一丶盒模型的属性(重要)
1.padding
padding是标准文档流,父子之间调整位置
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>padding</title>
<style>
*{
padding: 0;
margin: 0;
}
.box{
width: 200px;
height: 200px;
background-color: red;
/*上下左右*/
padding: 10px;
/*上下 左右*/
padding: 20px 30px;
/*上 左右 下*/
padding: 20px 30px 40px;
/*顺时针 上右下左*/
padding: 20px 30px 40px 50px;
}
</style>
</head>
<body>
<div class="box">alex</div>
</body>
</html>
padding
2.border
三要素: 线性的宽度 线性的样式 颜色
solid 实线 dotted小圆点 double双实线 bottom虚线
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>border</title>
<style>
*{
padding: 0;
margin: 0;
}
.box{
width: 200px;
height: 200px;
background-color: red;
/*根据方向来设置*/
border-left: 5px solid green;
border-right: 1px dotted yellow;
border-top: 5px double purple;
border-bottom: 1px dashed;
}
</style>
</head>
<body>
<div class="box">alex</div>
</body>
</html>
border
实例:制作三角形
transparent 透明
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>制作三角形</title>
<style type="text/css">
div{
width: 0;
height: 0;
border-bottom: 20px solid red;
border-left: 20px solid transparent;
border-right: 20px solid transparent; }
</style> </head>
<body>
<div> </div>
</body>
</html>
制作三角形
3.margin
前提:必须是在标准文档流下
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>margin</title>
<style>
.s1{
background-color: red;
margin-right: 30px;
}
.s2{
background-color: rgb(0,128,0);
margin-left: 30px;
}
</style>
</head>
<body>
<span class="s1">alex</span><span class="s2">wusir</span>
</body>
</html>
margin
margin垂直方向上的坑:
margin的水平不会出现任何问题
垂直方向上 margin会出现'塌陷问题'
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>margin坑</title>
<style>
.s1{
width: 200px;
height: 200px;
background-color: red;
margin-bottom: 40px;
}
.s2{
width: 200px;
height: 200px;
background-color: green;
margin-top: 100px;
}
</style>
</head>
<body>
<div class="s1"></div>
<div class="s2"></div>
</body>
</html>
margin(坑)
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>margin父子盒子的坑</title>
<style type="text/css">
.box{
width: 300px;
height: 300px;
background-color: red;
/*float: left;*/
}
.child{
width: 100px;
height: 100px;
background-color: green;
margin-left: 50px;
margin-top: 50px;
}
</style>
</head>
<body>
<div class="father">
<div class="child">
</div>
</div>
</body>
</html>
margin父子盒子的坑
二丶display显示
前提;必须是在标准文档流下
块级元素和行内元素的相互转换:
块级元素可以转换为行内元素:
display:inline
此时这个div不能设置宽度丶高度;
此时这个div可以和别人并排了
行内元素转换为块级元素:
display:block
此时这个span能够设置宽高
此时这个span必须霸占一行了,别人无法和他并排
如果不设置宽度,将撑满父亲
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>display</title>
<style>
.box{
width: 100px;
height: 100px;
background-color: red;
border: 1px solid yellow;
}
div a{
display: block;
width: 100px;
height: 100px;
}
span{
display: inline-block;
width: 300px;
height: 200px;
background-color: yellow;
}
</style>
</head>
<body>
<div class="box">alex</div>
<div class="box">wusir</div> <div>
<a href="#">
<img src="http://img07.tooopen.com/images/20170818/tooopen_sy_220999936848.jpg" alt="" width="300" height="300"/>
</a>
</div> <input type="text" /><br />
<span>哈哈哈哈</span>
<span>嘻嘻嘻嘻</span>
</body>
</html>
display
三丶浮动
float : none 表示不浮动,默认
left:表示左浮动
right:表示右浮动
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>浮动</title>
<style>
*{
padding: 0;
margin: 0;
}
.father{
width: 500px;
}
.box1{
width: 100px;
height: 100px;
background-color:red;
float: left;
}
.box2{
width: 100px;
height: 300px;
background-color:green;
float: left;
}
.box3{
width: 100px;
height: 100px;
background-color:blue;
float: left;
}
.father2{
width: 600px;
height: 200px;
background-color: yellow;
}
</style>
</head>
<body>
<div class="father">
<div class="box1">1</div>
<div class="box2">2</div>
<div class="box3">3</div>
</div>
<div class="father2"> </div>
</body>
</html>
浮动
我们该如何清除浮动呢?有以下几种方法
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>清除浮动</title>
<style>
*{
padding: 0;
margin: 0;
}
.father{
width: 500px;
height: 300px;
}
.box1{
width: 100px;
height: 100px;
background-color:red;
float: left;
}
.box2{
width: 100px;
height: 300px;
background-color:green;
float: left;
}
.box3{
width: 100px;
height: 100px;
background-color:blue;
float: left;
}
.father2{
width: 600px;
height: 200px;
background-color: yellow;
}
</style>
</head>
<body>
<div class="father">
<div class="box1">1</div>
<div class="box2">2</div>
<div class="box3">3</div>
</div>
<div class="father2"> </div>
</body>
</html>
固定高度
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>清除浮动</title>
<style>
*{
padding: 0;
margin: 0;
}
.father{
width: 500px;
}
.box1{
width: 100px;
height: 100px;
background-color:red;
float: left;
}
.box2{
width: 100px;
height: 300px;
background-color:green;
float: left;
}
.box3{
width: 100px;
height: 100px;
background-color:blue;
float: left;
}
.father2{
width: 600px;
height: 200px;
background-color: yellow;
}
.clearfix{
clear:both;
}
</style>
</head>
<body>
<div class="father">
<div class="box1">1</div>
<div class="box2">2</div>
<div class="box3">3</div>
<!-- 内墙法 -->
<div class="clearfix"></div>
</div>
<div class="father2"> </div>
</body>
</html>
clearfix内墙法
visibility:hidden; 设为隐藏
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>伪元素清除法</title>
<style>
*{
padding: 0;
margin: 0;
}
.father{
width: 500px;
}
.box1{
width: 100px;
height: 100px;
background-color:red;
float: left;
}
.box2{
width: 100px;
height: 300px;
background-color:green;
float: left;
}
.box3{
width: 100px;
height: 100px;
background-color:blue;
float: left;
}
.father2{
width: 600px;
height: 200px;
background-color: yellow;
} .clearfix:after{
content: '.';
clear: both;
display: block;
visibility: hidden;
height: 0;
}
</style>
</head>
<body>
<div class="box">
<div class="father clearfix">
<div class="box1">1</div>
<div class="box2">2</div>
<div class="box3">3</div> </div>
</div>
<div class="father2"></div>
</body>
</html>
伪元素清除法
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>伪元素清除法</title>
<style>
*{
padding: 0;
margin: 0;
}
.father{
width: 500px;
overflow: hidden;
}
.box1{
width: 100px;
height: 100px;
background-color:red;
float: left;
}
.box2{
width: 100px;
height: 300px;
background-color:green;
float: left;
}
.box3{
width: 100px;
height: 100px;
background-color:blue;
float: left;
}
.father2{
width: 600px;
height: 200px;
background-color: yellow;
}
</style>
</head>
<body>
<div class="box">
<div class="father">
<div class="box1">1</div>
<div class="box2">2</div>
<div class="box3">3</div> </div>
</div>
<div class="father2"></div>
</body>
</html>
overflow清除法