:root{--bg:#f4f7fb;--card:#fff;--text:#172033;--muted:#667085;--line:#dfe6ef;--primary:#2563eb;--primary2:#1d4ed8;--danger:#dc2626;--success:#15803d;--warning:#c2410c;--radius:18px;--shadow:0 12px 32px rgba(16,24,40,.08)}
*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,"Segoe UI",Tahoma,sans-serif;color:var(--text);background:var(--bg)}button,input,select,textarea{font:inherit}.page-bg{min-height:100vh}.topbar{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.95);backdrop-filter:blur(10px);border-bottom:1px solid var(--line);padding:14px 24px;display:flex;align-items:center;justify-content:space-between}.container{max-width:1180px;margin:28px auto;padding:0 18px}.container.wide{max-width:1450px}.container.narrow{max-width:620px}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:24px}.narrow-card{max-width:620px;margin:30px auto}.hero-icon{font-size:46px;text-align:center}.narrow-card h1{text-align:center;margin-bottom:8px}.muted{color:var(--muted)}.small{font-size:.88rem}.stack{display:grid;gap:15px}.stack label,.field{display:grid;gap:7px;font-weight:600}input,select,textarea{width:100%;border:1px solid #cfd8e6;border-radius:12px;padding:11px 13px;background:#fff;color:var(--text)}textarea{min-height:180px;resize:vertical;font-family:ui-monospace,SFMono-Regular,Consolas,monospace}input:focus,select:focus,textarea:focus{outline:3px solid rgba(37,99,235,.12);border-color:var(--primary)}.btn{border:1px solid var(--line);border-radius:11px;padding:10px 15px;background:#fff;cursor:pointer;font-weight:700}.btn:hover{filter:brightness(.98)}.btn:disabled{opacity:.55;cursor:not-allowed}.btn.primary{background:var(--primary);color:#fff;border-color:var(--primary)}.btn.primary:hover{background:var(--primary2)}.btn.danger{background:var(--danger);color:#fff;border-color:var(--danger)}.btn.success{background:var(--success);color:#fff;border-color:var(--success)}.btn.big{padding:13px 18px}.btn.full{width:100%}.link-btn{text-decoration:none;color:var(--primary);font-weight:700}.alert{padding:12px 14px;border-radius:12px;margin:12px 0}.alert.danger{background:#fef2f2;color:#991b1b;border:1px solid #fecaca}.alert.success{background:#f0fdf4;color:#166534;border:1px solid #bbf7d0}.alert.info{background:#eff6ff;color:#1e40af;border:1px solid #bfdbfe}.hidden{display:none!important}.exam-sticky{position:sticky;top:68px;z-index:15;border:1px solid var(--line);background:#fff;border-radius:15px;padding:12px 18px;margin-bottom:16px;display:flex;justify-content:space-between;gap:18px;align-items:center;box-shadow:0 8px 20px rgba(16,24,40,.06)}.exam-stats{display:flex;gap:15px;align-items:center;flex-wrap:wrap}.timer{font-weight:900;font-variant-numeric:tabular-nums;background:#eff6ff;color:#1d4ed8;padding:8px 12px;border-radius:10px}.timer.urgent{background:#fef2f2;color:#dc2626}.exam-layout{display:grid;grid-template-columns:230px 1fr;gap:18px}.nav-card{align-self:start;position:sticky;top:150px}.qnav{display:grid;grid-template-columns:repeat(5,1fr);gap:7px;margin:12px 0 18px}.qnav-btn{aspect-ratio:1;border:1px solid var(--line);border-radius:9px;background:#fff;cursor:pointer}.qnav-btn.answered{background:#dcfce7;border-color:#86efac}.qnav-btn.current{outline:3px solid rgba(37,99,235,.24);border-color:var(--primary)}.question-card{min-height:560px}.qhead{display:flex;justify-content:space-between;font-weight:800;color:#475467;margin-bottom:18px}.question-text{white-space:pre-wrap;font-family:ui-monospace,SFMono-Regular,Consolas,"Noto Sans Thai",monospace;font-size:1.02rem;line-height:1.72;background:#f8fafc;border:1px solid #e5e7eb;border-radius:14px;padding:18px;margin-bottom:20px}.options{display:grid;gap:11px}.option{display:flex;align-items:flex-start;gap:12px;border:1px solid var(--line);border-radius:14px;padding:14px;cursor:pointer}.option:hover{border-color:#9db8f6}.option.selected{background:#eff6ff;border-color:var(--primary)}.option input{width:auto;margin-top:5px}.option-letter{min-width:30px;height:30px;border-radius:50%;display:grid;place-items:center;background:#eef2f7;font-weight:900}.option.selected .option-letter{background:var(--primary);color:#fff}.option-text{white-space:pre-wrap;line-height:1.6}.question-actions{display:flex;justify-content:space-between;margin-top:28px}.score-box{font-size:1.4rem;background:#eff6ff;border-radius:14px;padding:18px;text-align:center;margin:18px 0}.score-box strong{font-size:2rem;color:var(--primary)}
.tabs{display:flex;gap:8px;overflow:auto;margin-bottom:16px}.tabs button{white-space:nowrap;border:1px solid var(--line);background:#fff;border-radius:11px;padding:10px 14px;font-weight:700;cursor:pointer}.tabs button.active{background:var(--primary);color:#fff;border-color:var(--primary)}.tab-panel{display:grid;gap:16px}.stats-grid{display:grid;grid-template-columns:repeat(5,minmax(130px,1fr));gap:12px}.stat-card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:16px}.stat-card .num{font-size:1.8rem;font-weight:900}.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:16px}.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.table-wrap{overflow:auto;background:#fff;border:1px solid var(--line);border-radius:14px}.data-table{width:100%;border-collapse:collapse;min-width:760px}.data-table th,.data-table td{padding:11px 12px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}.data-table th{background:#f8fafc;font-size:.9rem}.badge{display:inline-block;padding:4px 8px;border-radius:999px;background:#eef2ff;font-size:.82rem;font-weight:700}.badge.on{background:#dcfce7;color:#166534}.badge.off{background:#fee2e2;color:#991b1b}.toolbar{display:flex;gap:9px;flex-wrap:wrap;align-items:center;justify-content:space-between}.check-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.check-item{display:flex!important;align-items:center;gap:7px;font-weight:500!important}.check-item input{width:auto}.code-box{background:#0f172a;color:#e2e8f0;border-radius:14px;padding:16px;white-space:pre-wrap;overflow:auto;font:13px/1.55 ui-monospace,Consolas,monospace}.import-preview{background:#f8fafc;border:1px solid var(--line);border-radius:14px;padding:14px}.section-title{display:flex;justify-content:space-between;align-items:center;gap:10px}.modal{position:fixed;inset:0;background:rgba(15,23,42,.55);z-index:50;display:grid;place-items:center;padding:20px}.modal-card{width:min(920px,96vw);max-height:90vh;overflow:auto;background:#fff;border-radius:18px;padding:22px}.right{text-align:right}
@media(max-width:900px){.exam-layout{grid-template-columns:1fr}.nav-card{position:static}.stats-grid{grid-template-columns:repeat(2,1fr)}.grid-2,.grid-3{grid-template-columns:1fr}.check-grid{grid-template-columns:repeat(2,1fr)}.exam-sticky{position:static;align-items:flex-start;flex-direction:column}.exam-stats{width:100%;justify-content:space-between}}
@media(max-width:540px){.topbar{padding:12px}.container{padding:0 10px;margin:18px auto}.card{padding:16px}.qnav{grid-template-columns:repeat(6,1fr)}.stats-grid{grid-template-columns:1fr 1fr}.check-grid{grid-template-columns:1fr}.question-text{font-size:.95rem;padding:13px}}

.review-list{display:grid;gap:12px;text-align:left}.review-item{border:1px solid var(--line);border-radius:12px;padding:14px}.review-item.correct{border-left:5px solid #16a34a}.review-item.wrong{border-left:5px solid #dc2626}.review-q{white-space:pre-wrap;font-family:ui-monospace,Consolas,monospace;background:#f8fafc;padding:10px;border-radius:9px;margin:8px 0}