:root{color-scheme:light;font-family:Nunito,ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;line-height:1.6;color:#1e293b;font-size:16px}html{min-height:100%;background:linear-gradient(160deg,#f0f9ff,#e0f2fe 30%,#fefce8 70%,#fef3c7);background-attachment:fixed}body{margin:0;min-height:100vh;-webkit-font-smoothing:antialiased}.container{max-width:820px;margin:0 auto;padding:24px 16px 48px}.card{background:#fffffff2;border:2px solid rgba(30,41,59,.06);border-radius:20px;box-shadow:0 10px 40px #1e293b0f;padding:24px}.header{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:14px}.brand{font-weight:800;letter-spacing:-.02em}.muted{color:#0f172aa6}.title{font-size:1.5rem;font-weight:800;letter-spacing:-.02em;margin:8px 0 4px;line-height:1.35}.subtitle{margin:0 0 12px;color:#475569;line-height:1.6;font-size:1rem}.row{display:grid;grid-template-columns:1fr 1fr;gap:12px}@media(max-width:640px){.row{grid-template-columns:1fr}}label{display:block;font-size:.95rem;font-weight:700;color:#334155;margin-bottom:8px}input{width:100%;box-sizing:border-box;padding:12px 14px;border-radius:14px;border:2px solid #e2e8f0;background:#fff;outline:none;font-family:inherit;font-size:1rem}input:focus{border-color:#4f46e599;box-shadow:0 0 0 4px #4f46e51f}.btn{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:0;border-radius:16px;padding:14px 20px;font-weight:800;font-size:1rem;font-family:inherit;background:linear-gradient(135deg,#0ea5e9,#0284c7);color:#fff;cursor:pointer;box-shadow:0 4px 14px #0ea5e959;transition:transform .15s,box-shadow .15s}.btn:hover:not(:disabled){transform:translateY(-1px);box-shadow:0 6px 20px #0ea5e966}.btn:disabled{opacity:.6;cursor:not-allowed}.btn.secondary{background:#f1f5f9;color:#334155;border:2px solid #e2e8f0;box-shadow:none}.btn.secondary:hover:not(:disabled){background:#e2e8f0}.stack{display:grid;gap:10px}.pill{display:inline-flex;align-items:center;gap:8px;padding:8px 14px;border-radius:999px;background:#e0f2fe;color:#0369a1;font-size:.9rem;font-weight:700}.qcard{border:2px solid #e2e8f0;border-radius:20px;padding:20px;background:#fff}.qtitle{margin:0 0 14px;font-weight:800;font-size:1.15rem;line-height:1.4}.choices{display:grid;gap:10px}.choice{display:flex;gap:12px;align-items:flex-start;padding:14px 16px;border-radius:16px;border:2px solid #e2e8f0;background:#f8fafc;cursor:pointer;font-size:1rem;line-height:1.45;transition:border-color .2s,background .2s}.choice:hover{border-color:#94a3b8;background:#f1f5f9}.choice input{width:auto;margin-top:2px}.choice-correct{background:#ecfdf5!important;border-color:#10b981!important;color:#065f46}.choice-incorrect{background:#fef2f2!important;border-color:#ef4444!important;color:#991b1b}.alert{border-radius:12px;padding:10px 12px;border:1px solid rgba(15,23,42,.12);background:#fffc}.alert.error{border-color:#dc262640;background:#fef2f2e6;color:#991b1b}.alert.success{border-color:#10b98140;background:#ecfdf5e6;color:#065f46}.chapter-content-card{background:linear-gradient(180deg,#f0f9ff,#fff);border:2px solid #bae6fd;border-radius:20px}.intro-block{border-left:4px solid #0ea5e9}.chapter-carousel{position:relative}.carousel-btn{position:absolute;top:50%;transform:translateY(-50%);width:44px;height:44px;border-radius:50%;border:2px solid rgba(30,41,59,.15);background:#fffffff2;color:#1e293b;font-size:1.5rem;line-height:1;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:background .2s,border-color .2s}.carousel-btn:hover{background:#f1f5f9;border-color:#0ea5e9;color:#0ea5e9}.carousel-prev{left:12px}.carousel-next{right:12px}.carousel-dot{width:10px;height:10px;border-radius:50%;border:2px solid #cbd5e1;background:transparent;cursor:pointer;padding:0;transition:background .2s,border-color .2s}.carousel-dot:hover{border-color:#0ea5e9;background:#0ea5e94d}.carousel-dot.active{background:#0ea5e9;border-color:#0ea5e9}.audio-block{display:flex;flex-direction:column;padding:14px 16px;background:#0ea5e914;border:1px solid rgba(14,165,233,.2);border-radius:12px;margin-bottom:16px}.audio-block audio{width:100%;min-height:54px;margin-top:6px}.audio-label{font-size:.9375rem;font-weight:600;color:#0c4a6e}
