文本两端对齐
text-align:justify;text-align-last:justify;
元素两端对齐
display:flex;justify-content:space-between;flex-wrap:wrap;
flex布局，元素绝对居中
display:flex;align-items: center;justify-content: center;
{position: relative;left: 50%;top: 50%;-webkit-transform: translate(-50%,-50%);transform: translate(-50%,-50%);}
文本限制行数；超出则显示省略号
display: -webkit-box;-webkit-box-orient: vertical;-webkit-line-clamp: 2;overflow: hidden;