/* 新增下划线效果 */
a.active {
    color: #4a6bff; /* 选中状态文字颜色 */
}

a.active::after {
    content: '';
    position: absolute;
    bottom: -5px; /* 调整下划线位置 */
    left: 0;
    width: 100%;
    height: 3px;
    background-color: #4a6bff;
    border-radius: 3px;
    animation: underline 0.3s ease-out;
}

@keyframes underline {
    from {
        transform: scaleX(0);
    }
    to {
        transform: scaleX(1);
    }
}