body {
    font-family: 'Inter', sans-serif;
}
.quiz-container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem;
}
.option-btn {
    transition: background-color 0.2s, border-color 0.2s;
}
.option-btn:hover {
    background-color: #eef2ff; /* indigo-50 */
}
.correct {
    background-color: #dcfce7; /* green-100 */
    border-color: #22c55e; /* green-500 */
}
.incorrect {
    background-color: #fee2e2; /* red-100 */
    border-color: #ef4444; /* red-500 */
}