:root{
  --bg:#12343b; --bg2:#1d4d4f; --card:#ffffff; --ink:#1e293b; --muted:#64748b;
  --line:#e2e8f0; --brand:#0f766e; --brand2:#2563eb; --accent:#dc2626;
  --ok:#16a34a; --okbg:#dcfce7; --bad:#dc2626; --badbg:#fee2e2; --warn:#d97706;
  --soft:#f8fafc; --shadow:0 1px 3px rgba(15,23,42,.08),0 8px 24px rgba(15,23,42,.06);
  --radius:8px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,"PingFang SC","Microsoft YaHei",sans-serif;
  color:var(--ink);background:var(--soft);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.container{max-width:1080px;margin:0 auto;padding:0 20px}

/* Header */
.topbar{background:linear-gradient(135deg,var(--bg) 0%,var(--bg2) 100%);color:#fff;position:sticky;top:0;z-index:50;box-shadow:var(--shadow)}
.topbar .container{display:flex;align-items:center;gap:18px;height:60px}
.brand{font-weight:700;font-size:18px;color:#fff;display:flex;align-items:center;gap:9px}
.brand .logo{width:30px;height:30px;border-radius:8px;background:linear-gradient(135deg,var(--accent),var(--brand2));display:grid;place-items:center;font-size:16px}
.nav{margin-left:auto;display:flex;gap:6px;flex-wrap:wrap}
.nav a{color:#cbd5e1;padding:7px 13px;border-radius:9px;font-size:14px;font-weight:500}
.nav a:hover{background:rgba(255,255,255,.1);color:#fff;text-decoration:none}
.nav a.active{background:rgba(255,255,255,.16);color:#fff}

/* Hero */
.hero{background:linear-gradient(135deg,#12343b,#1d4d4f);color:#fff;padding:54px 0 60px}
.hero h1{font-size:40px;margin:0 0 8px;line-height:1.15}
.hero .sub{font-size:19px;color:#c7d2fe;margin:0 0 22px}
.hero .meta{display:flex;gap:10px;flex-wrap:wrap;margin-top:18px}
.pill{background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.18);color:#e0e7ff;
  padding:6px 14px;border-radius:999px;font-size:13.5px}
.cta{display:inline-flex;gap:10px;margin-top:26px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:8px;background:var(--brand);color:#fff;border:none;
  padding:12px 22px;border-radius:11px;font-size:15px;font-weight:600;cursor:pointer;transition:.15s}
.btn:hover{background:var(--brand2);text-decoration:none;transform:translateY(-1px)}
.btn.ghost{background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.25)}
.btn.lg{padding:14px 26px;font-size:16px}

/* Sections */
section.block{padding:40px 0}
h2.sec{font-size:26px;margin:0 0 6px}
.lead{color:var(--muted);margin:0 0 26px;font-size:16px}

/* Cards grid */
.grid{display:grid;gap:18px}
.grid.cards{grid-template-columns:repeat(auto-fill,minmax(300px,1fr))}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow);transition:.15s;display:flex;flex-direction:column}
.card:hover{transform:translateY(-3px);box-shadow:0 12px 30px rgba(15,23,42,.12)}
.card .num{font-size:13px;font-weight:700;color:var(--brand);letter-spacing:.04em;text-transform:uppercase}
.card h3{margin:6px 0 6px;font-size:19px}
.card .sections-tag{font-size:13px;color:var(--muted);margin-bottom:10px}
.card .desc{font-size:14.5px;color:#475569;flex:1}
.card .foot{display:flex;align-items:center;justify-content:space-between;margin-top:16px;padding-top:14px;border-top:1px solid var(--line)}
.qcount{font-size:13px;color:var(--muted)}
.card .go{font-size:14px;font-weight:600}

/* Lesson plan detail */
.lp{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);margin-bottom:26px;overflow:hidden}
.lp-head{background:linear-gradient(135deg,#ecfeff,#f0fdf4);padding:22px 24px;border-bottom:1px solid var(--line)}
.lp-head .num{font-size:13px;font-weight:700;color:var(--brand);text-transform:uppercase;letter-spacing:.04em}
.lp-head h3{margin:4px 0 4px;font-size:23px}
.lp-head .sections-tag{color:var(--muted);font-size:14px}
.lp-head .big{margin-top:10px;font-size:15px;color:#475569;font-style:italic}
.lp-body{padding:22px 24px}
.lp-body h4{font-size:15px;text-transform:uppercase;letter-spacing:.03em;color:var(--brand2);margin:18px 0 10px}
.lp-body h4:first-child{margin-top:0}
.obj{margin:0;padding-left:20px}
.obj li{margin:5px 0}
.timeline{border-left:2px solid var(--line);margin-left:6px;padding-left:0}
.tl-item{position:relative;padding:6px 0 14px 22px}
.tl-item::before{content:"";position:absolute;left:-7px;top:11px;width:12px;height:12px;border-radius:50%;background:var(--brand);border:2px solid #fff}
.tl-item.brk::before{background:var(--warn)}
.tl-time{font-size:12.5px;font-weight:700;color:var(--brand);font-variant-numeric:tabular-nums}
.tl-what{font-weight:600}
.tl-detail{font-size:14px;color:#475569}
.formulas{display:grid;gap:8px}
.formula{background:var(--soft);border:1px solid var(--line);border-radius:9px;padding:9px 13px;font-size:15px;overflow-x:auto}
.lp-foot{padding:16px 24px;background:var(--soft);border-top:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:10px}

/* Quiz */
.quiz-head{background:linear-gradient(135deg,#12343b,#1d4d4f);color:#fff;padding:30px 0 26px}
.quiz-head h1{margin:0 0 4px;font-size:28px}
.quiz-head .sub{color:#c7d2fe;font-size:15px}
.progwrap{position:sticky;top:60px;z-index:40;background:var(--soft);padding:12px 0;border-bottom:1px solid var(--line)}
.progrow{display:flex;align-items:center;gap:14px}
.progbar{flex:1;height:9px;background:var(--line);border-radius:999px;overflow:hidden}
.progbar > i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--accent),var(--brand));transition:width .3s}
.progtext{font-size:13px;color:var(--muted);white-space:nowrap;font-variant-numeric:tabular-nums}
.q{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:22px;margin:18px 0}
.q .qhead{display:flex;justify-content:space-between;gap:10px;margin-bottom:6px}
.q .qn{font-size:13px;font-weight:700;color:var(--brand)}
.q .src{font-size:12px;color:var(--muted)}
.q .stem{font-size:16.5px;margin:8px 0 16px}
.opts{display:grid;gap:10px}
.opt{display:flex;gap:12px;align-items:flex-start;border:1.5px solid var(--line);border-radius:11px;padding:12px 15px;cursor:pointer;background:#fff;transition:.12s;font-size:15.5px}
.opt:hover{border-color:var(--brand);background:#fafaff}
.opt .lab{flex:none;width:26px;height:26px;border-radius:7px;background:var(--soft);border:1px solid var(--line);display:grid;place-items:center;font-weight:700;font-size:13px;color:var(--muted)}
.opt.sel{border-color:var(--brand);background:#eef2ff}
.opt.sel .lab{background:var(--brand);color:#fff;border-color:var(--brand)}
.opt.correct{border-color:var(--ok);background:var(--okbg)}
.opt.correct .lab{background:var(--ok);color:#fff;border-color:var(--ok)}
.opt.wrong{border-color:var(--bad);background:var(--badbg)}
.opt.wrong .lab{background:var(--bad);color:#fff;border-color:var(--bad)}
.opt.locked{cursor:default}
.expl{margin-top:14px;padding:13px 15px;border-radius:10px;background:#f0f9ff;border:1px solid #bae6fd;font-size:14.5px;display:none}
.expl.show{display:block}
.expl .tag{font-weight:700;color:var(--accent);font-size:12.5px;text-transform:uppercase;letter-spacing:.03em;display:block;margin-bottom:3px}
.verdict{font-size:13px;font-weight:700;margin-bottom:8px}
.verdict.ok{color:var(--ok)}
.verdict.no{color:var(--bad)}

.quizbar{position:sticky;bottom:0;background:#fff;border-top:1px solid var(--line);padding:14px 0;box-shadow:0 -4px 16px rgba(15,23,42,.06);z-index:40}
.quizbar .container{display:flex;gap:12px;align-items:center;flex-wrap:wrap}
.quizbar .spacer{flex:1}
.btn.sm{padding:9px 16px;font-size:14px}
.btn.outline{background:#fff;color:var(--brand);border:1.5px solid var(--brand)}
.btn.outline:hover{background:#eef2ff}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}

/* Results modal */
.scorecard{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:28px;text-align:center;margin:24px 0}
.scorecard .big{font-size:52px;font-weight:800;color:var(--brand);line-height:1}
.scorecard .pct{font-size:16px;color:var(--muted);margin-top:6px}
.ring{--p:0;width:140px;height:140px;border-radius:50%;margin:0 auto 14px;
  background:conic-gradient(var(--brand) calc(var(--p)*1%), var(--line) 0);display:grid;place-items:center}
.ring > div{width:108px;height:108px;border-radius:50%;background:#fff;display:grid;place-items:center;flex-direction:column}
.ring b{font-size:30px}
.ring span{font-size:12px;color:var(--muted)}

.footer{padding:30px 0;color:var(--muted);font-size:13px;text-align:center;border-top:1px solid var(--line);margin-top:30px}
.notice{background:#fffbeb;border:1px solid #fde68a;border-radius:11px;padding:13px 16px;font-size:14px;color:#92400e;margin:14px 0}
.empty{padding:50px;text-align:center;color:var(--muted)}
.katex{font-size:1.04em}
/* Start card / forms */
.startcard{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:26px;max-width:560px}
.startcard h3{margin:0 0 8px;font-size:20px}
.fld{display:block;margin:14px 0 8px}
.fld span{display:block;font-size:13px;font-weight:600;color:var(--muted);margin-bottom:6px}
.namehint{display:block;color:var(--bad);font-weight:600;font-style:normal;font-size:13px;margin:2px 0 8px;line-height:1.45}
.fld input{width:100%;padding:12px 14px;border:1.5px solid var(--line);border-radius:10px;font-size:16px;font-family:inherit}
.fld input:focus{outline:none;border-color:var(--brand)}
.ferr{color:var(--bad);font-size:13.5px;min-height:18px;margin:4px 0 10px}
.ferr.ok{color:var(--ok)}

/* Result / submission */
.substatus{font-size:14px;margin:14px auto 4px;max-width:520px;padding:9px 13px;border-radius:9px;background:var(--soft);border:1px solid var(--line)}
.substatus.ok{background:var(--okbg);border-color:#86efac;color:#166534}
.substatus.warn{background:#fffbeb;border-color:#fde68a;color:#92400e}
.recap{display:flex;flex-wrap:wrap;gap:6px;justify-content:center;margin:16px 0}
.chip{font-size:12px;font-weight:700;padding:3px 8px;border-radius:7px}
.chip.ok{background:var(--okbg);color:#166534}
.chip.no{background:var(--badbg);color:#991b1b}
.codecard{margin-top:18px}
.codecard h3{margin:0 0 6px;font-size:18px}
.codebox{width:100%;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:12px;
  border:1.5px solid var(--line);border-radius:10px;padding:11px 13px;resize:vertical;background:var(--soft);color:#334155}

/* Toast (partial submit feedback) */
.toast{position:fixed;left:50%;bottom:78px;transform:translateX(-50%) translateY(20px);
  max-width:560px;width:calc(100% - 32px);background:#0f172a;color:#fff;border-radius:12px;
  padding:13px 18px;font-size:14px;box-shadow:0 10px 30px rgba(15,23,42,.3);opacity:0;
  pointer-events:none;transition:.25s;z-index:60}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0);pointer-events:auto}
.toast.warn{background:#78350f}
.toast .codebox{color:#0f172a}
.linklike{background:none;border:none;color:#93c5fd;text-decoration:underline;cursor:pointer;font:inherit;padding:0}

/* Progress badges */
.pbadge{display:inline-block;font-size:12px;font-weight:700;padding:3px 9px;border-radius:999px}
.pbadge.done{background:var(--okbg);color:#166534}
.pbadge.wip{background:#fef3c7;color:#92400e}
.wiprow td{background:#fffdf5}

/* Teacher dashboard */
.statgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:14px;margin:18px 0}
.statcard{background:var(--card);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);padding:16px 18px;text-align:center}
.statcard b{display:block;font-size:26px;color:var(--brand)}
.statcard span{font-size:12.5px;color:var(--muted)}
.tbar{display:flex;align-items:center;gap:10px;margin-bottom:12px;flex-wrap:wrap}
.tablewrap{overflow-x:auto}
.gradetable{width:100%;border-collapse:collapse;font-size:14px}
.gradetable th{text-align:left;font-size:12px;text-transform:uppercase;letter-spacing:.03em;color:var(--muted);padding:9px 10px;border-bottom:2px solid var(--line)}
.gradetable td{padding:10px;border-bottom:1px solid var(--line);vertical-align:middle}
.gradetable tr:hover td{background:var(--soft)}
.gradetable .muted{color:var(--muted);font-size:12.5px}
.gbadge{display:inline-grid;place-items:center;min-width:26px;height:26px;padding:0 6px;border-radius:7px;font-weight:700;font-size:13px;color:#fff}
.gbadge.gA{background:#16a34a}.gbadge.gB{background:#0ea5e9}.gbadge.gC{background:#d97706}.gbadge.gD{background:#f97316}.gbadge.gF{background:#dc2626}
.tbtn{border:1px solid var(--line);background:#fff;border-radius:8px;padding:5px 11px;font-size:13px;font-weight:600;color:var(--brand);cursor:pointer;margin-left:5px}
.tbtn:hover{background:#eef2ff}
.tbtn.del{color:var(--bad)}
.tbtn.del:hover{background:var(--badbg)}
.btn.danger{color:var(--bad);border-color:#fecaca}
.btn.danger:hover{background:var(--badbg)}
.detaillist{display:flex;flex-direction:column;gap:14px;margin-top:8px}
.dq{border:1px solid var(--line);border-left:4px solid var(--line);border-radius:10px;padding:14px 16px;background:#fff}
.dq.okrow{border-left-color:var(--ok)}
.dq.norow{border-left-color:var(--bad)}
.dqhead{display:flex;justify-content:space-between;gap:10px;font-size:13px;margin-bottom:6px}
.vok{color:var(--ok);font-weight:700}.vno{color:var(--bad);font-weight:700}
.opts.mini{gap:7px;margin-top:8px}
.opts.mini .opt{padding:8px 12px;font-size:14px;cursor:default}
.pickedtag{color:var(--brand);font-style:normal;font-weight:700;font-size:12px}
code{background:var(--soft);padding:1px 6px;border-radius:5px;font-size:13px}

/* Analytics */
.anselect{display:flex;align-items:center;gap:8px;font-size:13px;font-weight:600;color:var(--muted)}
.anselect select{padding:7px 10px;border:1.5px solid var(--line);border-radius:9px;font-size:14px;font-family:inherit;background:#fff;color:var(--ink)}
.anh{font-size:15px;text-transform:uppercase;letter-spacing:.03em;color:var(--brand2);margin:22px 0 4px}
.anlead{margin:0 0 12px;font-size:13px}
.accpill{display:inline-block;min-width:46px;text-align:center;font-weight:700;font-size:13px;padding:3px 9px;border-radius:999px}
.accpill.acc-hi{background:var(--okbg);color:#166534}
.accpill.acc-mid{background:#fef3c7;color:#92400e}
.accpill.acc-lo{background:var(--badbg);color:#991b1b}
.rankcell{font-size:16px;font-weight:700}
.diffstem{font-size:12.5px;color:var(--muted);max-width:380px;margin-top:3px;
  display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.answercell,.wrongcell{font-size:13px;max-width:340px;line-height:1.35}
.answerline{margin-bottom:6px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.answerline:last-child{margin-bottom:0}
.answerlabel{display:inline-block;min-width:48px;margin-right:4px;font-size:11px;font-weight:800;text-transform:uppercase;letter-spacing:.03em}
.answerline.correct .answerlabel{color:#166534}
.answerline.wrong .answerlabel{color:#991b1b}
.diffstem .katex,.answercell .katex,.wrongcell .katex{font-size:1em}
#diffTable td{vertical-align:top}

@media (max-width:640px){
  .hero h1{font-size:30px}
  .topbar .container{height:auto;min-height:52px;flex-wrap:wrap;gap:6px 10px;padding-top:8px;padding-bottom:8px}
  .brand{font-size:16px;width:100%}
  .nav{margin-left:0;width:100%;gap:4px}
  .nav a{padding:6px 11px;font-size:13px}
  .topbar{position:static}
  .progwrap{top:0}
  .hero{padding:34px 0 38px}
  .quizbar .container{gap:8px}
  .btn.sm{padding:8px 12px;font-size:13px}
}

/* ===== ChemES additions ===== */
.unit-block{margin:26px 0 8px}
.unit-title,.unit-h{display:flex;align-items:baseline;gap:10px;flex-wrap:wrap;font-size:20px;margin:26px 0 12px;color:var(--ink)}
.unit-tag{background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff;font-size:12px;font-weight:700;padding:3px 9px;border-radius:8px;letter-spacing:.5px}
.unit-blurb{font-size:13px;font-weight:400;color:var(--muted)}
.notice{margin-top:18px;background:#fff7ed;border:1px solid #fed7aa;color:#9a3412;padding:12px 16px;border-radius:12px;font-size:14px}
.muted{color:var(--muted);font-size:13px}
.btn.xs{padding:3px 9px;font-size:12px}
.cta.col{flex-direction:column;align-items:stretch;gap:8px;margin-top:14px}
.card.pad{padding:18px}

/* lesson hub */
.lesson-shell{display:grid;gap:22px}
.lesson-summary{display:block;overflow:hidden}
.lesson-summary:hover{transform:none}
.lesson-summary .obj{margin:6px 0 14px;padding-left:20px}
.lesson-summary .obj li{margin:4px 0}
.lesson-summary h4{margin:0 0 8px;font-size:13px;text-transform:uppercase;letter-spacing:.5px;color:var(--muted)}
.lesson-summary h4:not(:first-child){margin-top:16px}
.lesson-actionbar{margin:-18px;padding:14px 18px;background:#f8fafc;display:flex;align-items:center;justify-content:center;gap:18px;flex-wrap:wrap}
.lesson-actions{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap}

/* ===== Taste-style course experiment ===== */
.taste-home{
  background:#f4f7f2;
}
.taste-home .topbar{
  background:rgba(10,34,39,.94);
  backdrop-filter:saturate(140%) blur(14px);
}
.taste-home .brand .logo{
  border-radius:8px;
  background:#f25c3d;
}
.taste-home .nav a.active{
  background:#f2c94c;
  color:#10262a;
}
.home-hero{
  position:relative;
  min-height:50svh;
  display:grid;
  align-items:end;
  overflow:hidden;
  padding:36px 0 42px;
  background:
    linear-gradient(90deg,rgba(6,24,28,.9) 0%,rgba(6,24,28,.72) 44%,rgba(6,24,28,.14) 100%),
    linear-gradient(0deg,rgba(6,24,28,.7),rgba(6,24,28,0) 42%),
    var(--hero-img) center/cover no-repeat;
}
.home-hero::before{
  content:"";
  position:absolute;
  inset:0;
  background:
    radial-gradient(circle at 18% 24%,rgba(125,211,252,.18),transparent 22%);
  mix-blend-mode:screen;
  opacity:.56;
  pointer-events:none;
}
.home-hero::after{
  content:"";
  position:absolute;
  inset:auto 0 0;
  height:170px;
  background:linear-gradient(0deg,#f4f7f2 0%,rgba(244,247,242,0) 100%);
}
.hero-inner{
  position:relative;
  z-index:1;
}
.eyebrow{
  margin:0 0 12px;
  color:#f2c94c;
  font-size:13px;
  font-weight:800;
  text-transform:uppercase;
  letter-spacing:0;
}
.home-hero h1{
  max-width:720px;
  font-size:64px;
  line-height:.96;
  margin:0 0 12px;
  text-wrap:balance;
}
.home-hero .sub{
  max-width:650px;
  color:#e5f2ee;
  font-size:18px;
  line-height:1.45;
}
.hero-stats{
  max-width:820px;
}
.hero-stats .pill{
  border-radius:8px;
  border-color:rgba(255,255,255,.24);
  background:rgba(255,255,255,.13);
  color:#fff;
}
.hero-stats .pill b{
  color:#f2c94c;
  margin-right:5px;
}
.home-hero .btn{
  border-radius:8px;
  background:#f25c3d;
  box-shadow:0 14px 34px rgba(242,92,61,.25);
}
.home-hero .btn:hover{
  background:#f2c94c;
  color:#10262a;
}
.home-hero .btn.ghost{
  background:rgba(255,255,255,.12);
  box-shadow:none;
}
.home-hero .btn.ghost:hover{
  background:#fff;
}
.marquee{
  overflow:hidden;
  background:#10262a;
  color:#f2c94c;
  border-top:1px solid rgba(255,255,255,.12);
  border-bottom:1px solid rgba(255,255,255,.12);
}
.marquee-track{
  display:flex;
  width:max-content;
  animation:marqueeMove 28s linear infinite;
}
.marquee span{
  display:block;
  padding:13px 24px;
  font-size:13px;
  font-weight:900;
  letter-spacing:0;
}
@keyframes marqueeMove{
  from{transform:translateX(0)}
  to{transform:translateX(-50%)}
}
.visual-band{
  background:#f4f7f2;
  padding:26px 0 10px;
}
.visual-grid{
  display:grid;
  grid-template-columns:1.1fr .9fr .9fr;
  gap:16px;
  align-items:stretch;
}
.visual-tile{
  margin:0;
  min-height:230px;
  position:relative;
  overflow:hidden;
  border-radius:8px;
  background:#10262a;
  box-shadow:0 18px 44px rgba(16,38,42,.14);
}
.visual-tile:first-child{
  min-height:300px;
}
.visual-tile img{
  width:100%;
  height:100%;
  display:block;
  object-fit:cover;
}
.visual-tile::after{
  content:"";
  position:absolute;
  inset:0;
  background:linear-gradient(0deg,rgba(6,24,28,.68),transparent 58%);
}
.visual-tile figcaption{
  position:absolute;
  left:16px;
  right:16px;
  bottom:14px;
  z-index:1;
  color:#fff;
  font-weight:800;
  line-height:1.25;
}
.taste-section{
  background:#f4f7f2;
  padding-top:38px;
}
.taste-section .sec,
.taste-workflow .sec{
  font-size:44px;
  line-height:1;
}
.taste-section .lead{
  max-width:820px;
  color:#47605f;
  font-size:18px;
}
.unit-showcase{
  display:grid;
  gap:34px;
}
.taste-home .unit-block{
  margin:0;
  padding:26px 0 2px;
  border-top:2px solid #dbe7df;
}
.taste-home .unit-title{
  align-items:flex-start;
  margin:0 0 18px;
  gap:12px;
}
.taste-home .unit-tag{
  border-radius:8px;
  background:#10262a;
  color:#f2c94c;
  letter-spacing:0;
}
.taste-home .unit-blurb{
  flex-basis:100%;
  max-width:680px;
  color:#47605f;
}
.taste-home .grid.cards{
  grid-template-columns:repeat(auto-fill,minmax(270px,1fr));
}
.taste-home .card{
  border-radius:8px;
  border-color:#d9e4df;
  box-shadow:0 12px 30px rgba(16,38,42,.08);
}
.taste-home .lesson-card{
  min-height:250px;
  background:
    linear-gradient(135deg,#fff 0%,#fff 60%,#f9e7bb 100%);
}
.taste-home .card .num{
  color:#f25c3d;
  letter-spacing:0;
}
.taste-home .card h3{
  font-size:20px;
  line-height:1.2;
}
.taste-home .card .desc{
  color:#445b5b;
}
.taste-home .card:hover{
  border-color:#f25c3d;
  transform:translateY(-5px);
}
.taste-workflow{
  background:#10262a;
  color:#fff;
  border-top:none;
}
.taste-workflow .lead,
.taste-workflow .desc,
.taste-workflow .qcount{
  color:#d5e5e0;
}
.taste-workflow .card{
  background:#f8fbf8;
  color:#10262a;
  border-radius:8px;
}
.taste-workflow .notice{
  background:#fff8df;
  border-color:#f2c94c;
  color:#61450b;
}
.editorial-head{
  position:relative;
  overflow:hidden;
  padding:54px 0 48px;
  background:
    linear-gradient(90deg,rgba(6,24,28,.9),rgba(6,24,28,.58)),
    var(--hero-img) center/cover no-repeat;
}
.editorial-head::after{
  display:none;
}
.editorial-head .container{
  position:relative;
  z-index:1;
}
.editorial-head h1{
  font-size:66px;
  line-height:1;
}
.page-banner{
  padding:34px 0 32px;
  min-height:190px;
  display:flex;
  align-items:center;
}
.page-banner h1{
  font-size:42px;
  margin-bottom:8px;
}
.page-banner .sub{
  max-width:760px;
}
.page-banner .eyebrow{
  margin-bottom:8px;
}
.reveal{
  opacity:0;
  transform:translateY(18px);
  transition:opacity .55s ease,transform .55s ease;
}
.reveal.is-visible{
  opacity:1;
  transform:translateY(0);
}
@media (prefers-reduced-motion:reduce){
  .marquee-track{animation:none}
  .reveal{opacity:1;transform:none;transition:none}
}
@media (max-width:760px){
  .home-hero{
    min-height:50svh;
    padding:34px 0 36px;
    background:
      linear-gradient(0deg,rgba(6,24,28,.88),rgba(6,24,28,.5)),
      var(--hero-img) center/cover no-repeat;
  }
  .home-hero h1{
    font-size:38px;
  }
  .home-hero .sub{
    font-size:16px;
  }
  .taste-section .sec,
  .taste-workflow .sec,
  .editorial-head h1{
    font-size:34px;
  }
  .page-banner{
    min-height:170px;
    padding:30px 0 28px;
  }
  .page-banner h1{
    font-size:34px;
  }
  .hero-stats .pill{
    width:calc(50% - 5px);
    justify-content:center;
    text-align:center;
  }
  .visual-grid{
    grid-template-columns:1fr;
  }
  .visual-tile,
  .visual-tile:first-child{
    min-height:210px;
  }
  .marquee span{
    padding:11px 18px;
  }
  .taste-section .lead{
    font-size:16px;
  }
}
.lesson-actions .btn{white-space:nowrap}
.lesson-navbtn{min-width:118px;justify-content:center}
.lmain{min-width:0}
.tabs{display:flex;gap:6px;margin:0 auto 16px;max-width:1180px}
.tab{border:1px solid var(--line);background:#fff;padding:8px 16px;border-radius:10px 10px 0 0;cursor:pointer;font-size:14px;font-weight:600;color:var(--muted)}
.tab.active{color:var(--brand);border-bottom-color:#fff;background:#fff}
.frame{width:100%;height:78vh;min-height:520px;border:1px solid var(--line);border-radius:12px;background:#fff}
@media(max-width:860px){.lesson-actionbar{align-items:stretch}.lesson-actions{width:100%;justify-content:center}.frame{height:70vh}}

/* FlexBook-style local reader */
.reader-heading{max-width:1180px;margin:0 auto 16px;display:flex;align-items:baseline;gap:12px;color:var(--muted)}
.reader-heading span{font-size:13px;text-transform:uppercase;letter-spacing:.08em;font-weight:800;color:var(--brand)}
.reader-heading b{font-size:18px;color:var(--ink)}
.reader-layout{display:grid;grid-template-columns:minmax(150px,15fr) minmax(0,85fr);gap:18px;align-items:start;justify-content:center;width:100%;max-width:1180px;margin:0 auto}
.reader-toc{position:sticky;top:78px;max-height:calc(100vh - 96px);overflow:hidden;background:#fff;border:1px solid var(--line);border-radius:8px;padding:12px;box-shadow:var(--shadow);display:flex;flex-direction:column}
.toc-list{overflow:auto;min-height:0}
.toc-ch{border-bottom:1px solid var(--line);padding-bottom:10px;margin-bottom:10px}
.toc-ch:last-child{border-bottom:0;margin-bottom:0;padding-bottom:0}
.toc-ch>a{font-weight:800;color:var(--ink)}
.toc-ch div{display:grid;gap:5px;margin-top:8px}
.toc-ch div a{font-size:12.5px;line-height:1.35;color:#475569}
.toc-nav{display:grid;gap:8px;border-top:1px solid var(--line);padding-top:10px;margin-top:10px;background:#fff;flex-shrink:0}
.toc-nav-title{font-size:11px;text-transform:uppercase;letter-spacing:.06em;font-weight:800;color:var(--muted)}
.toc-nav .btn{width:100%;font-size:12.5px;padding:8px 9px}
.reader-content{display:grid;gap:18px}
.reader-chapter{background:#fff;border:1px solid var(--line);border-radius:8px;box-shadow:var(--shadow);overflow:hidden;scroll-margin-top:84px}
.reader-chapter>header{padding:28px 36px;border-bottom:1px solid var(--line);background:#f8fafc}
.reader-chapter h2{margin:3px 0 0;font-size:30px;line-height:1.2}
.reader-section{border-bottom:1px solid var(--line);scroll-margin-top:84px}
.reader-section:last-child{border-bottom:0}
.reader-section summary{list-style:none;cursor:pointer;padding:18px 36px;font-weight:800;color:#12343b;font-size:19px}
.reader-section summary::-webkit-details-marker{display:none}
.reader-section summary span{display:inline-block;min-width:54px;color:var(--brand)}
.reader-section.is-target summary{background:#ecfeff}
.reader-body{padding:0 36px 36px;font-size:19px;line-height:1.8;color:#334155}
.reader-body p{margin:0 0 18px}
.reader-figure{margin:18px 0;padding:14px;border:1px solid var(--line);border-radius:8px;background:#f8fafc}
.reader-figure img{display:block;max-width:100%;max-height:420px;margin:0 auto;border-radius:6px}
.reader-figure figcaption{font-size:13px;color:var(--muted);text-align:center;margin-top:8px}
.reader-check{margin:14px 0;padding:12px 14px;border-left:4px solid var(--brand);background:#f0fdfa;border-radius:0 8px 8px 0;font-weight:600}
.reader-resource{margin:14px 0;padding:12px 14px;border:1px solid #bae6fd;background:#f0f9ff;border-radius:8px;font-size:14px;color:#075985;word-break:break-word}
.reader-resource span{font-weight:800;text-transform:uppercase;font-size:11px;letter-spacing:.04em;margin-right:8px}
.notes-list{display:grid;gap:10px}
.note-item{display:grid;grid-template-columns:34px 1fr;gap:12px;background:#fff;border:1px solid var(--line);border-radius:8px;padding:12px 14px;box-shadow:var(--shadow)}
.note-item span{width:26px;height:26px;border-radius:6px;background:#ecfeff;color:var(--brand);display:grid;place-items:center;font-weight:800;font-size:12px}
.note-item p{margin:0;color:#334155}
@media(max-width:1120px){.reader-layout{grid-template-columns:1fr;max-width:900px}.reader-toc{position:static;max-height:none;overflow:visible}.toc-list{overflow:visible}.reader-toc .toc-ch div{display:flex;flex-wrap:wrap;gap:8px}.reader-toc .toc-ch{border-bottom:1px solid var(--line);width:100%}.toc-nav{grid-template-columns:1fr 1fr}.toc-nav-title{grid-column:1/-1}.toc-nav .btn{width:auto}}
@media(max-width:640px){.reader-chapter>header{padding:22px 20px}.reader-chapter h2{font-size:25px}.reader-section summary{padding:15px 20px;font-size:17px}.reader-body{padding:0 20px 24px;font-size:17px}.reader-section summary span{min-width:46px}}

/* flashcards */
.deckbar{display:flex;align-items:center;gap:12px;margin-bottom:18px}
.deckname{font-weight:700}
.flashcard{perspective:1400px;max-width:620px;margin:0 auto 18px;cursor:pointer}
.fc-inner{position:relative;width:100%;min-height:260px;transition:transform .5s;transform-style:preserve-3d}
.flashcard.flipped .fc-inner{transform:rotateY(180deg)}
.fc-face{position:absolute;inset:0;backface-visibility:hidden;border-radius:18px;box-shadow:var(--shadow);
  display:flex;flex-direction:column;align-items:center;justify-content:center;padding:30px;text-align:center}
.fc-front{background:linear-gradient(135deg,#312e81,#4f46e5);color:#fff}
.fc-back{background:#fff;border:1px solid var(--line);color:var(--ink);transform:rotateY(180deg)}
.fc-kicker{font-size:11px;letter-spacing:2px;opacity:.7;margin-bottom:14px}
.fc-term{font-size:30px;font-weight:800}
.fc-def{font-size:18px;line-height:1.5}
.fc-hint{position:absolute;bottom:14px;font-size:11px;opacity:.6}

/* dashboard */
.grid.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:14px;margin-bottom:18px}
.statcard{background:#fff;border:1px solid var(--line);border-radius:14px;padding:16px 18px;box-shadow:var(--shadow)}
.statcard b{display:block;font-size:24px;color:var(--brand)}
.statcard span{font-size:13px;color:var(--muted)}
.ptable{width:100%;border-collapse:collapse;background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden}
.ptable td{padding:9px 12px;border-top:1px solid var(--line);font-size:14px}
.ptable td.lc{width:42px;color:var(--muted);text-align:center}
.ptable td.st{width:140px}.ptable td.ac{width:64px;text-align:right}
.pbadge{display:inline-block;font-size:12px;padding:2px 9px;border-radius:999px;background:#f1f5f9;color:var(--muted)}
.pbadge.done{background:var(--okbg);color:#166534}
.pbadge.wip{background:#fef9c3;color:#854d0e}
#who{padding:4px 8px;border:1px solid rgba(255,255,255,.4);border-radius:8px;background:rgba(255,255,255,.12);color:#fff}
#who::placeholder{color:#c7d2fe}