/* style.css — 大语言模型学习站（零依赖、双主题） */

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  font-size: 16px;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-strong); text-decoration: underline; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 20px; }

/* ---------- 跳过链接 ---------- */
.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--primary); color: #fff;
  padding: 8px 16px; border-radius: 0 0 8px 0; z-index: 100;
}
.skip-link:focus { left: 0; color: #fff; }

/* ---------- 顶栏 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex; align-items: center; gap: 18px;
  padding: 10px 0; flex-wrap: wrap;
}
.brand {
  font-weight: 800; font-size: 18px; color: var(--text);
  display: flex; align-items: center; gap: 8px; white-space: nowrap;
}
.brand:hover { text-decoration: none; color: var(--text); }
.brand .logo {
  width: 28px; height: 28px; border-radius: 8px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: inline-flex; align-items: center; justify-content: center;
  color: #fff; font-size: 13px; font-weight: 800; letter-spacing: -1px;
}
.site-nav { display: flex; gap: 4px; flex-wrap: wrap; }
.site-nav a {
  color: var(--muted); padding: 6px 12px; border-radius: 8px; font-size: 14.5px;
}
.site-nav a:hover { color: var(--text); background: var(--surface2); text-decoration: none; }
.site-nav a[aria-current="page"] {
  color: var(--primary); background: var(--primary-soft); font-weight: 600;
}
.header-tools { margin-left: auto; display: flex; align-items: center; gap: 10px; }

/* ---------- 搜索 ---------- */
.search { position: relative; }
.search input {
  width: 230px; max-width: 52vw;
  padding: 7px 34px 7px 12px;
  border: 1px solid var(--border); border-radius: 10px;
  background: var(--surface); color: var(--text);
  font: inherit; font-size: 14px;
}
.search input:focus { border-color: var(--accent); outline: none; }
.search .search-hint {
  position: absolute; right: 10px; top: 50%; transform: translateY(-50%);
  color: var(--muted); font-size: 12px; border: 1px solid var(--border);
  border-radius: 4px; padding: 0 5px; pointer-events: none;
}
.search-results {
  position: absolute; right: 0; top: calc(100% + 6px);
  width: 340px; max-width: 84vw;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 12px; box-shadow: var(--shadow);
  overflow: hidden; z-index: 60;
}
.search-hit {
  display: block; padding: 9px 14px; border-bottom: 1px solid var(--border);
}
.search-hit:last-child { border-bottom: none; }
.search-hit:hover { background: var(--surface2); text-decoration: none; }
.hit-title { display: block; color: var(--text); font-weight: 600; font-size: 14px; }
.hit-meta { display: block; color: var(--muted); font-size: 12px; margin-top: 1px; }
.search-empty { padding: 14px; color: var(--muted); font-size: 14px; text-align: center; }

.icon-btn {
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
  width: 34px; height: 34px; border-radius: 10px; cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center;
  transition: background var(--speed) var(--ease);
}
.icon-btn:hover { background: var(--surface2); }
.icon-btn svg { width: 17px; height: 17px; }
.icon-btn .sun { display: none; }
[data-theme="dark"] .icon-btn .sun { display: block; }
[data-theme="dark"] .icon-btn .moon { display: none; }

/* ---------- 主体 ---------- */
main { padding: 28px 0 60px; }

/* ---------- 首页 hero ---------- */
.hero {
  border: 1px solid var(--border); border-radius: var(--radius);
  background:
    radial-gradient(1000px 300px at 85% -60%, var(--primary-soft), transparent),
    var(--surface);
  box-shadow: var(--shadow);
  padding: 34px 30px;
}
.hero .kicker {
  color: var(--accent); font-weight: 700; letter-spacing: 2px; font-size: 13px;
  text-transform: uppercase;
}
.hero h1 { margin: 8px 0 10px; font-size: 34px; line-height: 1.25; }
.hero .tagline { color: var(--muted); max-width: 720px; margin: 0; }
.hero-cta { display: flex; gap: 12px; margin-top: 20px; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 18px; border-radius: 10px; font: inherit; font-size: 15px;
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
  cursor: pointer; transition: transform var(--speed) var(--ease), background var(--speed) var(--ease);
}
.btn:hover { background: var(--surface2); text-decoration: none; }
.btn.primary {
  background: var(--primary); border-color: var(--primary); color: #fff; font-weight: 600;
}
.btn.primary:hover { background: var(--primary-strong); }
.btn.danger { color: #c0392b; border-color: color-mix(in srgb, #c0392b 40%, var(--border)); }
[data-theme="dark"] .btn.danger { color: #ff9a8a; }

/* ---------- 统计 ---------- */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 12px; margin-top: 18px; }
.stat {
  border: 1px solid var(--border); border-radius: 12px; background: var(--surface);
  padding: 12px 16px;
}
.stat b { display: block; font-size: 22px; }
.stat span { color: var(--muted); font-size: 13px; }

/* ---------- 进度条 ---------- */
.progress-line {
  height: 8px; border-radius: 99px; background: var(--surface2);
  overflow: hidden; border: 1px solid var(--border);
}
.progress-line > i {
  display: block; height: 100%; width: 0;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transition: width 400ms var(--ease);
}
.progress-meta { color: var(--muted); font-size: 13px; margin-top: 6px; }

/* ---------- 模块卡片 ---------- */
.section-title { font-size: 22px; margin: 38px 0 14px; }
.module-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(330px, 1fr)); gap: 16px; }
.module-card {
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--surface); padding: 18px; box-shadow: var(--shadow);
  display: flex; flex-direction: column; gap: 10px;
}
.module-card h3 { margin: 0; font-size: 17px; display: flex; align-items: center; gap: 8px; }
.module-card h3 .dot { width: 10px; height: 10px; border-radius: 50%; flex: none; }
.module-card .mdesc { color: var(--muted); font-size: 13.5px; margin: 0; }
.kp-chips { display: flex; flex-direction: column; gap: 4px; }
.kp-chip {
  display: flex; align-items: baseline; gap: 8px;
  color: var(--text); font-size: 13.5px; padding: 4px 6px; border-radius: 7px;
}
.kp-chip:hover { background: var(--surface2); text-decoration: none; }
.kp-chip .kid { color: var(--muted); font-family: var(--mono); font-size: 11.5px; flex: none; }
.kp-chip .lvdot { width: 7px; height: 7px; border-radius: 50%; flex: none; align-self: center; }
.kp-chip[data-state="done"] .ktitle { text-decoration: line-through; color: var(--muted); }

/* ---------- 徽章 ---------- */
.badge {
  display: inline-flex; align-items: center; gap: 5px;
  font-size: 12.5px; font-weight: 600; padding: 2px 10px;
  border-radius: 99px; border: 1px solid transparent; white-space: nowrap;
}
.badge[data-level="入门"] { color: var(--lv-1); border-color: color-mix(in srgb, var(--lv-1) 45%, transparent); background: color-mix(in srgb, var(--lv-1) 10%, transparent); }
.badge[data-level="核心"] { color: var(--lv-2); border-color: color-mix(in srgb, var(--lv-2) 45%, transparent); background: color-mix(in srgb, var(--lv-2) 10%, transparent); }
.badge[data-level="进阶"] { color: var(--lv-3); border-color: color-mix(in srgb, var(--lv-3) 45%, transparent); background: color-mix(in srgb, var(--lv-3) 10%, transparent); }
.badge[data-level="前沿"] { color: var(--lv-4); border-color: color-mix(in srgb, var(--lv-4) 45%, transparent); background: color-mix(in srgb, var(--lv-4) 10%, transparent); }
.badge.plain { color: var(--muted); border-color: var(--border); background: var(--surface2); }

/* ---------- 面包屑 ---------- */
.breadcrumb { color: var(--muted); font-size: 13.5px; margin-bottom: 14px; }
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb .sep { margin: 0 6px; color: var(--border); }

/* ---------- 知识点页 ---------- */
.kp-head {
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--surface); box-shadow: var(--shadow);
  padding: 24px 26px; margin-bottom: 20px;
}
.kp-head h1 { margin: 6px 0 12px; font-size: 27px; line-height: 1.3; }
.kp-meta { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.kp-actions {
  display: flex; gap: 10px; align-items: center; flex-wrap: wrap;
  margin-top: 16px; padding-top: 14px; border-top: 1px dashed var(--border);
}
.seg { display: inline-flex; border: 1px solid var(--border); border-radius: 10px; overflow: hidden; }
.seg button {
  border: none; background: var(--surface); color: var(--muted);
  padding: 7px 14px; font: inherit; font-size: 13.5px; cursor: pointer;
}
.seg button + button { border-left: 1px solid var(--border); }
.seg button.active { background: var(--primary); color: #fff; font-weight: 600; }
.pg-status { color: var(--muted); font-size: 13.5px; }

.rel-block { margin-top: 14px; }
.rel-block h2 { font-size: 14px; color: var(--muted); margin: 0 0 6px; text-transform: none; }
.rel-links { display: flex; flex-wrap: wrap; gap: 6px; }
.rel-links a {
  font-size: 13px; border: 1px solid var(--border); border-radius: 99px;
  padding: 3px 12px; color: var(--text); background: var(--surface);
}
.rel-links a:hover { border-color: var(--primary); color: var(--primary); text-decoration: none; }

/* ---------- 正文排版 ---------- */
.prose {
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--surface); padding: 26px 30px;
}
.prose h2 {
  font-size: 19px; margin: 30px 0 10px; padding-left: 10px;
  border-left: 4px solid var(--primary); line-height: 1.4;
}
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: 16px; margin: 20px 0 8px; }
.prose p { margin: 10px 0; }
.prose ul, .prose ol { margin: 8px 0; padding-left: 22px; }
.prose li { margin: 5px 0; }
.prose .li-extra { color: var(--muted); font-size: 14.5px; margin-top: 2px; }
.prose code {
  font-family: var(--mono); font-size: 0.88em;
  background: var(--surface2); border-radius: 5px; padding: 1px 6px;
}
.prose pre {
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: 10px; padding: 14px 16px; overflow-x: auto;
  font-size: 13.5px; line-height: 1.6;
}
.prose pre code { background: none; padding: 0; font-size: inherit; }
.prose pre.figure { border-left: 3px solid var(--accent); }
.prose .formula {
  background: var(--primary-soft); border: 1px solid color-mix(in srgb, var(--primary) 25%, transparent);
  border-radius: 10px; padding: 12px 18px; margin: 12px 0;
  font-family: var(--mono); font-size: 14.5px; overflow-x: auto; line-height: 1.8;
}
.prose blockquote {
  margin: 12px 0; padding: 8px 16px;
  border-left: 4px solid var(--border); color: var(--muted);
  background: var(--surface2); border-radius: 0 10px 10px 0;
}
.table-wrap { overflow-x: auto; margin: 12px 0; }
.prose table { border-collapse: collapse; width: 100%; font-size: 14px; }
.prose th, .prose td { border: 1px solid var(--border); padding: 7px 12px; text-align: left; vertical-align: top; }
.prose th { background: var(--surface2); white-space: nowrap; }
.prose td code { white-space: nowrap; }
.prose hr { border: none; border-top: 1px dashed var(--border); margin: 22px 0; }

/* ---------- 上下节导航 ---------- */
.pager { display: flex; gap: 14px; margin-top: 22px; }
.pager a {
  flex: 1; border: 1px solid var(--border); border-radius: 12px;
  background: var(--surface); padding: 12px 16px;
}
.pager a:hover { border-color: var(--primary); text-decoration: none; }
.pager .dir { display: block; color: var(--muted); font-size: 12.5px; }
.pager .pt { color: var(--text); font-weight: 600; font-size: 14.5px; }
.pager .next { text-align: right; }

/* ---------- 学习路径页 ---------- */
.path-list { display: flex; flex-direction: column; gap: 8px; counter-reset: step; }
.path-item {
  display: flex; align-items: center; gap: 12px;
  border: 1px solid var(--border); border-radius: 12px;
  background: var(--surface); padding: 10px 16px;
  transition: border-color var(--speed) var(--ease);
}
.path-item[data-state="done"] { border-color: color-mix(in srgb, var(--lv-1) 55%, transparent); }
.path-item[data-state="learning"] { border-color: color-mix(in srgb, var(--lv-4) 55%, transparent); }
.path-item .stepno {
  flex: none; width: 28px; height: 28px; border-radius: 50%;
  background: var(--surface2); color: var(--muted);
  display: inline-flex; align-items: center; justify-content: center;
  font-family: var(--mono); font-size: 12.5px; font-weight: 700;
}
.path-item[data-state="done"] .stepno { background: var(--lv-1); color: #fff; }
.path-item[data-state="learning"] .stepno { background: var(--lv-4); color: #fff; }
.path-item .ptitle { flex: 1; color: var(--text); font-weight: 600; font-size: 15px; }
.path-item .ptitle:hover { color: var(--primary); }
.path-item .pmeta { color: var(--muted); font-size: 12.5px; white-space: nowrap; }

/* ---------- 知识地图 ---------- */
.dep-scroll { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); padding: 8px; }
.dep-svg { display: block; min-width: 100%; height: auto; }
.dep-svg .lane-label { fill: var(--muted); font-size: 13px; font-weight: 700; }
.dep-svg .lane-sub { fill: var(--muted); font-size: 10.5px; opacity: 0.8; }
.dep-svg .node-rect { fill: var(--surface2); stroke: var(--border); stroke-width: 1.2; }
.dep-svg .node:hover .node-rect { stroke: var(--accent); }
.dep-svg .node-id { fill: var(--muted); font-family: var(--mono); font-size: 9.5px; }
.dep-svg .node-title { fill: var(--text); font-size: 11.5px; font-weight: 600; }
.dep-svg .edge { stroke: var(--edge); stroke-width: 1.1; fill: none; opacity: 0.85; }
.dep-svg .edge-head { fill: var(--edge); }
.dep-svg .node[data-level="入门"] .node-rect { stroke: color-mix(in srgb, var(--lv-1) 65%, var(--border)); }
.dep-svg .node[data-level="核心"] .node-rect { stroke: color-mix(in srgb, var(--lv-2) 65%, var(--border)); }
.dep-svg .node[data-level="进阶"] .node-rect { stroke: color-mix(in srgb, var(--lv-3) 65%, var(--border)); }
.dep-svg .node[data-level="前沿"] .node-rect { stroke: color-mix(in srgb, var(--lv-4) 65%, var(--border)); }
.legend { display: flex; flex-wrap: wrap; gap: 12px; color: var(--muted); font-size: 13px; margin: 10px 0 16px; }
.legend .lvdot { width: 9px; height: 9px; border-radius: 50%; display: inline-block; margin-right: 5px; }

/* ---------- 术语表 ---------- */
.gloss-tools { display: flex; gap: 10px; margin-bottom: 14px; }
.gloss-tools input {
  flex: 1; max-width: 380px; padding: 9px 14px;
  border: 1px solid var(--border); border-radius: 10px;
  background: var(--surface); color: var(--text); font: inherit; font-size: 14.5px;
}
.gloss-group h2 { font-size: 17px; margin: 26px 0 10px; }

/* ---------- 页脚 ---------- */
.site-footer { border-top: 1px solid var(--border); padding: 22px 0 40px; color: var(--muted); font-size: 13.5px; }
.site-footer a { color: var(--muted); }

/* ---------- 响应式 ---------- */
@media (max-width: 860px) {
  .header-inner { gap: 10px; }
  .site-nav { order: 3; width: 100%; overflow-x: auto; flex-wrap: nowrap; padding-bottom: 4px; }
  .site-nav a { white-space: nowrap; }
  .hero { padding: 24px 18px; }
  .hero h1 { font-size: 26px; }
  .kp-head, .prose { padding: 18px; }
  .pager { flex-direction: column; }
  .pager .next { text-align: left; }
}

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