<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<style>
div {
margin-top: 0.25rem;
margin-bottom: 0.25rem;
}
/* 使用margin属性居中 */
.margin-center {
margin: auto;
width: 50%;
border: 1px solid green;
padding: 20px;
}
/* 文本居中 */
.text-center {
text-align: center;
border: 1px solid green;
}
/* 图片居中 */
img {
display: block;
margin-left: auto;
margin-right: auto;
width: 100px;
}
/* 绝对定位居右 */
.position-right {
position: absolute;
right: 0px;
width: 300px;
border: 1px solid green;
padding: 20px;
}
/* 浮动居右 */
.clearfix {
overflow: auto;
}
.float-right {
float: right;
width: 300px;
border: 1px solid green;
padding: 10px;
}
/* 使用padding属性垂直居中对齐 */
.padding-vcenter {
padding: 30px 0;
border: 1px solid green;
text-align: center;
}
/* 使用line-height属性垂直居中对齐 */
.lineheight-vcenter {
height: 100px;
line-height: 100px;
border: 1px solid green;
text-align: center;
}
/* 使用transform属性居中对齐 */
.transform-center {
height: 200px;
position: relative;
border: 1px solid green;
}
.transform-center p {
margin: 0;
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
/* 使用flex布局直居中对齐 */
.flex-center {
display: flex;
justify-content: center;
align-items: center;
height: 50px;
border: 1px solid green;
}
</style>
</head>
<body>
<div class="margin-center">div 元素居中</div>
<div class="text-center">text居中</div>
<img src="https://www.w3school.com.cn/i/logo/w3logo-1.png" alt="" />
<div class="clearfix">
<div class="float-right">div 元素右对齐</div>
</div>
<div class="padding-vcenter">垂直居中</div>
<div class="lineheight-vcenter">垂直居中</div>
<div class="transform-center" style="height: 150px">
<p>居中<br />居中</p>
</div>
<div class="flex-center">居中</div>
<div class="position-right">div 元素右对齐</div>
</body>
</html>
