/* favicon样式 - 作为图标加载失败时的备用 */
.favicon-fallback {
    width: 16px;
    height: 16px;
    background: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
    border-radius: 4px;
    position: relative;
    display: inline-block;
}

.favicon-fallback::before {
    content: "D";
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-weight: bold;
    font-size: 10px;
    font-family: Arial, sans-serif;
}