为元素设置“float”样式之后，元素会脱离标准文档流，不再占据原来的空间。后续元素会向前移动，占据这个新的空间。后续的文本会围绕着浮动元素分布，形成一种环绕布局的现象。
示例代码：文章地址https://www.yii666.com/article/756121.html
<!DOCTYPE html>
<html>
<head>
<title>test page</title>
<meta charset="utf-8">
<style type="text/css">
#ele-1 {
width: 100px;
height: 50px;
background-color: #3E3;
float: left;
}
#ele-2 {
width: 500px;
background-color: #EE3;
}
</style>
</head>
<body>
<div id="ele-1">Div area!</div>
<p id="ele-2">
This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!This is a paragrapha!
</p>
</body>
</html>
显示效果如下：
现在分别为“<p>”标签添加“clear:left”和“overflow:hidden”样式，消除这种环绕效果！文章来源地址:https://www.yii666.com/article/756121.html
添加样式“clear:left”之后，显示效果如下：
添加样式“overflow:hidden”之后，显示效果如下：
网址:yii666.com
可以通过合理的使用这两种样式效果实现页面布局。