摘要:
首先我们来看一个代码:<div id=”layer1″ style=”margin:20px; border:1px solid #F88; width:400px; “> <div id=”layer2″ style=”position:absolute; background-color:#ccc;”>Absolute (layer2)</div> <div id=”layer3″ style=”margin:30px auto; width:200px; height:80px; background-color:#36F;”>Normal 阅读全文