案例：CSS3 案例     状态：可编辑再运行    进入竖版
 运行结果　
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<p><b>注释：</b>目前只有 Opera 支持 nav-* 属性。当您使用方向键导航时，请同时按下 Shift 键。</p>
 
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<!DOCTYPE html>
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<html>
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<head>
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<style>
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button
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{
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position:absolute;
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}
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​
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button#b1
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{
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top:20%;left:25%;
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nav-index:1;
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nav-right:#b2; nav-left:#b4;
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nav-down:#b2; nav-up:#b4;
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}
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​
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button#b2
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{
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top:40%;left:50%;
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nav-index:2;
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nav-right:#b3; nav-left:#b1;
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nav-down:#b3; nav-up:#b1;
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}
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​
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button#b3
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{
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top:70%;left:25%;
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nav-index:3;
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nav-right:#b4; nav-left:#b2;
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nav-down:#b4; nav-up:#b2;
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}
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​
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button#b4
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{
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top:40%;left:0%;
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nav-index:4;
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nav-right:#b1; nav-left:#b3;
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nav-down:#b1; nav-up:#b3;
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}
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</style>
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</head>
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<body>
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​
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<button id="b1">Button 1</button>
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<button id="b2">Button 2</button>
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<button id="b3">Button 3</button>
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<button id="b4">Button 4</button>