整理的前端css盒子水平垂直居中方案
A:父盒子:块级元素有宽高 子盒子:块级元素有宽高B:父盒子:块级元素有宽高 子盒子:行内元素由内容撑开1.适合A父盒子position: relative;子盒子position: absolute;top: 0; left: 0; right: 0; bottom: 0; margin: auto;2.适合B父盒子：display: table-cell; text-align: center; vertical-align: middle;3.适合A和B需要手动写死margin为子盒子宽度的一半父盒子position: relative;子盒子position: absolute;left:50%; top:50%;margin-top:-15px;margin-left:-15px）; 4.适合A和B父盒子position: relative;子盒子position: absolute;top: 50%; left: 50%;transform: translate(50%,-50%);5.适合A和B父盒子display: flex;justify-content: center;align-items: center;6.适合A和B父盒子display: flex;子盒子margin: auto;
