:root{
  --ms-blue:#0078d4; --ms-dark:#005a9e; --bg:#f5f5f5; --card:#ffffff;
  --text:#1b1a19; --muted:#605e5c; --border:#e1dfdd;
  --green:#107c10; --green-bg:#e6f4ea; --red:#a4262c; --red-bg:#fdecea;
  --amber:#ca5010; --amber-bg:#fff4e5; --radius:8px;
}
*{box-sizing:border-box}
body{margin:0;font-family:"Segoe UI",-apple-system,BlinkMacSystemFont,Roboto,"Helvetica Neue",Arial,sans-serif;background:var(--bg);color:var(--text);line-height:1.55}
a{color:var(--ms-blue)}
.container{max-width:960px;margin:0 auto;padding:24px 20px 60px}
.topbar{background:#fff;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:10}
.topbar-inner{max-width:960px;margin:0 auto;padding:12px 20px;display:flex;align-items:center;justify-content:space-between;gap:16px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--text)}
.brand-badge{background:var(--ms-blue);color:#fff;font-weight:700;border-radius:6px;padding:4px 10px;font-size:15px}
.brand-text{font-size:15px}
.topnav{display:flex;gap:4px}
.topnav a{text-decoration:none;color:var(--text);padding:8px 14px;border-radius:6px;font-size:14px}
.topnav a:hover,.topnav a.active{background:#f0f6fc;color:var(--ms-blue)}
.hero{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:32px;margin-top:16px}
.hero h1{margin:0 0 8px;font-size:28px}
.hero p.lead{color:var(--muted);font-size:16px;margin:0 0 20px}
.btn{display:inline-block;border:1px solid var(--ms-blue);background:var(--ms-blue);color:#fff;border-radius:6px;padding:10px 20px;font-size:15px;cursor:pointer;text-decoration:none;font-weight:600}
.btn:hover{background:var(--ms-dark)}
.btn.secondary{background:#fff;color:var(--ms-blue)}
.btn.secondary:hover{background:#f0f6fc}
.btn.ghost{background:#fff;color:var(--text);border-color:var(--border)}
.btn.small{padding:6px 12px;font-size:13px}
.btn:disabled{opacity:.5;cursor:not-allowed}
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:20px;margin:16px 0}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:16px}
@media(max-width:700px){.grid2{grid-template-columns:1fr}.topnav{display:none}}
.domain-row{display:flex;gap:12px;align-items:flex-start;padding:12px;border:1px solid var(--border);border-radius:8px;margin:10px 0}
.domain-dot{width:12px;height:12px;border-radius:50%;margin-top:6px;flex:none}
.weight-pill{background:#f0f6fc;color:var(--ms-blue);font-size:12px;font-weight:700;border-radius:20px;padding:2px 10px;white-space:nowrap}
.exam-bar{display:flex;gap:0;background:#fff;border:1px solid var(--border);border-radius:8px;overflow:hidden;margin:14px 0}
.exam-bar div{height:34px;display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:700;color:#fff}
.quiz-head{background:#fff;border:1px solid var(--border);border-radius:8px;padding:12px 16px;display:flex;flex-wrap:wrap;gap:10px;align-items:center;justify-content:space-between;margin:12px 0;position:sticky;top:57px;z-index:5}
.timer{font-variant-numeric:tabular-nums;font-weight:700;font-size:18px}
.timer.warn{color:var(--red)}
.progress{height:6px;background:#eee;border-radius:3px;overflow:hidden;margin:8px 0}
.progress>div{height:100%;background:var(--ms-blue);transition:width .2s}
.qtype-tag{font-size:12px;font-weight:700;text-transform:uppercase;letter-spacing:.04em;color:var(--ms-blue);background:#f0f6fc;border-radius:4px;padding:2px 8px}
.domain-tag{font-size:12px;color:var(--muted)}
.flag-btn{border:1px solid var(--border);background:#fff;border-radius:6px;padding:6px 12px;cursor:pointer;font-size:13px}
.flag-btn.flagged{background:var(--amber-bg);border-color:var(--amber);color:var(--amber)}
.opt{display:flex;gap:10px;align-items:flex-start;border:1px solid var(--border);border-radius:8px;padding:12px;margin:8px 0;cursor:pointer;background:#fff}
.opt:hover{border-color:var(--ms-blue)}
.opt.selected{border-color:var(--ms-blue);background:#f0f6fc}
.opt.correct{border-color:var(--green);background:var(--green-bg)}
.opt.wrong{border-color:var(--red);background:var(--red-bg)}
.opt input{margin-top:4px}
.opt-id{font-weight:700;min-width:22px}
.stmt-table{width:100%;border-collapse:collapse;margin:10px 0;background:#fff}
.stmt-table th,.stmt-table td{border:1px solid var(--border);padding:10px;text-align:left;font-size:14px}
.stmt-table th{background:#faf9f8}
.stmt-table td.center{text-align:center}
.match-row{display:grid;grid-template-columns:1fr 1fr;gap:10px;align-items:center;background:#fff;border:1px solid var(--border);border-radius:8px;padding:12px;margin:8px 0}
.match-row select{width:100%;padding:8px;border-radius:6px;border:1px solid var(--border);font-size:14px}
.order-item{display:flex;align-items:center;gap:10px;background:#fff;border:1px solid var(--border);border-radius:8px;padding:10px 12px;margin:8px 0}
.order-item .step-text{flex:1}
.order-item button{border:1px solid var(--border);background:#fff;border-radius:6px;padding:4px 10px;cursor:pointer;font-size:14px}
.feedback{border-radius:8px;padding:14px 16px;margin:14px 0;font-size:14px}
.feedback.ok{background:var(--green-bg);border:1px solid var(--green);color:#0b4d0b}
.feedback.no{background:var(--red-bg);border:1px solid var(--red);color:#7a1a1f}
.feedback .learn-link{display:block;margin-top:8px}
.quiz-nav{display:flex;gap:10px;flex-wrap:wrap;margin:16px 0}
.palette{display:grid;grid-template-columns:repeat(auto-fill,minmax(44px,1fr));gap:8px;margin:12px 0}
.palette button{aspect-ratio:1;border-radius:8px;border:1px solid var(--border);background:#fff;cursor:pointer;font-weight:700;font-size:14px;position:relative}
.palette button.answered{background:#f0f6fc;border-color:var(--ms-blue);color:var(--ms-blue)}
.palette button .flagdot{position:absolute;top:2px;right:4px;color:var(--amber);font-size:14px}
.palette button.current{outline:3px solid var(--ms-blue);outline-offset:1px}
.legend{display:flex;gap:16px;font-size:13px;color:var(--muted);flex-wrap:wrap}
.score-hero{text-align:center;padding:28px;background:#fff;border:1px solid var(--border);border-radius:12px;margin:16px 0}
.score-num{font-size:56px;font-weight:800;line-height:1}
.pass{color:var(--green)} .fail{color:var(--red)}
.bar-row{display:grid;grid-template-columns:220px 1fr 60px;gap:10px;align-items:center;margin:8px 0;font-size:14px}
.bar-track{background:#eee;border-radius:4px;height:12px;overflow:hidden}
.bar-fill{height:100%;background:var(--ms-blue)}
.setup label{display:block;font-weight:600;margin:14px 0 6px}
.setup input[type=number],.setup select{padding:8px;border-radius:6px;border:1px solid var(--border);font-size:14px;max-width:280px;width:100%}
.checkline{display:flex;gap:8px;align-items:center;font-weight:400 !important;margin:6px 0 !important}
.review-item{border:1px solid var(--border);border-radius:8px;padding:14px;margin:10px 0;background:#fff}
.review-item.correct{border-left:6px solid var(--green)}
.review-item.incorrect{border-left:6px solid var(--red)}
.explain{background:#faf9f8;border-radius:6px;padding:10px 12px;margin-top:8px;font-size:14px}
.footer{border-top:1px solid var(--border);background:#fff;color:var(--muted);font-size:13px}
.history-table{width:100%;border-collapse:collapse;font-size:14px}
.history-table th,.history-table td{border:1px solid var(--border);padding:8px;text-align:left}
.about-list li{margin:6px 0}
kbd{background:#eee;border:1px solid #ccc;border-radius:4px;padding:1px 6px;font-size:12px}