body {
    font-family: Arial, sans-serif;
    font-size: 16px;
    margin: 0;
    padding: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    height: 50vh;
    background-color: #FDF3DD;
}
.title {
    text-align: center;
    margin-top: 20px;
}
.question-container {
    font-size: 12px;
    display: none;
    text-align: center;
    margin: 20px;
    width: 80%; /* 定义一个宽度使内容不会过于分散 */
}
.centered {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
  }
.active {
    display: block;
}
#startTestBtn {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh; /* Set the height of the container to 100% of the viewport height */
}

#startTestBtn img {
    max-width: 100%; /* Make the image resizable based on the width of the container */
    height: auto; /* Maintain aspect ratio */
    z-index: -1;
    position: absolute;
    top: 80%;
    left: 50%;
    transform: translate(-50%, -50%);
}

#startTestBtn button {
    margin-top: 20px; /* Add space between the image and the button */
    position: absolute;
    top: 60%;
    left: 50%;
    transform: translate(-50%, -50%);
    margin-top: 10px;
    width: 40%;
}
.active {
    display: block;
}
#progressContainer {
    width: 80%;
    background-color: #ddd;
    margin: 20px 0;
    display: none;
}
#progressBar {
    width: 0%;
    height: 20px;
    background-color: #4CAF50;
}
button {
    font-size: 15px;
    display: block;
    width: 100%;
    margin: 10px 0;
    padding: 10px;
    cursor: pointer;
    background-color: #FDF0DD; /* Updated background color */
    border: 2px solid #ccc;
    border-radius: 5px;
    transition: background-color 1s ease;
}
.back {
    display: none;
    width: 80%;
}
.selected {
    background-color: #4CAF50; /* 选中时的背景色 */
    color: white; /* 选中时的文字颜色 */
}
button:hover {
    background-color: #e2e2e2; /* 鼠标悬停时的背景色 */
}
button.back:hover {
    background-color: #e2e2e2;
}