:root{
  --bg:#f4f6fb; --card:#fff; --ink:#12203a; --muted:#5b6b86; --line:#dfe5f0;
  --brand:#0d5cab; --brand-2:#0a8f7d; --accent:#f2a20c;
  --ok:#12805c; --ok-bg:#e6f6f0; --bad:#c0392b; --bad-bg:#fdeceb;
  --radius:14px; --shadow:0 1px 2px rgba(16,32,64,.06),0 8px 24px rgba(16,32,64,.07);
}
@media (prefers-color-scheme:dark){
  :root{
    --bg:#0e1626; --card:#16203a; --ink:#eaf0fb; --muted:#9fb0cc; --line:#2a3a5c;
    --brand:#5ea3f0; --brand-2:#4ecfb8; --ok-bg:#12352b; --bad-bg:#3a1c1c;
  }
}
*{box-sizing:border-box}
html,body{margin:0}
body{
  background:var(--bg); color:var(--ink); font:16px/1.55 system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  -webkit-text-size-adjust:100%;
}
a{color:var(--brand)}
h1,h2,h3{line-height:1.25;margin:0 0 .5rem}
h1{font-size:clamp(1.5rem,4.4vw,2.1rem)}
small{color:var(--muted)}

/* ---------- top bar ---------- */
.topbar{
  position:sticky; top:0; z-index:20; display:flex; gap:12px; align-items:center; justify-content:space-between;
  flex-wrap:wrap; padding:10px 16px; background:linear-gradient(120deg,var(--brand),var(--brand-2)); color:#fff;
  box-shadow:var(--shadow);
}
.brand{display:flex; align-items:center; gap:10px; color:#fff; text-decoration:none}
.brand .logo{
  display:grid; place-items:center; width:38px; height:38px; border-radius:10px; font-weight:700; letter-spacing:.5px;
  background:rgba(255,255,255,.18); border:1px solid rgba(255,255,255,.35);
}
.brand-txt{display:flex; flex-direction:column; line-height:1.2}
.brand-txt small{color:rgba(255,255,255,.82)}
.nav{display:flex; gap:6px; flex-wrap:wrap}
.nav a{
  color:#fff; text-decoration:none; padding:8px 12px; border-radius:999px; font-size:.95rem;
  border:1px solid rgba(255,255,255,.28);
}
.nav a:hover{background:rgba(255,255,255,.16)}
.nav a.active{background:#fff; color:var(--brand); border-color:#fff; font-weight:600}

/* ---------- layout ---------- */
.wrap{max-width:960px; margin:0 auto; padding:20px 16px 40px}
.card{background:var(--card); border:1px solid var(--line); border-radius:var(--radius); box-shadow:var(--shadow); padding:18px; margin-bottom:16px}
.grid{display:grid; gap:14px}
@media(min-width:720px){.grid.cols-3{grid-template-columns:repeat(3,1fr)}.grid.cols-2{grid-template-columns:1fr 1fr}}
.hero{padding:26px 20px}
.hero p{color:var(--muted); margin:.4rem 0 1.1rem}
.badge{display:inline-block; background:var(--ok-bg); color:var(--brand-2); font-weight:600; font-size:.8rem; padding:3px 10px; border-radius:999px}
.foot{text-align:center; color:var(--muted); font-size:.85rem; padding:0 16px 28px}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:8px; cursor:pointer;
  padding:11px 18px; border-radius:11px; border:1px solid var(--brand); background:var(--brand); color:#fff;
  font:inherit; font-weight:600; text-decoration:none;
}
.btn:hover{filter:brightness(1.08)}
.btn:focus-visible{outline:3px solid var(--accent); outline-offset:2px}
.btn.ghost{background:transparent; color:var(--brand)}
.btn.sub{background:var(--brand-2); border-color:var(--brand-2)}
.btn.danger{background:var(--bad); border-color:var(--bad)}
.btn[disabled]{opacity:.5; cursor:not-allowed}
.btn-row{display:flex; gap:10px; flex-wrap:wrap}
.tile{display:block; text-decoration:none; color:inherit; border:1px solid var(--line); border-radius:var(--radius); padding:16px; background:var(--card)}
.tile:hover{border-color:var(--brand); transform:translateY(-1px)}
.tile h3{margin-bottom:.25rem}
.tile p{margin:0; color:var(--muted); font-size:.92rem}

/* ---------- forms ---------- */
label{display:block; font-weight:600; font-size:.92rem; margin:10px 0 4px}
input[type=text],input[type=tel],input[type=search],select{
  width:100%; padding:11px 12px; border:1px solid var(--line); border-radius:10px; background:var(--card);
  color:var(--ink); font:inherit;
}
input:focus,select:focus{outline:2px solid var(--brand); outline-offset:1px}
.req{color:var(--bad)}
.err{color:var(--bad); font-size:.88rem; margin-top:4px; min-height:1em}
.check{display:flex; gap:10px; align-items:flex-start; margin:14px 0; font-weight:400}
.check input{width:18px; height:18px; margin-top:3px; flex:none}

/* ---------- exam ---------- */
.examhead{position:sticky; top:56px; z-index:10; display:flex; gap:12px; align-items:center; justify-content:space-between; flex-wrap:wrap; margin:-4px -4px 12px; padding:10px 14px; background:var(--card); border:1px solid var(--line); border-radius:var(--radius); box-shadow:var(--shadow)}
.clock{font-variant-numeric:tabular-nums; font-weight:700; font-size:1.15rem}
.clock.warn{color:var(--accent)}
.clock.danger{color:var(--bad); animation:pulse 1s infinite}
@keyframes pulse{50%{opacity:.45}}
.qmeta{color:var(--muted); font-size:.85rem}
.qtext{font-size:1.12rem; font-weight:600; margin:6px 0 14px}
.opts{display:grid; gap:10px}
.opt{
  display:flex; gap:12px; align-items:flex-start; width:100%; text-align:left; cursor:pointer;
  padding:13px 14px; border:1.5px solid var(--line); border-radius:12px; background:var(--card); color:inherit; font:inherit;
}
.opt:hover{border-color:var(--brand)}
.opt .key{flex:none; display:grid; place-items:center; width:28px; height:28px; border-radius:8px; background:var(--bg); border:1px solid var(--line); font-weight:700}
.opt.sel{border-color:var(--brand); background:color-mix(in srgb,var(--brand) 10%,var(--card))}
.opt.sel .key{background:var(--brand); color:#fff; border-color:var(--brand)}
.opt.correct{border-color:var(--ok); background:var(--ok-bg)}
.opt.wrong{border-color:var(--bad); background:var(--bad-bg)}
.opt.correct .key{background:var(--ok); color:#fff}
.opt.wrong .key{background:var(--bad); color:#fff}
.palette{display:flex; flex-wrap:wrap; gap:6px; margin-top:14px; padding-top:12px; border-top:1px dashed var(--line)}
.palette button{width:34px; height:34px; border-radius:9px; border:1px solid var(--line); background:var(--card); color:var(--ink); font:inherit; font-weight:600; cursor:pointer}
.palette button.done{background:var(--brand-2); border-color:var(--brand-2); color:#fff}
.palette button.cur{outline:2px solid var(--accent); outline-offset:1px}
.navbtns{display:flex; gap:10px; justify-content:space-between; margin-top:16px; flex-wrap:wrap}

/* ---------- result ---------- */
.score{display:flex; gap:20px; align-items:center; flex-wrap:wrap}
@media(max-width:560px){.score{flex-direction:column; align-items:flex-start; gap:12px}.score .stats{width:100%}}
.score .big{font-size:2.6rem; font-weight:800; line-height:1}
.stats{display:grid; gap:10px; grid-template-columns:repeat(auto-fit,minmax(130px,1fr)); margin-top:14px}
.stat{background:var(--bg); border:1px solid var(--line); border-radius:12px; padding:10px 12px}
.stat b{display:block; font-size:1.25rem}
.stat span{color:var(--muted); font-size:.85rem}
table{width:100%; border-collapse:collapse; font-size:.94rem}
th,td{padding:9px 8px; border-bottom:1px solid var(--line); text-align:left}
th{color:var(--muted); font-weight:600; font-size:.82rem; text-transform:uppercase; letter-spacing:.03em}
td.num,th.num{text-align:right; font-variant-numeric:tabular-nums}
.rank-1 td{background:linear-gradient(90deg,rgba(242,162,12,.16),transparent)}
.tablewrap{overflow-x:auto}

/* ---------- review ---------- */
.chips{display:flex; gap:8px; flex-wrap:wrap; margin:10px 0}
.chip{cursor:pointer; border:1px solid var(--line); background:var(--card); color:inherit; font:inherit; padding:7px 12px; border-radius:999px}
.chip.on{background:var(--brand); border-color:var(--brand); color:#fff; font-weight:600}
.qitem{border:1px solid var(--line); border-radius:12px; padding:12px 14px; margin-bottom:10px; background:var(--card)}
.qitem summary{cursor:pointer; font-weight:600; list-style:none}
.qitem summary::-webkit-details-marker{display:none}
.qitem summary::before{content:"▸ "; color:var(--brand)}
.qitem[open] summary::before{content:"▾ "}
.explain{margin-top:10px; padding:10px 12px; border-left:3px solid var(--brand-2); background:var(--ok-bg); border-radius:0 10px 10px 0; font-size:.94rem}
.tip{color:var(--muted); font-size:.86rem; margin-top:6px}

/* ---------- modal ---------- */
.modal{position:fixed; inset:0; background:rgba(8,16,32,.55); display:grid; place-items:center; padding:18px; z-index:50}
.modal-box{background:var(--card); color:var(--ink); border-radius:16px; padding:20px; max-width:440px; width:100%; box-shadow:var(--shadow)}
.modal-msg{color:var(--muted); white-space:pre-line}
.modal-actions{display:flex; gap:10px; justify-content:flex-end; margin-top:16px; flex-wrap:wrap}
[hidden]{display:none!important}
.print-only{display:none}
@media print{.topbar,.nav,.foot,.btn,.modal{display:none!important}.print-only{display:block}}