Why can't I use the p tag to set the center?_html/css_WEB-ITnose

75598ae0912b4c03dd28a6ab100b9481
ff9c23ada1bcecdd1a0fb5d5a0f18437
> 94b3e26ee717c64999d7867364b1b4a3

The #page I set {width:500px;height:30px;margin:0 auto;}
In IE it is centered, but in Firefox it is not centered ,
Later, I changed e388a4556c0f65e1904146cc1a846bee to dc6dce4a544fdca2df29d5ac0ea9906b or ff6d136ddc5fdfeffaf53ff6ee95f185 and it became centered. I don’t know why? e388a4556c0f65e1904146cc1a846bee is also a block element,

Reply to the discussion (solution)
For p, use

You can use firebug to track it under ff, and the generated document The tree has changed

 text-align : center

p can only contain inline elements, not block elements

<p id="page">   <form>       <input type="text" name="text">   </form></p>被解析成为 以下文档树了，自然不起作用了<p id="page"></p>     <form>      <input name="text" type="text">    </form><p></p>

There are rules for nesting elements, not how you want to nest them

The DOCTYPE definition is missing

Thanks to 2nd floor, I understand

o, bd

Try not to use blocks in P tags!