Center vertically-use line-height

For single-line text, we set the vertical center, you can use the height of line-height to be consistent with the height of the height.

Examples:

.center {
    line-height: 200px;
    height: 200px;
    border: 3px solid green;
    text-align: center;
}
 
/* 如果文本有多行，添加以下代码: */
.center p {
    line-height: 1.5;
    display: inline-block;
    vertical-align: middle;
}