/* Design tokens: modular type scale 1.25, 8px spacing grid, Material-style elevation */
:root{
  --fs-s:.875rem;--fs-b:1rem;--fs-m:1.25rem;--fs-l:1.563rem;--fs-xl:1.953rem;--fs-2xl:2.441rem;
  --bg:#f5f6fb;--surface:#fff;--surface-2:#f0f2fa;--ink:#121a30;--muted:#5b6682;--line:#e3e7f1;
  --brand:#4f46e5;--brand-ink:#fff;--brand-soft:#eceaff;--cyan:#0891b2;--accent:#f59e0b;--accent-soft:#fff4de;
  --good:#10b981;--good-soft:#e5f8f0;--bad:#ef4444;--bad-soft:#fdecec;--warn:#d97706;--warn-soft:#fff5e1;
  --navy:#0f1b3d;--r:16px;--r-s:10px;
  --e1:0 1px 2px rgba(18,26,48,.06),0 2px 8px rgba(18,26,48,.05);
  --e2:0 4px 12px rgba(18,26,48,.08),0 12px 32px rgba(18,26,48,.08);
  --font:Inter,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;--font-h:"Plus Jakarta Sans",Inter,system-ui,sans-serif;
}
[data-theme=dark]{
  --bg:#0a0f1f;--surface:#131a31;--surface-2:#1a2340;--ink:#e9edf9;--muted:#98a3c2;--line:#25305233;--line:#27325a;
  --brand:#8f8aff;--brand-ink:#0a0f1f;--brand-soft:#232a55;--accent:#fbbf24;--accent-soft:#3a2f12;
  --good:#34d399;--good-soft:#0f3a2d;--bad:#f87171;--bad-soft:#431a1f;--warn:#fbbf24;--warn-soft:#3a2f12;--navy:#0d1430;
  --e1:0 1px 2px rgba(0,0,0,.4);--e2:0 8px 30px rgba(0,0,0,.45);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font:400 var(--fs-b)/1.6 var(--font);-webkit-font-smoothing:antialiased;transition:background .25s,color .25s}
[hidden]{display:none!important}
h1,h2,h3{font-family:var(--font-h);line-height:1.2;margin:0 0 .5em;letter-spacing:-.01em}
h1{font-size:var(--fs-xl)}h2{font-size:var(--fs-l)}h3{font-size:var(--fs-m)}
.muted{color:var(--muted)}
.eyebrow{display:inline-block;font-size:.75rem;font-weight:700;letter-spacing:.08em;text-transform:uppercase;opacity:.85;margin-bottom:.4em}
:focus-visible{outline:3px solid var(--brand);outline-offset:2px}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
/* buttons (Fitts: generous hit area) */
.btn{border:1px solid var(--line);background:var(--surface);color:var(--ink);padding:.7em 1.2em;border-radius:12px;font:600 var(--fs-b)/1 var(--font);cursor:pointer;transition:transform .12s,box-shadow .15s,border-color .15s,background .15s;min-height:44px}
.btn:hover{border-color:var(--brand);color:var(--brand);box-shadow:var(--e1)}
.btn:active{transform:scale(.97)}
.btn.primary{background:linear-gradient(135deg,var(--brand),#7c6cff);color:var(--brand-ink);border-color:transparent;box-shadow:0 6px 18px rgba(79,70,229,.32)}
[data-theme=dark] .btn.primary{background:linear-gradient(135deg,#8f8aff,#6f9bff);box-shadow:0 6px 18px rgba(143,138,255,.25)}
.btn.primary:hover{filter:brightness(1.07);color:var(--brand-ink)}
.btn.danger{color:var(--bad)}
.btn.lg{padding:.9em 1.6em;font-size:1.05rem}
.btn.sm{padding:.45em .9em;font-size:var(--fs-s);min-height:36px}
.btn:disabled{opacity:.45;cursor:not-allowed;transform:none}
/* lock screen */
.lock{min-height:100vh;display:grid;place-items:center;padding:20px;background:radial-gradient(1200px 600px at 15% 0%,#4b45d6 0,transparent 60%),radial-gradient(900px 500px at 100% 100%,#0891b2 0,transparent 55%),#0a1030}
.lock-card{background:rgba(255,255,255,.96);color:#121a30;border-radius:28px;padding:44px 34px;width:100%;max-width:430px;text-align:center;box-shadow:0 40px 90px rgba(0,0,0,.45);backdrop-filter:blur(12px)}
.lock-card h1{font-size:var(--fs-2xl);margin:.1em 0}
.logo{width:112px;height:112px;border-radius:50%;box-shadow:0 10px 30px rgba(15,27,61,.35);animation:bob 3s ease-in-out infinite;object-fit:cover}
@keyframes bob{50%{transform:translateY(-6px)}}
.lock-card input{width:100%;padding:.9em 1em;margin:1.3em 0 .8em;border:1.5px solid #e3e7f1;border-radius:14px;font:inherit;text-align:center;font-size:1.1rem;color:#121a30;background:#fff}
.lock-card input:focus{outline:none;border-color:#4f46e5;box-shadow:0 0 0 4px rgba(79,70,229,.15)}
.lock-card .btn{width:100%}
.lock-card .btn.primary{background:linear-gradient(135deg,#4f46e5,#7c6cff);color:#fff;box-shadow:0 6px 18px rgba(79,70,229,.32)}
.lock-card .muted{color:#5b6682}
.err{color:var(--bad);min-height:1.4em;margin-top:.6em;font-size:var(--fs-s)}
.shake{animation:shake .35s}
@keyframes shake{25%{transform:translateX(-8px)}75%{transform:translateX(8px)}}
/* top bar */
.top{background:var(--navy);color:#fff;position:sticky;top:0;z-index:20;box-shadow:0 2px 14px rgba(0,0,0,.18)}
.top .in{max-width:1180px;margin:auto;padding:10px 20px;display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.brand{font:800 1.05rem var(--font-h);display:flex;gap:10px;align-items:center;cursor:pointer}
.brand img{border-radius:50%;box-shadow:0 0 0 2px rgba(255,255,255,.35)}
.top nav{margin-left:auto;display:flex;gap:4px;flex-wrap:wrap}
.top nav button{background:transparent;color:#c6cff0;border:0;padding:.55em 1em;border-radius:10px;font:600 var(--fs-s) var(--font);cursor:pointer;transition:.15s}
.top nav button:hover,.top nav button.on{background:rgba(255,255,255,.14);color:#fff}
.top nav button.on{box-shadow:inset 0 -2px 0 var(--accent)}
.wrap{max-width:1180px;margin:auto;padding:28px 20px 90px}
/* hero + next up */
.hero{background:linear-gradient(120deg,#3b3fb8,#0e8fb0);color:#fff;border-radius:26px;padding:40px 36px;box-shadow:var(--e2);margin-bottom:20px;position:relative;overflow:hidden}
.hero h1{font-size:var(--fs-2xl);margin-bottom:.25em}
.hero p{margin:0;opacity:.92;max-width:600px;font-size:1.05rem}
.hero:after{content:"";position:absolute;right:24px;bottom:-30px;width:170px;height:170px;border-radius:50%;background:url(logo-192.png) center/cover;opacity:.9;box-shadow:0 8px 30px rgba(0,0,0,.3)}
.hero.learn{background:linear-gradient(120deg,#d97706,#f59e0b 60%,#fbbf24);color:#2a1a00}
.hero.learn:after{content:"💡";background:none;box-shadow:none;font-size:110px;opacity:.28;width:auto;height:auto;right:30px;bottom:-10px;border-radius:0}
.nextup{display:flex;gap:16px;align-items:center;justify-content:space-between;flex-wrap:wrap;background:var(--surface);border:1px solid var(--line);border-left:5px solid var(--accent);border-radius:var(--r);padding:18px 22px;box-shadow:var(--e1);margin-bottom:24px}
.nextup h2{margin:0;font-size:var(--fs-m)}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:14px;margin-bottom:28px}
.stat{background:var(--surface);border-radius:var(--r);padding:18px 20px;box-shadow:var(--e1);border:1px solid var(--line)}
.stat b{display:block;font:800 var(--fs-xl) var(--font-h)}
.stat span{color:var(--muted);font-size:var(--fs-s)}
/* cards */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:16px}
.tcard{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:18px;box-shadow:var(--e1);display:flex;flex-direction:column;gap:10px;cursor:pointer;transition:transform .15s,box-shadow .15s,border-color .15s}
.tcard:hover{transform:translateY(-3px);border-color:var(--brand);box-shadow:var(--e2)}
.tcard h3{margin:0;font-size:1.05rem;display:flex;justify-content:space-between;align-items:center;gap:8px}
.badge{font-size:.72rem;font-weight:700;padding:.25em .7em;border-radius:99px;background:var(--brand-soft);color:var(--brand);white-space:nowrap}
.badge.done{background:var(--good-soft);color:var(--good)}.badge.prog{background:var(--warn-soft);color:var(--warn)}.badge.due{background:var(--bad-soft);color:var(--bad)}
.bar{height:8px;background:var(--surface-2);border-radius:9px;overflow:hidden}
.bar>i{display:block;height:100%;border-radius:9px;background:var(--brand);transition:width .6s cubic-bezier(.2,.8,.2,1)}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:24px;box-shadow:var(--e1);margin-bottom:20px}
.row{display:flex;gap:12px;flex-wrap:wrap;align-items:center}.sp{flex:1}
table{width:100%;border-collapse:collapse;font-size:.95rem}
th,td{padding:.7em .8em;text-align:left;border-bottom:1px solid var(--line)}
th{color:var(--muted);font-weight:600;font-size:.78rem;text-transform:uppercase;letter-spacing:.05em}
.tw{overflow-x:auto}
.good{color:var(--good)}.bad{color:var(--bad)}.warn{color:var(--warn)}
.opt-radio{display:flex;gap:12px;align-items:flex-start;padding:.9em 1em;border:1.5px solid var(--line);border-radius:14px;margin:10px 0;cursor:pointer;transition:.15s;background:var(--surface)}
.opt-radio:hover{border-color:var(--brand)}
.opt-radio.sel{border-color:var(--brand);background:var(--brand-soft)}
/* exam */
.exam{display:grid;grid-template-columns:1fr 280px;gap:20px;align-items:start}
.qhead{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px;gap:10px;flex-wrap:wrap}
.qtag{font-size:.78rem;font-weight:700;color:var(--brand);letter-spacing:.02em}
.stem{font-size:1.08rem;margin:6px 0 20px;white-space:pre-line;line-height:1.65}
.opt{display:flex;align-items:flex-start;gap:14px;padding:.9em 1.1em;border:1.5px solid var(--line);border-radius:14px;margin:10px 0;cursor:pointer;background:var(--surface);transition:border-color .12s,background .12s,transform .1s,box-shadow .12s}
.opt:hover{border-color:var(--brand);box-shadow:var(--e1)}
.opt:active{transform:scale(.995)}
.opt .l{flex:none;width:32px;height:32px;border-radius:50%;background:var(--surface-2);display:grid;place-items:center;font-weight:800;font-size:.9rem;transition:.15s}
.opt .t{flex:1;padding-top:4px}
.opt .x{flex:none;border:0;background:transparent;color:var(--muted);cursor:pointer;font-size:1rem;padding:4px 8px;border-radius:8px;opacity:.55}
.opt .x:hover{background:var(--surface-2);color:var(--bad);opacity:1}
.opt.sel{border-color:var(--brand);background:var(--brand-soft);box-shadow:0 0 0 3px rgba(79,70,229,.14)}
.opt.sel .l{background:var(--brand);color:var(--brand-ink)}
.opt.struck .t{text-decoration:line-through;color:var(--muted)}
.opt.ok{border-color:var(--good);background:var(--good-soft)}.opt.ok .l{background:var(--good);color:#fff}
.opt.no{border-color:var(--bad);background:var(--bad-soft)}.opt.no .l{background:var(--bad);color:#fff}
.timer{font:800 1.05rem var(--font-h);font-variant-numeric:tabular-nums;background:rgba(255,255,255,.12);padding:.3em .9em;border-radius:10px}
.timer.low{background:#dc2626;animation:pulse 1s infinite}
@keyframes pulse{50%{opacity:.7}}
.nav{position:sticky;top:76px}
.navgrid{display:grid;grid-template-columns:repeat(6,1fr);gap:6px;max-height:55vh;overflow:auto;padding:4px}
.navgrid button{border:1px solid var(--line);background:var(--surface);color:var(--ink);border-radius:8px;padding:.4em 0;font:600 .8rem var(--font);cursor:pointer;position:relative}
.navgrid button.ans{background:var(--brand-soft);border-color:var(--brand)}
.navgrid button.cur{outline:2px solid var(--brand)}
.navgrid button.fl:after{content:"⚑";position:absolute;top:-6px;right:-2px;font-size:.7rem;color:var(--warn)}
.foot{display:flex;gap:10px;margin-top:22px;flex-wrap:wrap}
.legend{font-size:.78rem;color:var(--muted);margin-top:10px}
/* results */
.score{display:flex;gap:28px;align-items:center;flex-wrap:wrap}
.ring{width:150px;height:150px;border-radius:50%;display:grid;place-items:center;flex:none}
.ring div{width:118px;height:118px;border-radius:50%;background:var(--surface);display:grid;place-items:center;text-align:center;font:800 2rem/1.1 var(--font-h)}
.ring small{display:block;font:600 .72rem var(--font);color:var(--muted)}
.ring.sm{width:56px;height:56px}.ring.sm div{width:44px;height:44px;font-size:.8rem}
.dbar{display:grid;grid-template-columns:230px 1fr 110px;gap:14px;align-items:center;margin:12px 0}
.dbar .bar{height:14px}
.tabs{display:flex;gap:8px;margin-bottom:16px;flex-wrap:wrap}
.tabs button{border:1px solid var(--line);background:var(--surface);color:var(--ink);padding:.5em 1em;border-radius:99px;font:600 var(--fs-s) var(--font);cursor:pointer;transition:.15s}
.tabs button:hover{border-color:var(--brand)}
.tabs button.on{background:var(--brand);color:var(--brand-ink);border-color:var(--brand)}
.rq{border:1px solid var(--line);border-radius:14px;padding:20px;margin-bottom:16px;background:var(--surface)}
.rq.w{border-left:5px solid var(--bad)}.rq.r{border-left:5px solid var(--good)}.rq.u{border-left:5px solid var(--warn)}
.expl{background:var(--surface-2);border-radius:12px;padding:14px 16px;margin-top:14px;font-size:.96rem}
.weak{border-left:5px solid var(--bad);background:var(--bad-soft);border-radius:12px;padding:14px 18px;margin:10px 0}
.weak.mid{border-color:var(--warn);background:var(--warn-soft)}
.weak.ok{border-color:var(--good);background:var(--good-soft)}
.weak.link{cursor:pointer;transition:.15s}.weak.link:hover{transform:translateX(4px)}
.weak .more{color:var(--brand);font-weight:700;font-size:var(--fs-s)}
.svgc{width:100%;height:auto}
.modal{position:fixed;inset:0;background:rgba(6,10,30,.6);display:grid;place-items:center;z-index:50;padding:20px;backdrop-filter:blur(4px)}
.modal .box{background:var(--surface);border-radius:20px;padding:28px;max-width:480px;width:100%;box-shadow:var(--e2)}
/* learn */
.chip{display:inline-flex;align-items:center;gap:6px;font-size:.74rem;font-weight:700;padding:.25em .7em;border-radius:99px;background:var(--surface-2);color:var(--muted)}
.chip i{width:8px;height:8px;border-radius:50%;display:inline-block}
.lgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:14px}
.lcard{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:16px 18px;display:flex;gap:14px;align-items:center;cursor:pointer;box-shadow:var(--e1);transition:.15s}
.lcard:hover{transform:translateY(-3px);box-shadow:var(--e2);border-color:var(--accent)}
.lcard b{display:block;font-family:var(--font-h)}
.lcard .meta{font-size:var(--fs-s);color:var(--muted)}
.hook{background:var(--accent-soft);border-left:5px solid var(--accent);border-radius:12px;padding:14px 18px;margin:0 0 18px;font-weight:600}
.ttd{display:grid;grid-template-columns:1fr 1fr 1.4fr;gap:0;border:1px solid var(--line);border-radius:14px;overflow:hidden;margin-bottom:20px}
.ttd>div{padding:12px 14px;border-bottom:1px solid var(--line);font-size:.94rem}
.ttd>div:nth-last-child(-n+3){border-bottom:0}
.ttd .h{background:var(--surface-2);font-size:.72rem;font-weight:800;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}
.ttd .a{background:var(--bad-soft)}.ttd .b{background:var(--warn-soft)}.ttd .c{background:var(--good-soft);font-weight:600}
.fc{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:22px;margin-bottom:16px;box-shadow:var(--e1)}
.fc .step{display:flex;gap:12px;margin-top:12px}
.fc .step b{flex:none;width:92px;font-size:.72rem;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);padding-top:3px}
.remember{background:var(--brand-soft);border-radius:12px;padding:12px 16px;margin-top:14px;font-weight:600}
.pbar{height:6px;background:var(--surface-2);border-radius:9px;overflow:hidden;margin-bottom:18px}
.pbar>i{display:block;height:100%;background:linear-gradient(90deg,var(--accent),var(--good));transition:width .4s}
.crumb{display:inline-flex;gap:6px;align-items:center;color:var(--muted);font-size:var(--fs-s);cursor:pointer;margin-bottom:14px}
.crumb:hover{color:var(--brand)}
.empty{text-align:center;padding:40px 20px;color:var(--muted)}
.empty .big{font-size:56px}
@media(max-width:900px){.exam{grid-template-columns:1fr}.nav{position:static}.dbar{grid-template-columns:1fr 90px}.dbar>span:first-child{grid-column:1/-1}.hero h1{font-size:var(--fs-xl)}.hero{padding:28px 22px}.ttd{grid-template-columns:1fr}.ttd .h{display:none}.fc .step{flex-direction:column;gap:2px}}
@media print{.top,.foot,.nav{display:none}}
.modal.solid{background:var(--bg);backdrop-filter:none}

.prov{margin-top:10px;font-size:.8rem;color:var(--muted);border-top:1px dashed var(--line);padding-top:8px}
.badge.hard{background:#fee2e2;color:#b91c1c}[data-theme=dark] .badge.hard{background:#4a1a1a;color:#fca5a5}