:root{color-scheme:light dark;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;--bg: #f5f6f8;--surface: #ffffff;--text: #1a1a1a;--muted: #6b7280;--border: #e2e4e8;--primary: #2f6fed;--correct: #1f9d55;--correct-bg: #e6f7ec;--wrong: #d64545;--wrong-bg: #fbe9e9}@media (prefers-color-scheme: dark){:root{--bg: #16181d;--surface: #1f232b;--text: #eef0f3;--muted: #9aa1ac;--border: #2c313b;--correct-bg: #12301f;--wrong-bg: #3a1c1c}}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text)}.app-shell{min-height:100vh}.page{max-width:780px;margin:0 auto;padding:24px 16px 64px}h1{margin:8px 0 4px}.subtitle{color:var(--muted);margin-top:0}.error{color:var(--wrong)}.back-link{color:var(--muted);text-decoration:none;font-size:.9rem}.back-link:hover{text-decoration:underline}.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:16px;margin-top:24px}.card{display:block;background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:20px;text-decoration:none;color:var(--text);transition:transform .1s ease,box-shadow .1s ease}.card:hover{transform:translateY(-2px);box-shadow:0 4px 16px #00000014}.card h2{margin:0 0 4px;font-size:1.1rem}.card-subtitle{margin:0;color:var(--muted);font-size:.9rem}.card-meta{margin:12px 0 0;font-size:.85rem;color:var(--primary)}.toggle-row{display:flex;align-items:center;gap:8px;margin:20px 0;font-size:.95rem}.mode-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px;margin-top:12px}.mode-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:20px}.mode-card h2{margin-top:0}.start-from{display:flex;align-items:center;gap:8px;margin:12px 0;font-size:.9rem}.start-from input{width:70px;padding:4px 6px}button{cursor:pointer;border:1px solid var(--border);background:var(--primary);color:#fff;border-radius:8px;padding:10px 16px;font-size:.95rem}button:disabled{opacity:.4;cursor:not-allowed}.runner-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px}.finish-button{background:var(--surface);color:var(--text)}.question-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:24px}.question-meta{color:var(--muted);font-size:.85rem;margin:0 0 8px}.question-text{margin:0 0 20px;font-size:1.15rem;line-height:1.4;white-space:pre-wrap}.options{display:flex;flex-direction:column;gap:10px}.option-button{background:var(--bg);color:var(--text);border:1px solid var(--border);text-align:left;padding:12px 16px;border-radius:8px;font-size:.95rem}.option-selected{border-color:var(--primary);box-shadow:0 0 0 2px var(--primary) inset}.option-correct{background:var(--correct-bg);border-color:var(--correct);color:var(--correct)}.option-wrong{background:var(--wrong-bg);border-color:var(--wrong);color:var(--wrong)}.nav-row{display:flex;justify-content:space-between;margin:20px 0}.progress-grid{display:flex;flex-wrap:wrap;gap:6px}.grid-cell{width:34px;height:34px;padding:0;border-radius:6px;background:var(--surface);color:var(--text);border:1px solid var(--border);font-size:.8rem}.grid-cell-current{border-color:var(--primary);border-width:2px}.grid-cell-answered{background:var(--border)}.grid-cell-correct{background:var(--correct-bg);border-color:var(--correct);color:var(--correct)}.grid-cell-wrong{background:var(--wrong-bg);border-color:var(--wrong);color:var(--wrong)}.score-summary{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:24px;text-align:center;margin:16px 0}.score-big{font-size:2.5rem;font-weight:700;margin:0}.wrong-list{margin-top:24px}.wrong-item{background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:16px;margin-bottom:12px}.wrong-item .question-text{font-size:1rem;margin-bottom:8px}.wrong-answer{color:var(--wrong);margin:4px 0}.correct-answer{color:var(--correct);margin:4px 0}