Article Directory
Summary of CSS horizontal and vertical centering method
Row-level element
Single line text is centered horizontally and vertically
html
<div>我要居中</div>
css
div{
width: 100px;
height: 100px;
background-color: yellow;
text-align: center;
line-height: 100px;
}
Block element
Known width and height (using positioning)
1. Use margin to move
After positioning, use margin-left to move half of the child's width, and use margin-top to move half of the child's height
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<style>
.father{
width: 500px;
height: 500px;
border: 1px solid yellow;
position: relative;
}
.son{
width: 100px;
height: 100px;
position: absolute;
left: 50%;
top: 50%;
margin-left: -50px;
margin-top: -50px;
background-color: green;
}
</style>
<body>
<div class="father">
<div class="son"></div>
</div>
</body>
</html>
2. Use margin: auto
html
<div class="father">
<div class="son"></div>
</div>
css
.father{
width: 500px;
height: 500px;
border: 1px solid yellow;
position: relative;
}
.son{
width: 100px;
height: 100px;
position: absolute;
left: 0;
top: 0;
right: 0;
bottom: 0;
margin: auto;
background-color: green;
}
Unknown
1. Use the translate method to move the center
html
<div class="father">
<div class="son">
<div style="width: 100px; height: 100px;background-color: green;"></div>
</div>
</div>
css
.father{
width: 500px;
height: 500px;
border: 1px solid yellow;
position: relative;
}
.son{
position: absolute;
left: 50%;
top: 50%;
transform: translate(-50%, -50%)
}
2. Use flex layout to center
html
<div class="father">
<div class="son">
<div style="width: 100px; height: 100px;background-color: green;"></div>
</div>
</div>
css
.father{
width: 500px;
height: 500px;
border: 1px solid yellow;
display: flex;
justify-content: center;
align-items: center;
}