#progress-bar {
    width: 0;
    height: 5px;
    background-color: green;
    margin-bottom: 20px;
    transition: width 0.3s;
}

#quiz-container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    border: 1px solid #ccc;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

fieldset {
    display: none;
}

fieldset:first-of-type {
    display: block;
}

#timer {
    font-size: 1.5em;
    margin-bottom: 20px;
}

button.next-question {
    margin-top: 10px;
}

.card {
    background-color: #f9f9f9;
    border: 1px solid #ddd;
    border-radius: 5px;
    padding: 10px;
    margin-bottom: 10px;
    box-shadow: 0 0 5px rgba(0,0,0,0.1);
}