/* ══════════════════════════════════════════════════════════════════════
   云窗拾锦 · code 前缀页面 —— Lesson Lab 外观
   System: Lesson Lab (html-anything / teaching) · Tokens: Clockless light
   配套页面：index.html / grade.html / lesson.html
   配套脚本：assets/code-site.js
   数据源  ：data/catalog.js + data/preview_map.js
   ⚠️ 与 asset/site.css、common/deck/*.css 互不引用、互不覆盖。
   ══════════════════════════════════════════════════════════════════════ */

/* ── Tokens（Clockless · 适配中文）────────────────── */
:root{
  /* Brand */
  --primary:#a03b00;
  --primary-container:#c94c00;
  --on-primary:#ffffff;
  --primary-fixed:#ffdbcd;
  --primary-fixed-dim:#ffb597;
  --accent-glow:#e8400d;

  --secondary:#7b40e0;
  --secondary-soft:#f0e9fd;
  --tertiary:#4d44e3;
  --accent-cyan:#00b8d9;
  --cyan-soft:#e3f7fb;

  /* Surfaces（暖米色） */
  --bg:#faf4ee;
  --surface:#fffaf4;
  --surface-1:#ffffff;
  --surface-2:#f4ece5;
  --surface-3:#ede3d9;

  /* Text */
  --fg-1:#22170f;
  --fg-2:#6b5140;
  --fg-muted:#9c8271;

  /* Borders */
  --border:rgba(34,23,15,.08);
  --border-strong:rgba(34,23,15,.16);

  /* Status */
  --green:#0ea57a; --green-soft:#e3f6ed;
  --blue:#3b82f6;  --blue-soft:#e8f1fd;
  --yellow:#d9911c;--yellow-soft:#fbf1dd;
  --red:#d64533;   --red-soft:#fbeae6;

  /* 深色舞台（压图时用） */
  --stage-1:#161008;
  --stage-2:#2b1407;
  --stage-glaze:rgba(16,9,4,.46);
  --stage-glaze-2:rgba(16,9,4,.72);

  /* Typography */
  --font-headline:'Space Grotesk','Plus Jakarta Sans','PingFang SC','Microsoft YaHei',system-ui,sans-serif;
  --font-body:'Plus Jakarta Sans','PingFang SC','Microsoft YaHei','Noto Sans SC',system-ui,sans-serif;
  --font-cjk:'Noto Serif SC','Songti SC','STSong','SimSun','PMingLiU',serif;
  --font-kai:'WMXKai','Kaiti SC','KaiTi',serif;
  --font-mono:'SF Mono','JetBrains Mono','Cascadia Mono',ui-monospace,Menlo,monospace;

  /* Spacing（4px 系） */
  --sp-1:4px; --sp-2:8px; --sp-3:12px; --sp-4:16px; --sp-5:20px;
  --sp-6:24px; --sp-7:32px; --sp-8:40px; --sp-9:48px; --sp-10:64px; --sp-11:80px;

  /* Radius */
  --r-sm:8px; --r-md:12px; --r-lg:16px; --r-xl:20px; --r-2xl:28px; --r-pill:999px;

  /* Shadows */
  --sh-sm:0 1px 2px rgba(34,23,15,.05);
  --sh-md:0 4px 14px rgba(34,23,15,.08);
  --sh-lg:0 12px 34px rgba(34,23,15,.12);
  --sh-xl:0 30px 70px -30px rgba(25,12,4,.5);
  --sh-accent:0 10px 30px -12px rgba(160,59,0,.45);

  /* Gradients */
  --grad-primary:linear-gradient(135deg,#a03b00 0%,#c94c00 100%);
  --grad-hero:linear-gradient(135deg,#a03b00 0%,#c94c00 60%,#7b40e0 100%);
  --grad-cream:linear-gradient(180deg,#faf4ee 0%,#f4ebe2 100%);

  /* Motion */
  --ease-out:cubic-bezier(.22,1,.36,1);
  --dur:260ms;

  /* Layout */
  --maxw:1200px;
  --sx:clamp(18px,4.5vw,60px);
}

/* ── Base ─────────────────────────────────────────── */
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth}
html[data-ha-style]{background:var(--bg)}
body{
  margin:0;background:var(--bg);color:var(--fg-1);
  font:15.5px/1.72 var(--font-body);
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
}
body.dim::before{
  content:"";position:fixed;inset:0;z-index:0;pointer-events:none;opacity:.4;
  background-image:radial-gradient(1200px 400px at 86% -6%,rgba(201,76,0,.05),transparent 60%),
    radial-gradient(900px 520px at 6% 108%,rgba(123,64,224,.05),transparent 60%);
}
a{color:inherit;text-decoration:none}
img{display:block;max-width:100%}
::selection{background:var(--primary-fixed-dim);color:var(--stage-1)}
button,select,input{font-family:inherit}
:focus-visible{outline:2px solid var(--primary-container);outline-offset:2px;border-radius:6px}
.num{font-family:var(--font-mono);font-variant-numeric:tabular-nums}

.wrap{max-width:var(--maxw);margin:0 auto;padding:0 var(--sx)}
.wrap-narrow{max-width:1010px;margin:0 auto;padding:0 var(--sx)}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
.rule{height:1px;background:var(--border);border:0}

@font-face{
  font-family:"WMXKai";
  src:url("fonts/wmxkai.woff2") format("woff2");
  font-weight:400;font-display:swap;
}

/* Google 字体（在线时生效，离线优雅回退系统字体） */
@import url("https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@500;600;700&family=Plus+Jakarta+Sans:wght@400;500;600;700&display=swap");

::file-selector-button{font-family:inherit}

.scrollbar::-webkit-scrollbar{height:10px}
.scrollbar::-webkit-scrollbar-thumb{background:#d9cbbd;border-radius:9px;border:3px solid transparent;background-clip:content-box}
.scrollbar::-webkit-scrollbar-track{background:transparent}

/* ── 顶部实验台栏 ─────────────────────────────────── */
.lab-bar{
  position:sticky;top:0;z-index:60;
  background:rgba(250,244,238,.82);backdrop-filter:blur(14px);
  border-bottom:1px solid var(--border);
}
.lab-bar .inside{max-width:var(--maxw);margin:0 auto;padding:0 var(--sx);
  display:flex;align-items:center;gap:18px;height:62px}
.brand{display:flex;align-items:center;gap:11px;white-space:nowrap;cursor:pointer;padding:6px 8px;border-radius:10px;text-decoration:none;color:inherit}
.brand:hover{background:rgba(0,0,0,.05)}
.brand .wc{width:34px;height:34px;border-radius:11px;flex:none;
  background:var(--grad-hero);color:#fff;display:grid;place-items:center;
  font-family:var(--font-kai);font-size:19px;box-shadow:var(--sh-accent)}
.brand .logo{height:38px;width:auto;object-fit:contain;flex:none}
.brand .bn{font-family:var(--font-cjk);font-size:20px;letter-spacing:.14em;color:var(--fg-1)}
.brand .bn b{color:var(--primary-container);font-weight:400}
.brand .sv{margin-left:2px;font-size:10.5px;letter-spacing:.24em;color:var(--fg-muted);
  padding:2px 8px;border:1px solid var(--border-strong);border-radius:99px}
.lab-tools{margin-left:auto;display:flex;align-items:center;gap:8px}
.lab-link{padding:8px 14px;border-radius:var(--r-pill);font-size:13.5px;color:var(--fg-2);
  transition:background var(--dur),color var(--dur)}
.lab-link:hover{background:var(--surface-2);color:var(--fg-1)}
.lab-link[aria-current="page"]{background:var(--fg-1);color:var(--surface-1);font-weight:600}
.lab-link.ghostw{border:1px solid var(--border-strong)}
.lab-pill{display:inline-flex;align-items:center;gap:8px;padding:7px 14px;border-radius:var(--r-pill);
  background:var(--surface-1);border:1px solid var(--border);font-size:13px;color:var(--fg-2);
  box-shadow:var(--sh-sm);white-space:nowrap}
.lab-pill .dot{width:7px;height:7px;border-radius:50%;background:var(--green);
  box-shadow:0 0 0 3px var(--green-soft)}

/* ── 按钮（try / cta）────────────────────────────── */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:9px;
  padding:12px 24px;border-radius:var(--r-pill);font-size:14.5px;font-weight:600;
  border:1px solid transparent;cursor:pointer;line-height:1.1;white-space:nowrap;
  transition:transform var(--dur) var(--ease-out),box-shadow var(--dur),background var(--dur),color var(--dur);
}
.btn:active{transform:translateY(1px) scale(.99)}
.btn.primary{background:var(--grad-primary);color:var(--on-primary);box-shadow:var(--sh-accent)}
.btn.primary:hover{transform:translateY(-2px);box-shadow:0 14px 34px -12px rgba(160,59,0,.55)}
.btn.dark{background:var(--fg-1);color:var(--surface-1)}
.btn.dark:hover{transform:translateY(-2px);box-shadow:var(--sh-lg)}
.btn.ghost{background:var(--surface-1);border-color:var(--border-strong);color:var(--fg-2)}
.btn.ghost:hover{border-color:var(--primary);color:var(--primary);transform:translateY(-2px)}
.btn.ice{background:rgba(255,255,255,.14);border-color:rgba(255,255,255,.4);color:#fff;backdrop-filter:blur(6px)}
.btn.ice:hover{background:rgba(255,255,255,.24);transform:translateY(-2px)}
.btn.sm{padding:9px 16px;font-size:13px}
.btn.lg{padding:16px 32px;font-size:16px}
.btn .arr{transition:transform var(--dur) var(--ease-out);display:inline-block}
.btn:hover .arr{transform:translateX(4px)}

/* ── chip / tag / 标注 ───────────────────────────── */
.chip{display:inline-flex;align-items:center;gap:7px;padding:5px 12px;border-radius:var(--r-pill);
  font-size:12.5px;font-weight:500;white-space:nowrap}
.chip .dot{width:6px;height:6px;border-radius:50%;background:currentColor}
.chip.ink{background:var(--surface-3);color:var(--fg-2)}
.chip.green{background:var(--green-soft);color:#0b7a5a}
.chip.red{background:var(--red-soft);color:#b22f1f}
.chip.violet{background:var(--secondary-soft);color:#5c27b4}
.chip.cyan{background:var(--cyan-soft);color:#0a7a90}
.chip.ghostw{background:rgba(255,255,255,.13);color:#fff;border:1px solid rgba(255,255,255,.38)}
.chip.on-ink{background:rgba(16,9,4,.5);color:#fff;border:1px solid rgba(255,255,255,.22)}

.kicker{display:inline-flex;align-items:center;gap:10px;font-family:var(--font-headline);
  font-size:12px;font-weight:700;letter-spacing:.22em;text-transform:uppercase;color:var(--primary)}
.kicker::before{content:"";width:22px;height:2px;border-radius:2px;background:var(--grad-primary)}
.kicker .idx{font-family:var(--font-mono);color:var(--fg-muted);letter-spacing:0;font-weight:600}

.tag{display:inline-flex;align-items:center;gap:6px;padding:4px 11px;border-radius:var(--r-sm);
  font-size:12px;font-weight:600;letter-spacing:.03em}
.tag.ready{background:var(--grad-primary);color:#fff;box-shadow:var(--sh-accent)}
.tag.stock{background:var(--jade-soft,#e3f6ed);color:#0b7a5a}
.tag.none{background:var(--surface-3);color:var(--fg-muted)}

/* ── 段落标题 ─────────────────────────────────────── */
.sec{display:flex;align-items:flex-end;gap:18px;flex-wrap:wrap;margin-bottom:26px}
.sec .t{flex:1 1 300px}
.sec h2{margin:8px 0 0;font-family:var(--font-cjk);font-size:clamp(25px,3vw,34px);
  line-height:1.2;font-weight:600;letter-spacing:.02em;color:var(--fg-1)}
.sec h2 b{color:var(--primary-container);font-weight:600}
.sec .sub{margin:7px 0 0;font-size:14px;color:var(--fg-muted)}
.sec .more{font-size:13.5px;color:var(--fg-2);font-weight:600;padding-bottom:4px}
.sec .more:hover{color:var(--primary)}
.sec .more .arr{display:inline-block;transition:transform var(--dur) var(--ease-out)}
.sec .more:hover .arr{transform:translateX(4px)}

/* ═══════════════════════════════════════════════════════
   首页 —— 实验台总览（Lesson Lab 首页画布）
   ═══════════════════════════════════════════════════════ */

/* 首屏：主舞台 = 封面展台 + 年级步进轨（try-control） */
.lab-work{display:grid;grid-template-columns:minmax(0,1fr) 344px;gap:26px;align-items:stretch;
  padding:34px 0 6px}

.stage-hero{position:relative;border-radius:var(--r-2xl);overflow:hidden;min-height:520px;
  color:#fff;box-shadow:var(--sh-xl);isolation:isolate}
.stage-hero .sh-bg{position:absolute;inset:0;background-size:cover;background-position:center;
  transition:opacity .7s var(--ease-out),transform 5s var(--ease-out)}
.stage-hero .sh-bg.blur{filter:blur(2px) saturate(1.08);transform:scale(1.06)}
.stage-hero .sh-fade{position:absolute;inset:0;
  background:
    linear-gradient(200deg,rgba(16,9,4,.1) 0%,transparent 45%),
    linear-gradient(0deg,rgba(16,9,4,.82) 0%,rgba(16,9,4,.34) 46%,rgba(16,9,4,.14) 100%)}
.stage-hero .sh-badge{position:absolute;left:22px;top:20px;display:inline-flex;gap:8px;z-index:2}
.stage-hero .sh-body{position:absolute;left:0;right:0;bottom:0;padding:0 28px 30px;z-index:2}
.stage-hero .sh-kick{display:flex;align-items:center;gap:9px;font-family:var(--font-headline);
  font-size:12.5px;font-weight:700;letter-spacing:.22em;color:#ffe2cf}
.stage-hero .sh-kick::after{content:"";flex:1;max-width:60px;height:1px;background:rgba(255,255,255,.4)}
.stage-hero h1{margin:12px 0 0;font-family:var(--font-cjk);font-size:clamp(30px,3.8vw,46px);
  line-height:1.18;font-weight:600;letter-spacing:.03em;text-shadow:0 8px 40px rgba(0,0,0,.5)}
.stage-hero .sh-meta{margin-top:10px;display:flex;gap:9px;flex-wrap:wrap}
.stage-hero .sh-cta{margin-top:22px}
.stage-hero .sh-ghost{position:absolute;inset:0;z-index:1;display:grid;place-items:center;
  background:
    radial-gradient(120% 90% at 78% 16%,rgba(201,76,0,.34),transparent 56%),
    linear-gradient(150deg,#2b1407 0%,#161008 70%,#100b06 100%)}
.stage-hero .sh-ghost .lg{font-family:var(--font-cjk);font-size:74px;letter-spacing:.2em;color:rgba(255,255,255,.9);
  text-shadow:0 14px 60px rgba(0,0,0,.6)}
.stage-hero .sh-ghost .lg em{font-style:normal;color:#ffb597}
.stage-hero .sh-ghost .lg-sub{margin-top:14px;font-size:14px;color:rgba(255,255,255,.72);letter-spacing:.3em}
.stage-swap{animation:stageSwap .7s var(--ease-out)}
@keyframes stageSwap{0%{opacity:0;transform:translateY(14px)}100%{opacity:1;transform:none}}

/* 步进轨（年级切换 = try-control） */
.rail{background:var(--surface-1);border:1px solid var(--border);border-radius:var(--r-2xl);
  box-shadow:var(--sh-lg);padding:18px;display:flex;flex-direction:column;gap:8px}
.rail-cap{display:flex;align-items:center;gap:8px;padding:2px 6px 12px;border-bottom:1px dashed var(--border-strong)}
.rail-cap .cap{font-family:var(--font-headline);font-size:11.5px;font-weight:700;letter-spacing:.2em;
  text-transform:uppercase;color:var(--fg-muted)}
.rail-cap .cap::after{content:"";display:inline-block;width:22px;height:1.5px;margin-left:9px;
  vertical-align:middle;background:var(--grad-primary);border-radius:2px}
.rail-cap .pill{margin-left:auto;font-family:var(--font-mono);font-size:12px;color:var(--fg-muted)}
.rail-step{
  position:relative;display:flex;align-items:center;gap:13px;width:100%;padding:12px 14px;
  border-radius:var(--r-lg);border:1px solid transparent;background:transparent;cursor:pointer;
  text-align:left;color:var(--fg-2);transition:background var(--dur),border-color var(--dur),transform var(--dur);
}
.rail-step:hover{background:var(--surface-2);transform:translateX(2px)}
.rail-step .rs-idx{flex:none;width:36px;height:36px;border-radius:11px;display:grid;place-items:center;
  font-family:var(--font-cjk);font-size:17px;background:var(--surface-3);color:var(--fg-2);
  transition:background var(--dur),color var(--dur)}
.rail-step .rs-bdy{flex:1;min-width:0}
.rail-step .rs-t{font-size:14px;font-weight:600;color:var(--fg-1);letter-spacing:.02em}
.rail-step .rs-s{margin-top:1px;font-size:11.5px;color:var(--fg-muted)}
.rail-step .rs-p{flex:none;font-family:var(--font-mono);font-size:12px;color:var(--fg-muted)}
.rail-step[aria-pressed="true"]{
  background:var(--surface-1);border-color:var(--primary);box-shadow:var(--sh-md);
}
.rail-step[aria-pressed="true"] .rs-idx{background:var(--grad-primary);color:#fff;box-shadow:var(--sh-accent)}
.rail-step[aria-pressed="true"] .rs-t{color:var(--primary-container)}
.rail-step .rs-done{position:absolute;right:10px;top:9px;width:8px;height:8px;border-radius:50%;
  background:var(--green);opacity:0;transition:opacity var(--dur)}
.rail-step.has-ready .rs-done{opacity:1}
.rail-foot{padding:12px 6px 2px;border-top:1px dashed var(--border-strong);font-size:12px;color:var(--fg-muted);line-height:1.7}

/* 计数条（recap-strip / 遥测） */
.tally{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:var(--border);
  border:1px solid var(--border);border-radius:var(--r-2xl);overflow:hidden;margin:30px 0 0;
  box-shadow:var(--sh-md)}
.tally .cell{background:var(--surface-1);padding:20px 8px 18px;text-align:center}
.tally .n{font-family:var(--font-mono);font-size:clamp(22px,2.6vw,32px);font-weight:700;line-height:1.1;
  letter-spacing:-.01em}
.tally .n.zhu{color:var(--primary-container)}
.tally .n.vio{color:var(--secondary)}
.tally .n.cyn{color:#0a7a90}
.tally .l{margin-top:5px;font-size:12.5px;color:var(--fg-muted)}

/* 概念抽屉（concept-drawer） */
.concept-drawer{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
/* 网页课件优势（为什么不用下载） */
.adv-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:18px;margin-top:18px}
.adv{position:relative;background:var(--surface-1);border:1px solid var(--border);border-radius:16px;padding:26px 24px 22px;overflow:hidden}
.adv:hover{transform:translateY(-4px);box-shadow:var(--sh-lg)}
.adv::after{content:"";position:absolute;top:0;left:0;right:0;height:3px;background:linear-gradient(90deg,#c94c00,#7b40e0)}
.adv-ic{display:inline-flex;align-items:center;justify-content:center;width:42px;height:42px;border-radius:12px;background:linear-gradient(150deg,#c94c00,#7b40e0);color:#fff;font-size:18px;margin-bottom:14px}
.adv h3{margin:0 0 8px;font-family:var(--font-cjk);font-size:20px;font-weight:600;letter-spacing:.02em}
.adv p{margin:0;font-size:13.5px;color:var(--fg-2);line-height:1.8}
.concept-card{position:relative;background:var(--surface-1);border:1px solid var(--border);
  border-radius:var(--r-xl);padding:24px 24px 22px;box-shadow:var(--sh-md);overflow:hidden;
  transition:transform var(--dur) var(--ease-out),box-shadow var(--dur)}
.concept-card:hover{transform:translateY(-5px);box-shadow:var(--sh-lg)}
.concept-card::after{content:"";position:absolute;top:0;left:0;right:0;height:3px;
  background:var(--grad-primary)}
.concept-card.cc2::after{background:linear-gradient(90deg,#7b40e0,#c94c00)}
.concept-card.cc3::after{background:linear-gradient(90deg,#00b8d9,#7b40e0)}
.concept-card .cc-badge{display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-headline);font-size:11.5px;font-weight:700;letter-spacing:.18em;
  text-transform:uppercase;color:var(--primary)}
.concept-card.cc2 .cc-badge{color:var(--secondary)}
.concept-card.cc3 .cc-badge{color:#0a7a90}
.concept-card h3{margin:14px 0 0;font-family:var(--font-cjk);font-size:21px;font-weight:600;letter-spacing:.02em}
.concept-card p{margin:10px 0 0;font-size:13.5px;color:var(--fg-2);line-height:1.8}
.concept-card .cc-meta{margin-top:14px;display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.concept-card .cc-go{margin-top:16px;display:inline-flex;align-items:center;gap:7px;font-size:13.5px;
  font-weight:600;color:var(--primary)}
.concept-card.cc2 .cc-go{color:var(--secondary)}
.concept-card.cc3 .cc-go{color:#0a7a90}
.concept-card .cc-go .arr{transition:transform var(--dur) var(--ease-out);display:inline-block}
.concept-card:hover .cc-go .arr{transform:translateX(4px)}
.concept-card .cc-ic{position:absolute;right:16px;bottom:10px;font-family:var(--font-cjk);
  font-size:64px;line-height:1;color:rgba(34,23,15,.045);user-select:none}

/* 成品展台（deck-stage） */
.deck-stage{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:20px}
.fcard{position:relative;border-radius:var(--r-xl);overflow:hidden;color:#fff;display:flex;flex-direction:column;
  box-shadow:var(--sh-lg);transition:transform var(--dur) var(--ease-out),box-shadow var(--dur)}
.fcard:hover{transform:translateY(-6px);box-shadow:var(--sh-xl)}
.fcard .fimg{position:relative;aspect-ratio:16/10;overflow:hidden;background:#efe6dd}
.fcard .fimg img{width:100%;height:100%;object-fit:cover;transition:transform .8s var(--ease-out)}
.fcard:hover .fimg img{transform:scale(1.08)}
.fcard .fimg::after{content:"";position:absolute;inset:0;
  background:linear-gradient(180deg,rgba(16,9,4,.05) 0%,transparent 38%,rgba(16,9,4,.72) 100%)}
.fcard .fno{position:absolute;left:14px;top:13px;z-index:2;font-family:var(--font-headline);
  font-size:11.5px;font-weight:700;letter-spacing:.16em;color:#fff;background:rgba(16,9,4,.4);
  padding:4px 11px;border-radius:var(--r-pill);backdrop-filter:blur(4px)}
.fcard .fmag{position:absolute;right:14px;top:13px;z-index:2;width:36px;height:36px;border-radius:50%;
  display:grid;place-items:center;background:rgba(255,255,255,.18);border:1px solid rgba(255,255,255,.5);
  font-size:15px;backdrop-filter:blur(4px);transition:transform var(--dur),background var(--dur)}
.fcard:hover .fmag{background:var(--primary-container);transform:scale(1.12) rotate(90deg)}
.fcard .fbody{position:absolute;left:0;right:0;bottom:0;z-index:2;padding:15px 17px 17px}
.fcard .fb-tags{display:flex;gap:7px;align-items:center;flex-wrap:wrap;margin-bottom:8px}
.fcard h3{margin:0;font-family:var(--font-cjk);font-size:20px;font-weight:600;line-height:1.3;letter-spacing:.02em}
.fcard .fmeta{margin-top:6px;font-size:12px;color:rgba(255,255,255,.78)}
.fcard .fgo{margin-top:14px;padding:10px 18px;display:none}
.fcard:hover .fgo{display:inline-flex}

/* 自习检查台（check-yourself） */
.check-panel{background:var(--surface-1);border:1px solid var(--border);border-radius:var(--r-2xl);
  box-shadow:var(--sh-lg);padding:26px 28px}
.check-panel .cp-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px 26px}
.cp-row{display:flex;align-items:center;gap:14px}
.cp-row .cp-name{flex:none;width:96px;font-weight:600;font-size:14px;color:var(--fg-1)}
.cp-row .cp-track{flex:1;height:7px;border-radius:4px;background:var(--surface-3);overflow:hidden}
.cp-row .cp-track i{display:block;height:100%;border-radius:4px;background:var(--grad-primary);
  transform-origin:left;transform:scaleX(0);transition:transform 1.1s var(--ease-out)}
.cp-row.in .cp-track i{transform:scaleX(var(--w,0))}
.cp-row .cp-n{flex:none;width:88px;text-align:right;font-family:var(--font-mono);font-size:12.5px;
  color:var(--fg-muted)}
.cp-row .cp-n b{color:var(--primary-container);font-weight:700}
.check-panel .cp-legend{margin-top:18px;padding-top:16px;border-top:1px dashed var(--border-strong);
  display:flex;gap:18px;flex-wrap:wrap;font-size:12.5px;color:var(--fg-muted)}
.check-panel .cp-legend .f{display:inline-flex;align-items:center;gap:7px}
.check-panel .cp-legend .sw{width:10px;height:10px;border-radius:3px}

/* 复习条（recap-strip） */
.recap-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--border);
  border:1px solid var(--border);border-radius:var(--r-2xl);overflow:hidden;box-shadow:var(--sh-md)}
.recap-strip .r{background:var(--surface-1);padding:22px 22px}
.recap-strip .r .h{font-family:var(--font-headline);font-size:11px;font-weight:700;letter-spacing:.2em;
  text-transform:uppercase;color:var(--fg-muted);display:flex;align-items:center;gap:8px}
.recap-strip .r .h::after{content:"";width:18px;height:1.5px;background:var(--grad-primary);border-radius:2px}
.recap-strip .r p{margin:9px 0 0;font-size:13.5px;color:var(--fg-2);line-height:1.75}

/* ═══════════════════════════════════════════════════════
   课文目录 —— 章/步进轨 + 章舞台
   ═══════════════════════════════════════════════════════ */
.bread{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--fg-muted);flex-wrap:wrap}
.bread a:hover{color:var(--primary)}
.bread .sep{opacity:.5}
.page-head{padding:38px 0 22px}
.page-head h1{margin:10px 0 0;font-family:var(--font-cjk);font-size:clamp(30px,4vw,44px);
  font-weight:600;letter-spacing:.02em;line-height:1.16}
.page-head h1 b{color:var(--primary-container);font-weight:600}
.page-head .ph-sub{margin:12px 0 0;max-width:680px;font-size:14.5px;color:var(--fg-2)}

.rail-page{display:grid;grid-template-columns:290px minmax(0,1fr);gap:30px;align-items:start;padding:6px 0 30px}
.rail-page .rail{position:sticky;top:82px}

.chapter-stage{min-width:0}
.stage-banner{position:relative;border-radius:var(--r-2xl);overflow:hidden;color:#fff;
  box-shadow:var(--sh-xl);margin-bottom:26px;isolation:isolate}
.stage-banner .sb-bgs{position:absolute;inset:0;background:linear-gradient(150deg,#2b1407,#161008)}
.stage-banner .sb-bgs img{position:absolute;height:160%;object-fit:cover;border-radius:var(--r-md);
  box-shadow:var(--sh-xl)}
.stage-banner .sb-bgs img.sb-main{height:100%;width:100%;border-radius:0;inset:0;filter:blur(2px) saturate(1.1);
  transform:scale(1.06);transition:transform 5s var(--ease-out)}
.stage-banner:hover .sb-bgs img.sb-main{transform:scale(1.12)}
.stage-banner .sb-fade{position:absolute;inset:0;
  background:linear-gradient(90deg,rgba(16,9,4,.82) 0%,rgba(16,9,4,.5) 48%,rgba(16,9,4,.12) 100%)}
.stage-banner .sb-in{position:relative;z-index:2;padding:40px var(--sx) 38px;max-width:600px}
.stage-banner .sb-in h2{margin:10px 0 0;font-family:var(--font-cjk);font-size:clamp(28px,3.6vw,40px);
  font-weight:600;letter-spacing:.08em}
.stage-banner .sb-meta{margin-top:10px;font-size:14px;color:rgba(255,255,255,.8)}
.stage-banner .sb-bar{margin-top:20px;height:6px;border-radius:3px;background:rgba(255,255,255,.18);
  overflow:hidden;max-width:360px}
.stage-banner .sb-bar i{display:block;height:100%;border-radius:3px;background:linear-gradient(90deg,#ffb597,#c94c00);
  transform-origin:left;transform:scaleX(0);transition:transform 1.2s var(--ease-out) .15s}
.stage-banner.in .sb-bar i{transform:scaleX(var(--w,0))}
.stage-banner .sb-chips{position:relative;z-index:2;margin-top:18px;display:flex;gap:9px;flex-wrap:wrap}

/* 章节（单元） */
.chapter{margin:0 0 4px}
.chapter-head{display:flex;align-items:center;gap:14px;margin:26px 0 18px}
.chapter-head .u-ic{flex:none;width:42px;height:42px;border-radius:13px;display:grid;place-items:center;
  background:var(--grad-primary);color:#fff;font-family:var(--font-cjk);font-size:19px;
  box-shadow:var(--sh-accent)}
.chapter-head .u-ic.alt{background:linear-gradient(135deg,#7b40e0,#4d44e3);box-shadow:0 10px 26px -12px rgba(123,64,224,.55)}
.chapter-head h3{margin:0;font-family:var(--font-cjk);font-size:20px;font-weight:600;letter-spacing:.02em}
.chapter-head .u-line{flex:1;height:1px;background:var(--border)}
.chapter-head .u-n{margin-left:auto;font-family:var(--font-mono);font-size:12px;color:var(--fg-muted)}

/* 课卡（整卡即入口：点任意处进本课环节页） */
.lgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(204px,1fr));gap:16px}
.lcard{position:relative;background:var(--surface-1);border:1px solid var(--border);
  border-radius:var(--r-xl);overflow:hidden;display:flex;flex-direction:column;
  text-decoration:none;color:inherit;cursor:pointer;
  box-shadow:var(--sh-md);transition:transform var(--dur) var(--ease-out),box-shadow var(--dur)}
.lcard:hover{transform:translateY(-6px);box-shadow:var(--sh-lg)}
.lcard.off{opacity:.86}
.lcard .limg{position:relative;aspect-ratio:16/7.6;overflow:hidden;background:var(--surface-3)}
.lcard .limg img{width:100%;height:100%;object-fit:cover;transition:transform .8s var(--ease-out)}
.lcard:hover .limg img{transform:scale(1.08)}
.lcard .limg::after{content:"";position:absolute;inset:0;
  background:linear-gradient(180deg,rgba(16,9,4,.08) 0%,transparent 40%,rgba(16,9,4,.5) 100%)}
.lcard .lph{position:relative;width:100%;height:100%;display:grid;place-items:center;color:#fff;overflow:hidden}
.lcard .lph .lph-char{font-family:var(--font-cjk);font-size:58px;line-height:1;text-shadow:0 10px 36px rgba(0,0,0,.4)}
.lcard .lph .lph-in{position:absolute;inset:0;
  background:radial-gradient(120% 120% at 30% 0%,rgba(255,255,255,.16),transparent 46%)}
.lcard .ltag{position:absolute;left:12px;top:12px;z-index:2}
.lcard .lplay{position:absolute;left:12px;bottom:12px;z-index:2;display:inline-flex;align-items:center;gap:6px;
  font-size:12px;color:#fff;background:rgba(16,9,4,.45);padding:5px 12px;border-radius:var(--r-pill);
  backdrop-filter:blur(4px);border:1px solid rgba(255,255,255,.25)}
.lcard .lbody{padding:12px 14px 13px;display:flex;flex-direction:column;flex:1}
.lcard .lkind{display:flex;align-items:center;gap:7px;flex-wrap:wrap;min-height:20px}
.lcard .lkind .k{font-size:11.5px;padding:3px 9px;border-radius:var(--r-sm);background:var(--surface-2);
  color:var(--fg-2);letter-spacing:.02em}
.lcard .lkind .k.kred{background:var(--red-soft);color:#b22f1f}
.lcard .lkind .k.kvio{background:var(--secondary-soft);color:#5c27b4}
.lcard .lkind .k.kcyn{background:var(--cyan-soft);color:#0a7a90}
.lcard h3{margin:8px 0 0;font-family:var(--font-cjk);font-size:16.5px;line-height:1.4;font-weight:600;letter-spacing:.01em}
.lcard .lblurb{margin-top:6px;font-size:12px;line-height:1.6;color:var(--fg-2);
  display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.lcard .lthumbs{margin-top:10px;display:flex;gap:5px;flex-wrap:wrap;min-height:20px;margin-top:auto;padding-top:10px}
.lcard .lthumbs i{display:inline-flex;align-items:center;gap:4px;font-style:normal;font-size:10.5px;
  color:var(--fg-muted);padding:3px 7px;border-radius:var(--r-sm);background:var(--surface-2)}
.lcard .lthumbs i.on{color:#b22f1f;background:var(--red-soft)}

/* ═══════════════════════════════════════════════════════
   本课环节 —— 步进轨驱动课台（Lesson Lab 核心）
   ═══════════════════════════════════════════════════════ */
.lesson-work{display:grid;grid-template-columns:290px minmax(0,1fr);gap:30px;align-items:start;
  padding:30px 0 6px}
.lesson-work .rail{position:sticky;top:82px}
.rail-step[data-state="none"]{opacity:.66}

/* 课台主舞台 */
.stage-lead{position:relative;border-radius:var(--r-2xl);overflow:hidden;color:#fff;
  box-shadow:var(--sh-xl);margin-bottom:16px;isolation:isolate}
.stage-lead .sl-bg{position:absolute;inset:0;background-size:cover;background-position:center;
  filter:blur(2px) saturate(1.06);transform:scale(1.07);transition:opacity .6s var(--ease-out)}
.stage-lead .sl-bg.ghost{filter:none}
.stage-lead .sl-fade{position:absolute;inset:0;
  background:linear-gradient(0deg,rgba(16,9,4,.86) 0%,rgba(16,9,4,.32) 55%,rgba(16,9,4,.16) 100%)}
.stage-lead .sl-in{position:relative;z-index:2;padding:44px var(--sx) 40px;max-width:100%}
.stage-lead .sl-in h1{margin:14px 0 0;font-family:var(--font-cjk);font-size:clamp(30px,4.2vw,50px);
  font-weight:600;letter-spacing:.05em;line-height:1.2;text-shadow:0 10px 50px rgba(0,0,0,.55)}
.stage-lead .sl-chips{margin-top:18px;display:flex;gap:9px;flex-wrap:wrap}
.stage-lead .sl-lead{margin-top:20px;max-width:640px;font-size:15px;color:rgba(255,255,255,.84)}

/* 齐备度四格（check panel 的迷你版） */
.probe{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:18px 0 0;max-width:760px}
.probe .p{
  display:flex;align-items:center;gap:11px;padding:12px 14px;border-radius:var(--r-lg);
  background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.16);backdrop-filter:blur(8px);
}
.probe .p.off{opacity:.45}
.probe .p .ic{flex:none;width:34px;height:34px;border-radius:10px;display:grid;place-items:center;
  font-size:14px;background:rgba(255,255,255,.16);color:#fff}
.probe .p.on .ic{background:var(--grad-primary);box-shadow:var(--sh-accent)}
.probe .p .tx{line-height:1.3}
.probe .p .tx b{display:block;font-size:13px;font-weight:600}
.probe .p .tx i{font-style:normal;font-size:11px;color:rgba(255,255,255,.66)}

/* 步骤详情台（rail 点击后切换） */
.step-stage{min-height:300px}
.step-stage .ss-cover{display:grid;grid-template-columns:minmax(0,1fr) 292px;gap:22px;align-items:center;
  background:var(--surface-1);border:1px solid var(--border);border-radius:var(--r-2xl);
  box-shadow:var(--sh-lg);padding:28px 30px;margin-bottom:14px;
  transition:background var(--dur)}
.step-stage .ss-cover.is-ready{background:linear-gradient(180deg,var(--surface-1) 0%,#fff4ee 100%)}
.step-stage h2{margin:0;font-family:var(--font-cjk);font-size:27px;font-weight:600;letter-spacing:.02em;
  display:flex;align-items:center;gap:13px;flex-wrap:wrap}
.step-stage h2 .ss-ic{flex:none;width:46px;height:46px;border-radius:13px;display:grid;place-items:center;
  font-size:19px;background:var(--surface-2);color:var(--fg-2)}
.step-stage .ss-cover.is-ready h2 .ss-ic{background:var(--grad-primary);color:#fff;box-shadow:var(--sh-accent)}
.step-stage .ss-desc{margin-top:10px;font-size:14px;color:var(--fg-2);line-height:1.85;max-width:560px}
.step-stage .ss-meta{margin-top:14px;display:flex;gap:8px;flex-wrap:wrap}
.step-stage .ss-act{margin-top:22px;display:flex;gap:12px;flex-wrap:wrap;align-items:center}
.step-stage .ss-side{border-left:1px dashed var(--border-strong);padding-left:24px}
.step-stage .ss-side .ss-tip{font-size:16.5px;color:var(--fg-2);line-height:1.95}
.ss-video{position:relative;border-radius:14px;overflow:hidden;aspect-ratio:16/9;background:#000;
  box-shadow:var(--sh-md);margin-top:18px}
.ss-video .ss-frame{position:absolute;inset:0;width:100%;height:100%;border:0;display:block}
.ss-vmeta{display:flex;align-items:center;gap:18px;flex-wrap:wrap;margin-top:12px;font-size:12.5px;color:var(--fg-muted)}
.ss-vmeta .kv b{color:var(--fg-2)}
.ss-vmeta a{margin-left:auto;color:var(--primary);font-weight:600;font-size:13px;text-decoration:none}
.ss-vmeta a:hover{text-decoration:underline}
.ss-swap{animation:stageSwap .55s var(--ease-out)}

/* 环节小卡（concept：step 摘要） */
.flow-mini{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin-top:20px}
.flow-mini .fm{display:flex;align-items:center;gap:12px;padding:15px 16px;border-radius:var(--r-lg);
  background:var(--surface-1);border:1px solid var(--border);box-shadow:var(--sh-sm);
  transition:transform var(--dur) var(--ease-out),border-color var(--dur)}
.flow-mini .fm:hover{transform:translateY(-3px);border-color:var(--primary)}
.flow-mini .fm .fm-ic{flex:none;width:38px;height:38px;border-radius:11px;display:grid;place-items:center;
  background:var(--surface-2);color:var(--fg-2);font-size:15px}
.flow-mini .fm.on .fm-ic{background:var(--green-soft);color:#0b7a5a}
.flow-mini .fm .fm-t{font-size:13.5px;font-weight:600}
.flow-mini .fm .fm-s{font-size:11.5px;color:var(--fg-muted);margin-top:1px}

/* 上一篇 / 下一篇（recap） */
.pager{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:18px;padding:44px 0 8px}
.pager a{position:relative;border-radius:var(--r-xl);overflow:hidden;padding:22px 24px;color:#fff;min-height:150px;
  display:flex;flex-direction:column;justify-content:flex-end;box-shadow:var(--sh-lg);
  transition:transform var(--dur) var(--ease-out),box-shadow var(--dur)}
.pager a:hover{transform:translateY(-5px);box-shadow:var(--sh-xl)}
.pager a .pgbg{position:absolute;inset:0;background-size:cover;background-position:center;
  transition:transform .8s var(--ease-out)}
.pager a:hover .pgbg{transform:scale(1.06)}
.pager a .pgbg::after{content:"";position:absolute;inset:0;
  background:linear-gradient(180deg,rgba(16,9,4,.14),rgba(16,9,4,.84))}
.pager a.next{text-align:right}
.pager .pdir{position:relative;z-index:2;font-family:var(--font-headline);font-size:11px;font-weight:700;
  letter-spacing:.22em;text-transform:uppercase;color:#ffd9c6}
.pager .ptitle{position:relative;z-index:2;margin-top:6px;font-family:var(--font-cjk);font-size:23px;
  letter-spacing:.04em}
.pager .pmeta{position:relative;z-index:2;font-size:11.5px;color:rgba(255,255,255,.72);margin-top:4px}

/* 空态 */
.empty{padding:76px 20px;text-align:center;color:var(--fg-muted);
  border:1.5px dashed var(--border-strong);border-radius:var(--r-2xl);margin:30px 0 10px;background:var(--surface)}
.empty .big{font-family:var(--font-cjk);font-size:44px;color:#cdbcae;margin-bottom:10px}
.empty a{color:var(--primary);text-decoration:underline}

/* ── 页脚 ─────────────────────────────────────────── */
.footz{margin-top:96px;border-top:1px solid var(--border);background:var(--grad-cream)}
.footz .wrap{display:flex;gap:34px;flex-wrap:wrap;padding-top:38px;padding-bottom:44px}
.footz .fc{flex:1 1 240px}
.footz .fbrand{display:flex;align-items:center;gap:10px;font-family:var(--font-cjk);font-size:19px;letter-spacing:.1em}
.footz .fbrand .wc{width:28px;height:28px;border-radius:9px;background:var(--grad-hero);color:#fff;
  display:grid;place-items:center;font-size:15px}
.footz .fbrand img.wc{background:#fff;object-fit:contain;padding:2px;box-shadow:var(--sh-sm)}
.footz .fbrand b{color:var(--primary-container);font-weight:400}
.footz .fdesc{margin-top:10px;font-size:13px;color:var(--fg-muted);max-width:310px;line-height:1.8}
.footz h4{margin:0 0 12px;font-family:var(--font-headline);font-size:11.5px;font-weight:700;
  letter-spacing:.18em;text-transform:uppercase;color:var(--fg-2)}
.footz a.flink{display:block;margin:7px 0;font-size:13.5px;color:var(--fg-2)}
.footz a.flink:hover{color:var(--primary)}
.footz .fnote{margin-top:16px;font-size:12px;color:var(--fg-muted);line-height:1.9}
.footz .fnote code{background:var(--surface-2);padding:1px 6px;border-radius:5px;font-size:11.5px}

/* ── 进入动画 ─────────────────────────────────────── */
.rv{opacity:0;transform:translateY(20px);transition:opacity .7s var(--ease-out),transform .7s var(--ease-out);
  transition-delay:calc(var(--d,0)*70ms)}
.rv.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{transition:none!important;animation:none!important}
  .rv{opacity:1;transform:none}
  .cp-row .cp-track i,.stage-banner .sb-bar i{transform:scaleX(var(--w,0))!important}
}

/* ── 首页封面轮播 ─────────────────────────────────── */
.carousel{position:relative;border-radius:var(--r-2xl);overflow:hidden;min-height:520px;
  box-shadow:var(--sh-xl);isolation:isolate;background:#efe6dd}
.carousel .cs-slide{position:absolute;inset:0;background-size:cover;background-position:center;
  opacity:0;transform:scale(1.04);transition:opacity 1.1s var(--ease-out),transform 6.5s var(--ease-out);
  pointer-events:none;color:#fff;display:block;text-decoration:none}
.carousel .cs-slide.on{opacity:1;transform:scale(1);pointer-events:auto;z-index:1}
.carousel .cs-shade{position:absolute;inset:0;
  background:linear-gradient(0deg,rgba(16,9,4,.78) 0%,rgba(16,9,4,.28) 46%,rgba(16,9,4,.12) 100%)}
.carousel .cs-body{position:absolute;left:0;right:0;bottom:54px;padding:0 30px;z-index:2}
.carousel .cs-kick{display:inline-flex;align-items:center;gap:9px;font-family:var(--font-headline);
  font-size:12.5px;font-weight:700;letter-spacing:.2em;color:#ffe2cf}
.carousel .cs-kick::after{content:"";flex:1;max-width:60px;height:1px;background:rgba(255,255,255,.4)}
.carousel .cs-title{margin-top:10px;display:block;font-family:var(--font-cjk);
  font-size:clamp(26px,3.2vw,40px);line-height:1.2;font-weight:600;letter-spacing:.03em;
  text-shadow:0 10px 44px rgba(0,0,0,.5)}
.carousel .cs-go{margin-top:16px;display:inline-flex;align-items:center;gap:8px;font-size:14px;font-weight:600;
  color:#ffd9c6;padding:10px 18px;border-radius:var(--r-pill);background:rgba(255,255,255,.13);
  border:1px solid rgba(255,255,255,.38);backdrop-filter:blur(6px);
  transition:background var(--dur),transform var(--dur) var(--ease-out)}
.carousel .cs-go .arr{transition:transform var(--dur) var(--ease-out);display:inline-block}
.carousel .cs-slide:hover .cs-go{background:var(--primary-container);transform:translateY(-2px)}
.carousel .cs-slide:hover .cs-go .arr{transform:translateX(4px)}
.carousel .cs-dots{position:absolute;left:0;right:0;bottom:18px;display:flex;justify-content:center;gap:8px;z-index:3}
.carousel .cs-dot{width:8px;height:8px;border-radius:99px;border:0;cursor:pointer;
  background:rgba(255,255,255,.38);transition:width var(--dur) var(--ease-out),background var(--dur)}
.carousel .cs-dot:hover{background:rgba(255,255,255,.7)}
.carousel .cs-dot.on{width:24px;background:#fff}
.carousel .cs-sub{display:block;margin-top:8px;font-size:14px;letter-spacing:.04em;color:rgba(255,255,255,.85)}

/* 年级入口卡：六个年级 · 两行三列 */
.grade-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}
@media (max-width:860px){.grade-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
.gcard{position:relative;display:flex;flex-direction:column;border-radius:var(--r-xl);overflow:hidden;
  background:var(--surface-1);border:1px solid var(--border);text-decoration:none;color:inherit;
  box-shadow:var(--sh-md);transition:transform var(--dur) var(--ease-out),box-shadow var(--dur)}
.gcard:hover{transform:translateY(-6px);box-shadow:var(--sh-lg)}
.gcard .gimg{position:relative;aspect-ratio:16/9;overflow:hidden;background:var(--surface-3)}
.gcard .gimg img{width:100%;height:100%;object-fit:cover;transition:transform .8s var(--ease-out)}
.gcard:hover .gimg img{transform:scale(1.07)}
.gcard .gimg::after{content:"";position:absolute;inset:0;
  background:linear-gradient(180deg,rgba(16,9,4,.06) 0%,transparent 42%,rgba(16,9,4,.42) 100%)}
.gcard .gbody{padding:14px 16px 15px;display:flex;flex-direction:column;gap:5px}
.gcard .gname{font-family:var(--font-cjk);font-size:18px;font-weight:600;letter-spacing:.02em}
.gcard .gsub{font-size:12px;color:var(--fg-muted);line-height:1.5}
.gcard .ggo{margin-top:6px;display:inline-flex;align-items:center;gap:7px;font-size:13px;font-weight:600;
  color:var(--primary)}
.gcard .ggo .arr{display:inline-block;transition:transform var(--dur) var(--ease-out)}
.gcard:hover .ggo .arr{transform:translateX(4px)}
.carousel-empty{height:100%;min-height:520px;display:grid;place-items:center;text-align:center;
  background:radial-gradient(120% 110% at 70% 10%,#2b1407,#100b06 70%);color:#fff;border-radius:var(--r-2xl)}
.carousel-empty .big{font-family:var(--font-cjk);font-size:clamp(34px,4vw,56px);letter-spacing:.16em;
  color:rgba(255,255,255,.92);text-shadow:0 14px 60px rgba(0,0,0,.6)}
.carousel-empty .sub{margin-top:12px;font-size:14px;color:rgba(255,255,255,.68);letter-spacing:.06em}

/* ── 金课进度：单元切换 + 现在在学 ─────────────────── */
.unit-chips{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:20px}
.unit-chip{font-size:13px;font-weight:600;color:var(--fg-2);background:var(--surface-1);
  border:1px solid var(--border-strong);border-radius:var(--r-pill);padding:8px 15px;cursor:pointer;
  transition:background var(--dur),color var(--dur),border-color var(--dur),transform var(--dur) var(--ease-out),box-shadow var(--dur)}
.unit-chip:hover{transform:translateY(-2px);border-color:var(--primary)}
.unit-chip.on{background:var(--grad-primary);color:#fff;border-color:transparent;box-shadow:var(--sh-accent)}
.fcard .fno.live{background:var(--accent-glow);color:#fff}
.sch-note{margin-top:18px;font-size:12.5px;color:var(--fg-muted)}
.sch-note b{color:var(--primary-container)}

/* ── 年级按钮行（首页 · 目录页共用 · 通栏六等分） ───── */
.grade-btns{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:12px;margin:0 0 26px}
.grade-btn{justify-content:center;font-size:15px;font-weight:600;letter-spacing:.08em;
  padding:15px 8px;border-radius:var(--r-lg);background:var(--surface-1);
  border:1px solid var(--border-strong);color:var(--fg-1);box-shadow:var(--sh-sm)}
.grade-btn:hover{transform:translateY(-2px);border-color:var(--primary);color:var(--primary);box-shadow:var(--sh-md)}
.grade-btn.on{background:var(--grad-primary);color:#fff;border-color:transparent;box-shadow:var(--sh-accent)}
.grade-btn:focus-visible{outline:2px solid var(--primary);outline-offset:3px}

/* ── 本课环节：三步切换（通栏 · 左轨已取消） ─────────── */
.step-tabs{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin:4px 0 24px}
.step-tabs .rail-step{background:var(--surface-1);border:1px solid var(--border);box-shadow:var(--sh-sm)}
.step-tabs .rail-step:hover{transform:translateY(-3px);box-shadow:var(--sh-md);border-color:var(--border-strong)}
.step-tabs .rail-step[aria-pressed="true"]{border-color:var(--primary);box-shadow:var(--sh-md)}

/* 目录页：横幅下方的「正在上第 N 单元」 */
.now-unit{margin:24px 0 10px;padding:22px 22px 24px;border-radius:var(--r-2xl);
  background:linear-gradient(180deg,var(--surface-2),var(--surface-1));
  border:1px solid var(--border-strong);box-shadow:var(--sh-md)}
.now-unit .sec .t h2 b{color:var(--primary)}
.now-unit .sec{margin-bottom:18px}
.now-unit .sec .t .sub{margin-top:6px}
/* 目录页列表：一行三个 */
#stage .lgrid{grid-template-columns:repeat(3,minmax(0,1fr))}

/* ── 本课环节：卡片直连 ───────────────────────────── */
.probe a.p{text-decoration:none;color:inherit;cursor:pointer}
.probe a.p:hover{transform:translateY(-2px);border-color:rgba(255,183,151,.75);background:rgba(255,255,255,.16)}
.probe .p .p-go{margin-left:auto;font-size:12px;opacity:.85;color:#ffd9c6;
  transition:transform var(--dur) var(--ease-out)}
.probe a.p:hover .p-go{transform:translate(2px,-1px)}
.flow-mini a.fm{text-decoration:none;color:inherit;cursor:pointer}
.flow-mini a.fm:hover{transform:translateY(-3px);border-color:var(--primary);box-shadow:var(--sh-md)}
.flow-mini .fm .fm-go{margin-left:auto;font-size:12px;opacity:.7;color:var(--fg-muted);
  transition:transform var(--dur) var(--ease-out),color var(--dur)}
.flow-mini a.fm:hover .fm-go{color:var(--primary);transform:translate(2px,0)}

/* ── 响应式 ─────────────────────────────────────────── */
@media (max-width:1080px){
  .lab-work,.lesson-work{grid-template-columns:minmax(0,1fr)}
  .rail-page{grid-template-columns:minmax(0,1fr)}
  #stage .lgrid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .now-unit{padding:18px 16px 20px}
  .grade-btns{grid-template-columns:repeat(3,minmax(0,1fr))}
  .rail-page .rail,.lesson-work .rail{position:static}
  .rail{flex-direction:row;overflow-x:auto;scrollbar-width:thin}
  .rail .rail-cap{display:none}
  .rail .rail-step{flex:none;width:210px}
  .rail .rail-step .rs-done{display:none}
  .rail-foot{display:none}
  .lesson-work .rail{gap:8px}
  .step-stage .ss-cover{grid-template-columns:1fr}
  .step-stage .ss-side{border-left:0;border-top:1px dashed var(--border-strong);padding-left:0;padding-top:18px}
  .probe{grid-template-columns:1fr 1fr}
  .concept-drawer{grid-template-columns:1fr 1fr}
.adv-grid{grid-template-columns:1fr}
}
@media (max-width:760px){
  .brand .sv{display:none}
  .lab-pill{display:none}
  #stage .lgrid{grid-template-columns:minmax(0,1fr)}
  .grade-btns{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}
  .grade-btn{font-size:14px;padding:13px 6px}
  .step-tabs{grid-template-columns:minmax(0,1fr);gap:10px}
  .now-unit{margin:18px 0 8px;padding:16px 13px 18px}
  .tally{grid-template-columns:1fr 1fr}
  .concept-drawer{grid-template-columns:1fr}
  .check-panel .cp-grid{grid-template-columns:1fr}
  .flow-mini{grid-template-columns:1fr}
  .probe{grid-template-columns:1fr 1fr}
  .stage-hero{min-height:480px}
  .stage-hero .sh-body{padding:0 20px 24px}
  .recap-strip{grid-template-columns:1fr}
}
/* ══════════════════════════════════════════════════════════════════════
   同单元其他课文（P2-16：课程页上下文内链）
   ══════════════════════════════════════════════════════════════════════ */
.unit-mates{margin-top:64px}
.um-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.um-card{display:flex;gap:12px;align-items:center;padding:14px 16px;background:var(--surface-1);border:1px solid var(--border);border-radius:var(--r-lg);text-decoration:none;transition:all var(--dur) var(--ease-out)}
.um-card:hover{border-color:var(--border-strong);transform:translateY(-2px);box-shadow:var(--sh-md)}
.um-img{width:64px;height:44px;border-radius:8px;overflow:hidden;flex-shrink:0;background:var(--surface-3)}
.um-img img{width:100%;height:100%;object-fit:cover}
.um-img .lph{width:100%;height:100%;display:flex;align-items:center;justify-content:center}
.um-img .lph-char{font-size:20px;font-weight:700;color:#fff}
.um-body{display:flex;flex-direction:column;gap:4px;min-width:0}
.um-tag{font-size:11px;color:var(--fg-muted)}
.um-t{font-size:14px;font-weight:600;color:var(--fg-1);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
@media (max-width:768px){
  .um-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:480px){
  .um-grid{grid-template-columns:1fr}
}