弹性盒子模型兼容性：
display: -webkit-flex;
display: -moz-flex;
display: -ms-flex;
display: -o-flex;
display: flex;
-webkit-align-items: center;
-moz-align-items: center;
-ms-align-items: center;
-o-align-items: center;
align-items: center;
-webkit-flex: 1;
-moz-flex: 1;
-ms-flex: 1;
-o-flex: 1;
flex: 1;
-webkit-flex-wrap: wrap;
-moz-flex-wrap: wrap;
-ms-flex-wrap: wrap;
-o-flex-wrap: wrap;
flex-wrap: wrap;
-webkit-justify-content: center;
-moz-justify-content: center;
-ms-justify-content: center;
-o-justify-content: center;
justify-content: center;
-webkit-justify-content: space-between;
-moz-justify-content: space-between;
-ms-justify-content: space-between;
-o-justify-content: space-between;
justify-content: space-between;
-webkit-flex-direction: column;
-moz-flex-direction: column;
-ms-flex-direction: column;
-o-flex-direction: column;
flex-direction: column;
-webkit-justify-content: flex-end;
-moz-justify-content: flex-end;
-ms-justify-content: flex-end;
-o-justify-content: flex-end;
justify-content: flex-end;