body {
    font-family: 'Arial', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #f4f4f4;
    color: #333;
}

.container {
    background-color: #fff;
    padding: 20px 40px;
    border-radius: 8px;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
    text-align: center;
    width: 90%;
    max-width: 600px;
}

header h1 {
    color: #333;
    margin-bottom: 20px;
}

#quiz-area {
    margin-bottom: 20px;
}

.hidden {
    display: none;
}

#options-container button {
    display: block;
    width: 100%;
    padding: 10px;
    margin: 10px 0;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1em;
}

#options-container button:hover {
    background-color: #0056b3;
}

#start-btn, #restart-btn {
    padding: 10px 20px;
    background-color: #28a745;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1.1em;
    margin-top: 10px;
}

#start-btn:hover, #restart-btn:hover {
    background-color: #1e7e34;
}

#progress-text {
    margin-top: 15px;
    font-size: 0.9em;
    color: #666;
}

footer {
    margin-top: 30px;
    font-size: 0.8em;
    color: #777;
}