如何将CSS框定位在一组具有浮动div的div下面？

我有一个工作布局，两个

div

s（橙色和蓝色）左右浮动，固定大小为中间

div

（绿色），应该扩展到底部

现在，我想添加一个页脚（红色），它显示在上面

div

s中最高的下方，但我只看到它显示在中间

div

下方，如下所示

我尝试了

溢出：auto

，但没有效果

左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动
右浮动右浮动右浮动

浮动权利浮动权利

浮动权利浮动权利

浮动权利浮动权利

浮动权利浮动权利

浮动权利浮动权利

浮动
中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间
页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚

将

清除：两者都添加到红色分区

<div style="float: left;width: 100px;border-style: solid;border-color: orange;">
left floating left floating left floating left floating left floating left floating left floating left floating left floating left floating left floating left floating left floating left floating left floating left floating left floating left floating left floating 
</div>
<div style="float: right;border-style: solid;border-color: blue;">
right floating right floating right<br/>
floating right floating right <br/>
floating right floating right <br/>
floating right floating right <br/>
floating right floating right <br/>
floating right floating right <br/>
floating 
</div>
<div style="layout:block;border-style: solid;border-color: green;">
middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle middle 
</div>
<div style="display:block;border-style: solid;border-color: red;clear: both">
footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer footer 
</div>


左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动左浮动
右浮动右浮动右浮动

浮动权利浮动权利

浮动权利浮动权利

浮动权利浮动权利

浮动权利浮动权利

浮动权利浮动权利

浮动
中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间中间
页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚页脚