:root{
  --bg:#f3f6fa; --card:#ffffff; --ink:#15202b; --muted:#5b6b7b; --line:#dbe3ec;
  --brand:#1f4e79; --brand-ink:#ffffff; --soft:#e8f0f8;
  --good:#1a7f4b; --good-bg:#e4f5ec; --bad:#c0392b; --bad-bg:#fdecea; --warn:#a15c00; --warn-bg:#fff3dc;
  --radius:16px; --shadow:0 1px 2px rgba(16,32,48,.06),0 6px 18px rgba(16,32,48,.06);
}
@media (prefers-color-scheme: dark){
  :root{ --bg:#0f1720; --card:#18232f; --ink:#e9eff5; --muted:#9db0c2; --line:#2a3a4b;
    --brand:#5aa2e0; --brand-ink:#08131d; --soft:#1f2f40;
    --good:#5fd39a; --good-bg:#15352a; --bad:#ff8a7a; --bad-bg:#3b1d1a; --warn:#ffc46b; --warn-bg:#3a2c12; --shadow:none; }
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.5 system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;}
button,input,select{font:inherit;color:inherit}
button{cursor:pointer;-webkit-tap-highlight-color:transparent}
h1,h2,h3{line-height:1.25;margin:0}
h1{font-size:1.5rem} h2{font-size:1.15rem} h3{font-size:1rem}
p{margin:0 0 .6em}
.wrap{max-width:720px;margin:0 auto;padding:0 16px calc(32px + env(safe-area-inset-bottom))}
header.top{background:var(--brand);color:var(--brand-ink)}
header.top .bar{max-width:720px;margin:0 auto;display:flex;align-items:center;gap:8px;padding:10px 16px}
header.top .logo{font-weight:800;letter-spacing:.2px;flex:1;background:none;border:0;color:inherit;text-align:left;padding:6px 0;font-size:1.05rem}
header.top .navbtn{background:rgba(255,255,255,.16);border:0;color:inherit;border-radius:999px;padding:8px 14px;font-weight:600;font-size:.9rem}
@media (prefers-color-scheme: dark){header.top .navbtn{background:rgba(0,0,0,.18)}}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px;margin:14px 0}
.muted{color:var(--muted)} .small{font-size:.875rem} .center{text-align:center}
.hero{padding:22px 0 4px}
.hero p{color:var(--muted);margin-top:6px}
.grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin:14px 0}
@media (min-width:600px){.grid{grid-template-columns:repeat(3,1fr)}}
.subject{display:flex;flex-direction:column;gap:6px;text-align:left;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:14px;box-shadow:var(--shadow);min-height:132px;border-top:5px solid var(--c)}
.subject .ico{font-size:1.7rem;line-height:1}
.subject .name{font-weight:700;line-height:1.2}
.subject .meta{margin-top:auto;font-size:.8rem;color:var(--muted)}
.subject:active{transform:scale(.985)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border-radius:12px;border:1px solid var(--line);background:var(--card);padding:12px 18px;font-weight:700;min-height:48px;text-decoration:none;color:var(--ink)}
.btn.primary{background:var(--brand);border-color:var(--brand);color:var(--brand-ink)}
.btn.good{background:var(--good);border-color:var(--good);color:#fff}
@media (prefers-color-scheme: dark){.btn.good{color:#06210f}}
.btn.ghost{background:transparent}
.btn.block{display:flex;width:100%}
.btn:disabled{opacity:.45;cursor:not-allowed}
.btn.sm{min-height:36px;padding:6px 12px;font-size:.85rem;border-radius:10px}
.row{display:flex;gap:10px;flex-wrap:wrap}
.row > .grow{flex:1}
.banner{display:flex;gap:12px;align-items:center;background:var(--warn-bg);border:1px solid transparent;color:var(--ink);border-radius:var(--radius);padding:12px 14px;margin:14px 0}
.banner .grow{flex:1}
label.field{display:block;font-weight:700;margin-bottom:6px}
input[type=text],input[type=password],select{width:100%;padding:13px 14px;border-radius:12px;border:1.5px solid var(--line);background:var(--card);font-size:1.05rem;min-height:50px}
input:focus,select:focus,button:focus-visible{outline:3px solid color-mix(in srgb,var(--brand) 45%,transparent);outline-offset:1px}
.chips{display:flex;gap:8px;flex-wrap:wrap;margin:10px 0}
.chip{border:1.5px solid var(--line);background:var(--card);border-radius:999px;padding:8px 14px;font-weight:600;min-height:40px}
.chip.on{background:var(--brand);border-color:var(--brand);color:var(--brand-ink)}
.testrow{display:flex;gap:12px;align-items:center;padding:12px 0;border-top:1px solid var(--line)}
.testrow:first-of-type{border-top:0}
.testrow .grow{flex:1;min-width:0}
.pill{display:inline-block;border-radius:999px;padding:2px 10px;font-size:.78rem;font-weight:700;background:var(--soft);color:var(--ink);white-space:nowrap}
.pill.EE{background:var(--good-bg);color:var(--good)} .pill.ME{background:var(--soft);color:var(--brand)}
.pill.AE{background:var(--warn-bg);color:var(--warn)} .pill.BE{background:var(--bad-bg);color:var(--bad)}

/* test screen */
.testhead{position:sticky;top:0;z-index:15;background:var(--bg);padding:10px 0 8px}
.testhead .line1{display:flex;align-items:center;gap:10px;font-size:.9rem;font-weight:700}
.testhead .line1 .grow{flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.progress{height:10px;border-radius:999px;background:var(--line);overflow:hidden;margin-top:8px}
.progress > i{display:block;height:100%;background:var(--good);border-radius:999px;transition:width .25s}
.passage{background:var(--soft);border-radius:14px;padding:4px 14px;margin:12px 0}
.passage summary{font-weight:700;padding:10px 0;cursor:pointer;font-size:.92rem}
.passage .body{max-height:42vh;overflow:auto;padding-bottom:10px;font-size:.98rem}
.passage .line{margin:0 0 .45em}
.passage ul{padding-left:20px;margin:.2em 0 .4em}
.blank{display:inline-block;min-width:3.2em;text-align:center;border-bottom:2px solid var(--muted);font-weight:700;color:var(--muted);padding:0 4px}
.blank.now{background:var(--warn-bg);color:var(--warn);border-color:var(--warn);border-radius:6px 6px 0 0}
.qnum{font-size:.85rem;font-weight:800;color:var(--brand);text-transform:uppercase;letter-spacing:.5px}
.instr{font-style:italic;color:var(--muted);margin:.3em 0}
.stem{font-size:1.12rem;font-weight:600;white-space:pre-line;margin:.35em 0 .9em}
table.mini{border-collapse:collapse;margin:0 0 1em;width:100%;table-layout:fixed;word-break:break-word;font-size:.92rem}
.passage .body:has(img){max-height:none}
.taphint{font-size:.8rem;color:var(--muted);margin:-.6em 0 1em}
table.mini td,table.mini th{border:1px solid var(--line);padding:8px;text-align:center}
.qimg{display:block;max-width:100%;height:auto;background:#fff;border-radius:10px;padding:6px;margin:0 0 1em;cursor:zoom-in}
.passage img{display:block;max-width:100%;height:auto;background:#fff;border-radius:10px;padding:6px;margin:6px 0;cursor:zoom-in}
.figure{margin:0 0 1em;color:var(--ink)} .figure svg{display:block;max-width:100%;height:auto;margin:0 auto}
.zoom{overflow:auto;max-height:70vh;background:#fff;border-radius:10px} .zoom img{display:block;max-width:none}
.opts{display:grid;gap:10px}
.opt{display:flex;gap:12px;align-items:center;text-align:left;width:100%;background:var(--card);border:2px solid var(--line);border-radius:14px;padding:12px 14px;min-height:56px;font-size:1.03rem}
.opt .let{flex:none;width:34px;height:34px;border-radius:50%;display:grid;place-items:center;font-weight:800;background:var(--soft)}
.opt.sel{border-color:var(--brand);background:var(--soft)}
.opt.sel .let{background:var(--brand);color:var(--brand-ink)}
.navbar{position:sticky;bottom:0;background:linear-gradient(transparent,var(--bg) 22%);padding:18px 0 calc(12px + env(safe-area-inset-bottom));display:flex;gap:10px;margin-top:8px}
.navbar .btn{flex:1}
.tools{display:flex;gap:10px;margin-top:14px}
.tools .btn{flex:1}
.flagged{color:var(--warn)}
.qgrid{display:grid;grid-template-columns:repeat(6,1fr);gap:8px;margin-top:12px}
.qgrid button{aspect-ratio:1;border-radius:10px;border:1.5px solid var(--line);background:var(--card);font-weight:700;position:relative}
.qgrid button.done{background:var(--good-bg);border-color:var(--good);color:var(--good)}
.qgrid button.cur{outline:3px solid var(--brand)}
.qgrid button.flag::after{content:"";position:absolute;top:4px;right:4px;width:8px;height:8px;border-radius:50%;background:var(--warn)}
.legend{display:flex;gap:14px;flex-wrap:wrap;font-size:.8rem;color:var(--muted);margin-top:10px}
.legend i{display:inline-block;width:10px;height:10px;border-radius:3px;margin-right:5px;vertical-align:middle}

/* modal */
.modal{position:fixed;inset:0;z-index:50;background:rgba(8,16,24,.55);display:flex;align-items:flex-end;justify-content:center;padding:0}
.modal .sheet{background:var(--card);width:100%;max-width:560px;border-radius:20px 20px 0 0;padding:20px 18px calc(20px + env(safe-area-inset-bottom));max-height:88vh;overflow:auto}
@media (min-width:600px){.modal{align-items:center}.modal .sheet{border-radius:20px}}

/* results */
.scorebox{display:flex;gap:16px;align-items:center}
.ring{flex:none;width:120px;height:120px;position:relative}
.ring svg{transform:rotate(-90deg)}
.ring .num{position:absolute;inset:0;display:grid;place-items:center;text-align:center;font-weight:800;font-size:1.7rem;line-height:1}
.ring .num small{display:block;font-size:.75rem;font-weight:600;color:var(--muted);margin-top:4px}
.topic{margin:12px 0}
.topic .t{display:flex;justify-content:space-between;gap:10px;font-size:.92rem;font-weight:600}
.meter{height:9px;border-radius:999px;background:var(--line);overflow:hidden;margin-top:5px}
.meter > i{display:block;height:100%;border-radius:999px}
.revise li{margin:.35em 0}
.revise{padding-left:20px;margin:.4em 0 0}
.wrong{border-top:1px solid var(--line);padding:14px 0}
.wrong:first-of-type{border-top:0}
.wrong .stem{font-size:1rem;margin:.2em 0 .6em}
.ans{border-radius:10px;padding:8px 12px;margin:6px 0;font-size:.95rem}
.ans.bad{background:var(--bad-bg);color:var(--bad)} .ans.ok{background:var(--good-bg);color:var(--good)}
.ans b{font-weight:800}
.why{background:var(--soft);border-radius:10px;padding:10px 12px;margin-top:8px;font-size:.95rem}
.tablewrap{overflow-x:auto;margin:0 -4px}
table.data{border-collapse:collapse;width:100%;font-size:.9rem;min-width:520px}
table.data th{text-align:left;color:var(--muted);font-size:.75rem;text-transform:uppercase;letter-spacing:.4px;padding:8px 6px;border-bottom:1.5px solid var(--line);white-space:nowrap}
table.data td{padding:10px 6px;border-bottom:1px solid var(--line);vertical-align:middle}
table.data td.num,table.data th.num{text-align:right;font-variant-numeric:tabular-nums;white-space:nowrap}
table.data tr.me td{background:var(--soft)}
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.stat{background:var(--soft);border-radius:12px;padding:12px;text-align:center}
.stat b{display:block;font-size:1.4rem}
.stat span{font-size:.78rem;color:var(--muted)}
.chart svg{width:100%;height:auto;display:block}
.note{font-size:.82rem;color:var(--muted);margin-top:8px}
.delta.up{color:var(--good)} .delta.down{color:var(--bad)}
.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);background:var(--ink);color:var(--bg);padding:10px 16px;border-radius:999px;font-size:.9rem;z-index:60;max-width:90vw}

/* ---------------------------------------------------------------- platform additions */
a{color:var(--brand)}
header.top nav{display:flex;gap:6px;align-items:center;flex-wrap:wrap}
header.top nav a{color:inherit;text-decoration:none;font-weight:600;font-size:.9rem;padding:8px 10px;border-radius:999px}
header.top nav a.on,header.top nav a:hover{background:rgba(255,255,255,.16)}
header.top form{margin:0}
.wrap.wide{max-width:1040px}
.who{font-size:.8rem;opacity:.85;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:220px}
.flash{border-radius:12px;padding:12px 14px;margin:14px 0;font-weight:600}
.flash.ok{background:var(--good-bg);color:var(--good)} .flash.error{background:var(--bad-bg);color:var(--bad)} .flash.info{background:var(--soft);color:var(--ink)}
form.stack{display:grid;gap:14px}
form.stack .hint{font-size:.82rem;color:var(--muted);margin-top:4px}
input[type=email],input[type=tel],input[type=number],input[type=date],textarea{width:100%;padding:13px 14px;border-radius:12px;border:1.5px solid var(--line);background:var(--card);font-size:1.05rem;min-height:50px;font:inherit}
textarea{min-height:140px;resize:vertical}
input.pin{letter-spacing:.6em;font-size:1.5rem;text-align:center;font-weight:800}
input.code{letter-spacing:.35em;font-size:1.35rem;text-align:center;font-weight:800;text-transform:uppercase}
.choice{display:grid;gap:12px;margin:18px 0}
.choice a{display:flex;gap:14px;align-items:center;text-decoration:none;color:var(--ink);background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px;box-shadow:var(--shadow)}
.choice a .ico{font-size:1.9rem}
.choice a b{display:block;font-size:1.05rem}
.choice a span.muted{font-size:.88rem}
.check{display:flex;gap:10px;align-items:flex-start;font-size:.95rem}
.check input{width:22px;height:22px;flex:none;margin-top:2px}
table.data td .btn{white-space:nowrap}
table.data td.chk,table.data th.chk{width:36px}
table.data input[type=checkbox]{width:20px;height:20px}
.toolbar{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:10px 0}
.toolbar .grow{flex:1}
.kpis{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:10px}
.tag{display:inline-block;font-size:.72rem;font-weight:700;border-radius:6px;padding:1px 7px;background:var(--soft);color:var(--muted)}
.tag.bad{background:var(--bad-bg);color:var(--bad)} .tag.good{background:var(--good-bg);color:var(--good)} .tag.warn{background:var(--warn-bg);color:var(--warn)}
.strandrow{display:grid;grid-template-columns:minmax(0,1fr) 120px 48px;gap:10px;align-items:center;padding:7px 0;border-top:1px solid var(--line);font-size:.92rem}
.strandrow:first-of-type{border-top:0}
.strandrow .meter{margin:0}
.strandrow b{text-align:right;font-variant-numeric:tabular-nums}
details.box{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:4px 16px;margin:14px 0}
details.box summary{font-weight:700;padding:12px 0;cursor:pointer}
details.box[open]{padding-bottom:16px}
.secret{font-family:ui-monospace,Consolas,monospace;font-size:1.1rem;font-weight:700;background:var(--soft);padding:10px 12px;border-radius:10px;word-break:break-all}
.qr{background:#fff;padding:12px;border-radius:12px;display:inline-block}
.grid2{display:grid;gap:14px}
@media (min-width:760px){.grid2{grid-template-columns:1fr 1fr}}
.inline{display:inline}
.consent{background:var(--soft);border-radius:12px;padding:12px 14px;font-size:.9rem}
.consent ul{padding-left:18px;margin:.4em 0}
footer.foot{max-width:1040px;margin:0 auto;padding:10px 16px 30px;font-size:.8rem;color:var(--muted)}
footer.foot a{color:var(--muted)}

/* login cards: 8 per A4 page */
.cards{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}
.lcard{border:2px dashed #888;border-radius:10px;padding:12px 14px;background:#fff;color:#111;break-inside:avoid;font-size:.9rem}
.lcard h3{font-size:1rem;margin:0 0 4px}
.lcard .row2{display:grid;grid-template-columns:auto 1fr;gap:2px 10px}
.lcard .big{font-family:ui-monospace,Consolas,monospace;font-size:1.15rem;font-weight:800;letter-spacing:.05em}
.lcard .parent{margin-top:8px;padding-top:6px;border-top:1px solid #ccc;font-size:.78rem}
.noprint{}
@media print{
  header.top,.noprint,footer.foot{display:none!important}
  body{background:#fff}
  .wrap{max-width:none;padding:0}
  .cards{gap:6mm}
  .lcard{height:62mm}
}
header.top .logo{white-space:nowrap}
header.top nav .navbtn{font-size:.9rem;padding:8px 12px}
@media (max-width:600px){
  header.top .bar{flex-wrap:wrap;row-gap:2px}
  header.top nav{width:100%;flex-wrap:nowrap;overflow-x:auto;gap:4px;padding-bottom:4px}
  header.top nav a,header.top nav .navbtn{font-size:.85rem;padding:7px 11px;white-space:nowrap}
  header.top nav form{margin-left:auto}
}

/* ---------------------------------------------------------------- classroom mode */
.steps{display:grid;gap:0}
.step{display:flex;gap:14px;align-items:flex-start}
.step .num{flex:none;width:36px;height:36px;border-radius:50%;background:var(--brand);color:var(--brand-ink);display:grid;place-items:center;font-weight:800}
.step h2{margin-bottom:4px}
label.testpick{padding:8px 0;border-top:1px solid var(--line)}
label.testpick:first-of-type{border-top:0}
.band-row{display:flex;height:22px;border-radius:8px;overflow:hidden;margin:8px 0}
.band-row i{display:block;height:100%}
.qbars{display:grid;grid-template-columns:repeat(auto-fill,minmax(64px,1fr));gap:8px}
.qbar{border:1px solid var(--line);border-radius:10px;padding:6px;text-align:center;font-size:.8rem;background:var(--card)}
.qbar b{display:block;font-size:1.05rem}
.qbar.low{background:var(--bad-bg);border-color:transparent} .qbar.mid{background:var(--warn-bg);border-color:transparent} .qbar.high{background:var(--good-bg);border-color:transparent}
.heat{border-collapse:collapse;font-size:.82rem}
.heat th,.heat td{border:1px solid var(--line);padding:5px 6px;text-align:center;white-space:nowrap}
.heat th.tp{writing-mode:vertical-rl;transform:rotate(180deg);text-align:left;max-height:240px;font-weight:600;font-size:.78rem;color:var(--ink)}
.heat td.nm{text-align:left;font-weight:600}
.heat td.c0{background:var(--bad-bg);color:var(--bad)} .heat td.c1{background:var(--warn-bg);color:var(--warn)} .heat td.c2{background:var(--soft)} .heat td.c3{background:var(--good-bg);color:var(--good)}
.chipline{display:flex;flex-wrap:wrap;gap:4px}
.chipline .tag{font-size:.75rem}
/* marks grid */
.mgrid{border-collapse:separate;border-spacing:0;font-size:.9rem}
.mgrid th,.mgrid td{border-bottom:1px solid var(--line);padding:0;text-align:center}
.mgrid th{position:sticky;top:0;background:var(--card);z-index:2;font-size:.75rem;padding:4px 2px;color:var(--muted)}
.mgrid th.key{color:var(--good);font-weight:800;font-size:.85rem}
.mgrid td.nm,.mgrid th.nm{position:sticky;left:0;background:var(--card);z-index:1;text-align:left;padding:4px 10px 4px 4px;white-space:nowrap;font-weight:600;min-width:130px}
.mgrid th.nm{z-index:3}
.mgrid input.cell{width:34px;height:34px;min-height:0;padding:0;text-align:center;font-weight:800;font-size:1rem;border-radius:6px;border:1.5px solid var(--line);margin:3px 1px;text-transform:uppercase}
.mgrid input.cell.ok{background:var(--good-bg);border-color:var(--good);color:var(--good)}
.mgrid input.cell.no{background:var(--bad-bg);border-color:var(--bad);color:var(--bad)}
.mgrid input.cell.w{background:var(--soft)}
.mgrid input.cell.flag{outline:3px solid var(--warn)}
.mgrid td.sc{font-weight:800;padding:0 8px;white-space:nowrap;font-variant-numeric:tabular-nums}
.mgrid tr.saving td.nm::after{content:" …";color:var(--muted)}
.mgrid tr.saved td.nm::after{content:" ✓";color:var(--good)}
.mgrid tr.err td.nm::after{content:" ⚠";color:var(--bad)}
.mgrid tr.cur td{background:var(--soft)}
.scanlist{display:grid;gap:10px;grid-template-columns:repeat(auto-fill,minmax(220px,1fr))}
.scanitem{border:1px solid var(--line);border-radius:12px;padding:8px;font-size:.85rem;background:var(--card)}
.scanitem canvas,.scanitem img{width:100%;height:auto;border-radius:8px;display:block;margin-bottom:6px;background:#fff}
.scanitem.bad{border-color:var(--bad)} .scanitem.good{border-color:var(--good)}
/* printed question paper */
.paper{background:#fff;color:#111;padding:18px 22px;border-radius:12px;margin:12px 0;font-size:15px}
.phead{border-bottom:2px solid #111;padding-bottom:10px;margin-bottom:12px;text-align:center}
.phead h1{font-size:1.35rem;margin:6px 0}
.phead .nameline{margin:12px 0 6px;text-align:left}
.pq{display:flex;gap:10px;padding:8px 0;break-inside:avoid;border-bottom:1px dotted #bbb}
.pq .pn{font-weight:800;min-width:28px}
.pq .grow{flex:1}
.pstem{white-space:pre-line;font-weight:600;margin-bottom:4px}
.popts{display:grid;grid-template-columns:1fr 1fr;gap:2px 18px}
.popts span.right{background:#dff3e7;font-weight:700}
.pans{margin-top:4px;font-size:.9em;background:#f2f5f8;padding:4px 8px;border-radius:6px}
.plines i{display:block;border-bottom:1px solid #999;height:26px}
.pimg{max-width:70%;max-height:240px;display:block;margin:4px 0}
.pfig svg{max-width:60%;height:auto;max-height:220px;color:#111}
.ppassage{border:1px solid #999;border-radius:8px;padding:8px 12px;margin:10px 0;break-inside:avoid-page}
@media print{ .paper{padding:0;margin:0;border-radius:0;font-size:12pt} }
div.stack{display:grid;gap:12px}