:root{
  --bg:#f6f7f9;
  --surface:#ffffff;
  --surface-2:#f0f2f5;
  --border:#dfe3e8;
  --text:#14181f;
  --muted:#5b6673;
  --accent:#12507e;
  --accent-soft:#e6eef6;
  --good:#1c7c4a;
  --good-soft:#e4f3ea;
  --bad:#b3261e;
  --bad-soft:#fbe9e7;
  --warn:#8a5a00;
  --warn-soft:#fdf1da;
  --radius:12px;
  --shadow:0 1px 2px rgba(16,24,40,.06), 0 4px 16px rgba(16,24,40,.05);
  --mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
@media (prefers-color-scheme: dark){
  :root{
    --bg:#0f1319; --surface:#161b23; --surface-2:#1d242e; --border:#2a323d;
    --text:#e8ecf1; --muted:#9aa6b4; --accent:#6db2e8; --accent-soft:#16283a;
    --good:#5bd08c; --good-soft:#12291d; --bad:#ff8f85; --bad-soft:#2d1614;
    --warn:#e8bd66; --warn-soft:#2c2313;
    --shadow:0 1px 2px rgba(0,0,0,.4), 0 4px 18px rgba(0,0,0,.3);
  }
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;background:var(--bg);color:var(--text);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  font-size:16px;line-height:1.55;
}
.wrap{max-width:980px;margin:0 auto;padding:0 20px}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}

/* ---------- top bar ---------- */
.topbar{background:var(--surface);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:20}
.topbar-inner{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:60px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;color:var(--text)}
.brand:hover{text-decoration:none}
.brand-mark{background:var(--accent);color:#fff;border-radius:8px;padding:4px 8px;font-size:13px;letter-spacing:.06em}
@media (prefers-color-scheme: dark){ .brand-mark{color:#0f1319} }
.brand-text{font-size:15px}
.topnav{display:flex;gap:6px}
.topnav a{padding:7px 12px;border-radius:999px;color:var(--muted);font-size:14px;font-weight:600}
.topnav a:hover{background:var(--surface-2);text-decoration:none}
.topnav a.active{background:var(--accent-soft);color:var(--accent)}

/* ---------- generic ---------- */
h1{font-size:28px;line-height:1.25;margin:28px 0 8px}
h2{font-size:20px;margin:28px 0 10px}
h3{font-size:16px;margin:20px 0 8px}
.lede{color:var(--muted);margin:0 0 4px;max-width:65ch}
.muted{color:var(--muted)}
.small{font-size:13px}
.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow)}
.pad{padding:18px}
.footer{margin-top:56px;padding:22px 0 40px;border-top:1px solid var(--border);color:var(--muted);font-size:13px}
.footer p{margin:0 0 8px;max-width:78ch}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  background:var(--accent);color:#fff;border:1px solid transparent;border-radius:9px;
  padding:10px 18px;font-size:15px;font-weight:600;cursor:pointer;font-family:inherit;
}
@media (prefers-color-scheme: dark){ .btn{color:#0f1319} }
.btn:hover{filter:brightness(1.07);text-decoration:none}
.btn:disabled{opacity:.45;cursor:not-allowed;filter:none}
.btn-ghost{background:transparent;color:var(--text);border-color:var(--border)}
.btn-ghost:hover{background:var(--surface-2)}
.btn-sm{padding:7px 13px;font-size:14px}
.btn-row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}

.badge{display:inline-block;padding:3px 9px;border-radius:999px;font-size:12px;font-weight:700;letter-spacing:.03em}
.badge-AUD{background:#e7eefb;color:#1a4fa0}
.badge-FAR{background:#e6f2ec;color:#1c6b45}
.badge-REG{background:#fdeee3;color:#9a5312}
.badge-BAR{background:#efe8fb;color:#5b3ba8}
.badge-ISC{background:#e3f1f5;color:#155e75}
.badge-TCP{background:#fbe8ef;color:#98305c}
.badge-MIX{background:#eceff2;color:#44505e}
.badge-CMA{background:#e8f0e2;color:#4a6b1f}
@media (prefers-color-scheme: dark){
  .badge-AUD{background:#16233d;color:#9dc0f5}
  .badge-FAR{background:#12291d;color:#86ddac}
  .badge-REG{background:#2f2013;color:#f0b183}
  .badge-BAR{background:#221a38;color:#bfa8f2}
  .badge-ISC{background:#122a33;color:#8fd4e8}
  .badge-TCP{background:#2f1723;color:#f0a1c0}
  .badge-MIX{background:#232a33;color:#b3bfcc}
  .badge-CMA{background:#1e2a16;color:#b3d68a}
}

/* ---------- exam list ---------- */
.stats-strip{display:flex;gap:10px;flex-wrap:wrap;margin:18px 0 6px}
.stat{background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:10px 14px;min-width:120px}
.stat .n{font-size:22px;font-weight:700;line-height:1.2}
.stat .l{font-size:12px;color:var(--muted);text-transform:uppercase;letter-spacing:.05em}

.filters{display:flex;gap:6px;flex-wrap:wrap;margin:22px 0 14px}
.chip{border:1px solid var(--border);background:var(--surface);color:var(--muted);
  border-radius:999px;padding:6px 14px;font-size:13px;font-weight:600;cursor:pointer;font-family:inherit}
.chip:hover{background:var(--surface-2)}
.chip.on{background:var(--accent);border-color:var(--accent);color:#fff}
@media (prefers-color-scheme: dark){ .chip.on{color:#0f1319} }

.exam-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:14px;margin-top:8px}
.exam-card{display:flex;flex-direction:column;gap:10px;padding:18px}
.exam-card h3{margin:0;font-size:17px}
.exam-card .meta{display:flex;gap:14px;flex-wrap:wrap;color:var(--muted);font-size:13px;margin-top:auto}
.exam-card .blurb{color:var(--muted);font-size:14px;margin:0}
.exam-head{display:flex;align-items:center;justify-content:space-between;gap:10px}
.score-pill{font-size:12px;font-weight:700;padding:3px 9px;border-radius:999px;background:var(--surface-2);color:var(--muted)}
.score-pill.pass{background:var(--good-soft);color:var(--good)}
.score-pill.fail{background:var(--bad-soft);color:var(--bad)}

/* ---------- exam runner ---------- */
.runner-bar{
  position:sticky;top:60px;z-index:10;background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius);padding:12px 16px;margin:18px 0;display:flex;align-items:center;
  justify-content:space-between;gap:14px;flex-wrap:wrap;box-shadow:var(--shadow)
}
.runner-bar .qcount{font-weight:700}
.timer{font-family:var(--mono);font-size:18px;font-weight:700;padding:4px 10px;border-radius:8px;background:var(--surface-2)}
.timer.low{background:var(--bad-soft);color:var(--bad)}
.progress-track{height:5px;background:var(--surface-2);border-radius:999px;overflow:hidden;width:100%;margin-top:10px}
.progress-fill{height:100%;background:var(--accent);transition:width .2s ease}

.qcard{padding:22px}
.qstem{font-size:17px;margin:0 0 6px;white-space:pre-wrap}
.qtopic{font-size:12px;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;margin-bottom:12px}
.qtable{border-collapse:collapse;margin:14px 0;font-size:14px;font-family:var(--mono)}
.qtable td,.qtable th{border:1px solid var(--border);padding:6px 12px;text-align:left}

.choices{list-style:none;margin:18px 0 0;padding:0;display:flex;flex-direction:column;gap:10px}
.choice{
  display:flex;gap:12px;align-items:flex-start;border:1px solid var(--border);background:var(--surface);
  border-radius:10px;padding:13px 15px;cursor:pointer;font-size:15px;text-align:left;width:100%;
  font-family:inherit;color:var(--text);line-height:1.5
}
.choice:hover{background:var(--surface-2)}
.choice .letter{
  flex:0 0 26px;height:26px;border-radius:50%;border:1.5px solid var(--border);
  display:flex;align-items:center;justify-content:center;font-size:13px;font-weight:700;color:var(--muted)
}
.choice.sel{border-color:var(--accent);background:var(--accent-soft)}
.choice.sel .letter{background:var(--accent);border-color:var(--accent);color:#fff}
@media (prefers-color-scheme: dark){ .choice.sel .letter{color:#0f1319} }
.choice.correct{border-color:var(--good);background:var(--good-soft)}
.choice.correct .letter{background:var(--good);border-color:var(--good);color:#fff}
.choice.wrong{border-color:var(--bad);background:var(--bad-soft)}
.choice.wrong .letter{background:var(--bad);border-color:var(--bad);color:#fff}
.choice[disabled]{cursor:default}

.nav-row{display:flex;justify-content:space-between;gap:10px;margin-top:18px;flex-wrap:wrap}
.palette{display:flex;flex-wrap:wrap;gap:6px;margin-top:16px}
.palette button{
  width:36px;height:36px;border-radius:8px;border:1px solid var(--border);background:var(--surface);
  color:var(--muted);font-weight:700;font-size:13px;cursor:pointer;font-family:inherit;position:relative
}
.palette button.answered{background:var(--accent-soft);border-color:var(--accent);color:var(--accent)}
.palette button.flagged::after{content:"";position:absolute;top:-3px;right:-3px;width:9px;height:9px;border-radius:50%;background:var(--warn)}
.palette button.cur{outline:2px solid var(--accent);outline-offset:1px}
.palette button.ok{background:var(--good-soft);border-color:var(--good);color:var(--good)}
.palette button.no{background:var(--bad-soft);border-color:var(--bad);color:var(--bad)}

.explain{margin-top:18px;border-left:3px solid var(--accent);background:var(--surface-2);padding:14px 16px;border-radius:0 10px 10px 0}
.explain h4{margin:0 0 6px;font-size:14px;text-transform:uppercase;letter-spacing:.05em;color:var(--muted)}
.explain p{margin:0;font-size:15px}

/* ---------- results ---------- */
.result-hero{text-align:center;padding:30px 22px}
.big-score{font-size:60px;font-weight:800;line-height:1;margin:6px 0}
.big-score.pass{color:var(--good)}
.big-score.fail{color:var(--bad)}
.verdict{font-size:17px;font-weight:700;margin:0}
.bd-row{display:flex;align-items:center;gap:12px;padding:9px 0;border-bottom:1px solid var(--border);font-size:14px}
.bd-row:last-child{border-bottom:none}
.bd-name{flex:1;min-width:0}
.bd-bar{flex:0 0 130px;height:7px;background:var(--surface-2);border-radius:999px;overflow:hidden}
.bd-bar span{display:block;height:100%;background:var(--accent)}
.bd-num{flex:0 0 58px;text-align:right;font-family:var(--mono);color:var(--muted)}

table.history{width:100%;border-collapse:collapse;font-size:14px}
table.history th,table.history td{text-align:left;padding:10px 8px;border-bottom:1px solid var(--border)}
table.history th{font-size:12px;text-transform:uppercase;letter-spacing:.05em;color:var(--muted);font-weight:700}

.empty{padding:34px 22px;text-align:center;color:var(--muted)}
.notice{background:var(--warn-soft);color:var(--warn);border-radius:10px;padding:12px 15px;font-size:14px;margin:14px 0}
ul.tips{margin:8px 0;padding-left:22px}
ul.tips li{margin-bottom:7px}
@media (max-width:560px){
  h1{font-size:23px}
  .runner-bar{position:static}
  .qcard{padding:17px}
}