flex布局兼容性代码

flex：定义布局为盒模型

flex-v：盒模型垂直布局

flex-1：子元素占据剩余的空间

flex-align-center：子元素垂直居中

flex-pack-center：子元素水平居中

flex-pack-justify：子元素两端对齐

.flex{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;}

.flex-v{-webkit-box-orient:vertical;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;}

.flex-1{-webkit-box-flex:1;-webkit-flex:1;-ms-flex:1;flex:1;}

.flex-align-center{-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;}

.flex-pack-center{-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;}

.flex-pack-justify{-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;}