:root{font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:#1f2937;background:#fff}*{box-sizing:border-box}body{margin:0;background:#fff}.app{max-width:860px;margin:0 auto;padding:32px 20px 56px}h1{margin:0 0 6px}.sub{margin:0 0 20px;color:#6b7280}.panel{border:1px solid #e5e7eb;border-radius:10px;padding:16px;margin-bottom:14px;background:#fff}.row{display:flex;gap:14px;align-items:flex-end;justify-content:space-between}.label{display:block;font-size:13px;color:#4b5563;margin-bottom:6px}.hint{margin:10px 0 0;font-size:12px;color:#6b7280}input[type=number]{width:120px}input,button{font:inherit}button{border:1px solid #d1d5db;background:#f9fafb;border-radius:8px;padding:8px 12px;cursor:pointer}button:disabled{cursor:not-allowed;opacity:.6}.stats{display:flex;gap:20px;flex-wrap:wrap}.meta{display:flex;justify-content:space-between;margin-bottom:10px}.chip{font-size:12px;color:#374151;background:#f3f4f6;border-radius:999px;padding:2px 8px}.choices{display:grid;gap:12px;margin-top:12px}.choice-block{display:flex;flex-direction:column;gap:6px}.choice{text-align:left;background:#fff;width:100%}.choice-explanation{margin:0 0 0 4px;padding:8px 10px;font-size:13px;line-height:1.45;color:#374151;background:#f9fafb;border:1px solid #e5e7eb;border-radius:8px;white-space:pre-wrap}.answer-explanation{margin-top:16px;padding:12px;border:1px solid #e5e7eb;border-radius:8px;background:#fafafa}.answer-explanation-title{margin:0 0 8px;font-size:14px;color:#111827}.answer-explanation-body{margin:0;font-size:13px;line-height:1.5;color:#374151;white-space:pre-wrap}.choice.picked{border-color:#9ca3af}.choice.correct{border-color:#16a34a;background:#dcfce7;color:#166534}.choice.wrong{border-color:#dc2626;background:#fee2e2;color:#991b1b}.actions{margin-top:14px;display:flex;gap:8px}.result{border-color:#86efac;background:#f0fdf4}