1、在需要hover的标签上加上
transition: all .2s ease-in-out;
2、让高亮更有层次
.nav-items a{
opacity: .69;
color:#fff;
cursor: pointer;
transition: all .2s ease-in-out;
}
.nav-items a.on{
color: #fff;
opacity: 1;
}
原文：https://www.cnblogs.com/weilingfamily/p/9083127.html