为什么要初始化css样式

1.浏览器差异

不同浏览器对有些标签的默认值是不同的，如果没对css初始化会出现浏览器之间的页面显示差异

2.提高编码质量

如果不初始化，整个页面做完会很糟糕，重复的css样式很多

最简单的初始化方法是：（不建议）

1 * {padding: 0; margin: 0;} 

淘宝样式 样式初始化

 1 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; }
 2 body, button, input, select, textarea { font:12px/1.5tahoma, arial, \5b8b\4f53; }
 3 h1, h2, h3, h4, h5, h6{ font-size:100%; }
 4 address, cite, dfn, em, var { font-style:normal; }
 5 code, kbd, pre, samp { font-family:couriernew, courier, monospace; }
 6 small{ font-size:12px; }
 7 ul, ol { list-style:none; }
 8 a { text-decoration:none; }
 9 a:hover { text-decoration:underline; }
10 sup { vertical-align:text-top; }
11 sub{ vertical-align:text-bottom; }
12 legend { color:#000; }
13 fieldset, img { border:0; }
14 button, input, select, textarea { font-size:100%; }
15 table { border-collapse:collapse; border-spacing:0; }

腾讯QQ官网 样式初始化

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

新浪官网 样式初始化

 1 body,ul,ol,li,p,h1,h2,h3,h4,h5,h6,form,fieldset,table,td,img,div{margin:0;padding:0;border:0;}
 2 body{background:#fff;color:#333;font-size:12px; margin-top:5px;font-family:"SimSun","宋体","Arial Narrow";}
 3
 4 ul,ol{list-style-type:none;}
 5 select,input,img,select{vertical-align:middle;}
 6
 7 a{text-decoration:none;}
 8 a:link{color:#009;}
 9 a:visited{color:#800080;}
10 a:hover,a:active,a:focus{color:#c00;text-decoration:underline;}

网易官网 样式初始化

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

原文地址：https://www.cnblogs.com/miluluyo/p/11152926.html