css利用负margin实现平均布局的示例

//HTML
<div class="father">
    <div  class="middle">
        <div  class="son1"></div>
        <div  class="son2"></div>
        <div  class="son3"></div>
    </div>
</div>

//CSS
.son1,.son2,son3{
    margin-right:50px;
    width:100px;
}
.father{
    width:400px;
}
.middle{
    margin-right:-50px;
}