案例：CSS3 案例     状态：可编辑再运行    进入竖版
 运行结果　
​x
 
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<html>
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<head>
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<style type="text/css">
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img.ex1
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{
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position:absolute;
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bottom:0px;
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}
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​
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img.ex2
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{
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position:relative;
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bottom:-100px;
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}
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</style>
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</head>
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​
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<body>
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<img class="ex1" src="/img/bg_flower.gif" />
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<h1>This is a heading</h1>
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<img class="ex2" src="/img/bg_flower.gif" />
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</body>
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</html>