linear-gradient(135deg, var(--c-panel), var(--c-bg-soft));
}
.tv-head h1 { margin: 0 0 6px; font-size: clamp(20px, 2.2vw, 28px); line-height: 1.35; }
.tv-head .tv-sub { margin: 0; font-size: 13.5px; color: var(--c-text-dim); }
.tv-head .tv-sub b { color: var(--c-accent-2); }
.tv-head .tv-doc { color: var(--c-accent); white-space: nowrap; }
.tv-head .tv-doc:hover { text-decoration: underline; }
.tv-ico {
  flex: 0 0 auto; width: 56px; height: 56px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center; font-size: 28px;
  background: var(--c-accent-soft); border: 1px solid var(--c-border);
}
.tv-headtxt { min-width: 0; }

/* ---------- 本类别基本介绍 ---------- */
.intro-box {
  border: 1px solid var(--c-border); border-left: 3px solid var(--c-accent);
  background: var(--c-panel); border-radius: var(--radius-sm);
  padding: 18px 22px; margin-bottom: 24px;
}
.ib-title { margin: 0 0 10px; font-size: 16px; }
.ib-main { margin: 0 0 14px; font-size: 15px; line-height: 1.95; color: var(--c-text); }
.ib-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 12px; margin-bottom: 14px; }
.ib-cell {
  background: var(--c-panel-2); border-radius: var(--radius-sm);
  padding: 12px 14px;
}
.ib-cell p { margin: 0; font-size: 13.5px; color: var(--c-text-dim); line-height: 1.85; }
.ib-lab {
  display: block; font-size: 12px; font-weight: 700; color: var(--c-accent-2);
  letter-spacing: .5px; margin-bottom: 5px;
}
.ib-tips {
  background: var(--c-accent-2-soft); border-radius: var(--radius-sm);
  padding: 12px 16px;
}
.ib-tips ul { margin: 0; padding-left: 20px; }
.ib-tips li { font-size: 13.5px; color: var(--c-text-dim); margin-bottom: 5px; line-height: 1.8; }
.ib-tips li:last-child { margin-bottom: 0; }

/* ---------- 工具清单 ---------- */
.sec-title { font-size: 17px; margin: 26px 0 14px; padding-left: 11px; border-left: 3px solid var(--c-accent); }
.t-block { margin-bottom: 26px; }
.tb-title {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  font-size: 18px; margin: 0 0 14px; padding-left: 11px;
  border-left: 3px solid var(--c-accent); line-height: 1.5;
}
.tb-count { font-size: 11.5px; padding: 2px 9px; border-radius: 999px; border: 1px solid var(--c-border); color: var(--c-text-faint); font-weight: 400; }
.tb-all { font-size: 12.5px; color: var(--c-accent); }
.t-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(330px, 1fr)); gap: 14px; }
.tcard {
  border: 1px solid var(--c-border); background: var(--c-panel);
  border-radius: var(--radius-sm); padding: 15px 17px; transition: .15s;
  display: flex; flex-direction: column;
}
.tcard:hover { border-color: var(--c-accent); transform: translateY(-2px); box-shadow: var(--shadow); }
.tc-top { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 8px; }
.tc-top h4 { margin: 0; font-size: 16px; }
.tc-top h4 a { color: var(--c-text); }
.tc-top h4 a:hover { color: var(--c-accent); text-decoration: none; }
.tbadge { font-size: 10.5px; padding: 1px 7px; border-radius: 999px; font-weight: 700; }
.tbadge.hot { background: var(--c-danger); color: #fff; }
.tbadge.new { background: var(--c-accent-2); color: #04222a; }
.tc-what { margin: 0 0 6px; font-size: 13.5px; color: var(--c-text-dim); line-height: 1.75; }
.tc-what b { color: var(--c-text); font-weight: 600; }
.tc-why { margin: 0 0 12px; font-size: 13.5px; color: var(--c-accent-2); line-height: 1.75; }
.tc-why b { color: var(--c-text); font-weight: 600; }
.tc-foot {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
  font-size: 12px; margin-top: auto; padding-top: 4px;
}
.tc-url { color: var(--c-text-faint); flex: 1; min-width: 110px; word-break: break-all; }
.tc-go {
  font-size: 12.5px; padding: 4px 13px; border-radius: 999px;
  background: var(--c-accent-soft); color: var(--c-accent); white-space: nowrap;
}
.tc-go:hover { background: var(--c-accent); color: #fff; text-decoration: none; }
.tpill { font-size: 11px; padding: 2px 9px; border-radius: 999px; border: 1px solid var(--c-border); color: var(--c-text-faint); }
.tpill.free { color: var(--c-ok); border-color: var(--c-ok); }
.tpill.part { color: var(--c-warn); border-color: var(--c-warn); }
.tpill.pay { color: var(--c-danger); border-color: var(--c-danger); }

/* ---------- 最近更新 ---------- */
.news-box {
  border: 1px solid var(--c-border); background: var(--c-panel);
  border-radius: var(--radius-sm); padding: 16px 20px; margin-bottom: 20px;
}
.news-box h3 { margin: 0 0 10px; font-size: 15.5px; }
.news-box ul { margin: 0; padding-left: 20px; }
.news-box li { font-size: 13.5px; color: var(--c-text-dim); line-height: 1.85; margin-bottom: 5px; }
.news-box.global { background: var(--c-panel-2); }
.nb-note { margin: 10px 0 0; font-size: 12.5px; color: var(--c-text-faint); }

/* ---------- 首页分类卡 ---------- */
.home-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; margin-bottom: 26px; }
.hcard {
  display: block; padding: 16px 18px; border: 1px solid var(--c-border);
  border-radius: var(--radius-sm); background: var(--c-panel); transition: .15s;
}
.hcard:hover { border-color: var(--c-accent); transform: translateY(-2px); box-shadow: var(--shadow); text-decoration: none; }
.hc-ico { display: block; font-size: 26px; margin-bottom: 8px; line-height: 1; }
.hc-name { display: block; font-size: 15px; font-weight: 600; color: var(--c-text); line-height: 1.5; }
.hc-num { display: block; font-size: 12px; color: var(--c-text-faint); margin-top: 4px; }
.hc-go { display: block; font-size: 12.5px; color: var(--c-accent); margin-top: 8px; }

.no-result { padding: 48px 20px; text-align: center; color: var(--c-text-faint); font-size: 14px; }

/* ---------- 响应式 ---------- */
@media (max-width: 1400px) {
  .tools-layout { grid-template-columns: 240px minmax(0, 1fr); }
}
@media (max-width: 1000px) {
  .tools-layout { grid-template-columns: 1fr; grid-template-rows: auto minmax(0, 1fr); }
  .tools-side {
    border-right: none; border-bottom: 1px solid var(--c-border);
    padding: 12px 12px 10px; overflow: visible;
  }
  .ts-head { padding-bottom: 2px; }
  .ts-sum { padding-bottom: 8px; }
  .ts-nav { flex-direction: row; overflow-x: auto; gap: 8px; padding-bottom: 4px; }
  .cat-item { flex: 0 0 auto; padding: 7px 12px; border: 1px solid var(--c-border); background: var(--c-panel); }
  .ci-num { display: none; }
  .ts-foot { display: none; }
  .tools-main { padding: 18px 16px 90px; }
  .t-grid { grid-template-columns: 1fr; }
}

/* ============================================================
   移动端抽屉
   ============================================================ */
.drawer {
  position: fixed; top: var(--topbar-h); left: 0; bottom: var(--footer-h); width: 310px;
  background: var(--c-bg-soft); border-right: 1px solid var(--c-border);
  transform: translateX(-100%); transition: transform .22s ease;
  z-index: 55; overflow-y: auto; padding-bottom: 40px;
}
.drawer.open { transform: translateX(0); }
.drawer-mask {
  position: fixed; left: 0; right: 0; top: var(--topbar-h); bottom: var(--footer-h);
  background: rgba(0, 0, 0, .45);
  opacity: 0; pointer-events: none; transition: opacity .22s; z-index: 54;
}
.drawer-mask.open { opacity: 1; pointer-events: auto; }

.d-group { border-bottom: 1px solid var(--c-border-soft); }
.d-l1 {
  padding: 13px 16px; font-size: 15px; font-weight: 600; cursor: pointer;
  display: flex; justify-content: space-between; align-items: center; color: var(--c-text);
}
.d-l1 .arw { transition: transform .18s; color: var(--c-text-faint); font-size: 12px; }
.d-group.open .d-l1 .arw { transform: rotate(90deg); }
.d-l2s { display: none; padding: 0 0 8px 14px; }
.d-group.open .d-l2s { display: block; }
.d-l2 {
  padding: 8px 16px; font-size: 13.5px; color: var(--c-text-dim); cursor: pointer;
  border-left: 2px solid var(--c-border); line-height: 1.6;
}
.d-l2.active { color: var(--c-accent); border-left-color: var(--c-accent); }
.d-l2.read { color: var(--c-read); }

/* 移动端 TOC（内容顶部） */
.mobile-toc {
  display: none; margin-bottom: 24px; border: 1px solid var(--c-border);
  border-radius: var(--radius-sm); background: var(--c-panel); padding: 12px 16px;
}
.mobile-toc .mt-head {
  font-size: 13.5px; font-weight: 700; cursor: pointer; display: flex;
  justify-content: space-between; color: var(--c-text);
}
.mobile-toc ul { display: none; margin: 10px 0 0; padding-left: 18px; }
.mobile-toc.open ul { display: block; }
.mobile-toc li { font-size: 13.5px; margin-bottom: 5px; }
.mobile-toc li a { color: var(--c-text-dim); }
.mobile-toc li a.read { color: var(--c-read); }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1500px) { .layout { grid-template-columns: 250px 272px minmax(0, 1fr) 224px; } }
@media (max-width: 1280px) {
  .layout { grid-template-columns: 232px 252px minmax(0, 1fr) 206px; }
  .nav-item { padding: 8px 10px; font-size: 13.5px; }
}
@media (max-width: 1100px) {
  .layout { grid-template-columns: 244px 266px minmax(0, 1fr); }
  .col-3 { display: none; }
  .mobile-toc { display: block; }
}
@media (max-width: 900px) {
  .layout { grid-template-columns: minmax(0, 1fr); }
  .col-1, .col-2 { display: none; }
  #btn-menu { display: grid; }
  .brand-text em { display: none; }
  .searchbox { max-width: none; min-width: 90px; }
  .pager { grid-template-columns: 1fr; }
  .chapter-hero { padding: 20px 20px; }
  .mainnav { order: 3; max-width: 52vw; }
}
@media (max-width: 720px) {
  .searchbox { display: none; }
  .mainnav { max-width: none; flex: 1; }
  .brand-text { display: none; }
}
@media (max-width: 560px) {
  .share-panel { right: 8px; left: 8px; width: auto; }
  .sp-list { grid-template-columns: 1fr; }
  .sp-urlbox input { font-size: 12px; }
}
@media (max-width: 560px) {
  :root { --topbar-h: 66px; }
  .brand-text strong { font-size: 16px; }
  .brand-text span.slogan { display: none; }
  .brand-mark { width: 38px; height: 38px; font-size: 20px; }
  .searchbox kbd { display: none; }
  .topbar { padding: 0 10px; gap: 8px; }
  .icon-btn { width: 38px; height: 38px; }
  .drawer { width: 84vw; }
  .footer-bar { font-size: 11px; }
  .footer-bar .hide-sm { display: none; }
  body { font-size: 15.5px; }
}