css - 这个伪类排序不冲突吗？

Question

我知道伪类必须按顺序排列，以免相互冲突。 (双重“按顺序”意在)

问题是我读到 CSS 从右到左读取(在找到匹配项时)，这让我对此产生了疑问:

a{
color:blue;
text-decoration:none;
}

a:hover,a:focus{
text-decoration:underline;
}

应该是a:focus,a:hover还是我现在这样就好了？

Answer 1

在这种情况下，这无关紧要，因为它们不能同时触发...考虑到 :hover 用于用鼠标和 触发的链接事件: focus 用于通过键盘触发的链接事件。

但是，读这个

The :link and :visited pseudo-classes should generally come first. Next should be :focus and :hover—they’re specified now so that they override and apply to both visited and unvisited links. If :focus precedes :hover, the hover effect will apply to links with keyboard input focus. The :active pseudo-class should always come last, since we usually want to indicate clearly any links that have been activated.

来自这里:http://reference.sitepoint.com/css/pseudoclasses

在这种情况下，我认为理想的是

a:link{
}

a:visited{
}

a:focus, a:hover{
}

a:active{
}