问题与对策：CSS的margin塌陷（collapse） - jerrylsxu

<span id="lnum2">   2: </span>

<span id="lnum3">   3: </span>

<span id="lnum4">   4:     <title></title></span>

<span id="lnum5">   5:     <metaname></metaname></span>

<span id="lnum6">   6: <style></style></span>

<span id="lnum7">   7: *{</span>

<span id="lnum8">   8:     margin:0px;</span>

<span id="lnum9">   9:     padding:0px;</span>

<span id="lnum10">  10: }</span>

<span id="lnum11">  11:  </span>

<span id="lnum12">  12: #no1{</span>

<span id="lnum13">  13:     background:#808000;</span>

<span id="lnum14">  14:     width:300px;</span>

<span id="lnum15">  15:     height:300px;</span>

<span id="lnum16">  16:     margin:100px 0 0 100px;</span>

<span id="lnum17">  17:     }</span>

<span id="lnum18">  18:  </span>

<span id="lnum19">  19: #no2{</span>

<span id="lnum20">  20:     background:#c0c0c0;</span>

<span id="lnum21">  21:     width:150px;</span>

<span id="lnum22">  22:     height:150px;</span>

<span id="lnum23">  23:     margin-left:20px;</span>

<span id="lnum24">  24:     margin-top:30px;</span>

<span id="lnum25">  25: }</span>

<span id="lnum26">  26: </span>

<span id="lnum27">  27: </span>

<span id="lnum28">  28:  </span>

<span id="lnum29">  29: </span>

<span id="lnum30">  30:  </span>

<span id="lnum31">  31: <div id="no1">
<pre class="brush:php;toolbar:false"><span id="lnum32">  32:     <div id="no2">Span2</div></span>

<span id="lnum33">  33: </span>