1.CSS²¼¾Ö³£Óõķ½·¨£º
float : none | left | right

È¡Öµ£º
none :£  ĬÈÏÖµ¡£¶ÔÏó²»Æ®¸¡
left :£  Îı¾Á÷Ïò¶ÔÏóµÄÓÒ±ß
right :£  Îı¾Á÷Ïò¶ÔÏóµÄ×ó±ß

ËüÊÇÔõÑù¹¤×÷µÄ£¬¿´¸öÒ»ÐÐÁ½ÁеÄÀý×Ó

xhtml:

<div id="warp">
 <div id="column1">ÕâÀïÊǵÚÒ»ÁÐ</div>
 <div id="column2">ÕâÀïÊǵڶþÁÐ</div>
 <div class="clear"></div>
</div>

CSS:

#wrap{ width:100%; height:auto;}
#column1{ float:left; width:40%;}
#column2{ float:right; width:60%;}
.clear{ clear:both;}

position : static | absolute | fixed | relative

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static :£  ĬÈÏÖµ¡£ÎÞÌØÊⶨ룬¶ÔÏó×ñÑ­HTML¶¨Î»¹æÔò
absolute :£  ½«¶ÔÏó´ÓÎĵµÁ÷ÖÐÍϳö£¬Ê¹Óà left £¬ right £¬ top £¬ bottom µÈÊôÐÔÏà¶ÔÓÚÆä×î½Ó½üµÄÒ»¸ö×îÓж¨Î»ÉèÖõĸ¸¶ÔÏó½øÐоø¶Ô¶¨Î»¡£Èç¹û²»´æÔÚÕâÑùµÄ¸¸¶ÔÏó£¬ÔòÒÀ¾Ý body ¶ÔÏ󡣶øÆä²ãµþͨ¹ý z-index ÊôÐÔ¶¨Òå
fixed :£  δ֧³Ö¡£¶ÔÏó¶¨Î»×ñ´Ó¾ø¶Ô(absolute)·½Ê½¡£µ«ÊÇÒª×ñÊØһЩ¹æ·¶
relative :£  ¶ÔÏ󲻿ɲãµþ£¬µ«½«ÒÀ¾Ý left £¬ right £¬ top £¬ bottom µÈÊôÐÔÔÚÕý³£ÎĵµÁ÷ÖÐÆ«ÒÆλÖÃ

ËüÀ´ÊµÏÖÒ»ÐÐÁ½ÁеÄÀý×Ó

xhtml:

<div id="warp">
 <div id="column1">ÕâÀïÊǵÚÒ»ÁÐ</div>
 <div id="column2">ÕâÀïÊǵڶþÁÐ</div>
</div>

CSS:

#wrap{ position:relative;/*Ïà¶Ô¶¨Î»*/width:770px;}
#column1{ position:absolute; top:0; left:0; width:300px;}
#column2{position:absolute; top:0; right:0; width:470px;}

ËûÃǵÄÇø±ðÔÚÄÄ?

ÏÔÈ»£¬floatÊÇÏà¶Ô¶¨Î»µÄ£¬»áËæ×Åä¯ÀÀÆ÷µÄ´óСºÍ·Ö±æÂʵı仯¶ø¸Ä±ä£¬¶øposition¾Í²»ÐÐÁË£¬ËùÒÔÒ»°ãÇé¿öÏ»¹ÊÇfloat²¼¾Ö£¡

2.CSS³£Óò¼¾ÖʵÀý

Ò»ÁÐ
µ¥ÐÐÒ»ÁÐ

body { margin: 0px;   padding: 0px;  text-align: center;  }
#content {  margin-left:auto;  margin-right:auto;  width: 400px;}

Á½ÐÐÒ»ÁÐ

body {  margin: 0px;   padding: 0px;   text-align: center;}
#content-top { margin-left:auto;   margin-right:auto; width: 400px; }
#content-end {margin-left:auto; margin-right:auto;  width: 400px; }

ÈýÐÐÒ»ÁÐ

body {  margin: 0px; padding: 0px;  text-align: center;  }
#content-top {  margin-left:auto;  margin-right:auto;  width: 400px;}
#content-mid { margin-left:auto; margin-right:auto;  width: 400px;}
#content-end { margin-left:auto; margin-right:auto; width: 400px;  }

Á½ÁÐ
µ¥ÐÐÁ½ÁÐ

#bodycenter { width: 700px;margin-right: auto; margin-left: auto;overflow: auto;  }
#bodycenter #dv1 {float: left;width: 280px;}
#bodycenter #dv2 {float: right;width: 410px;}

Á½ÐÐÁ½ÁÐ

#header{    width: 700px; margin-right: auto;margin-left: auto; overflow: auto;}
#bodycenter { width: 700px; margin-right: auto; margin-left: auto; overflow: auto; }
#bodycenter #dv1 { float: left; width: 280px;}
#bodycenter #dv2 { float: right;width: 410px;}

ÈýÐÐÁ½ÁÐ

#header{    width: 700px;margin-right: auto; margin-left: auto;  }
#bodycenter {width: 700px; margin-right: auto; margin-left: auto;  }
#bodycenter #dv1 {  float: left;width: 280px;}
#bodycenter #dv2 { float: right;  width: 410px;}
#footer{     width: 700px;  margin-right: auto; margin-left: auto;  overflow: auto;  }

ÈýÁÐ
µ¥ÐÐÈýÁÐ
¾ø¶Ô¶¨Î»

#left { position: absolute; top: 0px;  left: 0px; width: 120px;  }
#middle {margin: 20px 190px 20px 190px; }
#right {position: absolute;top: 0px; right: 0px;  width: 120px;}

float¶¨Î»

xhtml:

<div id="warp">
 <div id="column">
 <div id="column1">ÕâÀïÊǵÚÒ»ÁÐ</div>
 <div id="column2">ÕâÀïÊǵڶþÁÐ</div>
 <div class="clear"></div>
 </div>
 <div id="column3">ÕâÀïÊǵÚÈýÁÐ</div>
 <div class="clear"></div>
</div>

CSS:

#wrap{ width:100%; height:auto;}
#column{ float:left; width:60%;}
#column1{ float:left; width:30%;}
#column2{ float:right; width:30%;}
#column3{ float:right; width:40%;}
.clear{ clear:both;}