以下解决方案适用于单行或多行文本.
1. Flexbox：
h1 {
width: 200px;
height: 200px;
margin: 0;
background-color: gray;
color: white;
display: flex;
justify-content: center;
align-items: center;
text-align: center;
}
A quick brown fox
2. CSS表格单元格：
h1 {
width: 200px;
height: 200px;
margin: 0;
background-color: gray;
color: white;
display: table-cell;
vertical-align: middle;
text-align: center;
}
A quick brown fox
3.线高(< span>)：
h1 {
width: 200px;
height: 200px;
margin: 0;
background-color: gray;
color: white;
text-align: center;
line-height: 200px;
}
span {
display: inline-block;
vertical-align: middle;
line-height: normal;
}
