.iot-module-multiple-choice { margin-bottom: 30px; font-size: 16px; color: #333; }
.iot-module-multiple-choice .iot-q-text { margin-bottom: 20px; line-height: 1.6; color: #475569; }
.iot-module-multiple-choice .iot-option-label {
    display: flex; align-items: center; padding: 12px 20px; margin-bottom: 12px;
    border: 1px solid #cbd5e1; border-radius: 8px; background: #fff; cursor: pointer; transition: all 0.2s ease;
}
.iot-module-multiple-choice .iot-option-label:hover { border-color: #94a3b8; background: #f8fafc; }
.iot-module-multiple-choice .iot-input-checkbox { display: none; }

/* Giao diện Checkbox vuông góc bo tròn nhẹ */
.iot-module-multiple-choice .iot-checkbox-custom {
    width: 24px; height: 24px; border-radius: 4px; border: 2px solid #94a3b8;
    margin-right: 15px; position: relative; flex-shrink: 0; background: #fff; transition: all 0.1s; box-sizing: border-box;
    display: flex; align-items: center; justify-content: center;
}
.iot-module-multiple-choice .iot-checkbox-custom svg {
    width: 14px; height: 14px; color: #fff; opacity: 0; transform: scale(0.5); transition: all 0.2s;
}

/* Khi được check */
.iot-module-multiple-choice .iot-input-checkbox:checked + .iot-checkbox-custom { 
    background: #2563EB; border-color: #2563EB; 
}
.iot-module-multiple-choice .iot-input-checkbox:checked + .iot-checkbox-custom svg {
    opacity: 1; transform: scale(1);
}

.iot-module-multiple-choice .iot-opt-key { font-weight: 800; font-size: 16px; margin-right: 12px; color: #334155; }
.iot-module-multiple-choice .iot-input-checkbox:checked ~ .iot-opt-key { color: #0f172a; }
.iot-module-multiple-choice .iot-opt-val { flex: 1; color: #334155; }

/* CSS báo đúng sai khi xem kết quả */
.iot-module-multiple-choice .iot-option-label.iot-opt-correct { border-color: #16a34a !important; background: #f0fdf4 !important; }
.iot-module-multiple-choice .iot-option-label.iot-opt-correct .iot-checkbox-custom { background: #16a34a !important; border-color: #16a34a !important; }
.iot-module-multiple-choice .iot-option-label.iot-opt-correct .iot-checkbox-custom svg { opacity: 1 !important; transform: scale(1) !important; }
.iot-module-multiple-choice .iot-option-label.iot-opt-correct .iot-opt-key, .iot-module-multiple-choice .iot-option-label.iot-opt-correct .iot-opt-val { color: #16a34a !important; font-weight: bold; }

.iot-module-multiple-choice .iot-option-label.iot-opt-wrong { border-color: #dc2626 !important; background: #fef2f2 !important; }
.iot-module-multiple-choice .iot-option-label.iot-opt-wrong .iot-checkbox-custom { background: #dc2626 !important; border-color: #dc2626 !important; }
.iot-module-multiple-choice .iot-option-label.iot-opt-wrong .iot-opt-key, .iot-module-multiple-choice .iot-option-label.iot-opt-wrong .iot-opt-val { color: #dc2626 !important; }

/* Trạng thái học sinh chọn thừa/sai -> Màu Vàng */
.iot-module-multiple-choice .iot-option-label.iot-opt-yellow { border-color: #ffc107 !important; background: #fff3cd !important; }
.iot-module-multiple-choice .iot-option-label.iot-opt-yellow .iot-checkbox-custom { background: #ffc107 !important; border-color: #ffc107 !important; }
.iot-module-multiple-choice .iot-option-label.iot-opt-yellow .iot-checkbox-custom svg { opacity: 1 !important; transform: scale(1) !important; }
.iot-module-multiple-choice .iot-option-label.iot-opt-yellow .iot-opt-key, .iot-module-multiple-choice .iot-option-label.iot-opt-yellow .iot-opt-val { color: #856404 !important; font-weight: bold; }