/* course.css — Transformer 实现机制 · 设计系统「工程讲义」
   版式:<1400px 单列 46rem;≥1400px 双 panel(左=全课程导航,右=本课章节 scrollspy)+ 正文 50rem;
   ≥1600px 字号 17→18px。所有卡片与正文同一左右边线;唯一例外是 py-runner 单步调试整块临时加宽(功能需要)。
   签名元素:因果掩码进度条(token 方格:已学=实心 / 当前=描边 / 未学=斜线掩码),见 .tb-strip 与首页 .home-strip。
   色板与 assets/*.js canvas 动画、课文内联 SVG 保持同一组语义色(靛紫/琥珀/绿/红),改色需同步 JS。
   字体:标题/界面 IBM Plex Sans + Noto Sans SC;正文 Noto Serif SC;代码与数字 IBM Plex Mono。 */

/* ---------- 自托管字体(latin 子集,CJK 回落系统字体) ---------- */

@font-face {
  font-family: "IBM Plex Mono";
  font-weight: 400;
  font-display: swap;
  src: url("/shared/fonts/ibm-plex-mono-400.woff2") format("woff2");
}
@font-face {
  font-family: "IBM Plex Mono";
  font-weight: 600;
  font-display: swap;
  src: url("/shared/fonts/ibm-plex-mono-600.woff2") format("woff2");
}
@font-face {
  font-family: "IBM Plex Sans";
  font-weight: 600 700;
  font-display: swap;
  src: url("/shared/fonts/ibm-plex-sans-var.woff2") format("woff2");
}

/* ---------- 设计令牌 ---------- */

:root {
  --paper: #fbfaf7;
  --card: #ffffff;
  --ink: #1f2328;
  --ink-soft: #57606a;
  --ink-faint: #8a8578;
  --accent: #5b5bd6;
  --accent-deep: #3e3ea8;
  --accent-wash: #f0f0fb;
  --amber: #b45309;
  --amber-wash: #fef6e7;
  --green: #1a7f37;
  --green-wash: #eefbf1;
  --red: #c0392b;
  --red-wash: #fdeeec;
  --line: #e6e3da;
  --line-soft: #eeece4;
  --code-bg: #f7f5ef;
  --shadow-card: 0 1px 2px rgba(31, 35, 40, 0.04), 0 10px 28px -22px rgba(31, 35, 40, 0.3);
  --serif: "Source Han Serif SC", "Noto Serif CJK SC", "Noto Serif SC", "Songti SC", "SimSun", Georgia, serif;
  --sans: "IBM Plex Sans", "Source Han Sans SC", "Noto Sans CJK SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", "JetBrains Mono", "Cascadia Code", "Fira Code", Consolas, "Noto Sans Mono CJK SC", monospace;
  /* 因果掩码纹样:未学 token / 未发布课程卡的"看不见"质感 */
  --mask-hatch: repeating-linear-gradient(45deg, transparent 0 3px, rgba(31, 35, 40, 0.09) 3px 4.5px);
  --topbar-h: 52px;
}

* { box-sizing: border-box; }

html { font-size: 17px; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--accent-wash); color: var(--accent-deep); }

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

main {
  max-width: 46rem;
  margin: 0 auto;
  padding: 3rem 1.5rem 5rem;
}

@media (max-width: 640px) {
  html { font-size: 16px; }
  main { padding-top: 2.2rem; }
}

/* ---------- 吸顶导航(course-chrome.js 生成) ---------- */

.topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  height: var(--topbar-h);
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0 1.2rem;
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  -webkit-backdrop-filter: blur(10px) saturate(1.15);
  backdrop-filter: blur(10px) saturate(1.15);
  border-bottom: 1px solid var(--line);
  font-family: var(--sans);
  transform: translateY(-100%);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}
.topbar.on { transform: translateY(0); }
.topbar.scrolled { box-shadow: 0 6px 18px -14px rgba(31, 35, 40, 0.35); }

.tb-mark {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  grid-template-rows: repeat(2, 1fr);
  gap: 2px;
  width: 17px;
  height: 17px;
  flex: none;
}
.tb-mark span { background: var(--accent); border-radius: 1.5px; }
.tb-mark span:last-child { background: none; border: 1px solid var(--accent); background-image: var(--mask-hatch); }

.tb-course {
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
}
.tb-course:hover { color: var(--accent-deep); }

.tb-pos {
  font-family: var(--mono);
  font-size: 0.74rem;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.tb-strip {
  display: flex;
  gap: 3px;
  margin-left: auto;
  text-decoration: none;
  padding: 4px;
  border-radius: 6px;
}
.tb-strip i {
  width: 11px;
  height: 11px;
  border-radius: 2.5px;
  background: var(--accent);
  opacity: 0.32;
  transition: opacity 0.15s, transform 0.15s;
}
.tb-strip i.done { opacity: 1; }
.tb-strip i.mask {
  background: none;
  border: 1px solid var(--ink-faint);
  background-image: var(--mask-hatch);
  opacity: 0.9;
}
.tb-strip i.cur {
  opacity: 1;
  box-shadow: 0 0 0 2px var(--paper), 0 0 0 3.5px var(--accent);
  transform: scale(1.08);
}
.tb-strip:hover i.done { opacity: 0.85; }
.tb-strip:hover i:not(.cur):not(.mask) { opacity: 1; }

.tb-toc {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--accent-deep);
  text-decoration: none;
  white-space: nowrap;
  padding: 0.3rem 0.7rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--card);
  transition: border-color 0.15s;
}
.tb-toc:hover { border-color: var(--accent); }

@media (max-width: 900px) {
  .tb-pos { display: none; }
  .tb-course span.tb-course-sub { display: none; }
}
@media (max-width: 640px) {
  .topbar { gap: 0.6rem; padding: 0 0.8rem; }
  .tb-course { font-size: 0.78rem; }
  .tb-strip { margin-left: auto; }
  .tb-strip i { width: 8px; height: 8px; }
}

/* 吸顶导航可见时,单步调试的吸附控制条避让 */
body.tb-on .py-stepping .py-runner-stepbar { top: var(--topbar-h); }

/* 锚点跳转避让吸顶导航(窄屏顶栏 52px;宽屏无顶栏) */
html { scroll-padding-top: 64px; }

/* ---------- 宽屏双 panel(≥1400px,由 course-chrome.js 构建) ----------
   左 .sidenav:全课程清单,当前课高亮,未发布 = 掩码格;右 .tocside:本课 h2 章节 + scrollspy。
   单步调试(.tx-debug)时双 panel 让位给整块加宽的调试视图。 */

.sidenav, .tocside { display: none; }

@media (min-width: 1400px) {
  html { scroll-padding-top: 20px; }
  main { max-width: 50rem; }
  .topbar { display: none; }

  .sidenav {
    display: block;
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    width: 236px;
    padding: 1.1rem 0.8rem 1rem 1.2rem;
    border-right: 1px solid var(--line-soft);
    overflow-y: auto;
    overscroll-behavior: contain;
    font-family: var(--sans);
    font-size: 0.8rem;
    z-index: 40;
  }
  .sn-course {
    display: block;
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--ink);
    text-decoration: none;
    margin: 0.1rem 0 0.8rem 0.5rem;
  }
  .sn-course:hover { color: var(--accent-deep); }
  .sn-list { list-style: none; margin: 0; padding: 0; }
  .sn-list li { margin: 1px 0; }
  .sn-list a, .sn-list .todo {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
    padding: 0.28rem 0.5rem;
    border-radius: 6px;
    color: var(--ink-soft);
    text-decoration: none;
    line-height: 1.45;
  }
  .sn-list a:hover { background: var(--card); color: var(--accent-deep); }
  .sn-no {
    font-family: var(--mono);
    font-size: 0.7rem;
    color: var(--accent-deep);
    min-width: 1.7em;
    text-align: right;
    flex: none;
  }
  .sn-t { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .sn-list a.cur { background: var(--accent-wash); }
  .sn-list a.cur .sn-t { color: var(--accent-deep); font-weight: 600; }
  .sn-list .todo { cursor: default; }
  .sn-list .todo .sn-t { color: var(--ink-faint); }
  .sn-list .todo .sn-no {
    color: var(--ink-faint);
    border: 1px solid var(--line);
    background-image: var(--mask-hatch);
    border-radius: 3px;
  }
  .sn-other {
    display: block;
    margin-top: 1rem;
    padding: 0.7rem 0.5rem 0;
    border-top: 1px solid var(--line-soft);
    color: var(--ink-faint);
    font-size: 0.74rem;
    text-decoration: none;
  }
  .sn-other:hover { color: var(--accent-deep); }

  .tocside {
    display: block;
    position: fixed;
    top: 0;
    bottom: 0;
    right: 0;
    width: 216px;
    padding: 1.5rem 1rem 1rem 0.8rem;
    border-left: 1px solid var(--line-soft);
    overflow-y: auto;
    overscroll-behavior: contain;
    font-family: var(--sans);
    font-size: 0.78rem;
    z-index: 40;
  }
  .tc-head {
    display: block;
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.14em;
    color: var(--ink-faint);
    margin: 0 0 0.6rem 0.57rem;
  }
  .tocside ul { list-style: none; margin: 0; padding: 0; }
  .tocside li a {
    display: block;
    padding: 0.3rem 0.55rem;
    border-left: 2px solid var(--line-soft);
    color: var(--ink-soft);
    text-decoration: none;
    line-height: 1.5;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .tocside li a:hover { color: var(--accent-deep); }
  .tocside li a.on {
    color: var(--accent-deep);
    font-weight: 600;
    border-left-color: var(--accent);
    background: linear-gradient(90deg, var(--accent-wash), transparent 85%);
  }

  body.tx-debug .sidenav, body.tx-debug .tocside { display: none; }
}

@media (min-width: 1600px) {
  html { font-size: 18px; }
}

/* ---------- 课头 ---------- */

.lesson-header { margin-bottom: 2.6rem; }

.kicker {
  display: flex;
  align-items: center;
  gap: 0.55em;
  font-family: var(--sans);
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--accent-deep);
}
.kicker::before {
  content: "";
  width: 9px;
  height: 9px;
  flex: none;
  background: var(--accent);
  border-radius: 2px;
}

h1 {
  font-family: var(--sans);
  font-size: clamp(1.75rem, 1.45rem + 1.2vw, 2.25rem);
  font-weight: 700;
  line-height: 1.32;
  margin: 0.55rem 0 0.7rem;
  letter-spacing: 0.01em;
  text-wrap: balance;
}

.lesson-meta {
  font-family: var(--sans);
  font-size: 0.85rem;
  line-height: 1.9;
  color: var(--ink-soft);
  border-bottom: 1px solid var(--line);
  padding-bottom: 1.2rem;
  margin: 0;
}
.lesson-meta a { color: var(--accent-deep); }

/* ---------- 正文 ---------- */

h2 {
  font-family: var(--sans);
  display: flex;
  align-items: baseline;
  gap: 0.55em;
  font-size: 1.3rem;
  line-height: 1.4;
  margin-top: 3rem;
  margin-bottom: 0.9rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--line);
}
h2::before {
  content: "";
  width: 10px;
  height: 10px;
  flex: none;
  align-self: center;
  border: 2.5px solid var(--accent);
  border-radius: 2px;
}

h3 {
  font-family: var(--sans);
  font-size: 1.07rem;
  margin-top: 2.1rem;
  margin-bottom: 0.55rem;
}

p { margin: 0.9rem 0; }

a { color: var(--accent-deep); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--accent); }

strong { font-weight: 700; }

.term {
  font-style: normal;
  border-bottom: 2px dotted var(--accent);
  cursor: help;
}

ul, ol { padding-left: 1.6rem; }
li { margin: 0.35rem 0; }

hr { border: none; border-top: 1px solid var(--line); margin: 2.5rem 0; }

/* ---------- 引用块与提示框 ---------- */

blockquote {
  margin: 1.4rem 0;
  padding: 0.1rem 1.2rem;
  border-left: 3px solid var(--accent);
  color: var(--ink-soft);
  font-style: normal;
}

.callout {
  font-family: var(--sans);
  font-size: 0.93rem;
  line-height: 1.8;
  border: 1px solid var(--line);
  border-left-width: 3px;
  border-radius: 10px;
  padding: 1rem 1.3rem;
  margin: 1.6rem 0;
  background: var(--card);
  box-shadow: var(--shadow-card);
}
.callout .callout-title {
  display: flex;
  align-items: baseline;
  gap: 0.5em;
  font-weight: 700;
  margin-bottom: 0.45rem;
  font-size: 0.86rem;
  letter-spacing: 0.03em;
}
.callout .callout-title::before {
  content: "";
  width: 8px;
  height: 8px;
  flex: none;
  align-self: center;
  border-radius: 2px;
  background: var(--accent);
}
.callout.key { border-left-color: var(--accent); background: linear-gradient(0deg, var(--accent-wash) 0%, var(--card) 90%); }
.callout.key .callout-title { color: var(--accent-deep); }
.callout.warn { border-left-color: var(--amber); background: linear-gradient(0deg, var(--amber-wash) 0%, var(--card) 90%); }
.callout.warn .callout-title { color: var(--amber); }
.callout.warn .callout-title::before { background: var(--amber); }
.callout.win { border-left-color: var(--green); background: linear-gradient(0deg, var(--green-wash) 0%, var(--card) 90%); }
.callout.win .callout-title { color: var(--green); }
.callout.win .callout-title::before { background: var(--green); }
.callout.cite { background: transparent; border: 1px dashed var(--line); box-shadow: none; }
.callout.cite .callout-title { color: var(--ink-soft); }
.callout.cite .callout-title::before { background: var(--ink-faint); }

.callout .katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.2rem 0;
  margin: 0.6rem 0;
}
.katex-display { overflow-x: auto; overflow-y: hidden; padding: 0.2rem 0; }
.katex { font-size: 1.04em; }

/* ---------- 代码 ---------- */

code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--code-bg);
  border: 1px solid var(--line-soft);
  padding: 0.1em 0.38em;
  border-radius: 5px;
  font-variant-ligatures: none;
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1rem 1.2rem;
  overflow-x: auto;
  line-height: 1.6;
}

pre code { background: none; border: none; padding: 0; font-size: 0.84rem; }

/* ---------- 图表 ---------- */

figure { margin: 1.8rem 0; text-align: center; }
figure svg { max-width: 100%; height: auto; }
figcaption {
  font-family: var(--sans);
  font-size: 0.82rem;
  color: var(--ink-soft);
  margin-top: 0.6rem;
  line-height: 1.6;
}

table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.5rem 0;
  font-family: var(--sans);
  font-size: 0.88rem;
}
th, td { border: 1px solid var(--line); padding: 0.5rem 0.8rem; text-align: left; }
th { background: var(--accent-wash); font-weight: 600; }
td { font-variant-numeric: tabular-nums; }

/* ---------- 测验(quiz.js 渲染) ---------- */

.quiz {
  font-family: var(--sans);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1.3rem 1.5rem;
  margin: 2rem 0;
  background: var(--card);
  box-shadow: var(--shadow-card);
}
.quiz-title {
  display: flex;
  align-items: center;
  gap: 0.55em;
  font-weight: 700;
  font-size: 0.88rem;
  color: var(--accent-deep);
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
}
.quiz-title::before {
  content: "";
  width: 8px;
  height: 8px;
  flex: none;
  border-radius: 2px;
  background: var(--accent);
}
.quiz-q { margin-bottom: 1.4rem; }
.quiz-q-text { font-weight: 600; margin-bottom: 0.6rem; line-height: 1.7; }
.quiz-opt {
  display: block;
  width: 100%;
  text-align: left;
  font-family: var(--sans);
  font-size: 0.9rem;
  line-height: 1.6;
  padding: 0.55rem 0.95rem;
  margin: 0.4rem 0;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}
.quiz-opt:hover:not(:disabled) { border-color: var(--accent); }
.quiz-opt:disabled { cursor: default; opacity: 0.92; }
.quiz-opt.correct { background: var(--green-wash); border-color: var(--green); }
.quiz-opt.wrong { background: var(--red-wash); border-color: var(--red); }
.quiz-feedback {
  font-size: 0.86rem;
  line-height: 1.7;
  border-radius: 8px;
  padding: 0.7rem 1rem;
  margin-top: 0.6rem;
  display: none;
}
.quiz-feedback.ok { display: block; background: var(--green-wash); color: var(--green); }
.quiz-feedback.no { display: block; background: var(--red-wash); color: var(--red); }
.quiz-score { font-size: 0.85rem; color: var(--ink-soft); margin-top: 0.4rem; }

/* ---------- 注意力演示(attention-demo.js 渲染) ---------- */

.attn-demo {
  font-family: var(--sans);
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--card);
  padding: 1.2rem 1.4rem;
  margin: 2rem 0;
  box-shadow: var(--shadow-card);
}
.attn-caption { font-size: 0.9rem; color: var(--ink-soft); margin-bottom: 0.9rem; }
.attn-bar { display: flex; flex-wrap: wrap; gap: 0.45rem; align-items: baseline; }
.attn-tok {
  font-size: 1.05rem;
  line-height: 1;
  padding: 0.5rem 0.7rem;
  border-radius: 8px;
  border: 1px solid var(--line);
  cursor: pointer;
  user-select: none;
  transition: background 0.25s;
}
.attn-tok.attn-dim {
  color: #b7b1a3;
  cursor: default;
  border-style: dashed;
}
.attn-note {
  margin-top: 0.9rem;
  font-size: 0.88rem;
  color: var(--accent-deep);
  min-height: 1.4rem;
  font-weight: 600;
}

/* ---------- 实验卡公共质感(sound-lab / fourier / mel / matrix / wave-points / embed / feature-journey / bpe / cos / pe-slider) ---------- */

.sound-lab, .fourier-synth, .fourier-probe, .mel-lab, .matrix-lab,
.wave-points, .embed-pipe, .feature-journey, .bpe-lab, .cos-lab, .pe-slider {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--card);
  box-shadow: var(--shadow-card);
}

.sound-lab { font-family: var(--sans); padding: 1.2rem 1.4rem; margin: 2rem 0; }
.sl-controls { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 0.8rem; }
.sl-btn {
  font-family: var(--sans);
  font-size: 0.85rem;
  padding: 0.45rem 0.9rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--paper);
  cursor: pointer;
  transition: all 0.15s;
}
.sl-btn:hover { border-color: var(--accent); }
.sl-btn.active { background: var(--accent); border-color: var(--accent); color: #fff; }
.sl-play {
  font-family: var(--sans);
  font-size: 0.88rem;
  font-weight: 600;
  padding: 0.5rem 1.2rem;
  margin-bottom: 0.9rem;
  border: none;
  border-radius: 8px;
  background: var(--green-wash);
  color: var(--green);
  cursor: pointer;
}
.sl-play:hover { background: #ddf3e3; }
.sl-canvas {
  display: block;
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 6px;
  margin-bottom: 1rem;
}
.sl-cap { font-size: 0.82rem; color: var(--ink-soft); margin: 0.3rem 0 0.4rem; }

.fourier-synth, .fourier-probe { font-family: var(--sans); padding: 1.2rem 1.4rem; margin: 2rem 0; }
.fl-canvas { display: block; width: 100%; border: 1px solid var(--line); border-radius: 6px; margin-bottom: 1rem; }
.fl-controls { display: flex; flex-wrap: wrap; gap: 0.6rem; align-items: center; margin-bottom: 0.8rem; }
.fl-row { display: flex; flex-wrap: wrap; gap: 0.6rem; align-items: center; width: 100%; }
.fl-lab { font-size: 0.86rem; color: var(--ink); white-space: nowrap; }
.fl-val { font-size: 0.86rem; color: var(--accent-deep); font-weight: 600; min-width: 3.4em; text-align: right; }
.fl-readout {
  font-size: 1.05rem; font-weight: 700; color: var(--green);
  background: var(--green-wash); border-radius: 6px; padding: 0.1rem 0.5rem;
  font-variant-numeric: tabular-nums;
}
input[type="range"] { accent-color: var(--accent); }
.fl-hit { font-size: 0.88rem; margin: 0.2rem 0 1rem; padding: 0.5rem 0.9rem; border-radius: 8px; }
.fl-hit.yes { background: var(--green-wash); color: var(--green); font-weight: 600; }
.fl-hit.no { background: var(--paper); color: var(--ink-soft); }

.wave-points { font-family: var(--sans); padding: 1rem 1.2rem; margin: 1.6rem 0; }
.wp-svg { width: 100%; height: auto; display: block; }

.mel-lab { font-family: var(--sans); padding: 1.2rem 1.4rem; margin: 2rem 0; }
.mel-lab canvas { display: block; width: 100%; border: 1px solid var(--line); border-radius: 6px; margin-bottom: 1rem; }

.matrix-lab { font-family: var(--sans); padding: 1.2rem 1.4rem; margin: 2rem 0; }
.ml-title { font-weight: 700; color: var(--accent-deep); font-size: 0.95rem; margin-bottom: 1rem; }
.ml-body { min-height: 8.5rem; display: flex; flex-wrap: wrap; gap: 0.8rem; align-items: center; }
.ml-note { width: 100%; font-size: 0.86rem; color: var(--ink-soft); line-height: 1.7; }
.mtx { border-collapse: collapse; display: inline-table; vertical-align: middle; }
.mtx td {
  border: none;
  padding: 0.18rem 0.55rem;
  text-align: right;
  font-family: var(--mono);
  font-size: 0.86rem;
  min-width: 2.2em;
}
.mtx { border-left: 2px solid var(--ink); border-right: 2px solid var(--ink); border-radius: 0; }
.mtx tr.hl td { background: var(--amber-wash); font-weight: 700; }
.mtx.wmt td { background: var(--accent-wash); }
.mtx-wrap { display: inline-flex; align-items: center; gap: 0.45rem; }
.mtx-name { font-family: var(--mono); font-size: 0.82rem; color: var(--ink-soft); text-align: right; line-height: 1.4; }
.mtx-name small { color: #8a8578; font-size: 0.72rem; }

table.mt { border: none; }
table.mt td, table.mt th { border: none; padding: 0.15rem 0.5rem; font-family: var(--mono); font-size: 0.85rem; text-align: center; }
table.mt { border-left: 2px solid var(--ink); border-right: 2px solid var(--ink); }

.embed-pipe { font-family: var(--sans); padding: 1.2rem 1.4rem; margin: 2rem 0; }
.ep-canvas { display: block; width: 100%; border: 1px solid var(--line); border-radius: 6px; margin-bottom: 0.9rem; }
.ep-caption { font-size: 0.9rem; color: var(--ink); line-height: 1.7; min-height: 3rem; margin-bottom: 0.6rem; }
.ep-summary {
  font-size: 0.88rem; color: var(--ink-soft); background: var(--accent-wash);
  border-radius: 8px; padding: 0.5rem 0.9rem; margin: 0.6rem 0 0.8rem; line-height: 1.7;
}
.ep-summary b { color: var(--accent-deep); }

.feature-journey { font-family: var(--sans); padding: 1.2rem 1.4rem; margin: 2rem 0; }
.fj-canvas { display: block; width: 100%; border: 1px solid var(--line); border-radius: 6px; margin-bottom: 0.9rem; }
.feature-journey .ep-caption { min-height: 3.2rem; }

.bpe-lab { font-family: var(--sans); padding: 1.2rem 1.4rem; margin: 2rem 0; }
.bpe-step { font-size: 0.85rem; color: var(--ink-soft); margin-bottom: 0.8rem; }
.bpe-panel-title { font-size: 0.8rem; font-weight: 700; color: var(--ink-soft); letter-spacing: 0.04em; margin-bottom: 0.55rem; }
.bpe-cols { display: flex; flex-wrap: wrap; gap: 1.4rem; }
.bpe-words { flex: 1.25; min-width: 300px; display: flex; flex-direction: column; gap: 0.55rem; }
.bpe-word { display: flex; align-items: center; flex-wrap: wrap; gap: 0.3rem; }
.bpe-freq {
  font-size: 0.72rem; color: var(--ink-soft);
  background: var(--paper); border: 1px solid var(--line); border-radius: 999px;
  padding: 0.1rem 0.5rem; margin-right: 0.35rem; font-variant-numeric: tabular-nums;
}
.bpe-tok {
  font-family: var(--mono); font-size: 0.85rem;
  background: var(--paper); border: 1px solid var(--line); border-radius: 6px;
  padding: 0.18rem 0.5rem; transition: background 0.2s, border-color 0.2s;
}
.bpe-tok.big { background: var(--accent-wash); border-color: #b9b9ec; color: var(--accent-deep); }
.bpe-tok.hit { background: var(--amber-wash); border-color: var(--amber); color: var(--amber); font-weight: 700; }
.bpe-pairs { flex: 1; min-width: 240px; }
.bpe-pairrow {
  display: grid; grid-template-columns: 6.2rem 1fr 2.4rem;
  align-items: center; gap: 0.5rem; margin: 0.32rem 0;
}
.bpe-pair { font-family: var(--mono); font-size: 0.82rem; color: var(--ink); text-align: right; }
.bpe-pair.win { color: var(--amber); font-weight: 700; }
.bpe-bar { display: block; height: 0.55rem; background: var(--paper); border-radius: 999px; overflow: hidden; }
.bpe-fill { display: block; height: 100%; background: var(--accent); border-radius: 999px; opacity: 0.75; }
.bpe-n { font-size: 0.8rem; color: var(--ink-soft); text-align: right; font-variant-numeric: tabular-nums; }
.bpe-controls { display: flex; gap: 0.6rem; margin-top: 1.1rem; flex-wrap: wrap; }
.bpe-btn {
  font-family: var(--sans); font-size: 0.88rem; font-weight: 600;
  padding: 0.5rem 1.1rem; border: none; border-radius: 8px;
  background: var(--accent); color: #fff; cursor: pointer; transition: opacity 0.15s;
}
.bpe-btn:hover:not(:disabled) { opacity: 0.88; }
.bpe-btn:disabled { background: var(--line); color: var(--ink-soft); cursor: default; }
.bpe-btn.ghost { background: var(--paper); color: var(--ink-soft); border: 1px solid var(--line); font-weight: 400; }
.bpe-hist { margin-top: 1rem; display: flex; flex-wrap: wrap; gap: 0.4rem; align-items: baseline; }
.bpe-hist-chip {
  font-family: var(--mono); font-size: 0.78rem;
  background: var(--green-wash); color: var(--green); border-radius: 999px;
  padding: 0.12rem 0.6rem;
}
.bpe-vocab { margin-top: 1rem; display: flex; flex-wrap: wrap; gap: 0.3rem; align-items: baseline; }
.bpe-vocab .bpe-panel-title { margin-right: 0.4rem; }

.cos-lab { font-family: var(--sans); padding: 1.2rem 1.4rem; margin: 2rem 0; }
.coslab-canvas { display: block; width: 100%; height: auto; border: 1px solid var(--line); border-radius: 6px; touch-action: none; }
.coslab-readout { display: flex; flex-wrap: wrap; gap: 0 1.6rem; margin: 0.8rem 0 0.4rem; }
.coslab-row { display: flex; justify-content: space-between; gap: 0.8rem; min-width: 9.5em; font-size: 0.86rem; padding: 0.14rem 0; }
.coslab-row span { color: var(--ink-soft); }
.coslab-row b { font-variant-numeric: tabular-nums; color: var(--accent-deep); }
.coslab-verdict {
  width: 100%; margin-top: 0.4rem; font-size: 0.9rem; font-weight: 700;
  color: var(--green); background: var(--green-wash); border-radius: 6px; padding: 0.25rem 0.7rem;
}
.coslab-controls { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 0.5rem 0 0.7rem; }
.coslab-btn {
  font-family: var(--sans); font-size: 0.82rem; padding: 0.35rem 0.85rem;
  border: 1px solid var(--line); border-radius: 999px; background: var(--paper);
  cursor: pointer; transition: border-color 0.15s;
}
.coslab-btn:hover { border-color: var(--accent); }
.coslab-note { font-size: 0.84rem; color: var(--ink-soft); }

.pe-slider { font-family: var(--sans); padding: 1.2rem 1.4rem; margin: 2rem 0; }
.peslider-canvas { display: block; width: 100%; height: auto; border: 1px solid var(--line); border-radius: 6px; }
.peslider-controls { display: flex; align-items: center; gap: 0.7rem; margin: 0.7rem 0 0.4rem; }
.peslider-cap { font-size: 0.86rem; color: var(--ink-soft); white-space: nowrap; }
.peslider-range { flex: 1; }
.peslider-pos { font-size: 0.9rem; font-weight: 700; color: var(--accent-deep); font-variant-numeric: tabular-nums; }
.peslider-note { font-size: 0.84rem; color: var(--ink-soft); line-height: 1.7; }

/* ---------- 过程动画(gen-loop.js / rnn-wash.js / align-live.js 等渲染) ---------- */

.anim-card {
  font-family: var(--sans);
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--card);
  padding: 1.2rem 1.4rem;
  margin: 2rem 0;
  box-shadow: var(--shadow-card);
}
.anim-title { font-size: 0.95rem; font-weight: 700; color: var(--accent-deep); margin: 0 0 0.6rem; }
.anim-canvas { display: block; width: 100%; height: auto; border: 1px solid var(--line); border-radius: 6px; }
.anim-controls { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 0.7rem 0 0.5rem; }
.anim-btn {
  font-family: var(--sans); font-size: 0.82rem; padding: 0.35rem 0.95rem;
  border: 1px solid var(--line); border-radius: 999px; background: var(--paper);
  cursor: pointer; transition: border-color 0.15s;
}
.anim-btn:hover { border-color: var(--accent); }
.anim-btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.anim-note { font-size: 0.84rem; color: var(--ink-soft); line-height: 1.7; }
.anim-note b { color: var(--accent-deep); }

/* ---------- 课尾导航(course-chrome.js 升级为卡片;无 JS 时保底旧样式) ---------- */

.lesson-footer {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  font-family: var(--sans);
  font-size: 0.88rem;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
}
.lesson-footer a { text-decoration: none; }
.lesson-footer .next { color: var(--accent-deep); font-weight: 600; }

.lf-home {
  font-family: var(--sans);
  text-align: center;
  margin-top: 3.2rem;
  font-size: 0.84rem;
}
.lf-home a {
  color: var(--ink-soft);
  text-decoration: none;
  padding: 0.35rem 1rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--card);
  transition: border-color 0.15s, color 0.15s;
}
.lf-home a:hover { border-color: var(--accent); color: var(--accent-deep); }

.lf-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
  margin-top: 3.4rem;
}
.lf-card {
  display: block;
  font-family: var(--sans);
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--card);
  padding: 0.85rem 1.15rem;
  transition: border-color 0.15s, transform 0.15s, box-shadow 0.15s;
}
.lf-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}
.lf-card .lf-dir {
  display: block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--ink-faint);
  margin-bottom: 0.25rem;
}
.lf-card .lf-title {
  display: block;
  font-size: 0.92rem;
  font-weight: 600;
  line-height: 1.55;
  color: var(--accent-deep);
}
.lf-card.lf-next { text-align: right; }
@media (max-width: 640px) {
  .lf-grid { grid-template-columns: 1fr; }
  .lf-card.lf-next { text-align: left; }
}

/* ---------- panorama.js — Transformer 全景图(附录) ---------- */

.pn-map svg { display: block; width: 100%; height: auto; }
.pn-st { cursor: pointer; }
.pn-st rect.box { fill: #f6f4ee; stroke: #d5d0c4; stroke-width: 1.2; transition: all .18s; }
.pn-st:hover rect.box { stroke: #b45309; }
.pn-st.cur rect.box { fill: #fef6e7; stroke: #b45309; stroke-width: 2.6; }
.pn-detail {
  border: 1px solid var(--line); border-radius: 10px; padding: .8rem 1rem;
  margin-top: .8rem; background: #faf9f5; min-height: 5.4rem;
}
.pn-detail h4 { margin: .1rem 0 .45rem; font-size: .95rem; color: var(--accent-deep); }
.pn-detail p { margin: .28rem 0; font-size: .88rem; line-height: 1.68; }
.pn-detail .pn-lesson { font-size: .8rem; }
.pn-detail .pn-lesson a { color: var(--accent-deep); }

/* ---------- 宽度对齐:全部组件与正文同一条左右边线(2026-10-02 用户反馈"卡片要和文字对齐") ---------- */
/* 唯一例外:py-runner 单步调试模式自带整块加宽(功能需要),退出调试即回落 */

/* ---------- py-runner 覆盖(其样式由 shared/py-runner.js 运行时注入,同名规则后者胜出,故一律加高特异性) ---------- */

.py-runner {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--card);
  box-shadow: var(--shadow-card);
  margin: 2rem 0;
  overflow: hidden;
}
.py-runner .py-runner-bar {
  background: linear-gradient(0deg, var(--code-bg) 0%, var(--card) 100%);
  border-bottom: 1px solid var(--line);
  padding: 0.5em 0.9em;
}
.py-runner .py-runner-status { font-family: var(--sans); color: var(--ink-faint); }
.py-runner .py-runner-deps {
  font-family: var(--mono);
  color: var(--accent-deep);
  background: var(--accent-wash);
  border: 1px solid #dcdcf5;
}
.py-runner .py-runner-btn {
  font-family: var(--sans);
  font-weight: 600;
  background: var(--green);
  border-color: var(--green);
  border-radius: 7px;
}
.py-runner .py-runner-btn.py-runner-stepbtn { background: var(--accent); border-color: var(--accent); }
.py-runner .py-runner-btn.is-error { background: var(--red); border-color: var(--red); }
.py-runner .py-runner-code {
  font-family: var(--mono);
  background: #fdfcf9;
  padding: 0.9em 1em;
}
.py-runner .py-runner-code .py-codeline::before { color: #cdc9bd; font-family: var(--mono); }
.py-runner .py-runner-code .py-k { color: #b02a37; }
.py-runner .py-runner-code .py-n { color: #0550ae; }
.py-runner .py-runner-code.py-noedit { background: #fdfcf9; }
.py-runner .py-runner-out {
  font-family: var(--mono);
  background: #f7f6f1;
  border-top: 1px solid var(--line);
}
.py-runner .py-runner-out img { border-color: var(--line); }
.py-runner .py-step-btn { font-family: var(--sans); border-radius: 6px; }
.py-runner .py-step-btn:hover:not(:disabled) { border-color: var(--accent); }
.py-runner .py-runner-stepbar { background: var(--amber-wash); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.py-runner .py-step-label { font-family: var(--mono); }
.py-runner .py-vartable { font-family: var(--mono); }
.py-runner .py-vartable th { background: var(--code-bg); font-family: var(--sans); }

/* ---------- 课程目录页 ---------- */

.tx-home main { max-width: 60rem; padding-top: 3.5rem; }

.home-hero { padding: 1rem 0 2.6rem; }
.home-hero .kicker { margin-bottom: 1.1rem; }
.home-hero h1 {
  font-size: clamp(1.9rem, 1.4rem + 2vw, 2.7rem);
  line-height: 1.28;
  margin: 0 0 1rem;
}
.home-lede {
  font-size: 1.02rem;
  color: var(--ink-soft);
  max-width: 42rem;
  margin: 0 0 1.4rem;
}
.home-lede strong { color: var(--ink); }

.home-facts { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 2.2rem; }
.home-facts span {
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--ink-soft);
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 999px;
  padding: 0.28rem 0.85rem;
}
.home-facts span b { color: var(--accent-deep); font-weight: 600; }

.home-strip { display: flex; flex-wrap: wrap; gap: 6px; margin: 0 0 0.7rem; }
.home-strip a, .home-strip i {
  position: relative;
  width: 34px;
  height: 34px;
  border-radius: 7px;
  background: var(--accent);
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 600;
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  transition: transform 0.15s, box-shadow 0.15s;
}
.home-strip a:hover { transform: translateY(-2px); box-shadow: var(--shadow-card); }
.home-strip .todo {
  background: none;
  border: 1px solid var(--ink-faint);
  background-image: var(--mask-hatch);
  color: var(--ink-faint);
}
.home-strip .cur {
  box-shadow: 0 0 0 2px var(--paper), 0 0 0 4px var(--accent);
}
.home-strip .appx { background: var(--amber); }
.home-legend {
  font-family: var(--sans);
  font-size: 0.78rem;
  color: var(--ink-soft);
  display: flex;
  flex-wrap: wrap;
  gap: 1.4em;
  margin-bottom: 0.4rem;
}
.home-legend i {
  display: inline-block;
  width: 11px;
  height: 11px;
  border-radius: 3px;
  vertical-align: -1px;
  margin-right: 0.45em;
  background: var(--accent);
}
.home-legend i.l-todo { background: none; border: 1px solid var(--ink-faint); background-image: var(--mask-hatch); }
.home-legend i.l-cur { box-shadow: 0 0 0 1.5px var(--paper), 0 0 0 3px var(--accent); }

.home-phase { margin: 2.6rem 0 0; }
.home-phase > header {
  display: flex;
  align-items: baseline;
  gap: 0.9rem;
  border-bottom: 2px solid var(--ink);
  padding-bottom: 0.55rem;
  margin-bottom: 0.4rem;
}
.home-phase .ph-no {
  font-family: var(--mono);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent-deep);
  flex: none;
}
.home-phase h2 {
  all: unset;
  font-family: var(--sans);
  font-size: 1.22rem;
  font-weight: 700;
  flex: none;
}
.home-phase > header p {
  margin: 0;
  font-family: var(--sans);
  font-size: 0.84rem;
  color: var(--ink-soft);
}

.home-list { list-style: none; margin: 0; padding: 0; }
.home-list li { margin: 0; border-bottom: 1px solid var(--line-soft); }
.home-list a,
.home-list li.todo {
  display: grid;
  grid-template-columns: 3.4rem 1fr auto;
  align-items: center;
  gap: 1rem;
  padding: 0.85rem 0.4rem;
  text-decoration: none;
}
.home-list a {
  transition: background 0.15s, padding-left 0.15s;
}
.home-list a:hover { background: var(--card); padding-left: 0.75rem; }
.home-list .no {
  font-family: var(--mono);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--accent-deep);
  font-variant-numeric: tabular-nums;
}
.home-list .t {
  display: block;
  font-family: var(--sans);
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.5;
}
.home-list .t em {
  font-style: normal;
  font-size: 0.7em;
  font-weight: 600;
  color: var(--amber);
  border: 1px solid currentColor;
  border-radius: 4px;
  padding: 0.05em 0.4em;
  margin-left: 0.5em;
  vertical-align: 2px;
  white-space: nowrap;
}
.home-list a:hover .t { color: var(--accent-deep); }
.home-list .q {
  display: block;
  font-family: var(--sans);
  font-size: 0.83rem;
  color: var(--ink-soft);
  margin-top: 0.15rem;
}
.home-list .st {
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--green);
  white-space: nowrap;
}
.home-list li.todo { cursor: default; }
.home-list li.todo .no {
  color: var(--ink-faint);
  border: 1px solid var(--line);
  background-image: var(--mask-hatch);
  border-radius: 6px;
  text-align: center;
  font-size: 0.9rem;
}
.home-list li.todo .t { color: var(--ink-soft); font-weight: 500; }
.home-list li.todo .st {
  color: var(--ink-faint);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.1rem 0.6rem;
  letter-spacing: 0.06em;
}
@media (max-width: 640px) {
  .home-list a { grid-template-columns: 2.6rem 1fr; }
  .home-list .st { display: none; }
}

.home-extra { margin-top: 2.8rem; font-family: var(--sans); font-size: 0.9rem; }
.home-extra h2 {
  display: flex;
  align-items: baseline;
  gap: 0.55em;
  font-size: 1.1rem;
  margin: 0 0 0.8rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--line);
}
.home-extra h2::before {
  content: "";
  width: 9px;
  height: 9px;
  align-self: center;
  border: 2.5px solid var(--accent);
  border-radius: 2px;
}
.extra-links { display: flex; gap: 0.6rem; flex-wrap: wrap; }
.extra-links > * {
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 8px;
  padding: 0.4rem 0.9rem;
  color: var(--ink-soft);
}

.home-foot {
  margin-top: 3.5rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line);
  font-family: var(--sans);
  font-size: 0.84rem;
  color: var(--ink-faint);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.6rem;
}
.home-foot a { color: var(--ink-soft); }

/* ---------- 打印 ---------- */

@media print {
  html { font-size: 11pt; }
  body { background: #fff; }
  main { max-width: none; padding: 0; }
  .topbar, .lf-grid, .lf-home, .home-strip, .home-legend, .sidenav, .tocside { display: none; }
  .quiz, .callout { break-inside: avoid; box-shadow: none; }
  a { color: var(--ink); text-decoration: none; }
}

/* ---------- 动效减免 ---------- */

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