居中布局
居中均以不定宽为前提，定宽情况包含其中
1、水平居中
1.1 inline-block+text-align
.parent{
text-align: center;
}
.child{
display: inline-block;
}1.2 table+margin 也是一个水平居中
.child{
display: table;
margin: 0 auto;
}1.3 absolute+transform 定位实现
.parent{
position: relative;
height:1.5em;
}
.child{
position: absolute;
left: 50%;
transform: translateX(-50%);
}或者使用
.parent{
position: relative;
height:1.5em;
}
.child{
position: absolute;
width:100px;
left: 50%;
margin-left:-50px;
1.4 flex + justify-content
.parent{
display: flex;
justify-content: center;
}
.child{
margin: 0 auto;
}提示：flex是一个强大的css，生而为布局，它可以轻松的满足各种居中、对其、平分的布局要求，但由于现浏览器兼容性问题，此方案很少被使用，但是值得期待浏览器兼容性良好但那一天！
2、垂直居中
2.1 table-cell + vertial-align
.parent{
display: table-cell;
vertical-align: middle;
}目录
2.1 table-cell + vertial-align
2.2 absolute + transform
.parent{
position: relative;
}
.child{
position: absolute;
top: 50%;
transform: translateY(-50%);
2.3 flex + align-items
.parent{
display: flex;
align-items: center;
}提示：高版本浏览器兼容
3、水平居中
3.1 inline-block + table-cell + text-align + vertical-align
.parent{
text-align: center;
display: table-cell;
vertical-align: middle;
}
.child{
display: inline-block;
}3.2 absolute + transform
.parent{
position: relative;
}
.child{
position: absolute;
left: 50%;
top: 50%;
transform: translate(-50%,-50%);
}3.3 flex 兼容性差
.parent{
display: flex;
justify-content: center;
align-items: center;
}多列布局
1、一列定宽，一列自适应
1.1 float + margin
.left{
float: left;
width: 100px;
}
.right{
margin-left: 120px;
}提示：此方案对于定宽布局比较好，不定宽布局推荐方法1.2
1.2 float + overflow
.left{
float: left;
width: 100px;
margin-right: 20px;
}
.right{
overflow: hidden;
}提示：个人常用写法，此方案不管是多列定宽或是不定宽，都可以完美实现，同时可以实现登高布局
1.3 table
.parent{
display: table; width: 100%;
table-layout: fixed;
}
.left,.right{
display: table-cell;
}
.left{
width: 100px;
padding-right: 20px;
}1.4 flex
.parent{
display: flex;
}
.left{
width: 100px;
padding-right: 20px;
}
.right{
flex: 1;
}2、多列定宽，一列自适应
2.1 float + overflow
.left,.center{
float: left;
width: 100px;
margin-right: 20px;
}
.right{
overflow: hidden;
}2.2) table
.parent{
display: table; width: 100%;
table-layout: fixed;
}
.left,.center,.right{
display: table-cell;
}
.right{
width: 100px;
padding-right: 20px;
}2.3 flex
.parent{
display: flex;
}
.left,.center{
width: 100px;
padding-right: 20px;
}
.right{
flex: 1;
}3、一列不定宽，一列自适应
3.1 float + overflow
.left{
float: left;
margin-right: 20px;
}
.right{
overflow: hidden;
}
.left p{width: 200px;}3.2 table
.parent{
display: table; width: 100%;
}
.left,.right{
display: table-cell;
}
.left{
width: 0.1%;
padding-right: 20px;
}
.left p{width:200px;}3.3 flex
.parent{
display: flex;
}
.left{
margin-right: 20px;
}
.right{
flex: 1;
}
.left p{width: 200px;}4、多列不定宽，一列自适应
4.1 float + overflow
.left,.center{
float: left;
margin-right: 20px;
}
.right{
overflow: hidden;
}
.left p,.center p{
width: 100px;
}5、等分
5.1 float + margin
.parent{
margin-left: -20px;
}
.column{
float: left;
width: 25%;
padding-left: 20px;
box-sizing: border-box;
}5.2 table + margin
.parent-fix{
margin-left: -20px;
}
.parent{
display: table;
width:100%;
table-layout: fixed;
}
.column{
display: table-cell;
padding-left: 20px;
}5.3 flex
.parent{
display: flex;
}
.column{
flex: 1;
}
.column+.column{
margin-left:20px;
}6、等高
6.1 float + overflow
.parent{
overflow: hidden;
}
.left,.right{
padding-bottom: 9999px;
margin-bottom: -9999px;
}
.left{
float: left; width: 100px;
}
.right{
overflow: hidden;
}6.2 table
.parent{
display: table;
width: 100%;
}
.left{
display:table-cell;
width: 100px;
margin-right: 20px;
}
.right{
display:table-cell;
}6.3 flex
.parent{
display:flex;
width: 100%;
}
.left{
width: 100px;
}
.right{
flex:1;
}