/* 默认基础变量 */
:root {
    --bg-color: #f8f9fa;
    --text-color: #333333;
    --link-color: #20a53a;
    --beian-link-color: #666666;
    --toggle-bg: #e0e0e0;
    --toggle-icon-color: #ffc107;
    --header-border: #20a53a;
    /* 动态加载的变量占位符 */
    --bg-image: none;
    --container-bg: transparent;
}

.dark-mode {
    --bg-color: #121212;
    --text-color: #e0e0e0;
    --link-color: #4ade80;
    --beian-link-color: #999999;
    --toggle-bg: #333333;
    --toggle-icon-color: #f5f5f5;
    --header-border: #4ade80;
}

body {
    background-color: var(--bg-color);
    background-image: var(--bg-image);
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    color: var(--text-color);
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    transition: background-color 0.3s, color 0.3s;
    padding-bottom: 80px;
}

.container {
    width: 85%;
    max-width: 1000px;
    margin: 50px auto;
    background-color: var(--container-bg);
    padding: 40px;
    border-radius: 16px;
    transition: all 0.3s ease;
}

/* 布局样式保持不变 */
h1 { text-align: center; cursor: pointer; margin-bottom: 10px; }
.intro { font-style: italic; font-size: 0.95em; line-height: 1.6; color: var(--beian-link-color); border-left: 4px solid var(--header-border); padding-left: 15px; margin: 20px 0 40px; }
.sections-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 30px; }
.section-title { font-size: 1.2em; font-weight: bold; margin-bottom: 15px; padding-bottom: 8px; border-bottom: 2px solid var(--header-border); display: flex; align-items: center; }
.link-list { list-style: none; padding: 0; margin: 0; }
.link-list li { margin-bottom: 10px; }
.link-list a { text-decoration: none; color: var(--link-color); transition: opacity 0.2s; display: inline-block; }
.link-list a:hover { text-decoration: underline; opacity: 0.8; }

#beianInfo { position: fixed; bottom: 0; left: 0; right: 0; text-align: center; padding: 15px; background: rgba(var(--bg-color), 0.3); backdrop-filter: blur(5px); font-size: 12px; z-index: 100; }
#beianInfo a { color: var(--beian-link-color); text-decoration: none; margin: 0 10px; }

.mode-toggle { position: fixed; top: 20px; right: 20px; width: 40px; height: 40px; border: none; border-radius: 50%; background-color: var(--toggle-bg); color: var(--toggle-icon-color); cursor: pointer; font-size: 20px; display: flex; align-items: center; justify-content: center; z-index: 1000; }

@media (max-width: 600px) { .container { width: 90%; padding: 20px; margin: 20px auto; } .sections-grid { grid-template-columns: 1fr; } }