body {
    font-family: Arial, sans-serif;
    background-color: #f0f2f5;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.quiz-container {
    background: white; /* Changed from black to white for better visibility */
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    width: 90%;
    max-width: 400px;
    text-align: center;
}

.options-grid {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 20px;
}

.option-btn {
    padding: 12px;
    font-size: 16px;
    border: 2px solid #ddd;
    border-radius: 5px;
    cursor: pointer;
    background: white;
    text-align: left;
    transition: 0.2s;
}

.correct { background-color: #d4edda !important; border-color: #28a745 !important; }
.wrong { background-color: #f8d7da !important; border-color: #dc3545 !important; }

.hide { display: none; }

.restart-btn {
    margin-top: 20px;
    padding: 10px 20px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}