body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    color: #333;
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 600px;
    margin: auto;
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    font-size: 16px;
}

.controls, .navigation {
    text-align: center;
    margin: 20px 0;
}

label {
    margin-right: 10px;
}

select {
    padding: 5px;
    border-radius: 5px;
}

button {
    background-color: #5cb85c;
    color: white;
    border: none;
    padding: 10px 20px;
    margin: 5px;
    border-radius: 5px;
    cursor: pointer;
}

button:hover {
    background-color: #4cae4c;
}

#stats {
    text-align: center;
    margin: 20px 0;
    font-size: 1.1em;
}

#question-container {
    margin: 20px 0;
}

#question {
    font-size: 14px; /* 问题字号调小一号 */
}

#options div {
    margin: 10px 0;
}

#feedback {
    margin-top: 20px;
    font-weight: bold;
}