/* 深色模式样式 */
body.dark-mode {
    background-color: #1a1a1a;
    color: #e0fbfc;
}

body.dark-mode #footer {
    background: linear-gradient(135deg, #1e1e1e 0%, #2c2c2c 50%, #3c3c3c 100%);
    color: #e0fbfc;
}

body.dark-mode #back-to-top {
    background: #00ffcc;
    color: #333;
}