body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f8f9fa;
    color: #343a40;
    line-height: 1.7;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 960px;
    margin: 30px auto;
    background: #ffffff;
    border-radius: 8px;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.07);
    padding: 30px 40px;
}

h1 {
    color: #0056b3;
    text-align: center;
    margin-bottom: 15px;
    border-bottom: 2px solid #dee2e6;
    padding-bottom: 10px;
}

h2 {
    color: #17a2b8; /* 备份架构标题颜色 */
    margin-top: 35px;
    margin-bottom: 20px;
    padding-bottom: 8px;
    border-bottom: 1px solid #a6e3ec;
}

p {
    margin-bottom: 12px;
}

ul {
    padding-left: 25px;
    margin-top: 5px;
    margin-bottom: 15px;
}

li {
    margin-bottom: 8px;
}

strong {
    color: #495057;
}

.back-link {
    display: inline-block;
    margin-bottom: 25px;
    color: #007bff;
    text-decoration: none;
    padding: 8px 15px;
    border: 1px solid #007bff;
    border-radius: 5px;
    transition: background-color 0.3s, color 0.3s;
}

.back-link:hover {
    background-color: #007bff;
    color: #fff;
}

.backup-section {
    margin-bottom: 40px;
    padding: 25px;
    background-color: #fdfdfd;
    border: 1px solid #e9ecef;
    border-radius: 6px;
}

.backup-diagram {
    text-align: center;
    padding: 15px;
    background-color: #e9ecef;
    border-radius: 5px;
    margin-top: 15px;
    margin-bottom: 20px;
}

.backup-diagram img {
    max-width: 80%; /* 限制图示宽度 */
    height: auto;
    display: block;
    margin: 0 auto 10px auto;
    background-color: #fff;
    padding: 5px;
    border: 1px solid #ced4da;
}

.backup-info p:first-child {
    margin-top: 0;
}

.backup-info ul {
    margin-top: 8px;
}

/* 占位图片样式 */
img[alt] {
    min-height: 120px; /* 保证占位符有一定高度 */
    background-color: #f8f9fa;
    border: 1px dashed #adb5bd;
    color: #6c757d;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9em;
    width: 80%; /* 匹配图片宽度 */
    margin: 0 auto 10px auto; /* 居中 */
}