/* ============================================================
   《上游》 UPSTREAM — Haskell 小书 · 水文溯源风设计系统
   一张老水文测绘图:地图纸米白、墨蓝等高线、河道蓝、Haskell 紫航标。
   亮色 only(用户眼睛受不了暗色)。零依赖,系统字体栈。
   ============================================================ */

:root {
  /* —— 地图纸 —— */
  --paper: #FAF7F0;          /* 图纸米白 */
  --paper-deep: #F2EDE1;     /* 卡片、码头 */
  --paper-dim: #EAE3D3;      /* 分隔、浅滩 */
  --ink: #1C3A5E;            /* 测绘墨蓝(标题/重点) */
  --ink-body: #334152;       /* 正文 */
  --ink-faint: #6B7A8D;      /* 次要标注 */
  --line: #D8CFBC;           /* 图廓线 */
  --contour: rgba(28, 58, 94, 0.055);

  /* —— 水系 —— */
  --river: #2C7DA0;          /* 河道蓝 */
  --river-deep: #14597A;     /* 深泓线 */
  --river-mist: #E3EEF2;     /* 浅水面(ghci 块底) */
  --shoal: #3E7C59;          /* 浅滩绿(练习/通过) */
  --shoal-mist: #E7F0E8;
  --reef: #C4622D;           /* 暗礁赭(警示/错误) */
  --reef-mist: #F8EBDF;
  --lambda: #5E5086;         /* Haskell 紫(航标/关键字) */
  --lambda-mist: #EDE9F3;

  /* —— 代码 token —— */
  --tok-kw: #5E5086;
  --tok-type: #14597A;
  --tok-str: #3E7C59;
  --tok-num: #B0561F;
  --tok-com: #8C93A0;
  --tok-op: #2C7DA0;
  --tok-fn: #1C3A5E;

  --serif: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Source Han Sans SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", "Fira Code", Menlo, Consolas, "Liberation Mono", monospace;

  --topbar-h: 56px;
  --maxw: 780px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
html, body { overflow-x: hidden; }

body {
  font-family: var(--sans);
  background-color: var(--paper);
  /* 等高线纹理:两组错相位的波纹 */
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='340' height='240' viewBox='0 0 340 240'%3E%3Cg fill='none' stroke='%231C3A5E' stroke-opacity='0.05' stroke-width='1'%3E%3Cpath d='M-20 40 Q 65 8 150 40 T 360 40'/%3E%3Cpath d='M-20 88 Q 65 58 150 88 T 360 88'/%3E%3Cpath d='M-20 136 Q 65 104 150 136 T 360 136'/%3E%3Cpath d='M-20 184 Q 65 152 150 184 T 360 184'/%3E%3Cpath d='M-20 232 Q 65 200 150 232 T 360 232'/%3E%3C/g%3E%3C/svg%3E");
  color: var(--ink-body);
  line-height: 1.9;
  font-size: 16.5px;
  padding-top: var(--topbar-h);
}

::selection { background: rgba(44, 125, 160, 0.22); }

a { color: var(--river-deep); text-decoration: none; border-bottom: 1px solid rgba(44, 125, 160, 0.35); }
a:hover { color: var(--lambda); border-bottom-color: var(--lambda); }

code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: rgba(28, 58, 94, 0.07);
  border-radius: 4px;
  padding: 0.1em 0.4em;
  color: var(--ink);
  word-break: break-word;
}

strong { color: var(--ink); }
em { font-style: normal; color: var(--lambda); }

/* ============ 顶部测绘条(fixed) ============ */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 90;
  height: var(--topbar-h);
  background: rgba(250, 247, 240, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
  display: flex; align-items: center; gap: 14px;
  padding: 0 18px;
}
.topbar .brand {
  font-family: var(--serif);
  font-weight: 700; font-size: 19px; letter-spacing: 0.22em;
  color: var(--ink); border: none; white-space: nowrap;
  display: flex; align-items: center; gap: 9px;
}
.topbar .brand:hover { color: var(--lambda); }
.topbar .brand .lam {
  font-family: var(--mono); font-weight: 600; font-size: 15px;
  color: var(--paper); background: var(--lambda);
  width: 24px; height: 24px; border-radius: 5px;
  display: inline-flex; align-items: center; justify-content: center;
  letter-spacing: 0;
}
.topbar .river-wrap { flex: 1; min-width: 60px; height: 100%; position: relative; display: flex; align-items: center; }
.topbar .river-wrap svg { width: 100%; height: 40px; display: block; }
.topbar .river-bed { stroke: var(--paper-dim); }
.topbar .river-run { stroke: var(--river); }
.topbar .river-boat { fill: var(--lambda); }
.topbar .river-label {
  position: absolute; bottom: 1px; font-family: var(--mono);
  font-size: 9px; letter-spacing: 0.12em; color: var(--ink-faint);
  user-select: none; pointer-events: none;
}
.topbar .river-label.src { right: 0; }
.topbar .river-label.mouth { left: 0; }
.topbar .ch-pos {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em;
  color: var(--ink-faint); white-space: nowrap;
}
.topbar .ch-pos b { color: var(--river-deep); font-weight: 600; }
.topbar .toc-btn {
  font-family: var(--mono); font-size: 11.5px; letter-spacing: 0.14em;
  color: var(--ink); background: transparent;
  border: 1px solid var(--line); border-radius: 6px;
  padding: 6px 13px; cursor: pointer; white-space: nowrap;
}
.topbar .toc-btn:hover { border-color: var(--river); color: var(--river-deep); background: var(--river-mist); }
@media (max-width: 640px) {
  .topbar { gap: 10px; padding: 0 12px; }
  .topbar .ch-pos { display: none; }
  .topbar .river-label { display: none; }
}

/* ============ 目录覆盖层:纵向河道图 ============ */
.toc-overlay {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(250, 247, 240, 0.98);
  overflow-y: auto;
  opacity: 0; pointer-events: none;
  transition: opacity 0.22s ease;
}
.toc-overlay.open { opacity: 1; pointer-events: auto; }
.toc-inner { max-width: 700px; margin: 0 auto; padding: 60px 22px 90px; }
.toc-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 8px; }
.toc-head h2 {
  font-family: var(--serif); font-size: 30px; letter-spacing: 0.3em;
  color: var(--ink); font-weight: 700;
}
.toc-head .close {
  font-family: var(--mono); font-size: 12px; color: var(--ink-faint);
  background: none; border: 1px solid var(--line); border-radius: 6px;
  padding: 6px 12px; cursor: pointer;
}
.toc-head .close:hover { color: var(--reef); border-color: var(--reef); }
.toc-sub { font-family: var(--mono); font-size: 11px; letter-spacing: 0.18em; color: var(--ink-faint); margin-bottom: 34px; }

.toc-vol { position: relative; padding-left: 34px; margin-bottom: 8px; }
/* 纵向河道线 */
.toc-vol::before {
  content: ""; position: absolute; left: 10px; top: 6px; bottom: -8px;
  width: 3px; border-radius: 2px;
  background: linear-gradient(to bottom, var(--river) 0%, rgba(44,125,160,0.25) 100%);
}
.toc-vol:last-child::before { bottom: 12px; }
/* 水文站圆标 */
.toc-vol::after {
  content: ""; position: absolute; left: 4px; top: 8px;
  width: 15px; height: 15px; border-radius: 50%;
  background: var(--paper); border: 3px solid var(--lambda);
}
.toc-vol .vol-name {
  font-family: var(--mono); font-size: 11.5px; letter-spacing: 0.2em;
  color: var(--lambda); font-weight: 600; margin-bottom: 2px;
}
.toc-vol .vol-desc { font-size: 13px; color: var(--ink-faint); margin-bottom: 12px; }
.toc-vol ol { list-style: none; margin-bottom: 26px; }
.toc-vol li a {
  display: flex; align-items: baseline; gap: 12px;
  padding: 7px 10px; border: none; border-radius: 7px;
  color: var(--ink-body); font-size: 15px;
}
.toc-vol li a:hover { background: var(--river-mist); color: var(--river-deep); }
.toc-vol li a .no { font-family: var(--mono); font-size: 11px; color: var(--ink-faint); min-width: 22px; }
.toc-vol li a .demo-tag {
  margin-left: auto; font-family: var(--mono); font-size: 9.5px; letter-spacing: 0.08em;
  color: var(--lambda); border: 1px solid rgba(94, 80, 134, 0.4);
  border-radius: 4px; padding: 1px 6px; white-space: nowrap;
}
.toc-vol li a.cur { background: var(--lambda-mist); color: var(--lambda); font-weight: 600; }
.toc-vol li a.cur .no { color: var(--lambda); }

/* ============ 章节页骨架 ============ */
.content { display: block; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 22px; }

.chapter-head { padding: 58px 0 10px; }
.chapter-head .kicker {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.18em;
  color: var(--ink-faint); margin-bottom: 18px;
}
.chapter-head .kicker .vol { color: var(--lambda); font-weight: 600; }
.chapter-head .kicker .mile { color: var(--river-deep); }
.chapter-head .kicker .sep { width: 26px; height: 1px; background: var(--line); }
.chapter-head h1 {
  font-family: var(--serif); font-size: 40px; line-height: 1.35;
  color: var(--ink); font-weight: 700; letter-spacing: 0.02em;
  margin-bottom: 20px;
}
.chapter-head h1 em { font-style: normal; color: var(--river-deep); }
.chapter-head .lede {
  font-size: 17px; line-height: 2.0; color: var(--ink-body);
  border-left: 3px solid var(--river); padding-left: 18px;
  margin-bottom: 22px;
}
.chapter-head .tags { display: flex; gap: 8px; flex-wrap: wrap; }
.chapter-head .tags span {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.1em;
  color: var(--river-deep); background: var(--river-mist);
  border-radius: 5px; padding: 3px 10px;
}
.headrule {
  border: none; height: 10px; margin: 34px 0 8px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='10' viewBox='0 0 120 10'%3E%3Cpath d='M0 5 Q 15 0 30 5 T 60 5 T 90 5 T 120 5' fill='none' stroke='%232C7DA0' stroke-opacity='0.4' stroke-width='1.4'/%3E%3C/svg%3E");
  background-repeat: repeat-x; background-position: center;
}

/* ============ 正文排印 ============ */
.prose { padding-bottom: 30px; }
.prose h2 {
  font-family: var(--serif); font-size: 26px; color: var(--ink);
  font-weight: 700; line-height: 1.5;
  margin: 54px 0 18px; padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  position: relative;
}
.prose h2::after {
  content: ""; position: absolute; left: 0; bottom: -1px;
  width: 64px; height: 2px; background: var(--river);
}
.prose h3 {
  font-family: var(--serif); font-size: 20px; color: var(--ink);
  font-weight: 700; margin: 38px 0 14px;
  display: flex; align-items: center; gap: 10px;
}
.prose h3::before { content: "▍"; color: var(--river); font-size: 15px; }
.prose p { margin: 0 0 18px; }
.prose ul, .prose ol { margin: 0 0 18px; padding-left: 26px; }
.prose li { margin-bottom: 8px; }
.prose li::marker { color: var(--river); font-family: var(--mono); font-size: 0.9em; }
.prose hr { border: none; border-top: 1px dashed var(--line); margin: 40px 0; }

.prose table {
  width: 100%; border-collapse: collapse; margin: 22px 0;
  font-size: 14.5px; line-height: 1.75;
  background: rgba(255, 255, 255, 0.55);
}
.prose th, .prose td { border: 1px solid var(--line); padding: 9px 13px; text-align: left; vertical-align: top; }
.prose th {
  font-family: var(--mono); font-size: 11.5px; letter-spacing: 0.1em;
  color: var(--ink); background: var(--paper-deep); font-weight: 600;
  white-space: nowrap;
}
.table-scroll { overflow-x: auto; }
.table-scroll table { min-width: 560px; }

/* ============ 航道 callout 卡 ============ */
.co {
  border-radius: 10px; padding: 16px 20px 14px; margin: 24px 0;
  border: 1px solid; border-left-width: 4px;
  background: rgba(255, 255, 255, 0.5);
  font-size: 15.2px; line-height: 1.95;
}
.co .co-t {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.2em;
  font-weight: 700; margin-bottom: 8px; display: flex; align-items: center; gap: 8px;
}
.co p { margin-bottom: 10px; }
.co p:last-child { margin-bottom: 2px; }
.co code { background: rgba(28, 58, 94, 0.08); }

/* λ 源头碑:定义 */
.co.def { border-color: rgba(94, 80, 134, 0.45); border-left-color: var(--lambda); background: var(--lambda-mist); }
.co.def .co-t { color: var(--lambda); }
/* ▸ 下游对照:Kotlin/Java/TS 类比(本书灵魂) */
.co.down { border-color: rgba(44, 125, 160, 0.4); border-left-color: var(--river); background: var(--river-mist); }
.co.down .co-t { color: var(--river-deep); }
/* ◆ 水文记录:机制深潜 */
.co.log { border-color: var(--line); border-left-color: var(--ink); background: rgba(242, 237, 225, 0.6); }
.co.log .co-t { color: var(--ink); }
/* ⚠ 暗礁:坑与警示 */
.co.reef { border-color: rgba(196, 98, 45, 0.45); border-left-color: var(--reef); background: var(--reef-mist); }
.co.reef .co-t { color: var(--reef); }
/* ✚ 动手泅渡:练习 */
.co.swim { border-color: rgba(62, 124, 89, 0.45); border-left-color: var(--shoal); background: var(--shoal-mist); }
.co.swim .co-t { color: var(--shoal); }

/* ============ 代码块 ============ */
pre {
  font-family: var(--mono); font-size: 13.5px; line-height: 1.8;
  border-radius: 10px; padding: 18px 20px; margin: 22px 0;
  overflow-x: auto; position: relative;
  white-space: pre; tab-size: 4;
}
pre .tag-corner {
  position: absolute; top: 0; right: 0;
  font-size: 9.5px; letter-spacing: 0.14em; font-weight: 600;
  padding: 3px 10px; border-radius: 0 9px 0 8px;
  user-select: none;
}

/* Haskell 源码:白纸测绘卡 */
pre.code {
  background: #FFFFFF; color: var(--ink-body);
  border: 1px solid var(--line);
  box-shadow: 0 1px 0 rgba(28, 58, 94, 0.05);
}
pre.code .tag-corner { color: var(--lambda); background: var(--lambda-mist); }

/* GHCi 会话:浅水面 */
pre.ghci {
  background: var(--river-mist); color: var(--ink-body);
  border: 1px solid rgba(44, 125, 160, 0.3);
}
pre.ghci .tag-corner { color: #fff; background: var(--river); }
pre.ghci .gp { color: var(--lambda); font-weight: 700; user-select: none; }
pre.ghci .gout { color: var(--ink-faint); }
pre.ghci .gerr { color: var(--reef); }

/* 对照代码(kotlin/java/ts/python):码头灰纸 */
pre.cmp {
  background: var(--paper-deep); color: var(--ink-body);
  border: 1px solid var(--line);
}
pre.cmp .tag-corner { color: var(--ink); background: var(--paper-dim); }

/* 高亮 token */
.tk-kw { color: var(--tok-kw); font-weight: 600; }
.tk-ty { color: var(--tok-type); font-weight: 600; }
.tk-st { color: var(--tok-str); }
.tk-nu { color: var(--tok-num); }
.tk-co { color: var(--tok-com); font-style: italic; }
.tk-op { color: var(--tok-op); }
.tk-fn { color: var(--tok-fn); font-weight: 600; }

/* ============ Demo 泅渡点部件 ============ */
.demo {
  border: 1.5px solid var(--river); border-radius: 12px;
  margin: 30px 0; background: #fff;
  box-shadow: 0 2px 0 rgba(20, 89, 122, 0.12);
  overflow: hidden;
}
.demo-head {
  display: flex; align-items: center; gap: 10px;
  background: linear-gradient(to right, var(--river-mist), rgba(227, 238, 242, 0.3));
  border-bottom: 1px solid rgba(44, 125, 160, 0.25);
  padding: 9px 16px;
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.16em;
  color: var(--river-deep); font-weight: 600;
}
.demo-head .buoy {
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--lambda);
  box-shadow: 0 0 0 3px rgba(94, 80, 134, 0.18);
  animation: buoy-bob 2.6s ease-in-out infinite;
}
@keyframes buoy-bob { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-2px); } }
.demo-head .d-hint { margin-left: auto; color: var(--ink-faint); font-weight: 400; letter-spacing: 0.08em; font-size: 10px; }
.demo-body { padding: 16px; }

.d-row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-bottom: 12px; }
.d-row:last-child { margin-bottom: 0; }
.d-btn {
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.06em;
  background: var(--river); color: #fff;
  border: none; border-radius: 7px; padding: 7px 15px; cursor: pointer;
}
.d-btn:hover { background: var(--river-deep); }
.d-btn:disabled { background: var(--paper-dim); color: var(--ink-faint); cursor: not-allowed; }
.d-btn.ghost { background: transparent; color: var(--river-deep); border: 1px solid var(--river); }
.d-btn.ghost:hover { background: var(--river-mist); }
.d-btn.lam { background: var(--lambda); }
.d-btn.lam:hover { background: #4A3F6E; }
.d-in, .d-sel, textarea.d-in {
  font-family: var(--mono); font-size: 13px;
  border: 1px solid var(--line); border-radius: 7px;
  background: var(--paper); color: var(--ink);
  padding: 7px 11px; outline: none;
}
.d-in:focus, .d-sel:focus, textarea.d-in:focus { border-color: var(--river); background: #fff; }
textarea.d-in { width: 100%; resize: vertical; line-height: 1.7; white-space: pre; }
.d-note { font-size: 12.5px; color: var(--ink-faint); line-height: 1.7; }
.d-err { font-family: var(--mono); font-size: 12.5px; color: var(--reef); white-space: pre-wrap; }
.d-ok { font-family: var(--mono); font-size: 12.5px; color: var(--shoal); }

/* 终端(ghciterm) */
.d-term {
  font-family: var(--mono); font-size: 13px; line-height: 1.75;
  background: var(--river-mist); border: 1px solid rgba(44, 125, 160, 0.3);
  border-radius: 8px; padding: 12px 14px;
  max-height: 300px; overflow-y: auto; white-space: pre-wrap; word-break: break-all;
}
.d-term .tl-in .gp { color: var(--lambda); font-weight: 700; }
.d-term .tl-out { color: var(--ink-body); }
.d-term .tl-dim { color: var(--ink-faint); }
.d-term .tl-err { color: var(--reef); }
.d-term-input { display: flex; gap: 8px; margin-top: 10px; align-items: center; }
.d-term-input .gp { font-family: var(--mono); color: var(--lambda); font-weight: 700; font-size: 13px; }
.d-term-input input { flex: 1; }

/* SVG 舞台 */
.d-stage { width: 100%; border: 1px solid var(--line); border-radius: 8px; background: var(--paper); overflow: hidden; }
.d-stage svg { display: block; width: 100%; height: auto; }

/* 键值/徽章 */
.d-kv { font-family: var(--mono); font-size: 12px; color: var(--ink-faint); }
.d-kv b { color: var(--river-deep); font-weight: 600; }
.d-badge {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.08em;
  border-radius: 5px; padding: 2px 8px; white-space: nowrap;
}
.d-badge.ok { color: var(--shoal); background: var(--shoal-mist); border: 1px solid rgba(62,124,89,0.4); }
.d-badge.bad { color: var(--reef); background: var(--reef-mist); border: 1px solid rgba(196,98,45,0.4); }
.d-badge.info { color: var(--river-deep); background: var(--river-mist); border: 1px solid rgba(44,125,160,0.35); }

/* 用例表(quicklab 等) */
.d-cases { width: 100%; border-collapse: collapse; font-family: var(--mono); font-size: 12px; }
.d-cases th, .d-cases td { border: 1px solid var(--line); padding: 5px 9px; text-align: left; }
.d-cases th { background: var(--paper-deep); font-weight: 600; letter-spacing: 0.06em; }
.d-cases tr.fail td { background: var(--reef-mist); color: var(--reef); }
.d-cases tr.pass td { color: var(--ink-body); }
.d-cases-scroll { max-height: 260px; overflow: auto; border-radius: 6px; }

/* 解析树 / thunk 树 */
.d-tree { font-family: var(--mono); font-size: 12.5px; line-height: 1.9; }
.d-tree ul { list-style: none; padding-left: 20px; border-left: 1px dashed var(--line); margin-left: 6px; }
.d-tree > ul { border-left: none; margin-left: 0; padding-left: 0; }
.d-tree .nd { color: var(--ink); }
.d-tree .nd .nk { color: var(--lambda); font-weight: 600; }
.d-tree .nd .nv { color: var(--tok-num); }

/* adtlab 状态格 */
.d-states { display: flex; flex-wrap: wrap; gap: 6px; }
.d-states .st {
  font-family: var(--mono); font-size: 11px; border-radius: 6px;
  padding: 4px 9px; border: 1px solid var(--line); background: #fff; color: var(--ink-body);
}
.d-states .st.bad { border-color: rgba(196,98,45,0.5); background: var(--reef-mist); color: var(--reef); text-decoration: line-through; }
.d-states .st.good { border-color: rgba(62,124,89,0.5); background: var(--shoal-mist); color: var(--shoal); }

/* ============ 翻页(顺流/溯流) ============ */
.pager {
  display: grid; grid-template-columns: 1fr 1fr; gap: 14px;
  margin: 56px 0 30px;
}
.pager a {
  border: 1px solid var(--line); border-radius: 10px;
  padding: 15px 18px; background: rgba(255, 255, 255, 0.6);
  display: block; color: var(--ink-body);
}
.pager a:hover { border-color: var(--river); background: var(--river-mist); }
.pager a .dir {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.16em;
  color: var(--ink-faint); display: block; margin-bottom: 5px;
}
.pager a .t { font-size: 14.5px; color: var(--ink); font-weight: 600; }
.pager a.next { text-align: right; }
.pager a.none { visibility: hidden; }
@media (max-width: 560px) { .pager { grid-template-columns: 1fr; } .pager a.next { text-align: left; } }

.foot {
  border-top: 1px solid var(--line);
  padding: 22px 0 46px; text-align: center;
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.16em;
  color: var(--ink-faint);
}
.foot a { color: var(--river-deep); border: none; }

/* ============ 总览页(index) ============ */
.hero { padding: 72px 0 30px; position: relative; }
.hero .surv {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.3em;
  color: var(--river-deep); margin-bottom: 22px;
  display: flex; align-items: center; gap: 12px;
}
.hero .surv::after { content: ""; flex: 1; height: 1px; background: var(--line); }
.hero h1 {
  font-family: var(--serif); font-size: 74px; letter-spacing: 0.12em;
  color: var(--ink); font-weight: 700; line-height: 1.15; margin-bottom: 6px;
}
.hero h1 .lam-mark { color: var(--lambda); }
.hero .en {
  font-family: var(--mono); font-size: 13px; letter-spacing: 0.5em;
  color: var(--ink-faint); margin-bottom: 30px;
}
.hero .pitch { font-size: 17.5px; line-height: 2.05; max-width: 640px; margin-bottom: 14px; }
.hero .pitch strong { color: var(--river-deep); }
.hero-river { margin: 36px 0 8px; }
.hero-river svg { width: 100%; height: auto; display: block; }
.hero .meta-row { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 24px; }
.hero .meta-row span {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.12em;
  color: var(--ink); background: rgba(255, 255, 255, 0.65);
  border: 1px solid var(--line); border-radius: 6px; padding: 5px 12px;
}
.hero .meta-row span b { color: var(--lambda); font-weight: 600; }
@media (max-width: 640px) { .hero h1 { font-size: 52px; } }

.station { margin: 46px 0 12px; position: relative; }
.station .st-kick {
  display: flex; align-items: center; gap: 12px; margin-bottom: 6px;
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.22em; color: var(--lambda); font-weight: 700;
}
.station .st-kick .dot {
  width: 13px; height: 13px; border-radius: 50%;
  background: var(--paper); border: 3px solid var(--lambda); flex: none;
}
.station .st-kick .wave { flex: 1; height: 8px; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='90' height='8' viewBox='0 0 90 8'%3E%3Cpath d='M0 4 Q 11 0 22 4 T 45 4 T 68 4 T 90 4' fill='none' stroke='%232C7DA0' stroke-opacity='0.35' stroke-width='1.3'/%3E%3C/svg%3E"); background-repeat: repeat-x; background-position: center; }
.station h2 { font-family: var(--serif); font-size: 27px; color: var(--ink); font-weight: 700; margin-bottom: 4px; }
.station .st-desc { font-size: 14.5px; color: var(--ink-faint); margin-bottom: 20px; }

.ch-list { display: grid; gap: 12px; margin-bottom: 14px; }
.ch-card {
  display: flex; gap: 16px; align-items: baseline;
  border: 1px solid var(--line); border-radius: 10px;
  background: rgba(255, 255, 255, 0.62);
  padding: 15px 18px; color: var(--ink-body);
}
.ch-card:hover { border-color: var(--river); background: var(--river-mist); transform: translateX(4px); }
.ch-card { transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease; }
.ch-card .no {
  font-family: var(--mono); font-size: 13px; color: var(--river-deep);
  font-weight: 600; min-width: 30px;
}
.ch-card .body { flex: 1; }
.ch-card .t { font-size: 16.5px; color: var(--ink); font-weight: 600; margin-bottom: 3px; }
.ch-card .d { font-size: 13.5px; color: var(--ink-faint); line-height: 1.75; }
.ch-card .demo-tag {
  font-family: var(--mono); font-size: 9.5px; letter-spacing: 0.08em;
  color: var(--lambda); border: 1px solid rgba(94, 80, 134, 0.4);
  border-radius: 4px; padding: 2px 7px; white-space: nowrap; align-self: center;
}

/* ============ 杂项 ============ */
.kbd {
  font-family: var(--mono); font-size: 0.82em;
  border: 1px solid var(--line); border-bottom-width: 2px;
  border-radius: 5px; padding: 0.05em 0.45em;
  background: #fff; color: var(--ink);
}
.small-cap { font-family: var(--mono); font-size: 11px; letter-spacing: 0.18em; color: var(--ink-faint); }

@media (max-width: 640px) {
  body { font-size: 15.5px; }
  .chapter-head h1 { font-size: 30px; }
  .prose h2 { font-size: 22px; }
  pre { font-size: 12.5px; padding: 14px 14px; }
}