在Firefox, Opera, Internet Explorer, Chrome和Safari中测试。

hr {
    border-top: 1px solid red;
}

看小提琴。

因为我没有声誉来评论，我将在这里给出一些想法。

如果你想要一个可变高度的CSS，去掉所有的边框，并给出一个背景色。

    hr{
        height:2px;
        border:0px;
        background:green;
        margin:0px;/*sometimes useful*/
    }
    /*Doesn't work in ie7 and below and in Quirks Mode*/

if you want simply a style that you know that will work (example: to replace a border in a ::before element for most email clients or hr{ height:0px; border:0px; border-top:2px solid blue; margin:0px;/*useful sometimes*/ } In both ways, if you set a width, it will always have it's size. No need to set display:block; for this. To be totally safe, you can mix both, 'cause some browsers can get confused with height:0px;: hr{ height:1px; border:0px; background:blue; border-top:1px solid blue; margin:0px;/*useful sometimes*/ } With this method you can be sure that it will have at least 2px in height. It's a line more, but safety is safety. This is the method you should use to be compatible with almost everything. Remember: Gmail only detects inline css and some email clients may not support backgrounds or borders. If one fails, you will still have a 1px line. Better than nothing. In the worst cases, you can try to add color:blue;. In the worst of the worst cases, you can try to use a <font color="blue"></font> tag and put your precious <hr/> tag inside it. It will inherit the <font></font> tag color. With this method, you WILL want to do like this: <hr width="50" align="left"/>. Example: <span> awhieugfrafgtgtfhjjygfjyjg <font color="#42B3E5"><hr width="50" align="left"/></font> </span> <!--Doesn't work in ie7 and below and in Quirks Mode--> Here is a link for you to check: http://jsfiddle.net/sna2D/

你可以使用CSS来创建一条不同颜色的线，示例如下:

border-left: 1px solid rgb(216, 216, 216);
border-right: medium none;
border-width: medium medium medium 2px;
border-style: none none none solid;
border-color: -moz-use-text-color -moz-use-text-color -moz-use-text-color rgb(216, 216, 216);

该代码将显示垂直的灰线。

它很简单，也是我的最爱。

<hr style="background-color: #dd3333" />

你可以给<hr noshade>标签，然后到你的css文件中添加:

人力资源{ border-top: 0; 颜色:# 123455; ｝ <hr noshade /> 这是个测试 <hr noshade />

代码适用于旧的IE 尝试了很多颜色 <人力资源颜色=“黑色”> <人力资源颜色= "蓝色" >