水平居中
- 水平居中:给div设置一个宽度,然后添加margin:0 auto属性
div{
width:200px;
margin:0 auto;
}
div {
position: absolute;
width: 300px;
height: 300px;
margin: auto;
top: 0;
left: 0;
bottom: 0;
right: 0;
background-color: bule;
}
水平垂直居中
- 确定容器的宽高 宽500 高 300 的层 设置元素的外边距
div {
position: relative;
width:500px;
height:300px;
top: 50%;
left: 50%;
margin-top: -150px;
margin-left: -250px;
//margin:-150px 0 0 -250px;
background-color: blue;
}
div {
position: absolute;
width:500px;
height:300px;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
background-color: blue;
}
.container {
display: flex;
align-items: center;
justify-content: center;
}
.container div {
width: 100px;
height: 100px;
background-color: blue;
}