CSS Reset是指重设浏览器的样式。在各种浏览器中，都会对CSS的选择器默认一些数值，譬如当h1没有被设置数值时，显示一定大小。但并不是所有的浏览器都使用一样的数值，所以有了CSS Reset，以让网页的样式在各浏览器中表现一致。
下面介绍几个主流的CSS Reset代码：
1、Eric Meyer
html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed,
figure, figcaption, footer, header, hgroup,
menu, nav, output, ruby, section, summary,
time, mark, audio, video {
margin: 0;
padding: 0;
border: 0;
font-size: 100%;
font: inherit;
vertical-align: baseline;
}
/* HTML5 display-role reset for older browsers */
article, aside, details, figcaption, figure,
footer, header, hgroup, menu, nav, section {
display: block;
}
body {
line-height: 1;
}
ol, ul {
list-style: none;
}
blockquote, q {
quotes: none;
}
blockquote:before, blockquote:after,
q:before, q:after {
content: '';
content: none;
}
table {
border-collapse: collapse;
border-spacing: 0;
}
2、YUI
/*
YUI 3.4.1 (build 4118)
Copyright 2011 Yahoo! Inc. All rights reserved.
Licensed under the BSD License.
http://yuilibrary.com/license/
*/
/*
TODO will need to remove settings on HTML since we can't namespace it.
TODO with the prefix,should I group by selector or property for weight savings?
*/
html {
color:#000;
background:#FFF;
}
/*
TODO remove settings on BODY since we can't namespace it.
*/
/*
TODO test putting a class on HEAD.
- Fails on FF.
*/
body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,form,fieldset,legend,input,textarea,p,blockquote,th,td {
margin:0;
padding:0;
}
table {
border-collapse:collapse;
border-spacing:0;
}
fieldset,img {
border:0;
}
/*
TODO think about hanlding inheritence differently,maybe letting IE6 fail a bit...
*/
address,caption,cite,code,dfn,em,strong,th,var {
font-style:normal;
font-weight:normal;
}
ol,ul {
list-style:none;
}
caption,th {
text-align:left;
}
h1,h2,h3,h4,h5,h6 {
font-size:100%;
font-weight:normal;
}
q:before,q:after {
content:'';
}
abbr,acronym {
border:0;
font-variant:normal;
}
/* to preserve line-height and selector appearance */
sup {
vertical-align:text-top;
}
sub {
vertical-align:text-bottom;
}
input,textarea,select {
font-family:inherit;
font-size:inherit;
font-weight:inherit;
}
/*to enable resizing for IE*/
input,textarea,select {
*font-size:100%;
}
/*because legend doesn't inherit in IE */
legend {
color:#000;
}
3、csslab
html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, font, img, ins, kbd, q, s, samp, small, strike, sub, sup, tt, var, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, dialog, figure, header, footer, hgroup, menu, nav, section, time, mark, audio, video {
margin: 0;
padding: 0;
border: 0;
outline: 0;
font-weight: inherit;
font-style: inherit;
font-size: 100%;
}
article, aside, nav, section, dialog, figure, header, footer, hgroup {
display:block;
}
legend {
display:none;
}
:focus {
outline: 0;
}
table {
border-collapse: collapse;
border-spacing: 0;
}
caption, th, td {
text-align: left;
font-weight: normal;
}
a img, iframe {
border: none;
}
ul {
list-style: none;
}
input, textarea, select, button {
font-size: 100%;
font-family: inherit;
}
input, select {
vertical-align:middle;
}
select {
margin: inherit;
}
button {
border: 0;
padding: 0;
background: transparent;
cursor: pointer;
}
/* Fixes incorrect placement of numbers in ol's in IE6/7 */
ol { margin-left:2em; }
/* ========================================= clearfix == */
.clearfix:after {
content: ".";
display: block;
height: 0;
clear: both;
visibility: hidden;
}
.clearfix {display: inline-block;}
* html .clearfix {height: 1%;}
.clearfix {display: block;}
需要说明的是CSS Reset并不是一成不变的，具体还需要根据项目的不同需求做适当的修改，以达到浏览器的兼容和操作上的便利性。