Align <hr> to the left in an HTML5-compliant way

问题

Currently, I'm using

<hr align="left" />

on my HTML5 page, but I've read that the align property was deprecated in XHTML 4.01 and supposedly removed from HTML5. I'd like to be using CSS rather than an inline attribute like this, but when I tried

hr{align: left; max-width: 800px;}

or hr{text-align: left;} or hr{left: 0;} or hr{float: left;}, it just showed up in the center.

So what should I use instead of the inline attribute above?

回答1:

You're trying to use something in a way that (as Eliezer Bernart mentions.. and apparently that comment with the link to the MDN doc disappeared) no longer "works that way". You can, as long as you don't mind it being screwy in IE, just set the margin to zero - http://jsfiddle.net/s52wb/

hr {
    max-width: 100px;
    margin: 0px;
}

A better idea though would be to mimic the HR's old way of doing things by way of CSS without the use of the HR. Check out http://jsfiddle.net/p5ax9/1/ for a demo:

p:first-child:before {
    display: none;
}
p:before {
    content: " ";
    border: 1px solid black;
    margin-top: 15px;
    margin-bottom: 15px;
    display: block;
    max-width: 100px;
}

回答2:

One option would be to set the left margin to zero:

hr{max-width: 800px; margin-left:0;}

回答3:

I don't know what browsers were used for some above answers, but I found neither text-align:left nor margin-left:0 worked in both IE (11, Standards mode, HTML5) and Firefox (29).

• IE11: text-align:left works, margin-left:0 leaves rule centred.

• FF: margin-left:0 works, text-align:left leaves rule centred.

• So, either use both, or I found that margin-right:100% works for both!

回答4:

You can use div tag instead.

<div style="border: thin solid lightgray; width: 100px;"></div>

回答5:

do this

hr {
   display: inline;  //or inline-block
   text-align: left;
}

来源：https://stackoverflow.com/questions/20724891/align-hr-to-the-left-in-an-html5-compliant-way