/*全局样式*/
*{padding:0margin:0}
div,dl,dt,dd,form,h1,h2,h3,h4,h5,h6,img,ol,ul,li,table,th,td,p,span,a{border:0}
img,input{border:nonevertical-align:middle}
body{font-family:Tahoma,Arial,Helvetica,"宋体"font-size:12pxtext-align:centerbackground:#FFFcolor:#000}
html{overflow-y:scroll}
ul,ol{list-style-type:none}
th,td,input{font-size:12px}
h3{font-size:14px}
button{border:nonecursor:pointerfont-size:12pxbackground-color:transparent}
select{border-width:1px_zoom:1border-style:solidpadding-top:2pxfont-size:12px}
.clear{clear:bothfont-size:1pxheight:0visibility:hiddenline-height:0}
.clearfix:after{content:""display:blockclear:both}
.clearfix{zoom:1}
a:link,a:visited{text-decoration:nonecolor:#333}
a:hover,a:active{text-decoration:underlinecolor:#f60}
这就是个风格问题,怎么写都可以。一般来说是重置浏览器有争议的属性,比如边距什么的,再就是设置一些根样式以供其他元素继承,比如body的字体、颜色等,再就是一些公共样式,clearfix清空文档流之类的。当然还有一些高级的技巧,CSS专家也有很多建议,比如《CSS权威指南》作者Eric Meyer的建议是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
}