:root{
  --bg:#f7f8fa;--card:#ffffff;--soft:#f3f4f6;--soft2:#f9fafb;--border:#eaecf0;--border2:#d0d5dd;
  --text:#101828;--muted:#667085;--muted2:#98a2b3;
  --green:#22c55e;--green-strong:#16a34a;--green-text:#15803d;--green-soft:#ecfdf3;
  --blue:#2f6fed;--blue-soft:#eef4ff;--red:#ef4444;--red-soft:#fef3f2;--amber:#f59e0b;--amber-soft:#fffaeb;
  --primary:#101828;--primary-text:#ffffff;
  --shadow:0 1px 2px rgba(16,24,40,.04),0 10px 30px -18px rgba(16,24,40,.18);
  --r:18px;
}
[data-theme="dark"]{
  --bg:#0a0d12;--card:#11161d;--soft:#161c25;--soft2:#131921;--border:#222a35;--border2:#2f3947;
  --text:#e6e9ee;--muted:#98a2b3;--muted2:#667085;
  --green-text:#4ade80;--green-soft:rgba(34,197,94,.13);
  --blue-soft:rgba(47,111,237,.15);--red-soft:rgba(239,68,68,.13);--amber-soft:rgba(245,158,11,.13);
  --primary:#e6e9ee;--primary-text:#0a0d12;
  --shadow:0 1px 0 rgba(255,255,255,.02);
}
*{box-sizing:border-box}
html{color-scheme:light}
[data-theme="dark"]{color-scheme:dark}
body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased;line-height:1.5;transition:background .2s,color .2s}
a{color:inherit;text-decoration:none}
h1,h2,h3,h4,h5{margin:0 0 .4em;line-height:1.25;font-weight:600}
h1{font-size:28px;letter-spacing:-.02em}h2{font-size:22px;letter-spacing:-.01em}h3{font-size:17px}h4{font-size:15px}h5{font-size:14px;margin-top:14px}
p{margin:0 0 .6em}
.muted{color:var(--muted)}.sm{font-size:13px}.nowrap{white-space:nowrap}.right{text-align:right}
.row{display:flex;align-items:center}.between{justify-content:space-between}.gap{gap:10px}.end{justify-content:flex-end}.wrap-row{flex-wrap:wrap}

/* layout */
.wrap{max-width:760px;margin:0 auto;padding:0 18px}
.wrap.wide{max-width:1140px}
main.wrap{padding-top:26px;padding-bottom:60px}
.topbar{position:sticky;top:0;z-index:20;background:color-mix(in srgb,var(--bg) 82%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--border)}
.topbar .wrap{height:64px;gap:14px}
.brand{display:flex;align-items:center;gap:11px;margin-right:auto}
.brand b{display:block;font-size:15px}.brand small{display:block;color:var(--muted);font-size:12px;margin-top:-2px}
.logo{width:36px;height:36px;border-radius:11px;background:linear-gradient(135deg,#111827,#374151);color:#fff;display:grid;place-items:center;font-weight:700;font-size:14px;letter-spacing:.02em;box-shadow:inset 0 0 0 1px rgba(255,255,255,.1)}
[data-theme="dark"] .logo{background:linear-gradient(135deg,#22c55e,#15803d)}
.logo.big{width:52px;height:52px;border-radius:15px;font-size:19px;margin:0 auto 14px}
.icon-btn{width:38px;height:38px;border-radius:11px;border:1px solid var(--border);background:var(--card);color:var(--text);display:grid;place-items:center;cursor:pointer;flex:none;font-size:15px}
.icon-btn:hover{border-color:var(--border2)}
.icon-btn svg{width:18px;height:18px}

/* cards */
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--r);padding:20px;box-shadow:var(--shadow);margin-bottom:16px}
.card-wrap,.soft-card{background:var(--soft);border:1px solid var(--border);border-radius:calc(var(--r) + 4px);padding:6px;margin-bottom:22px}
.card-wrap>.card,.soft-card>.soft-body{margin:0;box-shadow:none}
.card-foot{padding:11px 14px 7px;font-size:13.5px;color:var(--muted);gap:12px;flex-wrap:wrap}
.card-foot b{color:var(--text)}
.card-foot svg{width:17px;height:17px;vertical-align:-3px;margin-right:4px}
.soft-head{padding:9px 12px 11px;font-size:14px;font-weight:500;color:var(--muted);display:flex;align-items:center;gap:8px}
.soft-head svg{width:20px;height:20px}
.soft-body{background:var(--card);border:1px solid var(--border);border-radius:var(--r);padding:4px 20px}

.hero{margin:6px 0 22px}
.hero p{max-width:560px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:16px;margin-bottom:24px}
.grid .card{margin:0}
.grid .card:only-child{grid-column:1/-1}
.test-card{display:flex;flex-direction:column;gap:6px;transition:transform .15s,border-color .15s}
.test-card:hover{transform:translateY(-2px);border-color:var(--border2)}
.test-card h3{margin-top:8px}
.clamp{display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;min-height:2.9em}
.link{font-size:14px;font-weight:600;color:var(--green-text);margin-top:4px}
.section-title{margin:8px 2px 10px;color:var(--muted);font-weight:500}
.back{display:inline-block;color:var(--muted);font-size:14px;margin-bottom:14px}
.back:hover{color:var(--text)}

.badge{display:inline-flex;align-items:center;font-size:11px;font-weight:700;letter-spacing:.05em;padding:4px 9px;border-radius:999px}
.badge.pre{background:var(--blue-soft);color:var(--blue)}
.badge.post{background:var(--green-soft);color:var(--green-text)}
.chip{display:inline-block;font-size:12px;font-weight:500;padding:3px 10px;border-radius:999px;background:var(--soft);border:1px solid var(--border);color:var(--muted)}
.pill{display:inline-block;font-size:12.5px;font-weight:600;padding:3px 10px;border-radius:999px;background:var(--soft);color:var(--muted)}
.pill.ok{background:var(--green-soft);color:var(--green-text)}
.pill.mid{background:var(--amber-soft);color:#b45309}
.pill.bad{background:var(--red-soft);color:var(--red)}
.pill.warn{background:var(--amber-soft);color:#b45309}
[data-theme="dark"] .pill.mid,[data-theme="dark"] .pill.warn{color:#fbbf24}

.list{padding:6px}
.list-item{display:flex;justify-content:space-between;align-items:center;padding:12px 14px;border-radius:12px}
.list-item:hover{background:var(--soft)}

/* forms */
label{display:block;font-size:13.5px;font-weight:500;margin-bottom:14px}
input,select,textarea{display:block;width:100%;margin-top:6px;font:inherit;font-size:14.5px;color:var(--text);background:var(--card);border:1px solid var(--border2);border-radius:11px;padding:10px 12px;outline:none;transition:border-color .15s,box-shadow .15s}
textarea{resize:vertical}
input:focus,select:focus,textarea:focus{border-color:var(--green);box-shadow:0 0 0 4px color-mix(in srgb,var(--green) 18%,transparent)}
label.check{display:flex;align-items:center;gap:9px;font-weight:500}
label.check input{width:17px;height:17px;margin:0;accent-color:var(--green-strong)}
label.inline{display:flex;align-items:center;gap:8px;margin:0;white-space:nowrap}
label.inline input{width:80px;margin:0}
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:0 16px}
.span2{grid-column:span 2}
.lbl{font-size:13.5px;font-weight:500;margin-bottom:8px}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;font:inherit;font-size:14px;font-weight:600;padding:10px 16px;border-radius:11px;border:1px solid var(--border2);background:var(--card);color:var(--text);cursor:pointer;transition:all .15s;white-space:nowrap}
.btn:hover{background:var(--soft)}
.btn:disabled{opacity:.45;cursor:not-allowed}
.btn.primary{background:var(--primary);border-color:var(--primary);color:var(--primary-text)}
.btn.primary:hover{opacity:.9}
.btn.danger{color:var(--red);border-color:color-mix(in srgb,var(--red) 35%,transparent)}
.btn.danger:hover{background:var(--red-soft)}
.btn.sm{padding:6px 11px;font-size:13px;border-radius:9px}
.btn.block{width:100%;padding:12px}
.btn.ghost{border-color:transparent;background:transparent;color:var(--muted)}
.btn.btn-active{background:var(--green-soft);color:var(--green-text);border-color:color-mix(in srgb,var(--green) 30%,transparent);font-weight:600}
.btn.btn-active:hover{opacity:.85}
.btn.btn-inactive{background:var(--red-soft);color:var(--red);border-color:color-mix(in srgb,var(--red) 30%,transparent);font-weight:600}
.btn.btn-inactive:hover{opacity:.85}

/* quiz */
.quiz-head{padding:16px 20px}
.progress{height:8px;background:var(--soft);border-radius:99px;overflow:hidden;margin:12px 0 8px}
.progress>div{height:100%;background:var(--green);border-radius:99px;transition:width .3s}
.timer{font-variant-numeric:tabular-nums;font-weight:700;font-size:15px;padding:7px 12px;border-radius:10px;background:var(--soft);border:1px solid var(--border)}
.timer.warn{color:var(--red);background:var(--red-soft);border-color:transparent;animation:pulse 1s infinite}
@keyframes pulse{50%{opacity:.6}}
.q-card{padding:24px}
.q-text{font-size:17px;font-weight:500;margin:16px 0 18px;white-space:pre-wrap}
.q-text.sm{font-size:14.5px;margin:12px 0 8px}
.opts{display:grid;gap:10px}
.opt{display:flex;align-items:center;gap:12px;text-align:left;width:100%;font:inherit;font-size:15px;color:var(--text);padding:13px 14px;border-radius:13px;border:1px solid var(--border2);background:var(--card);cursor:pointer;transition:all .15s}
.opt:hover{border-color:var(--muted2);background:var(--soft2)}
.opt.sel{border-color:var(--green);background:var(--green-soft);box-shadow:0 0 0 3px color-mix(in srgb,var(--green) 15%,transparent)}
.letter{flex:none;width:30px;height:30px;border-radius:9px;display:grid;place-items:center;font-weight:600;font-size:13px;background:var(--soft);border:1px solid var(--border);color:var(--muted)}
.opt.sel .letter{background:var(--green-strong);border-color:var(--green-strong);color:#fff}
.ans{margin-top:0}
.nav{margin:4px 0 16px}
.qgrid{display:flex;flex-wrap:wrap;gap:8px}
.qnum{width:38px;height:38px;border-radius:10px;border:1px solid var(--border2);background:var(--card);color:var(--muted);font:inherit;font-weight:600;font-size:13.5px;cursor:pointer;display:inline-grid;place-items:center;flex:none}
.qnum.done{background:var(--green-soft);border-color:transparent;color:var(--green-text)}
.qnum.cur{border-color:var(--text);color:var(--text);box-shadow:0 0 0 2px var(--text) inset}

/* result */
.result-head{margin:0 2px 16px}
.result-head h2{margin-top:10px}
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;padding:4px 6px 18px}
.stat{display:flex;gap:12px;align-items:flex-start}
.stat svg{width:24px;height:24px;flex:none;margin-top:2px}
.stat b{display:block;font-size:17px;font-weight:600}
.stat span{display:block;color:var(--muted);font-size:13.5px}
.stats.mini{display:flex;gap:10px;padding:0;margin:16px 0 4px}
.stats.mini>div{flex:1;background:var(--soft);border-radius:13px;padding:12px 14px}
.stats.mini b{display:block;font-size:19px}.stats.mini span{font-size:12.5px;color:var(--muted)}
.gradebar{position:relative;height:62px;border-radius:13px;background:var(--green-soft);overflow:hidden;display:flex;align-items:center}
.gradebar .fill{position:absolute;inset:0 auto 0 0;background:var(--green);border-radius:13px 0 0 13px;transition:width 1s cubic-bezier(.2,.8,.2,1)}
.gradebar .pct{position:relative;margin-left:18px;font-size:20px;font-weight:500;color:#14532d}
.gradebar .lbl{position:relative;margin-left:auto;margin-right:18px;font-size:14px;font-weight:600;color:var(--green-text);margin-bottom:0}
.gradebar.mid{background:var(--amber-soft)}.gradebar.mid .fill{background:#fbbf24}.gradebar.mid .pct{color:#78350f}.gradebar.mid .lbl{color:#b45309}
.gradebar.low{background:var(--red-soft)}.gradebar.low .fill{background:#f87171}.gradebar.low .pct{color:#7f1d1d}.gradebar.low .lbl{color:var(--red)}
[data-theme="dark"] .gradebar.mid .lbl{color:#fbbf24}

.compare{display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.compare .cv span{display:block;font-size:12.5px;color:var(--muted)}
.compare .cv b{font-size:22px}
.compare .arrow{color:var(--muted2);font-size:20px}
.delta{margin-left:auto;font-weight:700;font-size:15px;padding:7px 13px;border-radius:11px}
.delta.up{background:var(--green-soft);color:var(--green-text)}
.delta.down{background:var(--red-soft);color:var(--red)}

.rate-card{display:flex;gap:24px;align-items:center;justify-content:space-between;flex-wrap:wrap}
.rate-card>div:first-child{flex:1;min-width:220px}
.rate-card b svg{width:15px;height:15px;vertical-align:-2px;color:var(--muted2)}
.rate{position:relative;padding-top:36px}
.segs{display:flex;gap:4px}
.seg{width:21px;height:24px;border:none;padding:0;background:var(--c);cursor:pointer;border-radius:5px;transition:transform .15s,opacity .15s}
.seg:first-child{border-radius:12px 5px 5px 12px}
.seg:last-child{border-radius:5px 12px 12px 5px}
.seg:hover{transform:translateY(-2px)}
.segs.picked .seg{opacity:.35}
.segs.picked .seg.on{opacity:1;transform:translateY(-2px)}
.rate-bubble{position:absolute;top:0;transform:translateX(-50%);font-size:12px;font-weight:600;padding:4px 10px;border-radius:9px;background:var(--green-soft);color:var(--green-text);white-space:nowrap;opacity:0;transition:left .15s,opacity .15s;pointer-events:none}
.rate-bubble.show{opacity:1}
.rate-bubble::after{content:"";position:absolute;left:50%;bottom:-4px;width:8px;height:8px;background:inherit;transform:translateX(-50%) rotate(45deg)}

.lost{padding:16px 0;border-bottom:1px solid var(--border)}
.lost:last-child{border-bottom:none}
.lost h4{font-size:15px;margin-bottom:8px}
.lost p{font-size:14px;white-space:pre-wrap}
.fb{list-style:none;padding:0;margin:6px 0 0}
.fb li{display:flex;gap:9px;align-items:flex-start;font-size:14px;color:var(--muted);margin-bottom:6px}
.fb li svg{width:17px;height:17px;flex:none;margin-top:2px}
.success{text-align:center;padding:26px 10px}
.success svg{width:44px;height:44px;margin-bottom:6px}

/* admin */
.tabs{display:flex;gap:4px;background:var(--soft);padding:4px;border-radius:12px;border:1px solid var(--border)}
.tabs button{font:inherit;font-size:13.5px;font-weight:500;padding:7px 13px;border:none;border-radius:9px;background:transparent;color:var(--muted);cursor:pointer}
.tabs button.active{background:var(--card);color:var(--text);box-shadow:0 1px 2px rgba(16,24,40,.08)}
.page-head{margin:6px 0 16px;gap:12px;flex-wrap:wrap}
.page-head h2,.page-head h3{margin:0}
.page-head select{width:auto;margin:0;min-width:220px}
.table-wrap{padding:0;overflow-x:auto}
table{width:100%;border-collapse:collapse;font-size:14px}
th{text-align:left;font-size:12px;font-weight:600;color:var(--muted);text-transform:uppercase;letter-spacing:.04em;padding:12px 16px;border-bottom:1px solid var(--border);background:var(--soft2)}
td{padding:12px 16px;border-bottom:1px solid var(--border);vertical-align:middle}
tr:last-child td{border-bottom:none}
tbody tr:hover td{background:var(--soft2)}
.q-row{padding:16px 18px;margin-bottom:10px}
.opt-list{margin:8px 0 0;padding-left:22px;font-size:14px;color:var(--muted)}
.opt-list li{margin:2px 0}
.opt-list li.ok{color:var(--green-text);font-weight:600}
.opt-list li.ok::after{content:"  ✓"}
.opt-edit{display:flex;align-items:center;gap:9px;margin-bottom:8px}
.opt-edit input[type=radio]{width:18px;height:18px;margin:0;flex:none;accent-color:var(--green-strong)}
.opt-edit input:not([type]){margin:0}
.review{border:1px solid var(--border);border-left:4px solid var(--green);border-radius:12px;padding:12px 14px;margin-bottom:10px}
.review.bad{border-left-color:var(--red)}
.review.part{border-left-color:var(--amber)}
.grade-row{margin-top:10px;flex-wrap:wrap}
.grade-row>input{flex:1;min-width:180px;margin:0}
.login{max-width:380px;margin:50px auto;text-align:center;padding:30px}
.login label{text-align:left}

/* misc */
.empty{text-align:center;color:var(--muted);padding:36px 16px}
.spinner{width:28px;height:28px;border:3px solid var(--border);border-top-color:var(--green);border-radius:50%;margin:30px auto;animation:spin .8s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
#toast{position:fixed;left:50%;bottom:24px;transform:translate(-50%,20px);background:var(--primary);color:var(--primary-text);padding:11px 18px;border-radius:12px;font-size:14px;font-weight:500;opacity:0;pointer-events:none;transition:all .25s;z-index:100;max-width:90vw}
#toast.show{opacity:1;transform:translate(-50%,0)}
#toast.err{background:var(--red);color:#fff}
.modal{position:fixed;inset:0;background:rgba(10,13,18,.55);backdrop-filter:blur(3px);z-index:50;display:flex;align-items:flex-start;justify-content:center;padding:40px 16px;overflow-y:auto}
.modal-card{width:100%;max-width:620px;margin:0}
.modal-card.wide{max-width:860px}

@media (max-width:640px){
  h1{font-size:24px}
  .stats{grid-template-columns:1fr 1fr 1fr;gap:8px}
  .stat{flex-direction:column;gap:6px}
  .form-grid{grid-template-columns:1fr}.span2{grid-column:auto}
  .seg{width:17px}
  .rate-card{gap:12px}
  .card{padding:16px}
  .topbar .tabs button{padding:6px 8px;font-size:12.5px}
  .brand small{display:none}
}