CSS实现分隔线中间带文字的方法，取代fieldset-legend

<div class="demo-container demo">
<style type="text/css">
.demo{
    width: 600px;
    margin：10px;
}
.line_01{
    padding: 0 20px 0;
    margin: 20px 0;
    line-height: 1px;
    border-left: 200px solid #ddd;
    border-right: 200px solid #ddd;
    text-align: center;
}
.line_02{
    height: 1px;
    border-top: 1px solid #ddd;
    text-align: center;
}
.line_02 span{
    position: relative;
    top: -12px;
    background: #fff;
    padding: 0 20px;
}
.line_03{
    width:600px;
}
.line_03 b{
    background: #ddd;
    margin-top: 4px;
    display: inline-block;
    width: 180px;
    height: 1px;
    _overflow: hidden;
    vertical-align: middle;
}
.line_03 span{
    display: inline-block;
    width: 220px;
    vertical-align: middle;
text-align: center;
}
.line_04{
    width:600px;
}
.line_04{
    overflow: hidden;
    _zoom: 1;
}
.line_04 b{
    background: #ddd;
    margin-top: 12px;
    float: left;
    width: 26%;
    height: 1px;
    _overflow: hidden;
}
.line_04 span{
    padding: 0 10px;
    width: 32%;
    float: left;
    text-align: center;
}
.line_05{
    letter-spacing: -1px;
    color: #ddd;
}
.line_05 span{
    letter-spacing: 0;
    color: #222;
    margin:0 20px;
}
</style>

<div class="line_01">小小分隔线 单标签实现</div>
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<div class="line_02"><span>小小分隔线 巧用色实现</span></div>
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<div class="line_03"><b></b><span>小小分隔线 inline-block实现</span><b></b></div>
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<div class="line_04"><b></b><span>小小分隔线 浮动来实现</span><b></b></div>
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<div class="line_05">———————————<span>小小分隔线 字符来实现</span>————————————</div>
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</div>