/* ============================================================
   ML/AI 课程 — 设计系统「Latent Space Lab · 潜空间实验室」
   概念：arXiv 论文衬线排版 × 终端磷光 × CV 标注框 × 训练日志
   字体：Instrument Serif（展示）+ IBM Plex Mono（技术声音）
        + PingFang SC（中文正文）
   ============================================================ */

:root {
  /* —— 油墨与磷光 —— */
  --ink: #0a0b09;            /* 近黑，微暖 */
  --ink-2: #10120e;          /* 卡片底 */
  --ink-3: #161812;          /* 内嵌底 */
  --paper: #e9ebdf;          /* 暖纸白文字 */
  --paper-dim: #8d9183;      /* 次级文字 */
  --line: #272a20;           /* 分隔线 */
  --line-bright: #3a3e30;
  --signal: #b8f04d;         /* 磷光绿：主信号色 */
  --signal-dim: rgba(184, 240, 77, 0.13);
  --amber: #f0b94d;          /* 琥珀：时间戳/警示 */
  --cyan: #6fd7c8;           /* 残差青：链接/次级强调 */
  --red: #ef7b6d;
  --radius: 4px;             /* 锐利小圆角——实验室器械感 */
  --font-display: "Instrument Serif", "Songti SC", serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "IBM Plex Mono", "SF Mono", Menlo, monospace;
}

* { box-sizing: border-box; }
::selection { background: var(--signal); color: var(--ink); }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 16.5px;
  line-height: 1.95;
  -webkit-font-smoothing: antialiased;
  position: relative;
}

/* —— 坐标纸网格底纹 + 顶部磷光晕 —— */
body::before {
  content: "";
  position: fixed; inset: 0; pointer-events: none; z-index: 0;
  background:
    radial-gradient(ellipse 70% 40% at 50% -5%, rgba(184,240,77,0.07), transparent 60%),
    linear-gradient(to right, rgba(233,235,223,0.025) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(233,235,223,0.025) 1px, transparent 1px);
  background-size: 100% 100%, 48px 48px, 48px 48px;
}
/* —— 胶片颗粒 —— */
body::after {
  content: "";
  position: fixed; inset: 0; pointer-events: none; z-index: 1;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)' opacity='1'/%3E%3C/svg%3E");
}

.container { max-width: 860px; margin: 0 auto; padding: 0 28px 120px; position: relative; z-index: 2; }

/* ============ 顶部：终端状态栏 ============ */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: rgba(10, 11, 9, 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}
.topbar-inner {
  max-width: 860px; margin: 0 auto; padding: 11px 28px;
  display: flex; align-items: center; gap: 18px;
  font-family: var(--font-mono); font-size: 12.5px;
}
.topbar a { color: var(--paper-dim); text-decoration: none; letter-spacing: 0.02em; }
.topbar a:hover { color: var(--signal); }
.topbar a.lang-switch {
  border: 1px solid var(--line); border-radius: 5px; padding: 1px 8px;
  color: var(--paper); letter-spacing: 0.06em;
}
.topbar a.lang-switch:hover { border-color: var(--signal); color: var(--signal); }
.topbar .brand { color: var(--signal); font-weight: 500; }
.topbar .brand::before { content: "❯ "; color: var(--paper-dim); }
.topbar .brand::after {
  content: "▊"; margin-left: 2px; color: var(--signal);
  animation: blink 1.1s steps(1) infinite;
}
.topbar .spacer { flex: 1; }
@keyframes blink { 50% { opacity: 0; } }

#read-progress {
  position: fixed; top: 0; left: 0; height: 2px; width: 0;
  background: var(--signal);
  box-shadow: 0 0 12px rgba(184,240,77,0.7);
  z-index: 100; transition: width 0.1s linear;
}

/* ============ 排版 ============ */
h1 {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 6vw, 3.4rem);
  font-weight: 400; line-height: 1.18;
  margin: 56px 0 12px; letter-spacing: 0.01em;
}
h1 em { font-style: italic; color: var(--signal); }
h2 {
  font-family: var(--font-display);
  font-size: 1.7rem; font-weight: 400;
  margin: 80px 0 18px; padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  display: flex; align-items: baseline; gap: 14px;
}
h2::before {
  content: "§" counter(section);
  counter-increment: section;
  font-family: var(--font-mono); font-size: 0.85rem;
  color: var(--signal); letter-spacing: 0.05em;
}
body { counter-reset: section; }
h3 { font-size: 1.12rem; margin: 44px 0 12px; color: var(--cyan); font-weight: 600; }
h3::before { content: "· "; color: var(--signal); }
p { margin: 15px 0; }
a { color: var(--cyan); text-underline-offset: 3px; text-decoration-color: rgba(111,215,200,0.4); }
a:hover { text-decoration-color: var(--cyan); }
strong { color: #fff; font-weight: 600; }
.subtitle {
  font-family: var(--font-mono); color: var(--paper-dim);
  font-size: 13.5px; margin-bottom: 40px; letter-spacing: 0.03em;
}
.subtitle::before { content: "// "; color: var(--signal); }

.lead {
  font-size: 1.08rem; color: #cfd2c4;
  border-left: 2px solid var(--signal); padding-left: 20px; margin: 28px 0;
}

ul, ol { padding-left: 26px; }
li { margin: 9px 0; }
li::marker { color: var(--signal); font-family: var(--font-mono); }

table { border-collapse: collapse; width: 100%; margin: 22px 0; font-size: 14.5px; }
th, td { border: 1px solid var(--line); padding: 10px 14px; text-align: left; }
th { background: var(--ink-2); font-family: var(--font-mono); font-size: 12.5px; letter-spacing: 0.05em; color: var(--paper-dim); }
tr:nth-child(even) td { background: rgba(233,235,223,0.015); }

/* ============ 代码 ============ */
code {
  font-family: var(--font-mono); font-size: 0.84em;
  background: var(--ink-3); border: 1px solid var(--line);
  padding: 2px 6px; border-radius: var(--radius); color: var(--signal);
}
pre {
  background: var(--ink-3); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 20px 22px; overflow-x: auto;
  line-height: 1.65; margin: 22px 0; position: relative;
}
pre::before {
  content: "● ● ●"; position: absolute; top: 10px; right: 14px;
  font-size: 8px; letter-spacing: 3px; color: var(--line-bright);
}
pre code { background: none; border: none; padding: 0; color: #d6d9c8; font-size: 13.5px; }
.code-label {
  display: inline-block; font-family: var(--font-mono); font-size: 11.5px;
  color: var(--amber); background: var(--ink-3);
  border: 1px solid var(--line); border-bottom: none;
  padding: 4px 14px; border-radius: var(--radius) var(--radius) 0 0;
  margin-bottom: -23px; margin-left: 10px; position: relative; z-index: 1;
  letter-spacing: 0.05em;
}
.code-label::before { content: "$ "; color: var(--signal); }

/* ============ 信息框：训练日志风格 ============ */
.note, .warn, .insight {
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 16px 20px; margin: 26px 0; font-size: 15px;
  background: var(--ink-2); position: relative;
}
.note::before, .warn::before, .insight::before {
  font-family: var(--font-mono); font-size: 11.5px; font-weight: 600;
  letter-spacing: 0.08em; display: block; margin-bottom: 6px;
}
.note { border-left: 2px solid var(--signal); }
.note::before { content: "[INFO] 要点"; color: var(--signal); }
.warn { border-left: 2px solid var(--amber); }
.warn::before { content: "[WARN] 常见误区"; color: var(--amber); }
.insight { border-left: 2px solid var(--cyan); }
.insight::before { content: "[DEEP] 深入理解"; color: var(--cyan); }

/* ============ 边界框角标（CV 标注美学，核心装饰语言） ============ */
.bbox { position: relative; }
.bbox::before, .bbox::after {
  content: ""; position: absolute; width: 14px; height: 14px;
  border-color: var(--signal); border-style: solid; opacity: 0.85;
  transition: width 0.2s, height 0.2s;
}
.bbox::before { top: -1px; left: -1px; border-width: 1.5px 0 0 1.5px; }
.bbox::after { bottom: -1px; right: -1px; border-width: 0 1.5px 1.5px 0; }
.bbox:hover::before, .bbox:hover::after { width: 22px; height: 22px; }

/* ============ 视频卡片 ============ */
.video-card {
  background: var(--ink-2); border: 1px solid var(--line);
  border-radius: var(--radius); margin: 36px 0;
}
.video-card .v-tag {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.1em;
  color: var(--amber); padding: 10px 18px 0; display: block;
}
.video-card .v-tag::before { content: "▸ REC "; color: var(--red); animation: blink 2s steps(1) infinite; }
.video-frame { position: relative; aspect-ratio: 16/9; background: #000; cursor: pointer; margin: 10px 14px 0; overflow: hidden; }
.video-frame img {
  width: 100%; height: 100%; object-fit: cover; display: block;
  filter: saturate(0.85) contrast(1.05);
  transition: opacity 0.2s, transform 0.5s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.video-frame:hover img { opacity: 0.7; transform: scale(1.025); }
.video-frame .play-btn {
  position: absolute; inset: 0; margin: auto; width: 64px; height: 64px;
  background: var(--ink); border: 1.5px solid var(--signal);
  display: flex; align-items: center; justify-content: center;
  transition: transform 0.2s, box-shadow 0.2s; pointer-events: none;
}
.video-frame:hover .play-btn {
  transform: scale(1.1);
  box-shadow: 0 0 28px rgba(184,240,77,0.45);
}
.play-btn::after {
  content: ""; border-style: solid; border-width: 11px 0 11px 18px;
  border-color: transparent transparent transparent var(--signal); margin-left: 4px;
}
.video-frame iframe { width: 100%; height: 100%; border: 0; display: block; }
.video-meta { padding: 14px 18px 4px; }
.video-meta .v-title { font-weight: 600; font-size: 1.02rem; color: #fff; }
.video-meta .v-author {
  font-family: var(--font-mono); color: var(--paper-dim); font-size: 12px; margin-top: 4px;
}
.video-meta .v-author .v-duration {
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1px 8px; margin-left: 10px; color: var(--amber); font-size: 11px;
}
.video-guide { padding: 2px 18px 16px; }
.video-guide summary {
  cursor: pointer; color: var(--cyan); font-size: 13.5px; font-weight: 600;
  user-select: none; padding: 6px 0; font-family: var(--font-mono); letter-spacing: 0.02em;
}
.video-guide summary::marker { color: var(--signal); }
.video-guide ul { margin: 8px 0 4px; font-size: 14px; color: #c4c7b8; }
.video-guide .ts {
  font-family: var(--font-mono); font-size: 11.5px; color: var(--amber);
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 0 7px; margin-right: 9px;
}

/* ============ Playground ============ */
.playground {
  background: var(--ink-2); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 24px; margin: 36px 0;
}
.playground h4 {
  margin: 0 0 4px; font-size: 1.05rem; color: #fff;
  font-family: var(--font-mono); letter-spacing: 0.02em;
}
.playground h4::before { content: "experiment://"; color: var(--signal); font-size: 0.8em; margin-right: 8px; }
.playground .pg-hint { color: var(--paper-dim); font-size: 13.5px; margin: 2px 0 16px; }
.playground canvas {
  width: 100%; border-radius: var(--radius); background: var(--ink);
  border: 1px solid var(--line); display: block; cursor: crosshair;
}
.pg-controls { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-top: 16px; }
.pg-controls button {
  background: var(--signal); color: var(--ink); border: 1px solid var(--signal);
  border-radius: var(--radius); padding: 8px 18px;
  font-family: var(--font-mono); font-size: 13px; font-weight: 600;
  cursor: pointer; letter-spacing: 0.02em;
  transition: box-shadow 0.15s, transform 0.1s;
}
.pg-controls button:hover { box-shadow: 0 0 18px rgba(184,240,77,0.4); }
.pg-controls button:active { transform: scale(0.96); }
.pg-controls button.secondary {
  background: transparent; border-color: var(--line-bright); color: var(--paper);
}
.pg-controls button.secondary:hover { border-color: var(--signal); color: var(--signal); box-shadow: none; }
.pg-controls label {
  font-family: var(--font-mono); font-size: 12px; color: var(--paper-dim);
  display: flex; align-items: center; gap: 8px;
}
.pg-controls input[type="range"] { accent-color: var(--signal); width: 130px; }
.pg-controls select {
  background: var(--ink-3); color: var(--paper); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 7px 10px;
  font-family: var(--font-mono); font-size: 12.5px;
}
.pg-readout {
  margin-top: 14px; font-family: var(--font-mono); font-size: 12.5px;
  background: var(--ink); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 12px 16px; color: var(--paper-dim);
  display: flex; gap: 26px; flex-wrap: wrap;
}
.pg-readout b { color: var(--signal); font-weight: 500; }

/* ============ Quiz ============ */
.quiz {
  background: var(--ink-2); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px; margin: 36px 0;
}
.quiz > h4 {
  margin: 0 0 6px; font-size: 1.05rem; font-family: var(--font-mono); color: #fff;
}
.quiz > h4::before { content: "eval://"; color: var(--signal); font-size: 0.8em; margin-right: 8px; }
.quiz .quiz-progress { font-family: var(--font-mono); font-size: 12px; color: var(--paper-dim); margin-bottom: 18px; }
.quiz-q { border-top: 1px dashed var(--line); padding: 20px 0 8px; }
.quiz-q .q-text { font-weight: 600; margin-bottom: 12px; color: #fff; }
.quiz-q .q-text .q-num {
  font-family: var(--font-mono); color: var(--signal); margin-right: 10px; font-weight: 500;
}
.quiz-opt {
  display: block; width: 100%; text-align: left; margin: 8px 0;
  background: var(--ink-3); color: var(--paper);
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 11px 16px; font-size: 14.5px; cursor: pointer;
  font-family: var(--font-body); line-height: 1.65;
  transition: border-color 0.15s, background 0.15s, transform 0.1s;
}
.quiz-opt:hover:not(:disabled) { border-color: var(--signal); background: var(--signal-dim); transform: translateX(3px); }
.quiz-opt:disabled { cursor: default; opacity: 0.7; }
.quiz-opt.correct { border-color: var(--signal); background: var(--signal-dim); opacity: 1; color: #eaffd0; }
.quiz-opt.wrong { border-color: var(--red); background: rgba(239,123,109,0.08); }
.quiz-explain {
  display: none; margin: 10px 0 14px; padding: 13px 16px;
  background: var(--ink); border-left: 2px solid var(--cyan);
  border-radius: 0 var(--radius) var(--radius) 0; font-size: 14px; color: #c4c7b8;
}
.quiz-explain.show { display: block; animation: fadeIn 0.3s; }
.quiz-score {
  margin-top: 20px; padding: 14px 18px; border-radius: var(--radius);
  background: var(--signal-dim); border: 1px solid rgba(184,240,77,0.35);
  font-family: var(--font-mono); font-size: 14px; display: none;
}
.quiz-score.show { display: block; }
.quiz-reset { margin-top: 12px; }

/* ============ 思考题 ============ */
details.think {
  background: var(--ink-2); border: 1px dashed var(--line-bright);
  border-radius: var(--radius); padding: 14px 20px; margin: 22px 0;
}
details.think summary { cursor: pointer; font-weight: 600; color: var(--amber); user-select: none; }
details.think summary::before { content: "?? "; font-family: var(--font-mono); color: var(--signal); }
details.think summary::after { content: " 思考题"; font-size: 0.85em; color: var(--paper-dim); font-weight: 400; }
details.think .answer { margin-top: 12px; padding-top: 12px; border-top: 1px dashed var(--line); font-size: 14.5px; }

/* ============ 首页章节卡片 ============ */
.chapter-grid { display: grid; grid-template-columns: 1fr; gap: 12px; margin: 32px 0; }
.chapter-card {
  display: flex; gap: 20px; align-items: flex-start;
  background: var(--ink-2); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 20px 24px; text-decoration: none;
  color: var(--paper); position: relative;
  transition: border-color 0.2s, background 0.2s;
}
a.chapter-card:hover { border-color: var(--line-bright); background: #14160f; }
a.chapter-card:hover .ch-num { color: var(--signal); text-shadow: 0 0 16px rgba(184,240,77,0.6); }
.chapter-card.locked { opacity: 0.45; }
.chapter-card .ch-num {
  font-family: var(--font-mono); font-size: 1.5rem; font-weight: 300;
  color: var(--paper-dim); min-width: 48px; line-height: 1.4;
  transition: color 0.2s, text-shadow 0.2s;
}
.chapter-card .ch-title { font-weight: 600; font-size: 1.05rem; color: #fff; }
.chapter-card .ch-desc { color: var(--paper-dim); font-size: 13.5px; margin-top: 5px; line-height: 1.7; }
.chapter-card .ch-badge {
  margin-left: auto; flex-shrink: 0;
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.05em;
  padding: 3px 10px; border-radius: var(--radius); border: 1px solid;
}
.ch-badge.ready { color: var(--signal); border-color: rgba(184,240,77,0.4); }
.ch-badge.ready::before { content: "● "; animation: pulse 2s ease-in-out infinite; }
.ch-badge.soon { color: var(--paper-dim); border-color: var(--line); }
.ch-badge.soon::before { content: "○ "; }
.ch-progress {
  font-family: var(--font-mono); font-size: 11px; color: var(--amber);
  margin-top: 7px; letter-spacing: 0.03em;
}
.ch-progress.full { color: var(--signal); }
@keyframes pulse { 50% { opacity: 0.3; } }

/* ============ 章节导航 ============ */
.chapter-nav { display: flex; gap: 12px; margin-top: 72px; }
.chapter-nav a {
  flex: 1; background: var(--ink-2); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 16px 20px; text-decoration: none;
  color: var(--paper); transition: border-color 0.15s;
}
.chapter-nav a:hover { border-color: var(--signal); }
.chapter-nav .nav-label { font-family: var(--font-mono); font-size: 11px; color: var(--paper-dim); letter-spacing: 0.08em; }
.chapter-nav .nav-title { font-weight: 600; margin-top: 5px; font-size: 0.95rem; }
.chapter-nav .next { text-align: right; }

/* ============ 目录 ============ */
.toc {
  background: var(--ink-2); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 20px 26px; margin: 32px 0; font-size: 14.5px;
}
.toc .toc-title {
  font-family: var(--font-mono); font-weight: 500; margin-bottom: 10px;
  color: var(--paper-dim); font-size: 11.5px; letter-spacing: 0.15em;
}
.toc .toc-title::before { content: "▤ "; color: var(--signal); }
.toc ol { margin: 0; padding-left: 22px; }
.toc a { text-decoration: none; color: var(--paper); }
.toc a:hover { color: var(--signal); }

/* ============ 首页 Hero ============ */
.hero { padding-top: 36px; }
.hero .eyebrow {
  font-family: var(--font-mono); font-size: 12px; color: var(--signal);
  letter-spacing: 0.12em; animation: fadeUp 0.6s both;
}
.hero h1 { animation: fadeUp 0.6s 0.1s both; margin-top: 16px; }
.hero .subtitle { animation: fadeUp 0.6s 0.2s both; }
.hero .lead { animation: fadeUp 0.6s 0.3s both; }
.token-stream {
  font-family: var(--font-mono); font-size: 12.5px; color: var(--paper-dim);
  margin-top: 26px; min-height: 22px; animation: fadeUp 0.6s 0.4s both;
}
.token-stream .tok {
  display: inline-block; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 0 7px; margin: 0 3px 6px 0;
  animation: tokIn 0.25s both;
}
.token-stream .tok.hot { color: var(--signal); border-color: rgba(184,240,77,0.5); }
.token-stream .prob { color: var(--line-bright); font-size: 10px; margin-left: 4px; }
@keyframes tokIn { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: none; } }
@keyframes fadeUp { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
@keyframes fadeIn { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: none; } }

/* ============ 语音讲解（音频卡片） ============ */
.audio-card {
  display: flex; align-items: center; gap: 16px;
  background: var(--ink-2); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 14px 18px; margin: 24px 0;
}
.audio-card .a-icon { font-size: 22px; }
.audio-card > div { flex: 1; }
.audio-card .a-label { font-family: var(--font-mono); font-size: 12px; color: var(--amber); letter-spacing: 0.05em; margin-bottom: 6px; }
.audio-card audio { width: 100%; height: 36px; filter: invert(0.9) hue-rotate(180deg); }

/* ============ 全站搜索 ============ */
#search-box { position: relative; margin: 30px 0 6px; }
#search-box input {
  width: 100%; background: var(--ink-2); color: var(--paper);
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 13px 18px; font-family: var(--font-mono); font-size: 14px;
}
#search-box input:focus { outline: none; border-color: var(--signal); box-shadow: 0 0 16px rgba(184,240,77,0.15); }
#search-box input::placeholder { color: var(--paper-dim); }
.search-results {
  display: none; position: absolute; top: calc(100% + 6px); left: 0; right: 0; z-index: 40;
  background: var(--ink-2); border: 1px solid var(--line-bright); border-radius: var(--radius);
  max-height: 380px; overflow-y: auto; box-shadow: 0 16px 48px rgba(0,0,0,0.6);
}
.search-results.show { display: block; }
.sr-item {
  display: flex; justify-content: space-between; gap: 14px; align-items: baseline;
  padding: 11px 16px; text-decoration: none; border-bottom: 1px solid var(--line);
}
.sr-item:hover, .sr-item.active { background: var(--signal-dim); }
.sr-item .sr-title { color: var(--paper); font-size: 14px; }
.sr-item .sr-sub { color: var(--paper-dim); font-family: var(--font-mono); font-size: 11px; flex-shrink: 0; }
.sr-empty { padding: 14px 16px; color: var(--paper-dim); font-size: 13px; }

/* ============ Agent 循环模拟器 ============ */
.ag-card {
  background: var(--ink); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 13px 17px; margin: 9px 0;
  font-size: 14.5px; animation: fadeIn 0.3s;
}
.ag-card .ag-head {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.06em;
  margin-bottom: 5px;
}
.ag-card.ag-think { border-style: dashed; }
.ag-card.ag-tool { border-left: 2px solid var(--signal); margin-left: 22px; }
.ag-card.ag-done { border-color: rgba(184,240,77,0.4); background: var(--signal-dim); }
.ag-card pre { background: var(--ink-3); border: 1px solid var(--line); }

/* ============ 自注意力步进计算器 ============ */
.sa-toolbar { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.sa-toolbar button {
  background: var(--signal); color: var(--ink); border: 1px solid var(--signal);
  border-radius: var(--radius); padding: 7px 16px;
  font-family: var(--font-mono); font-size: 13px; font-weight: 600; cursor: pointer;
}
.sa-toolbar button.secondary { background: transparent; border-color: var(--line-bright); color: var(--paper); }
.sa-toolbar button:disabled { opacity: 0.3; cursor: default; }
.sa-toolbar #sa-stage-num { font-family: var(--font-mono); font-size: 12px; color: var(--paper-dim); }
.sa-title {
  font-family: var(--font-mono); font-size: 15px; color: var(--signal);
  margin-top: 16px; font-weight: 600;
}
.sa-grid { display: grid; gap: 4px; margin-top: 14px; }
.sa-cell {
  font-family: var(--font-mono); font-size: 12.5px; text-align: center;
  padding: 10px 4px; border-radius: var(--radius);
  border: 1px solid var(--line); color: var(--paper);
  transition: background 0.25s;
}
.sa-cell.sa-head { border: none; color: var(--paper-dim); font-size: 12px; background: none !important; }

/* ============ 注意力对齐实验室 ============ */
.attn-row { display: flex; align-items: center; gap: 14px; margin: 14px 0; flex-wrap: wrap; }
.attn-side-label {
  font-family: var(--font-mono); font-size: 11px; color: var(--paper-dim);
  min-width: 86px; letter-spacing: 0.05em;
}
.attn-tokens { display: flex; gap: 8px; flex-wrap: wrap; }
.attn-tok {
  font-family: var(--font-mono); font-size: 15px;
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 7px 13px; background: var(--ink); color: var(--paper);
  transition: background 0.18s, border-color 0.18s, color 0.18s;
}
.attn-tok-tgt { cursor: pointer; }
.attn-tok-tgt:hover { border-color: var(--cyan); }
.attn-tok-tgt.active {
  border-color: var(--cyan); color: var(--cyan);
  box-shadow: 0 0 14px rgba(111,215,200,0.35);
}
.attn-bars { display: flex; gap: 14px; align-items: flex-end; margin-top: 18px; padding: 0 100px; }
.attn-bar-wrap { display: flex; flex-direction: column; align-items: center; gap: 5px; flex: 1; }
.attn-bar {
  width: 100%; max-width: 46px; height: 90px;
  background: var(--ink); border: 1px solid var(--line); border-radius: var(--radius);
  display: flex; align-items: flex-end; overflow: hidden;
}
.attn-bar-fill { width: 100%; background: var(--signal); transition: height 0.18s; }
.attn-bar-label { font-size: 13px; }
.attn-bar-val { font-family: var(--font-mono); font-size: 10.5px; color: var(--paper-dim); }
@media (max-width: 640px) { .attn-bars { padding: 0; } }

/* ============ 卷积核实验室 ============ */
.cv-row {
  display: grid; grid-template-columns: 1fr auto 1fr; gap: 18px;
  align-items: center; margin-top: 6px;
}
.cv-row canvas {
  width: 100%; image-rendering: pixelated; border-radius: var(--radius);
  border: 1px solid var(--line); display: block; cursor: default !important;
}
.cv-col-label {
  font-family: var(--font-mono); font-size: 11px; color: var(--paper-dim);
  text-align: center; margin-top: 8px; letter-spacing: 0.06em;
}
#cv-kernel {
  display: grid; grid-template-columns: repeat(3, 54px); gap: 5px;
}
#cv-kernel input {
  width: 54px; height: 44px; text-align: center;
  background: var(--ink); color: var(--signal);
  border: 1px solid var(--line-bright); border-radius: var(--radius);
  font-family: var(--font-mono); font-size: 13px;
}
#cv-kernel input:focus { outline: none; border-color: var(--signal); }
.cv-presets { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 16px; }
.cv-presets button {
  background: transparent; border: 1px solid var(--line-bright);
  color: var(--paper-dim); border-radius: var(--radius);
  font-family: var(--font-mono); font-size: 11.5px; padding: 5px 11px; cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
.cv-presets button:hover { border-color: var(--signal); color: var(--signal); }
@media (max-width: 640px) {
  .cv-row { grid-template-columns: 1fr; }
  #cv-kernel { justify-content: center; margin: 0 auto; }
}

/* ============ 历史时间轴（无限画布） ============ */
.tl-wrap {
  background: var(--ink-2); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 18px; margin: 36px 0;
}
#tl-canvas {
  width: 100%; display: block; border-radius: var(--radius);
  background: var(--ink); border: 1px solid var(--line);
  touch-action: pan-y; user-select: none; -webkit-user-select: none;
}
.tl-toolbar {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  margin-bottom: 12px;
}
.tl-toolbar .tl-jumps { display: flex; flex-wrap: wrap; gap: 6px; }
.tl-toolbar button[data-tl-jump] {
  background: transparent; border: 1px solid var(--line-bright);
  color: var(--paper-dim); border-radius: var(--radius);
  font-family: var(--font-mono); font-size: 11.5px; padding: 5px 12px;
  cursor: pointer; letter-spacing: 0.03em;
  transition: border-color 0.15s, color 0.15s;
}
.tl-toolbar button[data-tl-jump]:hover { border-color: var(--signal); color: var(--signal); }
#tl-legend { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 12px; }
.tl-chip {
  background: transparent; border: 1px solid var(--chip);
  color: var(--chip); border-radius: var(--radius);
  font-family: var(--font-mono); font-size: 11px; padding: 4px 11px;
  cursor: pointer; transition: opacity 0.15s; letter-spacing: 0.02em;
}
.tl-chip::before { content: "● "; }
.tl-chip.off { opacity: 0.3; border-color: var(--line); }
.tl-chip.off::before { content: "○ "; }
#tl-detail {
  display: none; margin-top: 14px; padding: 18px 20px;
  background: var(--ink); border: 1px solid var(--line);
  border-left: 2px solid var(--signal); border-radius: var(--radius);
  animation: fadeIn 0.25s;
}
#tl-detail.show { display: block; }
#tl-detail .tl-d-head { display: flex; align-items: center; gap: 12px; }
#tl-detail .tl-d-year {
  font-family: var(--font-display); font-size: 1.8rem; color: var(--signal);
}
#tl-detail .tl-d-cat {
  font-family: var(--font-mono); font-size: 11px; border: 1px solid;
  border-radius: var(--radius); padding: 2px 9px; letter-spacing: 0.04em;
}
#tl-detail .tl-d-title { font-weight: 700; font-size: 1.1rem; color: #fff; margin-top: 6px; }
#tl-detail .tl-d-body { font-size: 14.5px; color: #c4c7b8; margin-top: 8px; line-height: 1.85; }

@media (max-width: 640px) {
  body { font-size: 15.5px; }
  .chapter-card { flex-wrap: wrap; }
  .chapter-nav { flex-direction: column; }
  body::before { background-size: 100% 100%, 32px 32px, 32px 32px; }
}


/* Lucide icons (inline SVG, replacing emoji) */
svg.lucide { width: 1em; height: 1em; vertical-align: -0.14em; }
.audio-card .a-icon svg.lucide { width: 22px; height: 22px; vertical-align: middle; }
.ch-progress svg.lucide, .pr-stats svg.lucide, .ag-head svg.lucide { width: 0.95em; height: 0.95em; vertical-align: -0.12em; }