雅虎 YUI

/*
YUI 3.18.1 (build f7e7bcb)
Copyright 2014 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;
    *font-size:100%; /*to enable resizing for IE*/
}
/*because legend doesn't inherit in IE */
legend {
    color:#000;
}

/* YUI CSS Detection Stamp */
#yui3-css-stamp.cssreset { display: none; }

腾讯

body,ol,ul,h1,h2,h3,h4,h5,h6,p,th,td,dl,dd,form,fieldset,legend,input,textarea,select{margin:0;padding:0} 
body{font:12px"宋体","Arial Narrow",HELVETICA;background:#fff;-webkit-text-size-adjust:100%;} 
a{color:#2d374b;text-decoration:none} 
a:hover{color:#cd0200;text-decoration:underline} 
em{font-style:normal} 
li{list-style:none} 
img{border:0;vertical-align:middle} 
table{border-collapse:collapse;border-spacing:0} 
p{word-wrap:break-word} 

新浪

/* 初始化CSS */

html, body, ul, li, ol, dl, dd, dt, p, h1, h2, h3, h4, h5, h6, form, fieldset, legend, img { margin:0; padding:0; }
fieldset, img { border:none; }
img{display: block;}
address, caption, cite, code, dfn, th, var { font-style:normal; font-weight:normal; }
ul, ol { list-style:none; }
input { padding-top:0; padding-bottom:0; font-family: "SimSun","宋体";}
input::-moz-focus-inner { border:none; padding:0; }
select, input { vertical-align:middle; }
select, input, textarea { font-size:12px; margin:0; }
input[type="text"], input[type="password"], textarea { outline-style:none; -webkit-appearance:none; }
textarea { resize:none; }
table { border-collapse:collapse; }
body { color:#333; padding:5px 0; font:12px/20px "SimSun","宋体","Arial Narrow",HELVETICA; background:#fff;/* overflow-y:scroll;*/ }
.clearfix:after { content:"."; display:block; height:0; visibility:hidden; clear:both; }
.clearfix { zoom:1; }
.clearit { clear:both; height:0; font-size:0; overflow:hidden; }
a { color:#666; text-decoration:none; }
a:visited { color:#666; }
a:hover, a:active, a:focus { color:#ff8400; text-decoration:underline; }

淘宝

body, h1, h2, h3, h4, h5, h6, hr, p, blockquote, dl, dt, dd, ul, ol, li, pre, form, fieldset, legend, button, input, textarea, th, td { margin:0; padding:0; } 
body, button, input, select, textarea { font:12px/1.5tahoma, arial, \5b8b\4f53; } 
h1, h2, h3, h4, h5, h6{ font-size:100%; } 
address, cite, dfn, em, var { font-style:normal; } 
code, kbd, pre, samp { font-family:couriernew, courier, monospace; } 
small{ font-size:12px; } 
ul, ol { list-style:none; } 
a { text-decoration:none; } 
a:hover { text-decoration:underline; } 
sup { vertical-align:text-top; } 
sub{ vertical-align:text-bottom; } 
legend { color:#000; } 
fieldset, img { border:0; }
button, input, select, textarea { font-size:100%; } 
table { border-collapse:collapse; border-spacing:0; } 

网易

html {overflow-y:scroll;}
body {margin:0; padding:29px00; font:12px"\5B8B\4F53",sans-serif;background:#ffffff;}
div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,form,fieldset,input,textarea,blockquote,p{padding:0; margin:0;}
table,td,tr,th{font-size:12px;}
li{list-style-type:none;}
img{vertical-align:top;border:0;}
ol,ul {list-style:none;}
h1,h2,h3,h4,h5,h6{font-size:12px; font-weight:normal;}
address,cite,code,em,th {font-weight:normal; font-style:normal;}

百度

body,h1,h2,h3,h4,h5,h6,hr,p,blockquote,dl,dt,dd,ul,ol,li,pre,form,fieldset,legend,button,input,textarea,th,td{margin:0;padding:0}
html{color:#000;overflow-y:scroll;overflow:-moz-scrollbars-vertical}
body,button,input,select,textarea{font-size:12px;font-family:arial,'Hiragino Sans GB','Microsoft Yahei','微软雅黑','宋体',\5b8b\4f53,Tahoma,Arial,Helvetica,STHeiti}
h1,h2,h3,h4,h5,h6{font-size:100%}
em{font-style:normal}
small{font-size:12px}
ul,ol{list-style:none}
a{text-decoration:none}
a:hover{text-decoration:underline}
legend{color:#000}
fieldset,img{border:0}
button,input,select,textarea{font-size:100%}
table{border-collapse:collapse;border-spacing:0}
img{-ms-interpolation-mode:bicubic}
textarea{resize:vertical}
.left{float:left}
.right{float:right}
.overflow{overflow:hidden}
.hide{display:none}
.block{display:block}
.inline{display:inline}
.error{color:#F00;font-size:12px}
label,button{cursor:pointer}
.clearfix:after{content:'\20';display:block;height:0;clear:both}
.clearfix{zoom:1}.clear{clear:both;height:0;line-height:0;font-size:0;visibility:hidden;overflow:hidden}
.wordwrap{word-break:break-all;word-wrap:break-word}
pre.wordwrap{white-space:pre-wrap}
body{text-align:center}
body,form{position:relative}
td{text-align:left}
img{border:0}

搜狐

/* 全局CSS定义 */
body{font-family:"\5B8B\4F53","Arial Narrow",HELVETICA;text-align:center;margin:0 auto;padding:0;background:#FFF;font-size:12px;color:#333;}
body > div{text-align:center;margin-right:auto;margin-left:auto;}
div,form,ul,ol,li,span,p{margin:0;padding:0;border:0;}
img,a img{border:0;margin:0;padding:0;}
h1,h2,h3,h4,h5,h6{margin:0;padding:0;font-size:12px;font-weight:normal;}
ul,ol,li{list-style:none}
table,td,input{font-size:12px;padding:0}

/* 默认链接颜色 */
a{outline-style:none;color:#333;text-decoration:none}
a:hover{color:#c00;text-decoration:underline;}

/*清除链接虚框*/
/*a,area {blr:expression(this.onFocus=this.blur()) }  for IE
:focus {-moz-outline-style: none; }  for Firefox  

优酷

@charset "utf-8";
article,aside,details,figcaption,figure,footer,header,hgroup,nav,section{display:block}
audio,canvas,video{display:inline-block;*display:inline;*zoom:1}
audio:not([controls]){display:none}
html{-webkit-text-size-adjust:100%;-ms-text-size-adjust:100%}
a:focus{outline:thin dotted #333;outline:5px auto -webkit-focus-ring-color;outline-offset:-2px}
a:hover,a:active{outline:0}
figure{padding:0;margin:0}
sub,sup{position:relative;font-size:75%;line-height:0;vertical-align:baseline}
sup{top:-0.5em}
sub{bottom:-0.25em}
img{vertical-align:middle;border:0;-ms-interpolation-mode:bicubic}
button,input,select,textarea{margin:0;font-size:100%;vertical-align:middle}
button,input{*overflow:visible;line-height:normal}
button::-moz-focus-inner,input::-moz-focus-inner{padding:0;border:0}
button,input[type="button"],input[type="reset"],input[type="submit"]{-webkit-appearance:button;cursor:pointer}
input[type="search"]{-webkit-box-sizing:content-box;-moz-box-sizing:content-box;box-sizing:content-box;-webkit-appearance:textfield}
input[type="search"]::-webkit-search-decoration,input[type="search"]::-webkit-search-cancel-button{-webkit-appearance:none}
textarea{overflow:auto;vertical-align:top}
ol,ul,dl{list-style:none}
body,p,ol,ul,dl{padding:0;margin:0}
a:link,a:visited{text-decoration:none;color:#555}
a:hover{color:#c31}
a.white{color:#fff}
a.blue{color:#3399e0} 

美团

blockquote,body,code,dd,div,dl,dt,fieldset,form,h1,h2,h3,h4,h5,h6,input,legend,li,ol,p,pre,td,textarea,th,ul{margin:0;padding:0}
table{border-collapse:collapse;border-spacing:0}
fieldset,img{border:0}
address,caption,cite,code,dfn,em,var{font-style:normal;font-weight:400}
li{list-style:none}
caption,th{text-align:left}
h1,h2,h3,h4,h5,h6{font-size:100%}
q:after,q:before{content:''}
abbr,acronym{border:0;font-variant:normal}
sup{vertical-align:text-top}
sub{vertical-align:text-bottom}
input,select,textarea{font-family:inherit;font-size:inherit;*font-size:100%;font-weight:inherit}
legend{color:#333}html{background-color:#eee}
body{font:400 14px/1.5 "Hiragino Sans GB","WenQuanYi Micro Hei",tahoma,sans-serif;color:#666;background-color:#fff}
a{color:#2bb8aa;text-decoration:none}a:hover{text-decoration:underline}
h1,h2,h3,h4,h5,h6{font-family:"Hiragino Sans GB"," Microsoft YaHei","WenQuanYi Micro Hei",arial,sans-serif;color:#333;-webkit-font-smoothing:antialiased}
input[type=password]{font-family:arial,sans-serif}

Eric Meyer’s CSS reset

/* http://meyerweb.com/eric/tools/css/reset/ 
   v2.0 | 20110126
   License: none (public domain)
*/

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;
}