* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Segoe UI', sans-serif; }
body { background-color: #f0f4f8; overflow: hidden; }

.container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    padding: 20px;
}

.question-header {
    background: white;
    padding: 20px;
    border-radius: 16px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    margin-bottom: 20px;
}

.play-area {
    display: flex;
    flex: 1;
    align-items: center;
    justify-content: space-around;
    gap: 20px;
}

.answer-box {
    flex: 1;
    height: 60%;
    background: white;
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
    text-align: center;
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
}

.answer-box h3 { font-size: 32px; margin-bottom: 10px; color: #ff5722; }
.answer-box p { font-size: 24px; font-weight: bold; }

/* Hiệu ứng khi chọn đáp án */
.selected-a { background-color: #d4edda !important; border: 4px solid #28a745; }
.selected-b { background-color: #f8d7da !important; border: 4px solid #dc3545; }

.camera-wrapper {
    position: relative;
    width: 360px;
    height: 360px;
    border-radius: 50%;
    overflow: hidden;
    border: 6px solid #4a90e2;
    box-shadow: 0 8px 24px rgba(0,0,0,0.15);
}

#output-canvas {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transform: scaleX(-1); /* Lật gương camera cho tự nhiên */
}

#status-overlay {
    position: absolute;
    bottom: 20px;
    width: 100%;
    text-align: center;
    color: white;
    font-weight: bold;
    text-shadow: 0 2px 4px rgba(0,0,0,0.8);
}