/* 站点样式 —— 单文件，语义类名，双主题由 tokens.css 变量驱动 */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--c-bg); color: var(--c-text);
  font-family: var(--font-ui); font-size: 16px; line-height: 1.75;
}
a { color: var(--c-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible { outline: 2px solid var(--c-primary); outline-offset: 2px; border-radius: 4px; }
.shell { max-width: 1060px; margin: 0 auto; padding: 0 20px; }
.skip-link {
  position: absolute; left: -999px; top: 0; background: var(--c-primary); color: #fff;
  padding: 8px 14px; border-radius: 0 0 var(--radius-s) 0; z-index: 99;
}
.skip-link:focus { left: 0; }

/* 头部 */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--c-bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--c-border);
}
@supports not (background: color-mix(in srgb, red 50%, blue)) { .site-header { background: var(--c-bg); } }
.header-inner { display: flex; align-items: center; gap: 18px; min-height: 58px; flex-wrap: wrap; padding-top: 6px; padding-bottom: 6px; }
.brand { font-weight: 800; font-size: 17px; color: var(--c-text); display: flex; align-items: center; gap: 8px; }
.brand:hover { text-decoration: none; }
.brand-mark { font-family: var(--font-mono); color: var(--c-primary); font-weight: 700; }
.site-nav { display: flex; gap: 4px; }
.site-nav a { color: var(--c-text-2); padding: 6px 10px; border-radius: var(--radius-s); font-size: 14.5px; }
.site-nav a:hover { color: var(--c-text); background: var(--c-surface-2); text-decoration: none; }
.site-nav a.active { color: var(--c-primary); background: var(--c-primary-soft); font-weight: 600; }
.header-tools { margin-left: auto; display: flex; align-items: center; gap: 10px; }
.search-wrap { position: relative; }
#search-input {
  width: 230px; max-width: 52vw; padding: 7px 12px; font-size: 14px; color: var(--c-text);
  background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius-m);
}
#search-input::placeholder { color: var(--c-text-2); }
.search-results {
  position: absolute; right: 0; top: calc(100% + 6px); width: 400px; max-width: 86vw;
  background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius-m);
  box-shadow: var(--shadow-2); overflow: hidden; z-index: 30;
}
.search-item { display: flex; flex-direction: column; gap: 2px; padding: 10px 14px; border-bottom: 1px solid var(--c-border); color: var(--c-text); }
.search-item:last-child { border-bottom: 0; }
.search-item:hover { background: var(--c-surface-2); text-decoration: none; }
.si-title { font-weight: 600; font-size: 14.5px; }
.si-meta { font-size: 12.5px; color: var(--c-text-2); }
.search-empty { padding: 12px 14px; color: var(--c-text-2); font-size: 14px; }
.icon-btn {
  border: 1px solid var(--c-border); background: var(--c-surface); color: var(--c-text);
  width: 36px; height: 36px; border-radius: var(--radius-m); cursor: pointer; font-size: 16px;
}
.icon-btn:hover { border-color: var(--c-primary); }

/* 通用组件 */
.chip {
  display: inline-block; padding: 1px 9px; border-radius: 999px; font-size: 12px; font-weight: 600;
  background: var(--c-surface-2); color: var(--c-text-2); border: 1px solid var(--c-border);
  white-space: nowrap;
}
.chip[data-level="入门"] { background: color-mix(in srgb, #0E9F6E 14%, transparent); color: var(--c-accent-text); border-color: transparent; }
.chip[data-level="核心"] { background: color-mix(in srgb, #4F46E5 12%, transparent); color: var(--c-primary); border-color: transparent; }
.chip[data-level="进阶"] { background: color-mix(in srgb, #B45309 14%, transparent); color: var(--c-warn); border-color: transparent; }
.chip[data-level="前沿"] { background: color-mix(in srgb, #BE123C 12%, transparent); color: #BE123C; border-color: transparent; }
[data-theme="dark"] .chip[data-level="前沿"] { color: #FB7185; }
.chip-path { background: var(--c-primary-soft); color: var(--c-primary); border-color: transparent; margin-left: 6px; vertical-align: 2px; }
.btn {
  display: inline-flex; align-items: center; gap: 6px; padding: 9px 18px; border-radius: var(--radius-m);
  border: 1px solid var(--c-border); background: var(--c-surface); color: var(--c-text);
  font-size: 14.5px; font-weight: 600; cursor: pointer; transition: transform var(--motion-fast) var(--ease), box-shadow var(--motion-fast) var(--ease);
}
.btn:hover { text-decoration: none; box-shadow: var(--shadow-1); border-color: var(--c-edge); }
.btn-primary { background: var(--c-primary); border-color: var(--c-primary); color: #fff; }
.btn-primary:hover { background: var(--c-primary-strong); color: #fff; }
[data-theme="dark"] .btn-primary { color: #0F1216; }
[data-theme="dark"] .btn-primary:hover { background: var(--c-primary-strong); color: #0F1216; }
.btn-sm { padding: 5px 12px; font-size: 13px; }
.bar { height: 10px; border-radius: 999px; background: var(--c-surface-2); border: 1px solid var(--c-border); overflow: hidden; }
.bar-fill { height: 100%; width: 0%; background: linear-gradient(90deg, var(--c-primary), var(--c-accent)); transition: width var(--motion) var(--ease); }
.progress-line { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; font-size: 14px; color: var(--c-text-2); }
.progress-btns { display: flex; gap: 8px; }

/* 首页 hero */
.hero { padding: 54px 0 10px; }
.hero-kicker { font-family: var(--font-mono); color: var(--c-text-2); font-size: 13px; margin: 0 0 10px; letter-spacing: .08em; }
.hero h1 { font-size: clamp(28px, 4.6vw, 44px); line-height: 1.25; margin: 0 0 14px; letter-spacing: .01em; }
.hero h1 em { font-style: normal; color: var(--c-primary); }
.hero-sub { font-size: 17px; color: var(--c-text-2); max-width: 46em; margin: 0 0 22px; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 26px; }
.stats { display: flex; gap: 14px; flex-wrap: wrap; }
.stat { background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius-m); padding: 10px 18px; display: flex; flex-direction: column; min-width: 96px; box-shadow: var(--shadow-1); }
.stat strong { font-size: 22px; color: var(--c-primary); line-height: 1.2; }
.stat span { font-size: 12.5px; color: var(--c-text-2); }
.progress-card { margin-top: 20px; background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius-m); padding: 14px 18px; display: flex; flex-direction: column; gap: 8px; box-shadow: var(--shadow-1); }
.intro-card { margin: 30px 0 8px; background: var(--c-surface); border: 1px solid var(--c-border); border-left: 4px solid var(--c-accent); border-radius: var(--radius-m); padding: 18px 22px; }
.muted { color: var(--c-text-2); font-size: 14px; }

/* 模块与卡片 */
.mod-section { margin: 34px 0; }
.mod-head { display: flex; align-items: baseline; gap: 12px; border-bottom: 2px solid var(--mc, var(--c-border)); padding-bottom: 8px; margin-bottom: 14px; }
.mod-head h2 { margin: 0; font-size: 20px; }
.mod-count { color: var(--c-text-2); font-size: 13px; }
.kp-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 12px; }
.kp-card {
  display: flex; flex-direction: column; gap: 6px; padding: 14px 16px;
  background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius-m);
  color: var(--c-text); transition: transform var(--motion-fast) var(--ease), box-shadow var(--motion-fast) var(--ease), border-color var(--motion-fast) var(--ease);
}
.kp-card:hover { text-decoration: none; transform: translateY(-2px); box-shadow: var(--shadow-1); border-color: var(--mc, var(--c-primary)); }
.kp-card-title { font-weight: 700; font-size: 15px; line-height: 1.5; }
.kp-card-meta { font-size: 12.5px; color: var(--c-text-2); display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.kp-card-summary { font-size: 13px; color: var(--c-text-2); line-height: 1.6; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }

/* 页头 */
.page-head { padding: 34px 0 8px; }
.page-head h1 { margin: 0 0 8px; font-size: clamp(24px, 3.4vw, 32px); }
.page-head p { color: var(--c-text-2); margin: 0 0 14px; max-width: 52em; }

/* 学习路径 */
.path-block { margin: 26px 0; }
.path-block h2 { font-size: 19px; border-bottom: 1px solid var(--c-border); padding-bottom: 8px; }
.path-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; counter-reset: path; }
.path-item { display: flex; align-items: center; gap: 12px; background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius-m); padding: 10px 14px; flex-wrap: wrap; }
.path-item a { color: var(--c-text); font-weight: 600; flex: 1; min-width: 200px; }
.path-num { display: inline-flex; width: 22px; height: 22px; border-radius: 50%; background: var(--c-primary-soft); color: var(--c-primary); align-items: center; justify-content: center; font-size: 12.5px; font-weight: 700; margin-right: 6px; }
.path-meta { display: flex; gap: 8px; align-items: center; color: var(--c-text-2); font-size: 13px; }
.path-check {
  width: 26px; height: 26px; border-radius: 8px; border: 1.5px solid var(--c-border); background: var(--c-surface);
  color: transparent; cursor: pointer; font-size: 14px; line-height: 1; flex: none;
}
.path-check.done { background: var(--c-accent); border-color: var(--c-accent); color: #fff; }
[data-theme="dark"] .path-check.done { color: #0F1216; }

/* 知识地图 */
.map-legend { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; color: var(--c-text-2); font-size: 13.5px; margin-bottom: 10px; }
.map-scroll { overflow-x: auto; border: 1px solid var(--c-border); border-radius: var(--radius-m); background: var(--c-surface); padding: 8px; }
.map-svg { display: block; max-width: none; }
.map-mod { font-size: 13px; font-weight: 800; fill: var(--mc, var(--c-text)); }
.map-rect { fill: var(--mc, var(--c-primary)); fill-opacity: .10; stroke: var(--mc, var(--c-primary)); stroke-width: 1.2; }
.map-title { font-size: 12.5px; font-weight: 700; fill: var(--c-text); }
.map-meta { font-size: 10.5px; fill: var(--c-text-2); font-family: var(--font-mono); }
.map-edge { fill: none; stroke: var(--c-edge); stroke-width: 1.1; opacity: .8; }
.map-edge.hot { stroke: var(--c-primary); stroke-width: 2; opacity: 1; }
.map-node { cursor: pointer; }
.map-node:hover .map-rect, .map-node:focus-visible .map-rect { fill-opacity: .22; }

/* 知识点页 */
.breadcrumb { display: flex; gap: 8px; align-items: center; padding: 22px 0 4px; font-size: 13.5px; color: var(--c-text-2); flex-wrap: wrap; }
.breadcrumb a { color: var(--c-text-2); }
.breadcrumb a:hover { color: var(--c-primary); }
.kp-page { padding-bottom: 60px; }
.kp-head { border-bottom: 2px solid var(--mc, var(--c-border)); padding-bottom: 14px; margin-bottom: 16px; }
.kp-head h1 { margin: 0 0 10px; font-size: clamp(23px, 3.2vw, 31px); line-height: 1.35; }
.kp-meta { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-bottom: 10px; }
.kp-id { font-family: var(--font-mono); font-size: 13px; color: var(--c-text-2); }
.progress-ctl { display: flex; gap: 8px; }
.progress-ctl button {
  padding: 5px 14px; font-size: 13px; border-radius: 999px; border: 1.5px solid var(--c-border);
  background: var(--c-surface); color: var(--c-text-2); cursor: pointer; font-weight: 600;
}
.progress-ctl button:hover { border-color: var(--c-primary); color: var(--c-primary); }
.progress-ctl button.on { background: var(--c-primary); border-color: var(--c-primary); color: #fff; }
[data-theme="dark"] .progress-ctl button.on { color: #0F1216; }
.kp-deps { margin: 18px 0; }
.deps-title { font-size: 14px; color: var(--c-text-2); margin: 0 0 8px; text-transform: uppercase; letter-spacing: .06em; }
.dep-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 10px; }
.dep-cards .kp-card-summary { display: none; }
.kp-tags { margin: 22px 0 0; display: flex; gap: 8px; flex-wrap: wrap; }
.tag { font-size: 12.5px; color: var(--c-text-2); background: var(--c-surface-2); padding: 2px 10px; border-radius: 999px; }
.pager { display: flex; justify-content: space-between; gap: 12px; margin-top: 26px; }
.pager-link { flex: 1; display: flex; flex-direction: column; gap: 3px; padding: 12px 16px; border: 1px solid var(--c-border); border-radius: var(--radius-m); background: var(--c-surface); color: var(--c-text); min-width: 0; }
.pager-link span { font-size: 12px; color: var(--c-text-2); }
.pager-link strong { font-size: 14px; }
.pager-link:hover { text-decoration: none; border-color: var(--c-primary); }
.pager-link.next { text-align: right; }

/* 正文排版 */
.md-doc { font-size: 16px; }
.md-doc .md-h { scroll-margin-top: 80px; }
.md-doc h3 { font-size: 18.5px; margin: 26px 0 10px; color: var(--c-text); }
.md-doc h3::before { content: ""; display: inline-block; width: 8px; height: 8px; border-radius: 2px; background: var(--mc, var(--c-primary)); margin-right: 8px; vertical-align: 2px; }
.md-doc h4 { font-size: 16px; margin: 20px 0 8px; color: var(--c-text-2); }
.md-doc p { margin: 10px 0; }
.md-doc ul, .md-doc ol { margin: 10px 0; padding-left: 1.5em; }
.md-doc li { margin: 5px 0; }
.md-doc li::marker { color: var(--mc, var(--c-primary)); font-weight: 700; }
.md-doc blockquote { margin: 14px 0; padding: 8px 16px; border-left: 3px solid var(--mc, var(--c-primary)); background: var(--c-surface-2); border-radius: 0 var(--radius-s) var(--radius-s) 0; color: var(--c-text-2); }
.md-doc code { font-family: var(--font-mono); font-size: .88em; background: var(--c-surface-2); border: 1px solid var(--c-border); padding: 1px 5px; border-radius: 5px; }
.md-doc hr { border: 0; border-top: 1px solid var(--c-border); margin: 22px 0; }
.md-doc strong { color: var(--c-text); }
.md-doc .table-wrap { overflow-x: auto; margin: 14px 0; }
.md-doc table { border-collapse: collapse; width: 100%; font-size: 14.5px; }
.md-doc th, .md-doc td { border: 1px solid var(--c-border); padding: 7px 12px; text-align: left; }
.md-doc th { background: var(--c-surface-2); }
.codeblock { position: relative; margin: 14px 0; }
.codeblock pre {
  margin: 0; padding: 14px 16px; overflow-x: auto; background: var(--c-code-bg);
  border: 1px solid var(--c-border); border-radius: var(--radius-m);
}
.codeblock code { font-family: var(--font-mono); font-size: 13.5px; line-height: 1.65; background: none; border: 0; padding: 0; color: var(--c-text); }
.codeblock::before {
  content: attr(data-lang); position: absolute; right: 10px; top: 8px; font-family: var(--font-mono);
  font-size: 11px; color: var(--c-text-2); text-transform: uppercase; letter-spacing: .08em; opacity: .8;
}
.tok-k { color: var(--c-primary); font-weight: 600; }
.tok-s { color: var(--c-accent-text); }
.tok-c { color: var(--c-text-2); font-style: italic; }
.tok-n { color: var(--c-warn); }
[data-theme="dark"] .tok-s { color: #6EE7B7; }

/* 页脚 */
.site-footer { border-top: 1px solid var(--c-border); margin-top: 40px; padding: 22px 0 34px; color: var(--c-text-2); font-size: 13.5px; }
.site-footer p { margin: 4px 0; }

/* 响应式 */
@media (max-width: 760px) {
  .header-inner { gap: 10px; }
  .site-nav { order: 3; width: 100%; overflow-x: auto; padding-bottom: 4px; }
  .header-tools { margin-left: auto; }
  #search-input { width: 160px; }
  .hero { padding-top: 34px; }
  .pager { flex-direction: column; }
  .pager-link.next { text-align: left; }
  .kp-grid { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}