10个非常有用的CSS技巧 优化https://developers.google.com/speed/articles/ p

1. 将网页或元素居中       

      

    
HTML：

<div class="wrap">
</div><!-- end wrap -->

 

CSS：

.wrap { width:960px; margin:0 auto;}

2.Sticky Footer (让页脚永远停靠在页面底部，而不是根据绝对位置)
    

    

  
HTML：

<div id="wrap">

<div id="main" class="clearfix">

</div>

</div>

<div id="footer">

</div>

CSS：

* { margin:0; padding:0; }

html, body, #wrap { height: 100%; }

body > #wrap {height: auto; min-height: 100%;}

#main { padding-bottom: 150px; }  /* must be same height as the footer */

#footer {
        position: relative;
 margin-top: -150px; /* negative value of footer height */
 height: 150px;
 clear:both;}

/* CLEAR FIX*/
.clearfix:after {content: ".";
 display: block;
 height: 0;
 clear: both;
 visibility: hidden;}
.clearfix {display: inline-block;}
/* Hides from IE-mac */
* html .clearfix { height: 1%;}
.clearfix {display: block;}
/* End hide from IE-mac */

3.跨浏览器最小高度设置      

       

 CSS：

.element { min-height:600px; height:auto !important; height:600px; }

4.Box阴影(CSS3)
    

    

    
CSS：

.box { box-shadow: 5px 5px 5px #666;  -moz-box-shadow: 5px 5px 5px #666;  -webkit-box-shadow: 5px 5px 5px #666; }

5.文字阴影（CSS3）

    

        

CSS：

.text { text-shadow: 1px 1px 1px #666; filter: Shadow(Color=#666666, Direction=135, Strength=5); }

6.跨浏览器的CSS透明度
    

CSS：

.transparent {

  /* Modern Browsers */ opacity: 0.7;

  /* IE 8 */ -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=70)";

  /* IE 5-7 */ filter: alpha(opacity=70);

  /* Netscape */ -moz-opacity: 0.7;

  /* Safari 1 */ -khtml-opacity: 0.7;

}

7.著名的 Meyer Reset（重置）
    

CSS：

  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, strong, sub, sup, tt, var,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td {
 margin: 0;
 padding: 0;
 border: 0;
 outline: 0;
 font-weight: inherit;
 font-style: inherit;
 font-size: 100%;
 font-family: inherit;
 vertical-align: baseline;
}
/* remember to define focus styles! */
:focus {
 outline: 0;
}
body {
 line-height: 1;
 color: black;
 background: white;
}
ol, ul {
 list-style: none;
}
/* tables still need 'cellspacing="0"' in the markup */
table {
 border-collapse: separate;
 border-spacing: 0;
}
caption, th, td {
 text-align: left;
 font-weight: normal;
}
blockquote:before, blockquote:after,
q:before, q:after {
 content: "";
}
blockquote, q {
 quotes: "" "";
}

8.删除虚线轮廓      

    

CSS：

a, a:active { outline: none; }

9.圆角
    

         

CSS：

.element {
 -moz-border-radius: 5px;
 -webkit-border-radius: 5px;
 border-radius: 5px; /* future proofing */
}
.element-top-left-corner {
 -moz-border-radius-topleft: 5px;
 -webkit-border-top-left-radius: 5px;
}

10.覆盖内联的样式

     

 CSS:

.override {
 font-size: 14px !important;
}