투명 플로트 및 폐쇄형 플로트 소개

<h1>清除浮动</h1>
<div class="border-div clear">
    <div class="div1">
        
    </div>
    <div class="div2">
        
    </div>
</div>


// 伪元素 :after
.clear:after{
    clear:both;
    content:".";
    display:table;
    width:0;
    height:0;
    visibility:hidden;
}

子元素 float:left

额外增加元素 clear:both

<div class="main">
    <div class="sub"></div>
    <div class="sub"></div>
    <div style="clear:both"></div>
</div>

<div class="main">
    <div class="sub"></div>
    <div class="sub"></div>
    <br clear="all">
</div>