### flex布局封装 ```css /* flex布局 */ .u-f,.u-f-ac,.u-f-ajc{ display: flex; } .u-f-ac,.u-f-ajc{ align-items: center; } .u-f-ajc{ justify-content: center; } .u-f-jsb{ justify-content: space-between; } .u-f1{ flex: 1; } .u-f-column{ flex-direction: column; } ```