一丶盒模型的屬性(重要)
1.padding
padding是標準文檔流,父子之間調整位置

<!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;
/*順時針 上右下左*/
padding: 20px 30px 40px 50px;
}
</style>
</head>
<body>
<div class="box">alex</div>
</body>
</html>
2.border
三要素:?線性的寬度? 線性的樣式? 顏色
solid?實線 dotted小圓點 double雙實線 bottom虛線

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>border</title>
<style>
*{
padding: 0;
margin: 0;
}
.box{
width: 200px;
height: 200px;
background-color: red;
/*根據方向來設置*/
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>
實例: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>
3.margin
前提:必須是在標準文檔流下

<!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垂直方向上的坑:
margin的水平不會出現任何問題
垂直方向上?margin會出現'塌陷問題'

<!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>

<!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>
?
?二丶display顯示
前提;必須是在標準文檔流下
塊級元素和行內元素的相互轉換:
塊級元素可以轉換為行內元素:
display:inline
此時這個div不能設置寬度丶高度;
此時這個div可以和別人并排了
行內元素轉換為塊級元素:
display:block
此時這個span能夠設置寬高
此時這個span必須霸占一行了,別人無法和他并排
如果不設置寬度,將撐滿父親

<!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>
?
三丶浮動
float :? ? none? 表示不浮動,默認
? left:表示左浮動
? right:表示右浮動

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>浮動</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>
我們該如何清除浮動呢?有以下幾種方法

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>清除浮動</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>

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>清除浮動</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>
<!-- 內墻法 -->
<div class="clearfix"></div>
</div>
<div class="father2">
</div>
</body>
</html>
? ?visibility:hidden;?設為隱藏

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>偽元素清除法</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>

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>偽元素清除法</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>
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