html – 悬停边框位置

<div class="box">
    <ul>
        <li><a href="#">test 1</a></li>
        <li><a href="#">test 2</a></li>
    </ul>
</div>

ul{
    list-style: none;
    padding: 0 0 10px;
    margin: 0;
    border-bottom: 5px solid green;
    overflow: hidden;
}

ul li{
    float: left;
    margin-left: 20px;
}

a{
    text-decoration: none;
    display: block;     
}

a:hover{
    border-bottom: 5px solid red;    
}

解决方法@H_607_21@

您想要定位ul和li – 将子li的底部偏移到边框的宽度,同时将其设置为透明,然后使用li：hover事件/选择器将broder颜色设置为红色.

Demo Fiddle

使用以下CSS：

ul {
    list-style: none;
    margin: 0;
    border-bottom: 5px solid green;
    position:relative;
    padding:0;
}
ul li {
    padding:10px 10px;
    margin-left: 20px;
    display:inline-block;
    position:relative;
    bottom:-5px; /* <-- offset bottom of li by border width so it overlaps ul green border */
    border-bottom: 5px solid transparent; /* add border,make transparent so it doesnt 'jump' on hover */
}
a {
    text-decoration: none;
    display: block;
}
li:hover {
    border-color:red; /* <-- use the li hover event (not a hover) to color the border */
}