:root{
  --brand:#4f46e5; --brand-d:#4338ca; --brand-l:#eef2ff;
  --ink:#111827; --body:#374151; --mut:#6b7280; --line:#e5e7eb;
  --bg:#f8fafc; --card:#fff; --amber:#f59e0b;
  --board:#dbeafe; --board-t:#1e40af; --sample:#dcfce7; --sample-t:#166534;
  --maxw:1080px; --radius:14px; --shadow:0 1px 2px rgba(0,0,0,.04),0 8px 24px rgba(17,24,39,.06);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  background:var(--bg);color:var(--body);line-height:1.6;font-size:16px;-webkit-text-size-adjust:100%}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto}
h1,h2,h3{color:var(--ink);line-height:1.25;margin:0 0 .4em;letter-spacing:-.015em}
h1{font-size:1.62rem;font-weight:800}
h2{font-size:1.3rem;font-weight:800;margin-top:1.3em}
main .wrap>h2::before{content:"";display:inline-block;width:4px;height:.85em;background:var(--brand);border-radius:2px;margin-right:9px;vertical-align:-1px}
h3{font-size:1.05rem;font-weight:700}
sub,sup{line-height:0}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 16px}
.skip{position:absolute;left:-9999px;top:0;background:#fff;padding:8px 14px;z-index:100;border-radius:0 0 8px 0}
.skip:focus{left:0}

/* header */
header.site{position:sticky;top:0;z-index:40;background:#fff;border-bottom:1px solid var(--line)}
.hbar{display:flex;align-items:center;gap:12px;height:60px}
.logo{display:flex;align-items:center;gap:8px;font-weight:800;color:var(--ink);font-size:1.2rem}
.logo:hover{text-decoration:none}
.logo .mark{background:var(--brand);color:#fff;border-radius:9px;width:30px;height:30px;display:grid;place-items:center;font-size:1rem}
.logo b{color:var(--brand)}
.mainnav{display:flex;gap:4px;margin-left:auto;align-items:center}
.mainnav a{color:var(--body);font-weight:600;font-size:.94rem;padding:8px 12px;border-radius:8px}
.mainnav a:hover{background:var(--brand-l);color:var(--brand-d);text-decoration:none}
.mainnav a.soon{color:var(--mut);pointer-events:none}
.mainnav a.soon::after{content:"soon";font-size:.62rem;background:#f1f5f9;color:var(--mut);border-radius:6px;padding:1px 5px;margin-left:5px;vertical-align:middle;font-weight:700}
.searchbtn{border:1px solid var(--line);background:#fff;border-radius:9px;padding:8px 12px;cursor:pointer;color:var(--mut);font-size:.9rem;display:flex;gap:6px;align-items:center}
.searchbtn:hover{border-color:var(--brand);color:var(--brand)}
.hamburger{display:none;border:1px solid var(--line);background:#fff;border-radius:9px;width:40px;height:40px;cursor:pointer;font-size:1.2rem;margin-left:auto}
@media(max-width:820px){
  .mainnav{position:fixed;inset:60px 0 auto 0;background:#fff;flex-direction:column;gap:0;padding:8px;
    border-bottom:1px solid var(--line);box-shadow:var(--shadow);display:none;align-items:stretch;margin-left:0}
  .mainnav.open{display:flex}
  .mainnav a{padding:12px 14px;border-radius:8px}
  .hamburger{display:block}
  .searchbtn{margin-left:0}
}

/* breadcrumb */
.crumbs{background:#fff;border-bottom:1px solid var(--line);font-size:.83rem}
.crumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:6px;margin:0;padding:10px 16px;max-width:var(--maxw);margin:0 auto}
.crumbs li{display:flex;gap:6px;align-items:center;color:var(--mut)}
.crumbs li+li::before{content:"›";color:#cbd5e1}
.crumbs a{color:var(--mut);font-weight:600}
.crumbs li[aria-current]{color:var(--ink);font-weight:700}

main{display:block;padding:22px 0 20px}
.lead{color:var(--mut);font-size:1rem;margin:-.2em 0 1em;max-width:60ch}

/* hero */
.hero{position:relative;overflow:hidden;background:linear-gradient(135deg,var(--brand),#6366f1 55%,#7c73f0);color:#fff;border-radius:20px;padding:38px 26px;margin-bottom:22px}
.hero::before{content:"";position:absolute;inset:0;opacity:.5;pointer-events:none;
  background:radial-gradient(560px 220px at 88% -30%,rgba(255,255,255,.22),transparent),
  linear-gradient(rgba(255,255,255,.06) 1px,transparent 1px) 0 0/100% 34px}
.hero>*{position:relative}
.hero h1{color:#fff;font-size:2.15rem;letter-spacing:-.02em;line-height:1.15}
.hero p{opacity:.95;margin:.55em 0 0;max-width:60ch;font-size:1.03rem}
.hero .eyebrow{display:inline-flex;align-items:center;gap:6px;background:rgba(255,255,255,.16);color:#fff;
  font-weight:700;font-size:.72rem;letter-spacing:.05em;text-transform:uppercase;padding:5px 12px;border-radius:999px;margin-bottom:14px}

/* grids & cards */
.grid{display:grid;gap:16px;grid-template-columns:repeat(auto-fill,minmax(250px,1fr))}
.grid.two{grid-template-columns:repeat(auto-fill,minmax(320px,1fr))}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px 20px;
  box-shadow:var(--shadow);transition:transform .12s,box-shadow .12s,border-color .12s;color:inherit;display:block}
a.card:hover{transform:translateY(-3px);box-shadow:0 10px 30px rgba(79,70,229,.13);border-color:#c7d2fe;text-decoration:none}
.card h2,.card h3{margin-top:0}
.card .meta{color:var(--mut);font-size:.85rem}
.card .go{color:var(--brand);font-weight:700;font-size:.9rem;margin-top:12px;display:inline-block}
.tile{text-align:center;padding:26px 20px}
.tile .big{font-size:1.5rem;font-weight:800;color:var(--brand)}
.tile.soon{opacity:.6}
.tile.soon .big{color:var(--mut)}
.badge{display:inline-block;border-radius:999px;padding:2px 10px;font-size:.72rem;font-weight:700}
.b-soon{background:#f1f5f9;color:var(--mut)}
.b-live{background:var(--sample);color:var(--sample-t)}
/* compact subject cards with icon */
.card.subj{padding:14px 16px}
.subj-h{display:flex;align-items:center;gap:11px;margin:0 0 5px}
.subj-ic{width:40px;height:40px;flex:none;display:grid;place-items:center;background:var(--brand-l);color:var(--brand);border-radius:11px}
.subj-ic svg{width:23px;height:23px;display:block}
.card.subj h3{margin:0;font-size:1.06rem}
.card.subj .meta{font-size:.82rem;line-height:1.45}
.card.subj .go{margin-top:8px;font-size:.86rem}
/* subject-index chips (tappable pills) */
.chipgroup{margin:12px 0 6px}
.chipgroup .cg-label{font-weight:700;color:var(--ink);font-size:.92rem;margin:0 0 8px}
.chips-nav{display:flex;flex-wrap:wrap;gap:8px}
.chipl{display:inline-block;padding:8px 14px;border-radius:999px;background:#fff;border:1px solid var(--line);color:var(--body);font-size:.86rem;font-weight:600;line-height:1}
.chipl:hover{border-color:#c7d2fe;background:var(--brand-l);color:var(--brand-d);text-decoration:none}

/* stat row */
.stats{display:flex;flex-wrap:wrap;gap:10px;margin:14px 0}
.stat{background:#fff;border:1px solid var(--line);border-radius:12px;padding:10px 14px;flex:1;min-width:120px}
.stat b{display:block;font-size:1.3rem;color:var(--ink)}
.stat span{color:var(--mut);font-size:.8rem}

/* subject hub action cards */
.actions{display:grid;gap:14px;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));margin:18px 0}
.action{border:1px solid var(--line);border-radius:var(--radius);padding:20px;background:#fff;box-shadow:var(--shadow)}
.action .ico{font-size:1.6rem}
.action h3{margin:.4em 0 .2em}
.action p{color:var(--mut);font-size:.9rem;margin:0 0 10px}
.btn{display:inline-block;background:var(--brand);color:#fff;border-radius:10px;padding:9px 16px;font-weight:700;font-size:.92rem;border:none;cursor:pointer}
.btn:hover{background:var(--brand-d);text-decoration:none;color:#fff}
.btn.ghost{background:#fff;color:var(--brand);border:1px solid var(--line)}
.btn.ghost:hover{border-color:var(--brand);background:var(--brand-l)}

/* year badges */
.chips{display:flex;flex-wrap:wrap;gap:4px;margin:4px 0}
.chip{display:inline-block;border-radius:7px;padding:1px 8px;font-size:.74rem;font-weight:700}
.c-board{background:var(--board);color:var(--board-t)}
.c-sample{background:var(--sample);color:var(--sample-t)}
.c-count{background:#fef3c7;color:#92400e}
.c-marks{background:#ede9fe;color:#5b21b6}
.stars{color:var(--amber);letter-spacing:1px}

/* tables */
.tbl{width:100%;border-collapse:collapse;font-size:.92rem;background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden}
.tbl th,.tbl td{padding:9px 11px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
.tbl th{background:#f8fafc;color:var(--mut);font-size:.75rem;text-transform:uppercase;letter-spacing:.03em}
.tbl tr:last-child td{border-bottom:0}
.scroll{overflow-x:auto}

/* question blocks */
.chapsec{margin:22px 0 6px;color:var(--brand-d);font-size:1.05rem;font-weight:700;border-bottom:2px solid var(--brand-l);padding-bottom:5px}
.q{background:#fff;border:1px solid var(--line);border-radius:12px;padding:14px 16px;margin-bottom:12px;box-shadow:var(--shadow)}
.q .qhead{font-weight:700;color:var(--ink)}
.qtext{background:#f8fafc;border-left:4px solid var(--brand);border-radius:0 8px 8px 0;padding:10px 13px;margin-top:8px;white-space:pre-wrap;font-size:.94rem}
.qfig{display:block;max-width:min(460px,100%);margin:10px auto 2px;border:1px solid var(--line);border-radius:8px;background:#fff}
.why{background:#fffbeb;border:1px dashed #fcd34d;border-radius:8px;padding:7px 11px;font-size:.83rem;color:#78350f;margin-top:8px}
.hide-why .why{display:none}

/* controls */
.controls{display:flex;gap:10px;flex-wrap:wrap;margin:14px 0}
select,input[type=search]{padding:10px 12px;border:1px solid var(--line);border-radius:10px;font-size:.92rem;background:#fff;color:var(--ink)}
input[type=search]{flex:1;min-width:200px}
.note{color:var(--mut);font-size:.84rem;margin:10px 0}

/* guess paper */
.paperhead{text-align:center;background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px;margin-bottom:14px;box-shadow:var(--shadow)}
.paperhead .t{font-weight:800;font-size:1.15rem;color:var(--ink)}
.section-h{background:var(--brand);color:#fff;border-radius:10px;padding:9px 15px;margin:20px 0 10px;font-weight:700}
.section-h small{display:block;opacity:.85;font-weight:400;font-size:.82rem}
.gq{display:flex;gap:10px}
.gq .no{font-weight:800;color:var(--brand);min-width:2.3em}
.gq .mk{margin-left:auto;color:var(--mut);font-size:.85rem;white-space:nowrap;padding-left:10px}

/* faq */
.faq details{background:#fff;border:1px solid var(--line);border-radius:12px;padding:2px 16px;margin-bottom:10px}
.faq summary{cursor:pointer;font-weight:700;color:var(--ink);padding:12px 0;list-style:none}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";float:right;color:var(--brand);font-size:1.2rem}
.faq details[open] summary::after{content:"–"}
.faq p{margin:0 0 12px;color:var(--body)}

/* footer */
.faq{margin-bottom:4px}
footer.site{background:#0f172a;color:#cbd5e1;padding:30px 0;margin-top:22px;font-size:.9rem}
footer.site a{color:#c7d2fe}
footer.site .cols{display:grid;gap:20px;grid-template-columns:repeat(auto-fit,minmax(160px,1fr))}
footer.site h4{color:#fff;font-size:.9rem;margin:0 0 8px}
footer.site ul{list-style:none;margin:0;padding:0}
footer.site li{margin:4px 0}
footer.site .fine{border-top:1px solid #1e293b;margin-top:22px;padding-top:16px;color:#94a3b8;font-size:.82rem}

/* search overlay */
.searchov{position:fixed;inset:0;background:rgba(15,23,42,.5);z-index:60;display:none;padding:60px 16px}
.searchov.open{display:block}
.searchbox{max-width:640px;margin:0 auto;background:#fff;border-radius:14px;box-shadow:0 20px 60px rgba(0,0,0,.3);overflow:hidden}
.searchbox input{width:100%;border:0;border-bottom:1px solid var(--line);padding:16px;font-size:1.05rem;border-radius:0}
.searchbox input:focus{outline:none}
.results{max-height:60vh;overflow:auto}
.results a{display:block;padding:12px 16px;border-bottom:1px solid var(--line);color:var(--ink)}
.results a:hover{background:var(--brand-l);text-decoration:none}
.results a .ctx{display:block;color:var(--mut);font-size:.8rem}
.results .empty{padding:16px;color:var(--mut)}

/* logo mark (inline SVG) */
.logo svg{width:32px;height:32px;display:block;flex:none}
.logo .wm{color:var(--ink)}.logo .wm b{color:var(--brand)}

/* share bar */
.sharebar{display:flex;align-items:center;flex-wrap:wrap;gap:8px;margin:16px 0}
.sharebar .shl{font-size:.85rem;color:var(--mut);font-weight:700}
.sh{display:inline-flex;align-items:center;font-weight:600;font-size:.82rem;line-height:1;padding:8px 13px;border-radius:20px;text-decoration:none;border:1px solid transparent;cursor:pointer;white-space:nowrap}
.sh:hover{text-decoration:none;filter:brightness(.95)}
.sh.wa{background:#25d366;color:#fff}.sh.tg{background:#29a9eb;color:#fff}.sh.tw{background:#0f1419;color:#fff}
.sh.cp,.sh.nt{background:var(--brand-l);color:var(--brand-d);border-color:#c7d2fe}

/* key-facts box, prose intro, updated date */
.keyfacts{background:var(--brand-l);border:1px solid #c7d2fe;border-radius:12px;padding:14px 18px;margin:18px 0}
.keyfacts h2{margin:0 0 6px;font-size:1rem;color:var(--brand-d)}
.keyfacts ul{margin:0;padding-left:18px}.keyfacts li{margin:3px 0}
.prose{max-width:72ch}.prose p{margin:0 0 12px}.prose h2{font-size:1.15rem}
.updated{color:var(--mut);font-size:.8rem;margin:2px 0 0}
.trust{color:var(--mut);font-size:.85rem;border-left:3px solid var(--amber);padding:2px 0 2px 12px;margin:14px 0}

@media print{
  header.site,.crumbs,footer.site,.controls,.no-print,.searchov,.actions{display:none!important}
  body{background:#fff}
  .q,.paperhead{border:0;box-shadow:none;padding:6px 0;margin:0}
  .qtext{background:#fff;border-left:2px solid #999}
  .hide-why .why{display:none}
}