:root{--bg: #f7f8fa;--surface: #ffffff;--border: #e2e5ea;--text: #1a1d23;--text-muted: #6b7280;--primary: #3654ec;--primary-hover: #2a42c4;--danger: #dc3545;--danger-bg: #fdecec;--warn: #b45309;--warn-bg: #fff7e6;--success: #16803c;--success-bg: #e9f9ef;--radius: 8px}*{box-sizing:border-box}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--text)}.page-loading{padding:3rem;text-align:center;color:var(--text-muted)}.auth-shell{min-height:100vh;display:flex;align-items:center;justify-content:center}.auth-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:2.5rem;width:340px}.auth-card h1{font-size:1.25rem;margin:0 0 1.5rem}input,select,textarea{width:100%;padding:.55rem .7rem;border:1px solid var(--border);border-radius:6px;font-size:.95rem;background:var(--surface);color:var(--text)}label{display:block;font-size:.85rem;color:var(--text-muted);margin:.9rem 0 .3rem}button{cursor:pointer;border:none;border-radius:6px;padding:.55rem 1rem;font-size:.95rem;background:var(--primary);color:#fff;font-weight:500}button:hover{background:var(--primary-hover)}button.secondary{background:var(--surface);color:var(--text);border:1px solid var(--border)}button.danger{background:var(--danger)}button:disabled{opacity:.5;cursor:not-allowed}.error-banner{background:var(--danger-bg);color:var(--danger);padding:.6rem .8rem;border-radius:6px;font-size:.9rem;margin:.75rem 0}.app-shell{display:flex;min-height:100vh}.sidebar{width:200px;background:var(--surface);border-right:1px solid var(--border);padding:1.5rem 1rem;flex-shrink:0}.sidebar h2{font-size:1rem;margin:0 0 1.5rem}.sidebar a{display:block;padding:.5rem .7rem;border-radius:6px;color:var(--text);text-decoration:none;font-size:.9rem;margin-bottom:.2rem}.sidebar a.active,.sidebar a:hover{background:var(--bg)}.main-content{flex:1;padding:2rem;max-width:1100px}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.25rem 1.5rem;margin-bottom:1.25rem}table{width:100%;border-collapse:collapse;font-size:.9rem}th,td{text-align:left;padding:.55rem .6rem;border-bottom:1px solid var(--border)}th{color:var(--text-muted);font-weight:500;font-size:.8rem;text-transform:uppercase}.badge{display:inline-block;padding:.15rem .55rem;border-radius:100px;font-size:.78rem;font-weight:500}.badge.status-in_progress{background:var(--warn-bg);color:var(--warn)}.badge.status-submitted{background:var(--success-bg);color:var(--success)}.badge.status-auto_submitted_time,.badge.status-auto_submitted_violations{background:var(--danger-bg);color:var(--danger)}.flex-row{display:flex;gap:.75rem;align-items:center}.flex-between{display:flex;justify-content:space-between;align-items:center}.muted{color:var(--text-muted);font-size:.85rem}.exam-shell{min-height:100vh;background:var(--bg);user-select:none;-webkit-user-select:none}.exam-header{position:sticky;top:0;background:var(--surface);border-bottom:1px solid var(--border);padding:.9rem 2rem;display:flex;justify-content:space-between;align-items:center;z-index:10}.timer{font-variant-numeric:tabular-nums;font-weight:600}.timer.low{color:var(--danger)}.strike-indicator{font-size:.85rem}.strike-indicator.warn{color:var(--danger);font-weight:600}.exam-body{max-width:780px;margin:0 auto;padding:2rem 1.5rem 6rem}.question-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.5rem;margin-bottom:1.25rem}.question-card .qnum{color:var(--text-muted);font-size:.85rem;margin-bottom:.4rem}.question-card .qtext{font-size:1.05rem;margin-bottom:1rem}.option-row{display:flex;align-items:center;gap:.6rem;padding:.6rem .75rem;border:1px solid var(--border);border-radius:6px;margin-bottom:.5rem;cursor:pointer}.option-row:hover{border-color:var(--primary)}.option-row.selected{border-color:var(--primary);background:#eef0fe}.option-row input{width:auto}.violation-toast{position:fixed;top:4.5rem;right:1.5rem;background:var(--danger);color:#fff;padding:.9rem 1.2rem;border-radius:var(--radius);max-width:320px;z-index:100;box-shadow:0 4px 16px #00000026}.submit-bar{position:sticky;bottom:0;background:var(--surface);border-top:1px solid var(--border);padding:1rem 2rem;display:flex;justify-content:flex-end}.instructions-list{line-height:1.7}.instructions-list li{margin-bottom:.4rem}.modal-backdrop{position:fixed;top:0;right:0;bottom:0;left:0;background:#0006;display:flex;align-items:center;justify-content:center;z-index:200}.modal{background:var(--surface);border-radius:var(--radius);padding:1.5rem;width:380px}@media (prefers-color-scheme: dark){:root{--bg: #16181d;--surface: #1e2128;--border: #2c303a;--text: #e6e8eb;--text-muted: #9298a4;--danger-bg: #3a1f22;--warn-bg: #3a2f18;--success-bg: #16321f}.option-row.selected{background:#232a4e}}