body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-color: #fff;
    color: #000;
}

header {
    background-color: #f8f8f8;
    padding: 10px 0;
    border-bottom: 1px solid #ddd;
}

nav ul {
    list-style: none;
    padding: 0;
    text-align: center;
}

nav ul li {
    display: inline;
    margin: 0 15px;
}

nav ul li a {
    text-decoration: none;
    color: #00f;
}

main {
    max-width: 800px;
    margin: 20px auto;
    padding: 0 20px;
}

h1, h2 {
    text-align: center;
}

img {
    width: 100%; /* 图片宽度 */
    height: auto;
    margin-top: 20px;
    border-radius: 8px;
    border: 1px solid #333;
 }

section {
    margin-bottom: 20px;
}

.download-button {
    display: block;
    margin: 20px 0;
    padding: 10px 20px;
    background-color: #808080;
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
    font-size: 16px;
}

.download-button:hover {
    background-color: #404040;
}