:root{--brand: #d40b0b;--brand-dark: #a80808;--bg: #f4f5f7;--surface: #ffffff;--border: #e2e4e8;--text: #1f2328;--text-muted: #6b7280;--success: #1a7f37;--success-bg: #e8f5ec;--danger: #d40b0b;--danger-bg: #fdecec;--warning: #b45309;font-family:-apple-system,Segoe UI,PingFang TC,Microsoft JhengHei,sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);line-height:1.7}h1{font-size:22px;margin:0 0 8px}h2{font-size:17px;margin:0 0 12px}h3{font-size:15px;margin:0 0 8px}code{background:#eef0f3;padding:1px 5px;border-radius:4px;font-size:13px}.app-shell{min-height:100vh;display:flex;flex-direction:column}.topbar{background:var(--surface);border-bottom:1px solid var(--border);padding:10px 24px;display:flex;align-items:center;justify-content:space-between;position:sticky;top:0;z-index:20;box-shadow:0 1px 2px #1014180a;flex-wrap:wrap;gap:8px}.topbar .brand{font-weight:700;color:var(--text);font-size:15px;text-decoration:none}.topbar nav{display:flex;gap:16px;align-items:center;flex-wrap:wrap}.topbar nav a{color:var(--text);text-decoration:none;font-size:14px}.topbar nav a:hover,.topbar nav a.active{color:var(--brand)}.topbar-user{color:var(--text-muted);font-size:13px}.main{flex:1;padding:24px}.narrow{max-width:640px;margin:0 auto}.wide{max-width:960px;margin:0 auto}.page-loading{padding:60px;text-align:center;color:var(--text-muted)}.card{background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:20px;margin-bottom:16px}.muted{color:var(--text-muted);font-size:14px}.center{text-align:center}.error{color:var(--danger);background:var(--danger-bg);border-radius:6px;padding:8px 12px;font-size:14px}.success{color:var(--success);background:var(--success-bg);border-radius:6px;padding:8px 12px;font-size:14px}.error-card{border-color:var(--danger)}.error-card ul{margin:0;padding-left:20px;font-size:14px}.section-title{margin:24px 0 12px;font-size:17px}.form,.filters,.editor{display:flex;flex-direction:column;gap:12px}.filters{flex-direction:row;flex-wrap:wrap;align-items:flex-end}label{display:flex;flex-direction:column;gap:4px;font-size:14px;font-weight:600}input,select,textarea{font:inherit;font-weight:400;padding:8px 10px;border:1px solid var(--border);border-radius:6px;background:#fff;color:var(--text);width:100%}textarea{resize:vertical;line-height:1.6}input:focus,select:focus,textarea:focus{outline:2px solid rgba(212,11,11,.25);border-color:var(--brand)}.inline-radio{flex-direction:row;align-items:center;gap:6px;font-weight:400;white-space:nowrap}.inline-radio input{width:auto}.option-field{flex-direction:row;align-items:center;gap:10px}.toolbar{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin:12px 0}.btn{font:inherit;font-size:14px;padding:8px 16px;border-radius:6px;border:1px solid transparent;cursor:pointer;text-decoration:none;display:inline-block}.btn:disabled{opacity:.5;cursor:not-allowed}.btn-primary{background:var(--brand);color:#fff}.btn-primary:hover:not(:disabled){background:var(--brand-dark)}.btn-ghost{background:transparent;border-color:var(--border);color:var(--text)}.btn-ghost:hover:not(:disabled){border-color:var(--brand);color:var(--brand)}.btn-danger-ghost{background:transparent;border-color:var(--border);color:var(--danger);font:inherit;font-size:14px;padding:8px 12px;border-radius:6px;cursor:pointer}.btn-icon{font:inherit;background:transparent;border:1px solid var(--border);border-radius:4px;cursor:pointer;padding:0 6px;margin-right:2px}.table{width:100%;border-collapse:collapse;background:var(--surface);border:1px solid var(--border);border-radius:8px;overflow:hidden;font-size:14px;margin-bottom:16px}.table th,.table td{padding:10px 12px;border-bottom:1px solid var(--border);text-align:left;vertical-align:top}.table th{background:#fafbfc;font-weight:600;white-space:nowrap}.table tbody tr:last-child td{border-bottom:none}.row-muted td{color:var(--text-muted);background:#fbfbfc}.cell-body{font-weight:500}.cell-sub{color:var(--text-muted);font-size:13px}.scoring-table{margin:16px 0 20px}.total-row td{font-weight:700;background:#fafbfc}.warn-inline{color:var(--warning);font-size:13px}.pool-warning{color:var(--warning);font-size:14px;background:#fff7ed;border-radius:6px;padding:8px 12px}.pager{display:flex;gap:12px;align-items:center;justify-content:center;font-size:14px;color:var(--text-muted)}.tabs{display:flex;gap:4px;border-bottom:1px solid var(--border);margin-bottom:12px;flex-wrap:wrap}.tab{font:inherit;font-size:14px;background:transparent;border:1px solid transparent;border-bottom:none;padding:8px 16px;border-radius:8px 8px 0 0;cursor:pointer;color:var(--text-muted)}.tab.active{background:var(--surface);border-color:var(--border);color:var(--text);font-weight:600;margin-bottom:-1px}.tab-count{display:inline-block;margin-left:6px;background:#eef0f3;border-radius:10px;padding:0 7px;font-size:12px}.exam-header{display:flex;justify-content:space-between;align-items:flex-start;gap:12px;flex-wrap:wrap;margin-bottom:12px}.progress-badge{background:var(--surface);border:1px solid var(--border);border-radius:20px;padding:6px 14px;font-size:14px;font-weight:600}.question{padding:14px 0;border-top:1px solid var(--border)}.question:first-of-type{border-top:none}.question-body{margin:0 0 10px;font-weight:500}.question-no{color:var(--brand);font-weight:700;margin-right:4px}.options{display:flex;flex-direction:column;gap:6px}.option{display:flex;align-items:flex-start;gap:8px;padding:8px 12px;border:1px solid var(--border);border-radius:6px;cursor:pointer;font-weight:400;flex-direction:row;background:#fff}label.option:hover{border-color:var(--brand)}.option input{width:auto;margin-top:5px}.option.selected{border-color:var(--brand);background:#fff5f5}.option-key{font-weight:700;min-width:18px}.option-text{flex:1;white-space:pre-wrap}.option-mark{font-size:12px;color:var(--text-muted);white-space:nowrap}.option.correct{border-color:var(--success);background:var(--success-bg)}.option.wrong{border-color:var(--danger);background:var(--danger-bg)}.submit-bar{position:sticky;bottom:0;background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:12px 20px;display:flex;justify-content:space-between;align-items:center;gap:12px;box-shadow:0 -2px 8px #1014180f}.score-card{text-align:center}.score-hero{margin:12px 0}.score-number{font-size:56px;font-weight:800;color:var(--brand);line-height:1}.score-max{font-size:18px;color:var(--text-muted);margin-left:6px}.score-card .table,.score-card .table th,.score-card .table td{text-align:center}.detail.is-correct{border-left:4px solid var(--success)}.detail.is-wrong{border-left:4px solid var(--danger)}.detail-tag{font-size:12px;color:var(--text-muted);border:1px solid var(--border);border-radius:10px;padding:1px 8px;margin-left:8px;white-space:nowrap}.badge{font-size:12px;border-radius:10px;padding:1px 8px;margin-left:8px;white-space:nowrap}.badge-ok{background:var(--success-bg);color:var(--success)}.badge-bad{background:var(--danger-bg);color:var(--danger)}.explanation{margin:10px 0 0;font-size:14px;background:#fafbfc;border-radius:6px;padding:10px 12px;white-space:pre-wrap}.accuracy-low{color:var(--danger);font-weight:700}.dist{display:flex;gap:6px;flex-wrap:wrap}.dist-item{font-size:12px;background:#eef0f3;border-radius:4px;padding:1px 7px;white-space:nowrap}.dist-item.correct{background:var(--success-bg);color:var(--success);font-weight:600}.login-shell{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px}.login-card{width:100%;max-width:360px;display:flex;flex-direction:column;gap:12px}.sample{background:#fafbfc;border:1px solid var(--border);border-radius:6px;padding:12px;font-size:13px;white-space:pre-wrap;overflow-x:auto}@media (max-width: 640px){.main{padding:16px 12px}.topbar{padding:10px 12px}.table{display:block;overflow-x:auto}}.section-note{color:var(--text-muted);font-size:14px;font-weight:400;margin-left:12px}.table td .btn,.table td .btn-danger-ghost{padding:5px 10px;margin:0 2px 2px 0}