CSS初始化是指重设浏览器的样式。不同的浏览器默认的样式可能不尽相同，所以开发时的第一件事可能就是如何把它们统一。如果没对CSS初始化往往会出现 浏览器之间的页面差异。每次新开发网站或新网页时候通过初始化CSS样式的属性，为我们将用到的CSS或html标签更加方便准确，使得我们开发网页内容 时更加方便简洁，同时减少CSS代码量，节约网页下载时间。
最耗资源的，最简单的
* { padding: 0; margin: 0; border: 0; }
选择性初始化举例（综合）
body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,legend,button form,fieldset,input,textarea,p,blockquote,th,td { padding: 0; margin: 0; } /* 酌情修改 */ body { background:#fff;color:#333;font-size:12px; margin-top:5px;font-family:"SimSun","宋体","Arial Narrow"; } /* 短引用的内容可取值：''或"" */ q:before,q:after {content:”;} /* 缩写，图片等无边框 */ fieldset,img,abbr,acronym {border: 0 none;} abbr,acronym {font-variant: normal;} legend {color:#000;} /* 清除特殊标记的字体和字号 */ address,caption,cite,code,dfn,em,strong,th,var { font-weight: normal; font-style: normal; } /* 上下标 */ sup {vertical-align: text-top;} sub {vertical-align: text-bottom;} /* 设置表格的边框被合并为一个单一的边框, 指定分隔边框模型中单元格边界之间的距离为0*/ table { border-collapse: collapse; border-spacing: 0; } /* 表格标题及内容居左显示 */ caption,th {text-align: left;} input,img,select {vertical-align:middle;} /* 清除列表样式 */ ol,ul {list-style: none;} /* 输入控件字体 */ input,button,textarea,select,optgroup,option { font-family:inherit; font-size:inherit; font-style:inherit; font-weight:inherit; } /* 标题元素样式清除 */ h1,h2,h3,h4,h5,h6 { font-weight: normal; font-size: 100%; } /* 链接样式，颜色可酌情修改 */ del,ins,a {text-decoration:none;} a:link {color:#009;} a:visited {color:#800080;} a:hover,a:active,a:focus {color:#c00; text-decoration:underline;} /* 鼠标样式 */ input[type="submit"] {cursor: pointer;} button {cursor: pointer;} input::-moz-focus-inner { border: 0; padding: 0;} .clear {clear:both;}
腾讯QQ官网(http://www.qq.com)样式初始化
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}
新浪官网(http://www.sina.com.cn/)样式初始化
body,ul,ol,li,p,h1,h2,h3,h4,h5,h6,form,fieldset,table,td,img,div{margin:0;padding:0;border:0;} body{background:#fff;color:#333;font-size:12px; margin-top:5px;font-family:"SimSun","宋体","Arial Narrow";} ul,ol{list-style-type:none;} select,input,img,select{vertical-align:middle;} a{text-decoration:none;} a:link{color:#009;} a:visited{color:#800080;} a:hover,a:active,a:focus{color:#c00;text-decoration:underline;}
淘宝官网(http://www.taobao.com/)样式初始化
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, 5b8b4f53; } 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; }
网易官网(http://www.163.com/)样式初始化
html {overflow-y:scroll;} body {margin:0; padding:29px00; font:12px"5B8B4F53",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;}
雅虎样式初始化
html{background:none repeat scroll 0 0#FFFFFF;color:#000000;} 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 none;} address,caption,cite,code,dfn,em,strong,th,var{font-style:normal;font-weight:normal;} li{list-style:none outside 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 none;font-variant:normal;} sup{vertical-align:text-top;} sub{vertical-align:text-bottom;} input,textarea,select{font-family:inherit;font-size:inherit;font-weight:inherit;} input,textarea,select{} legend{color:#000000;} body{font:13px/1.231 arial,helvetica,clean,sans-serif;} select,input,button,textarea{font:99%arial,helvetica,clean,sans-serif;} table{font-size:inherit;} pre,code,kbd,samp,tt{font-family:monospace;line-height:100%;} a{text-decoration:none;} a:hover,a:focus{text-decoration:underline;} strong{font-weight:bold;} input[type="submit"]{cursor:pointer;} button{cursor:pointer;}
WEB开发者
/* css reset www.admin10000.com */ body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,form,fieldset,legend,input,button,textarea,p,blockquote,th,td { margin:0; padding:0; } body { background:#fff; color:#555; font-size:14px; font-family: Verdana, Arial, Helvetica, sans-serif; } td,th,caption { font-size:14px; } h1, h2, h3, h4, h5, h6 { font-weight:normal; font-size:100%; } address, caption, cite, code, dfn, em, strong, th, var { font-style:normal; font-weight:normal;} a { color:#555; text-decoration:none; } a:hover { text-decoration:underline; } img { border:none; } ol,ul,li { list-style:none; } input, textarea, select, button { font:14px Verdana,Helvetica,Arial,sans-serif; } table { border-collapse:collapse; } html {overflow-y: scroll;} /* css common */ .clearfix:after {content: "."; display: block; height:0; clear:both; visibility: hidden;} .clearfix { *zoom:1; }
博客园
/*version: 2.7.0*/ html,body{color:#000;background:#FFF;} body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,form,fieldset,legend,input,button,textarea,p,blockquote,th,td{ margin:0;padding:0; } table{border-collapse:collapse;border-spacing:0;} fieldset,img{border:0;} address,caption,cite,code,dfn,em,strong,th,var,optgroup{ font-style:inherit;font-weight:inherit; } del,ins{text-decoration:none;} li{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;} sup{vertical-align:baseline;} sub{vertical-align:baseline;} legend{color:#000;} input,button,textarea,select,optgroup,option{ font-family:inherit;font-size:inherit;font-style:inherit;font-weight:inherit; } input,button,textarea,select{*font-size:100%;} .clear{clear:both;} input::-moz-focus-inner{ border: 0;padding: 0;} /*added*/ input[type=button],input[type=submit] {-webkit-appearance: button;}