/* ============================================================
   Python+AI 精英培养课件 · 全站样式
   设计体系移植自 m3-03 课件配置：
   - 三主题（右上角切换）：科技深色 / 清爽浅色 / 教育暖色
   - localStorage key: noi-theme
   ============================================================ */
:root {
  --blue: #04A3F0; --pink: #FFA290;
  --blue-rgb: 4,163,240; --pink-rgb: 255,162,144;
  --green-rgb: 52,211,153; --red-rgb: 248,113,113; --yellow-rgb: 251,191,36;
  --dark: #0b1120; --dark2: #0f172a;
  --card: rgba(30,41,59,0.55); --card-solid: #1e293b;
  --text: #e2e8f0; --sub: #94a3b8; --line: rgba(255,255,255,0.08);
  --green: #34d399; --red: #f87171; --yellow: #fbbf24; --orange: #fb923c;
  --body-text: #cbd5e1; --strong: #ffffff; --on-accent: #0b1120;
  --code-bg: #0a0f1e; --code-head: #131b2e; --code-text: #dbe4f3; --run-bg: #07120d;
  --code-line: rgba(255,255,255,0.12);
  --toc-bg: rgba(11,17,32,0.88); --panel-strong: rgba(15,23,42,0.95);
  --faint: rgba(255,255,255,0.025);
  --hint-text: #fde68a; --err-title: #fca5a5;
  --glow-op: 0.14;
  --thumb: rgba(255,255,255,0.2); --thumb-hover: rgba(255,255,255,0.4);
  --panel-shadow: 0 4px 24px rgba(0,0,0,0.4);
  --side-op: 0.95;
  --nav-bg: rgba(11,17,32,0.92);
}
/* Theme 2: light */
[data-theme="light"] {
  --dark: #f5f8fc; --dark2: #e9eff7;
  --card: rgba(255,255,255,0.78); --card-solid: #ffffff;
  --text: #1e293b; --sub: #5b6b7f; --line: rgba(15,23,42,0.1);
  --body-text: #334155; --strong: #0f172a;
  --toc-bg: rgba(255,255,255,0.92); --panel-strong: rgba(255,255,255,0.96);
  --faint: rgba(15,23,42,0.035);
  --hint-text: #92400e; --err-title: #dc2626;
  --glow-op: 0.08;
  --thumb: rgba(15,23,42,0.18); --thumb-hover: rgba(15,23,42,0.32);
  --panel-shadow: 0 4px 24px rgba(15,23,42,0.14);
  --nav-bg: rgba(255,255,255,0.92);
}
/* Theme 3: edu warm */
[data-theme="edu"] {
  --blue: #EE7D24; --pink: #2E9E6B;
  --blue-rgb: 238,125,36; --pink-rgb: 46,158,107;
  --dark: #faf6ee; --dark2: #f1e9d8;
  --card: rgba(255,255,255,0.8); --card-solid: #fffdf8;
  --text: #3f3629; --sub: #7d7361; --line: rgba(90,70,40,0.14);
  --body-text: #57503f; --strong: #33291a;
  --toc-bg: rgba(250,246,238,0.94); --panel-strong: rgba(255,253,248,0.97);
  --faint: rgba(90,70,40,0.05);
  --hint-text: #92400e; --err-title: #c2410c;
  --glow-op: 0.1;
  --thumb: rgba(90,70,40,0.22); --thumb-hover: rgba(90,70,40,0.38);
  --panel-shadow: 0 4px 24px rgba(120,90,40,0.18);
  --nav-bg: rgba(250,246,238,0.92);
}
* { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior:smooth; }
body {
  font-family:'Inter','Segoe UI','Microsoft YaHei',sans-serif;
  background:var(--dark); color:var(--text); line-height:1.7; overflow-x:hidden; position:relative;
  padding-right:20px;
}
body::before {
  content:''; position:fixed; inset:0;
  background-image:linear-gradient(rgba(var(--blue-rgb),0.03) 1px,transparent 1px),
    linear-gradient(90deg,rgba(var(--blue-rgb),0.03) 1px,transparent 1px);
  background-size:42px 42px; z-index:-2;
}
.glow { position:fixed; border-radius:50%; filter:blur(130px); opacity:var(--glow-op); z-index:-1; pointer-events:none; }
.g1 { width:560px; height:560px; background:var(--blue); top:-180px; left:-120px; }
.g2 { width:480px; height:480px; background:var(--pink); bottom:-120px; right:-120px; }
.wrap { max-width:1080px; margin:0 auto; padding:0 20px; }

/* ================= 顶部站点导航 ================= */
.site-nav {
  position:sticky; top:0; z-index:120; background:var(--nav-bg);
  backdrop-filter:blur(12px); border-bottom:1px solid var(--line);
}
.site-nav .in { max-width:1080px; margin:0 auto; padding:0 20px; display:flex; align-items:center; gap:18px; height:56px; }
.site-nav .logo { font-weight:800; font-size:1.05rem; color:var(--strong); text-decoration:none; letter-spacing:.5px; white-space:nowrap; }
.site-nav .logo .dot { color:var(--blue); }
.site-nav .links { display:flex; gap:2px; flex-wrap:nowrap; overflow-x:auto; scrollbar-width:none; }
.site-nav .links::-webkit-scrollbar { display:none; }
.site-nav .links a { color:var(--sub); text-decoration:none; font-size:.88rem; padding:8px 11px; border-radius:8px; white-space:nowrap; transition:.2s; }
.site-nav .links a:hover { color:var(--blue); background:rgba(var(--blue-rgb),0.08); }
.site-nav .links a.active { color:var(--blue); font-weight:700; }
.site-nav .links .sep { color:var(--line); align-self:center; }

/* ================= Hero ================= */
.hero { text-align:center; padding:60px 20px 26px; }
.crumb { display:inline-block; font-size:.8rem; color:var(--sub); letter-spacing:1px; margin-bottom:16px; }
.crumb a { color:var(--blue); text-decoration:none; }
.badge { display:inline-block; padding:6px 16px; border-radius:20px; background:rgba(var(--blue-rgb),0.14);
  border:1px solid rgba(var(--blue-rgb),0.32); color:var(--blue); font-size:.82rem; font-weight:600; margin-bottom:18px; letter-spacing:1px; }
h1.hero-title { font-size:2.9rem; font-weight:800; line-height:1.15; margin-bottom:12px; }
.grad { background:linear-gradient(90deg,var(--blue),var(--pink)); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; }
.hero .sub { color:var(--sub); font-size:1.05rem; max-width:760px; margin:0 auto; }
.pills { display:flex; justify-content:center; flex-wrap:wrap; gap:12px; margin-top:24px; }
.pill { background:rgba(var(--blue-rgb),0.08); border:1px solid rgba(var(--blue-rgb),0.25); border-radius:999px;
  padding:6px 16px; font-size:.85rem; color:var(--text); }
.pill b { color:var(--pink); }

/* ================= Sticky TOC ================= */
.toc { position:sticky; top:56px; z-index:50; background:var(--toc-bg); backdrop-filter:blur(10px);
  border-top:1px solid var(--line); border-bottom:1px solid var(--line); margin-top:30px; }
.toc .in { max-width:1080px; margin:0 auto; padding:0 12px; display:flex; flex-wrap:wrap; justify-content:center; gap:4px; }
.toc a { color:var(--sub); text-decoration:none; font-size:.9rem; padding:12px 14px; transition:.2s; white-space:nowrap; }
.toc a:hover { color:var(--blue); background:rgba(var(--blue-rgb),0.08); border-radius:6px; }

/* ================= Section / Card ================= */
section.module { padding:54px 0 8px; }
.mod-head { display:flex; align-items:center; gap:14px; margin-bottom:8px; }
.mod-num { font-size:.85rem; font-weight:700; color:var(--on-accent); background:linear-gradient(135deg,var(--blue),var(--pink));
  border-radius:8px; padding:4px 12px; letter-spacing:1px; flex-shrink:0; }
.mod-head h2 { font-size:1.7rem; font-weight:700; }
.mod-desc { color:var(--sub); font-size:.95rem; margin-bottom:20px; }
.card { background:var(--card); backdrop-filter:blur(12px); border:1px solid var(--line);
  border-radius:16px; padding:26px; margin-bottom:20px; animation:slideUp .6s ease both; }
.sub-title { display:flex; align-items:center; gap:10px; color:var(--blue); font-size:1.12rem; font-weight:700; margin:26px 0 12px; }
.sub-title:first-child { margin-top:0; }
.sub-title .ico { width:26px; height:26px; border-radius:8px; background:rgba(var(--blue-rgb),0.15);
  border:1px solid rgba(var(--blue-rgb),0.35); color:var(--blue); display:inline-flex; align-items:center; justify-content:center; font-size:.9rem; flex-shrink:0; }
.sub-title.pinkv { color:var(--pink); }
.sub-title.pinkv .ico { background:rgba(var(--pink-rgb),0.14); border-color:rgba(var(--pink-rgb),0.4); color:var(--pink); }
p.txt { color:var(--body-text); font-size:.97rem; margin:10px 0; }
.txt b { color:var(--pink); }
.txt .bl { color:var(--blue); font-weight:600; }

/* ================= 故事框 / 类比 / 口诀 ================= */
.story-box { position:relative; background:linear-gradient(135deg,rgba(var(--blue-rgb),0.06),rgba(var(--pink-rgb),0.06));
  border:1px solid rgba(var(--blue-rgb),0.15); border-radius:14px; padding:24px; margin:16px 0; overflow:hidden; }
.story-box::before { content:''; position:absolute; top:0; left:0; width:4px; height:100%;
  background:linear-gradient(180deg,var(--blue),var(--pink)); border-radius:4px 0 0 4px; }
.analogy-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(220px,1fr)); gap:14px; margin:14px 0; }
.analogy { background:var(--faint); border:1px solid var(--line); border-radius:12px; padding:18px; transition:.2s; }
.analogy:hover { border-color:var(--blue); transform:translateY(-3px); }
.analogy .em { font-size:1.6rem; }
.analogy h4 { color:var(--strong); font-size:1.02rem; margin:8px 0 4px; }
.analogy p { color:var(--sub); font-size:.87rem; }
.analogy .map { display:inline-block; margin-top:8px; font-size:.78rem; color:var(--blue); background:rgba(var(--blue-rgb),0.1); padding:2px 9px; border-radius:6px; }
.motto { background:linear-gradient(135deg,rgba(var(--blue-rgb),0.12),rgba(var(--pink-rgb),0.12)); border:1px solid rgba(var(--blue-rgb),0.25); border-radius:12px; padding:16px 20px; margin:16px 0; color:var(--strong); font-size:1rem; text-align:center; letter-spacing:.5px; }
.motto .tag2 { display:block; color:var(--pink); font-size:.78rem; font-weight:700; letter-spacing:2px; margin-bottom:6px; text-align:center; }

/* ================= 表格 ================= */
table.tbl { width:100%; border-collapse:collapse; margin:16px 0; font-size:.9rem; background:var(--faint); border-radius:12px; overflow:hidden; }
table.tbl th { background:rgba(var(--blue-rgb),0.14); color:var(--blue); text-align:left; padding:11px 14px; font-weight:700; border-bottom:1px solid rgba(var(--blue-rgb),0.25); }
table.tbl td { padding:10px 14px; color:var(--body-text); border-bottom:1px solid var(--line); vertical-align:top; }
table.tbl tr:last-child td { border-bottom:none; }
table.tbl td.mono { font-family:ui-monospace,'Cascadia Code','Consolas',monospace; color:var(--pink); font-size:.85rem; }

/* ================= 代码块 / 运行结果 ================= */
.code-block { border-radius:12px; overflow:hidden; border:1px solid var(--code-line); margin:14px 0; background:var(--code-bg); }
.code-head { display:flex; align-items:center; justify-content:space-between; background:var(--code-head); padding:8px 14px; border-bottom:1px solid rgba(255,255,255,0.08); gap:12px; }
.code-lang { font-size:.72rem; font-weight:700; color:#fff; background:linear-gradient(135deg,var(--blue),var(--pink)); border-radius:6px; padding:2px 9px; flex:none; }
.code-title { color:#94a3b8; font-size:.8rem; text-align:right; }
pre { padding:16px; overflow-x:auto; }
pre code { font-family:ui-monospace,'Cascadia Code','Consolas',monospace; font-size:.88rem; line-height:1.65; color:var(--code-text); white-space:pre; }
.kw { color:#7dd3fc; font-weight:600; }
.str { color:#fca5a5; }
.cmt { color:#64748b; font-style:italic; }
.num { color:#fbbf24; }
.run-result { border-radius:12px; overflow:hidden; border:1px solid rgba(var(--green-rgb),0.25); margin:10px 0 16px; background:var(--run-bg); }
.run-head { background:rgba(var(--green-rgb),0.12); color:var(--green); font-size:.78rem; font-weight:700; letter-spacing:3px; padding:6px 14px; border-bottom:1px solid rgba(var(--green-rgb),0.2); }
.run-result pre { padding:12px 16px; padding-top:20px; }
.run-result pre code { color:#6ee7b7; }

/* ================= 课时卡片 ================= */
.lesson-card { border:1px solid var(--line); border-radius:14px; padding:20px 22px; margin:14px 0; background:var(--faint); transition:.25s; }
.lesson-card:hover { border-color:rgba(var(--blue-rgb),0.45); transform:translateY(-2px); box-shadow:0 6px 20px rgba(0,0,0,0.18); }
.lesson-card.final { border-color:rgba(var(--pink-rgb),0.5); background:linear-gradient(135deg,rgba(var(--pink-rgb),0.07),rgba(var(--blue-rgb),0.07)); }
.lesson-top { display:flex; align-items:center; gap:10px; flex-wrap:wrap; margin-bottom:8px; }
.lesson-no { font-size:.72rem; font-weight:800; color:var(--on-accent); background:linear-gradient(135deg,var(--blue),var(--pink)); border-radius:6px; padding:3px 10px; letter-spacing:1px; flex:none; }
.lesson-card.final .lesson-no { background:linear-gradient(135deg,var(--pink),var(--yellow)); }
.lesson-title { color:var(--strong); font-size:1.08rem; font-weight:700; }
.lesson-meta { display:flex; flex-wrap:wrap; gap:8px 18px; font-size:.87rem; margin:6px 0; color:var(--body-text); }
.lesson-meta .lb { color:var(--sub); flex:none; }
.lesson-meta b { color:var(--pink); font-weight:600; }
.pts { display:flex; flex-wrap:wrap; gap:6px; margin-top:10px; }
.pt { font-size:.78rem; color:var(--blue); background:rgba(var(--blue-rgb),0.1); border:1px solid rgba(var(--blue-rgb),0.28); border-radius:6px; padding:2px 10px; }
.diff { display:inline-flex; gap:3px; margin-left:auto; }
.diff i { width:9px; height:9px; border-radius:50%; background:var(--line); }
.diff .on { background:var(--pink); }

/* ================= 提示框 ================= */
.tip-box { padding:13px 18px; border-radius:10px; margin:14px 0; font-size:.9rem; display:flex; align-items:flex-start; gap:10px; }
.tip-box.info { background:rgba(var(--blue-rgb),.1); border-left:4px solid var(--blue); color:var(--blue); }
.tip-box.warn { background:rgba(231,76,60,.1); border-left:4px solid #E74C3C; color:#E74C3C; }
.tip-box.ok { background:rgba(var(--green-rgb),.1); border-left:4px solid var(--green); color:var(--green); }

/* ================= 易错点 ================= */
.err-card { border:1px solid rgba(var(--red-rgb),0.22); border-radius:14px; padding:20px; margin:16px 0; background:rgba(var(--red-rgb),0.04); }
.err-head { display:flex; align-items:center; gap:10px; margin-bottom:6px; }
.err-tag { font-size:.7rem; font-weight:700; color:var(--on-accent); background:var(--red); border-radius:6px; padding:2px 9px; letter-spacing:1px; flex:none; }
.err-head h4 { color:var(--err-title); font-size:1.05rem; }
.err-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(300px,1fr)); gap:14px; margin-top:12px; }
.err-cell { border-radius:10px; overflow:hidden; border:1px solid var(--line); }
.err-cell .lb { font-size:.72rem; font-weight:700; letter-spacing:1px; padding:6px 12px; }
.lb.bad { background:rgba(var(--red-rgb),0.14); color:var(--red); }
.lb.good { background:rgba(var(--green-rgb),0.12); color:var(--green); }
.err-cell pre { padding:12px; background:var(--code-bg); }
.err-cell pre code { font-size:.82rem; }
.motto-line { margin-top:12px; background:rgba(var(--blue-rgb),0.08); border:1px solid rgba(var(--blue-rgb),0.25); border-radius:10px; padding:10px 16px; color:var(--strong); font-size:.9rem; }
.motto-line b { color:var(--blue); }

/* ================= 作业 / 练习 ================= */
.hw-section { background:linear-gradient(180deg,rgba(var(--pink-rgb),0.05),rgba(var(--blue-rgb),0.05)); border-top:1px solid var(--line); margin-top:50px; padding:50px 0 30px; }
.hw-head { text-align:center; margin-bottom:26px; }
.hw-head .badge2 { display:inline-block; padding:5px 15px; border-radius:20px; background:rgba(var(--pink-rgb),0.13); border:1px solid rgba(var(--pink-rgb),0.35); color:var(--pink); font-size:.8rem; font-weight:700; letter-spacing:1px; margin-bottom:12px; }
.hw-head h2 { font-size:1.8rem; font-weight:800; }
.hw-head p { color:var(--sub); font-size:.95rem; margin-top:6px; }
.q-card { border:1px solid var(--line); border-radius:14px; padding:20px; margin:14px 0; background:var(--faint); }
.q-top { display:flex; align-items:center; gap:10px; flex-wrap:wrap; margin-bottom:8px; }
.q-badge { font-size:.72rem; font-weight:700; border-radius:6px; padding:3px 10px; }
.qb-a { background:rgba(var(--green-rgb),0.14); color:var(--green); border:1px solid rgba(var(--green-rgb),0.3); }
.qb-b { background:rgba(var(--yellow-rgb),0.12); color:var(--yellow); border:1px solid rgba(var(--yellow-rgb),0.3); }
.qb-c { background:rgba(var(--pink-rgb),0.13); color:var(--pink); border:1px solid rgba(var(--pink-rgb),0.32); }
.q-card h4 { color:var(--strong); font-size:1.02rem; margin-bottom:6px; }
.q-card ol, .q-card ul { padding-left:20px; }
.q-card li { color:var(--body-text); font-size:.92rem; margin:6px 0; }

/* ================= 思考框 / 笔记卡 ================= */
.thought-box { background:linear-gradient(135deg,rgba(var(--blue-rgb),0.08),rgba(var(--pink-rgb),0.08)); border:1px solid rgba(var(--blue-rgb),0.3); border-radius:14px; padding:22px; margin:20px 0; position:relative; overflow:hidden; }
.thought-box::before { content:'💭'; position:absolute; top:-10px; right:-10px; font-size:3rem; opacity:.1; }
.thought-box h4 { color:var(--blue); font-size:1.1rem; margin-bottom:10px; }
.thought-box p { color:var(--body-text); font-size:.95rem; margin:6px 0; }
.note-card { background:linear-gradient(135deg,rgba(var(--blue-rgb),0.06),rgba(var(--pink-rgb),0.06)); border:1px dashed rgba(var(--blue-rgb),0.3); border-radius:14px; padding:24px; margin-top:24px; }
.note-card .note-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(240px,1fr)); gap:12px; margin-top:14px; }
.note-card .note-item { background:var(--faint); border:1px solid var(--line); border-radius:10px; padding:14px; transition:.3s; }
.note-card .note-item:hover { border-color:var(--blue); transform:translateY(-2px); box-shadow:0 4px 12px rgba(var(--blue-rgb),0.1); }
.note-card .note-item h5 { color:var(--blue); font-size:.9rem; margin-bottom:6px; }
.note-card .note-item p { color:var(--sub); font-size:.85rem; line-height:1.55; }
.note-card .note-item .pts { margin-top:8px; }

/* ================= 右侧导航 / 快捷工具 ================= */
.quick-tools { position:fixed; top:66px; right:16px; z-index:130; display:flex; align-items:center; gap:8px; }
.sidebar-toggle { width:40px; height:40px; border-radius:10px; background:rgba(var(--blue-rgb),0.15); border:1px solid rgba(var(--blue-rgb),0.35); color:var(--blue); font-size:1.2rem; cursor:pointer; display:flex; align-items:center; justify-content:center; transition:all .3s; backdrop-filter:blur(6px); }
.sidebar-toggle:hover { background:var(--blue); color:#fff; transform:scale(1.05); }
.theme-switch { position:relative; flex:none; }
.theme-btn { width:40px; height:40px; border-radius:10px; border:1px solid rgba(var(--blue-rgb),0.35); background:rgba(var(--blue-rgb),0.15); color:var(--blue); cursor:pointer; display:flex; align-items:center; justify-content:center; transition:all .25s; backdrop-filter:blur(6px); }
.theme-btn:hover { border-color:rgba(var(--pink-rgb),0.55); color:var(--pink); background:rgba(var(--pink-rgb),0.1); transform:rotate(18deg); }
.theme-btn svg { width:20px; height:20px; }
.theme-menu { position:absolute; top:calc(100% + 10px); right:0; width:250px; z-index:50; background:var(--panel-strong); border:1px solid var(--line); border-radius:14px; padding:10px; box-shadow:var(--panel-shadow); opacity:0; transform:translateY(-6px); pointer-events:none; transition:opacity .22s ease, transform .22s ease; backdrop-filter:blur(14px); }
.theme-switch.open .theme-menu { opacity:1; transform:none; pointer-events:auto; }
.tm-title { font-size:.68rem; color:var(--sub); letter-spacing:2px; padding:4px 8px 8px; }
.tm-item { display:flex; align-items:center; gap:10px; width:100%; padding:9px 10px; border-radius:10px; border:1px solid transparent; background:transparent; color:var(--text); cursor:pointer; text-align:left; font-family:inherit; transition:all .2s; }
.tm-item:hover { background:rgba(var(--blue-rgb),0.08); border-color:rgba(var(--blue-rgb),0.3); }
.tm-item.active { border-color:rgba(var(--pink-rgb),0.5); background:rgba(var(--pink-rgb),0.08); }
.tm-dots { display:flex; gap:4px; flex:none; }
.tm-dots i { width:12px; height:12px; border-radius:50%; display:block; border:1px solid rgba(128,128,128,0.35); }
.tm-name { font-size:.84rem; font-weight:600; display:flex; flex-direction:column; line-height:1.35; }
.tm-name em { font-style:normal; font-size:.66rem; color:var(--sub); font-weight:400; }
.tm-check { margin-left:auto; color:var(--pink); opacity:0; font-weight:700; }
.tm-item.active .tm-check { opacity:1; }
.side-op-box { display:flex; align-items:center; gap:8px; margin-top:10px; padding:9px 8px 2px; border-top:1px dashed var(--line); font-size:.72rem; color:var(--sub); }
.side-op-box b { color:var(--blue); font-size:.72rem; font-weight:700; min-width:36px; text-align:right; }
.side-op-box input[type=range] { flex:1; min-width:0; accent-color:var(--blue); cursor:pointer; }

.sidebar-nav {
  position:fixed; right:16px; top:122px; width:212px; max-height:calc(100vh - 150px); overflow-y:auto;
  background:var(--panel-strong); backdrop-filter:blur(14px); border:1px solid var(--line);
  border-radius:14px; padding:14px 10px; z-index:110; box-shadow:var(--panel-shadow); font-size:.82rem;
  transition:transform .35s cubic-bezier(.4,0,.2,1), opacity .35s ease, background .35s ease, border-color .35s ease;
  transform:translateX(0); opacity:var(--side-op, .95);
}
.sidebar-nav.collapsed { transform:translateX(110%); opacity:0; pointer-events:none; }
.sidebar-nav h4 { color:var(--blue); font-size:.85rem; text-align:center; margin-bottom:10px; padding-bottom:8px; border-bottom:1px solid var(--line); letter-spacing:1px; }
.sidebar-nav h4::after { content:''; display:inline-block; width:6px; height:6px; border-radius:50%; background:var(--blue); margin-left:6px; animation:breathe 2s infinite; }
@keyframes breathe { 0%,100% { opacity:1; box-shadow:0 0 4px var(--blue); } 50% { opacity:.5; box-shadow:0 0 8px var(--blue); } }
.sidebar-nav .nav-group { margin-bottom:8px; }
.sidebar-nav .nav-group-title { color:var(--pink); font-weight:700; font-size:.78rem; padding:4px 8px; letter-spacing:.5px; }
.sidebar-nav a { display:block; color:var(--sub); text-decoration:none; padding:5px 10px; border-radius:6px; transition:all .2s; font-size:.78rem; line-height:1.5; position:relative; overflow:hidden; }
.sidebar-nav a:hover { background:rgba(var(--blue-rgb),0.1); color:var(--strong); padding-left:14px; }
.sidebar-nav a.active { background:var(--blue); color:var(--on-accent); font-weight:700; }
.sidebar-nav a::before { content:''; position:absolute; left:0; top:0; width:3px; height:100%; background:var(--blue); transform:scaleY(0); transition:transform .2s; }
.sidebar-nav a:hover::before, .sidebar-nav a.active::before { transform:scaleY(1); }
.sidebar-nav::-webkit-scrollbar { width:4px; }
.sidebar-nav::-webkit-scrollbar-track { background:transparent; }
.sidebar-nav::-webkit-scrollbar-thumb { background:var(--thumb); border-radius:2px; }
@media (max-width:1200px) { .sidebar-nav { display:none; } }

/* ================= 学期切换 / 页脚 / 回顶 ================= */
.term-nav { display:flex; flex-wrap:wrap; justify-content:center; gap:8px; margin:26px 0 8px; }
.term-nav a { font-size:.85rem; color:var(--sub); text-decoration:none; border:1px solid var(--line); border-radius:10px; padding:7px 15px; transition:.2s; background:var(--faint); }
.term-nav a:hover { color:var(--blue); border-color:rgba(var(--blue-rgb),0.4); }
.term-nav a.active { color:var(--on-accent); background:linear-gradient(135deg,var(--blue),var(--pink)); border-color:transparent; font-weight:700; }
footer { text-align:center; padding:42px 20px 50px; border-top:1px solid var(--line); margin-top:46px; }
.signature { font-size:1.25rem; font-weight:700; background:linear-gradient(90deg,var(--blue),var(--pink)); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; letter-spacing:2px; }
.small { color:var(--sub); font-size:.8rem; margin-top:10px; }
footer .flinks { display:flex; justify-content:center; flex-wrap:wrap; gap:6px 14px; margin-top:14px; }
footer .flinks a { color:var(--sub); font-size:.8rem; text-decoration:none; }
footer .flinks a:hover { color:var(--blue); }
#toTop { position:fixed; right:22px; bottom:22px; width:44px; height:44px; border-radius:50%; background:rgba(var(--blue-rgb),0.2);
  border:1px solid rgba(var(--blue-rgb),0.4); color:var(--blue); font-size:1.2rem; cursor:pointer; display:none; align-items:center; justify-content:center; z-index:140; backdrop-filter:blur(6px); }
#toTop:hover { background:var(--blue); color:#fff; }

/* ================= 首页 / 总览特有组件 ================= */
.stats { display:grid; grid-template-columns:repeat(auto-fit,minmax(130px,1fr)); gap:14px; margin:26px 0; }
.stat { background:var(--card); border:1px solid var(--line); border-radius:14px; padding:18px 10px; text-align:center; transition:.2s; }
.stat:hover { border-color:rgba(var(--blue-rgb),0.4); transform:translateY(-3px); }
.stat .n { font-size:2rem; font-weight:800; background:linear-gradient(135deg,var(--blue),var(--pink)); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; }
.stat .l { color:var(--sub); font-size:.82rem; margin-top:2px; }
.stage-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(280px,1fr)); gap:18px; margin:20px 0; }
.stage-card { background:var(--card); border:1px solid var(--line); border-radius:18px; padding:26px; text-decoration:none; display:flex; flex-direction:column; gap:10px; transition:.25s; position:relative; overflow:hidden; }
.stage-card:hover { transform:translateY(-5px); border-color:rgba(var(--blue-rgb),0.5); box-shadow:0 12px 32px rgba(0,0,0,0.25); }
.stage-card::after { content:''; position:absolute; bottom:0; left:0; width:100%; height:3px; background:linear-gradient(90deg,var(--blue),var(--pink),var(--blue)); background-size:200% 100%; animation:shimmer 3s infinite; }
@keyframes shimmer { 0% { background-position:-200% 0; } 100% { background-position:200% 0; } }
.stage-card .tag { font-size:.72rem; font-weight:700; color:var(--blue); letter-spacing:2px; }
.stage-card h3 { color:var(--strong); font-size:1.25rem; }
.stage-card p { color:var(--sub); font-size:.88rem; }
.stage-card .more { margin-top:auto; color:var(--pink); font-size:.85rem; font-weight:600; }
.term-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(230px,1fr)); gap:12px; margin:18px 0; }
.term-card { background:var(--faint); border:1px solid var(--line); border-radius:12px; padding:16px; text-decoration:none; transition:.2s; display:flex; flex-direction:column; gap:5px; }
.term-card:hover { border-color:var(--blue); transform:translateY(-3px); }
.term-card .tt { color:var(--strong); font-weight:700; font-size:.95rem; }
.term-card .ts { color:var(--sub); font-size:.8rem; }
.term-card .tf { font-size:.78rem; color:var(--blue); margin-top:4px; }

/* ================= 搜索 ================= */
.search-box { position:relative; max-width:560px; margin:26px auto 0; }
.search-box input { width:100%; padding:13px 18px; border-radius:12px; border:1px solid rgba(var(--blue-rgb),0.35); background:var(--panel-strong); color:var(--text); font-size:.95rem; font-family:inherit; outline:none; transition:.2s; backdrop-filter:blur(8px); }
.search-box input:focus { border-color:var(--blue); box-shadow:0 0 0 3px rgba(var(--blue-rgb),0.15); }
.search-box input::placeholder { color:var(--sub); }
.search-results { position:absolute; top:calc(100% + 8px); left:0; right:0; z-index:80; background:var(--panel-strong); border:1px solid var(--line); border-radius:14px; box-shadow:var(--panel-shadow); max-height:380px; overflow-y:auto; display:none; backdrop-filter:blur(14px); }
.search-results.show { display:block; }
.sr-item { display:block; padding:11px 16px; text-decoration:none; border-bottom:1px solid var(--line); transition:.15s; }
.sr-item:last-child { border-bottom:none; }
.sr-item:hover { background:rgba(var(--blue-rgb),0.08); }
.sr-item .t { color:var(--strong); font-size:.9rem; font-weight:600; }
.sr-item .t em { font-style:normal; color:var(--pink); }
.sr-item .d { color:var(--sub); font-size:.78rem; margin-top:2px; }
.sr-empty { padding:18px; text-align:center; color:var(--sub); font-size:.88rem; }

/* ================= 时间轴 ================= */
.timeline { margin:20px 0; padding-left:22px; border-left:2px solid rgba(var(--blue-rgb),0.3); }
.tl-item { position:relative; padding:0 0 22px 18px; }
.tl-item::before { content:''; position:absolute; left:-28px; top:6px; width:12px; height:12px; border-radius:50%; background:var(--blue); box-shadow:0 0 0 4px rgba(var(--blue-rgb),0.15); }
.tl-item .when { color:var(--pink); font-weight:700; font-size:.85rem; }
.tl-item .what { color:var(--body-text); font-size:.92rem; margin-top:2px; }

/* ================= 动画 / 响应式 ================= */
.fade-in { animation:fadeIn .6s ease both; }
@keyframes fadeIn { from { opacity:0; transform:translateY(20px); } to { opacity:1; transform:translateY(0); } }
@keyframes slideUp { from { opacity:0; transform:translateY(30px); } to { opacity:1; transform:translateY(0); } }
.delay-1 { animation-delay:.1s; } .delay-2 { animation-delay:.2s; }
.delay-3 { animation-delay:.3s; } .delay-4 { animation-delay:.4s; } .delay-5 { animation-delay:.5s; }
.reveal { opacity:0; transform:translateY(24px); transition:opacity .6s ease, transform .6s ease; }
.reveal.on { opacity:1; transform:translateY(0); }
[id] { scroll-margin-top:120px; }

@media (max-width:640px){
  h1.hero-title { font-size:2.1rem; }
  .toc a { padding:10px 8px; font-size:.8rem; }
  body { padding-right:0; }
  .quick-tools { top:auto; bottom:16px; right:16px; }
  #toTop { right:70px; bottom:24px; }
  .sidebar-nav { display:none; }
  .card { padding:18px; }
}

/* ================= 打印样式 ================= */
@media print {
  body { background:#fff !important; color:#111 !important; padding:0; }
  body::before, .glow, .quick-tools, .sidebar-nav, #toTop, .toc, .site-nav,
  .term-nav, .search-box, .hw-section, footer .flinks { display:none !important; }
  .card, .lesson-card, .err-card, .q-card { border:1px solid #bbb !important; background:#fff !important; color:#111 !important; box-shadow:none !important; break-inside:avoid; }
  .mod-head h2, .lesson-title, h1.hero-title { color:#000 !important; -webkit-text-fill-color:#000; }
  p.txt, .mod-desc, table.tbl td { color:#222 !important; }
  table.tbl { background:#fff; }
  table.tbl th { background:#eee !important; color:#000 !important; }
  pre code { color:#222 !important; }
  section.module { padding:18px 0; }
  footer { border:none; padding:10px; }
  .signature { color:#000 !important; -webkit-text-fill-color:#000; }
}

/* ================= 精讲课件横幅（第01章 · 小学三年级上配套） ================= */
/* 两段式布局：.kb-head 信息头（图标+标题+说明+整册按钮） / .kit-lessons 独立课卡网格 */
.kit-banner {
  display:block;
  background:linear-gradient(135deg, rgba(var(--blue-rgb,4,163,240),.10), rgba(var(--pink-rgb,255,162,144),.13));
  border:1px solid var(--line); border-radius:16px;
  padding:22px 24px 20px; margin:2px 0 16px; position:relative; overflow:hidden;
}
.kit-banner::after{content:""; position:absolute; right:-46px; top:-46px; width:170px; height:170px;
  border-radius:50%; background:radial-gradient(circle, rgba(var(--blue-rgb,4,163,240),.15), transparent 70%); pointer-events:none;}
.kit-banner .kb-head{display:flex; align-items:center; gap:16px; flex-wrap:wrap; position:relative; z-index:1;}
.kit-banner .kb-em{font-size:2.5rem; flex:none; filter:drop-shadow(0 4px 10px rgba(4,163,240,.25)); line-height:1;}
.kit-banner .kb-main{flex:1 1 300px; min-width:0;}
.kit-banner .kb-title{font-size:1.12rem; font-weight:800; color:var(--strong); margin-bottom:5px; line-height:1.5;}
.kit-banner .kb-tag{display:inline-block; font-size:.64rem; font-weight:800; letter-spacing:.12em;
  color:#fff; background:linear-gradient(135deg,var(--blue),var(--pink)); border-radius:5px;
  padding:2px 9px; margin-right:9px; vertical-align:2px;}
.kit-banner .kb-desc{font-size:.88rem; color:var(--sub); line-height:1.7;}
.kit-banner .kb-hint{display:block; margin-top:7px; font-size:.76rem; color:var(--sub); opacity:.92;}
.kit-banner .kb-hint b{color:var(--blue);}
.kit-btn{display:inline-flex; align-items:center; gap:8px; flex:none; margin-left:auto;
  background:linear-gradient(135deg,var(--blue),var(--pink)); color:#fff !important; font-weight:700;
  padding:11px 18px; border-radius:10px; text-decoration:none !important; font-size:.9rem; white-space:nowrap;
  box-shadow:0 6px 18px rgba(var(--blue-rgb,4,163,240),.3); transition:transform .18s ease, box-shadow .18s ease;}
.kit-btn:hover{transform:translateY(-2px); box-shadow:0 10px 24px rgba(var(--blue-rgb,4,163,240),.42);}
.kit-lessons{display:grid; grid-template-columns:repeat(auto-fill,minmax(148px,1fr)); gap:9px;
  margin-top:16px; padding-top:15px; border-top:1px dashed var(--line); position:relative; z-index:1;}
.kit-lesson{display:flex; flex-direction:column; justify-content:center; gap:3px; text-decoration:none !important;
  border:1px solid var(--line); border-radius:10px; padding:10px 13px; min-height:54px;
  background:var(--card); transition:border-color .15s ease, transform .15s ease, box-shadow .15s ease;}
.kit-lesson:hover{border-color:var(--blue); transform:translateY(-2px);
  box-shadow:0 6px 14px rgba(var(--blue-rgb,4,163,240),.18);}
.kit-lesson b{font-size:.8rem; color:var(--blue); font-weight:800; white-space:nowrap; overflow:hidden; text-overflow:ellipsis;}
.kit-lesson span{font-size:.73rem; color:var(--sub); line-height:1.35;
  display:-webkit-box; -webkit-line-clamp:2; -webkit-box-orient:vertical; overflow:hidden; word-break:break-all;}
@media (max-width:560px){
  .kit-banner .kb-em{display:none;}
  .kit-btn{margin-left:0; width:100%; justify-content:center;}
}
.lesson-kit{display:inline-block; margin-top:12px; font-size:.8rem; font-weight:700;
  color:#fff !important; text-decoration:none !important;
  background:linear-gradient(135deg,var(--blue),var(--pink)); border-radius:8px; padding:6px 13px;
  box-shadow:0 4px 12px rgba(var(--blue-rgb,4,163,240),.25); transition:transform .15s ease;}
.lesson-kit:hover{transform:translateY(-1px);}
@media print { .kit-banner{display:none !important;} .lesson-kit{display:none !important;} }

/* ================= 《从入门到上课》图文教程专用组件 ================= */
.g-num{display:inline-flex; flex:none; width:28px; height:28px; border-radius:50%; align-items:center; justify-content:center;
  background:linear-gradient(135deg,var(--blue),var(--pink)); color:#fff; font-weight:800; font-size:.95rem;
  box-shadow:0 3px 8px rgba(var(--blue-rgb,4,163,240),.3);}
.g-step{display:flex; gap:13px; align-items:flex-start; margin:11px 0;}
.g-step .g-body{flex:1; min-width:0;}
.g-step .g-title{font-weight:800; color:var(--strong); margin-bottom:3px; line-height:1.55;}
.g-step .g-body p, .g-step .g-body ul{margin:4px 0;}
.g-step .g-where{display:inline-block; background:rgba(var(--blue-rgb,4,163,240),.12); color:var(--blue);
  border:1px dashed rgba(var(--blue-rgb,4,163,240),.5); border-radius:6px; padding:1px 8px;
  font-size:.78rem; font-weight:600; margin-left:4px; white-space:nowrap;}
.g-btn{display:inline-flex; align-items:center; gap:6px; margin:4px 6px 4px 0;
  background:linear-gradient(135deg,var(--blue),var(--pink)); color:#fff !important; text-decoration:none !important;
  font-weight:700; font-size:.83rem; padding:8px 15px; border-radius:9px;
  box-shadow:0 4px 12px rgba(var(--blue-rgb,4,163,240),.25); transition:transform .15s ease, box-shadow .15s ease; white-space:nowrap;}
.g-btn:hover{transform:translateY(-2px); box-shadow:0 8px 18px rgba(var(--blue-rgb,4,163,240),.38);}
.g-btn.ghost{background:transparent; color:var(--blue) !important; border:1px solid rgba(var(--blue-rgb,4,163,240),.55); box-shadow:none;}
.g-btn .go{font-size:.75rem; opacity:.9;}
.g-tree{font-family:"SF Mono",Consolas,"Courier New",monospace; font-size:.82rem; line-height:1.8; color:var(--sub);
  background:var(--faint); border:1px solid var(--line); border-radius:12px; padding:14px 16px; overflow-x:auto; white-space:pre;}
.g-tree b{color:var(--blue); font-weight:800;}
.g-tree .hl{color:var(--strong);}
.g-arrow{text-align:center; color:var(--blue); font-weight:800; margin:2px 0; font-size:.9rem;}
.g-key{display:inline-block; border:1px solid var(--line); border-bottom-width:2px; background:var(--card);
  border-radius:5px; padding:0 7px; font-size:.78rem; font-weight:700; color:var(--strong);
  font-family:"SF Mono",Consolas,monospace; box-shadow:0 1px 0 rgba(0,0,0,.06);}
.g-vline{border-left:3px solid rgba(var(--blue-rgb,4,163,240),.35); padding-left:16px; margin:10px 0 14px;}
@media print{ .g-btn,.g-where{display:none !important;} }