媒体查询
@media (max-width: @screen-xs-max) { ... }
@media (min-width: @screen-sm-min) and (max-width: @screen-sm-max) { ... }
@media (min-width: @screen-md-min) and (max-width: @screen-md-max) { ... }
@media (min-width: @screen-lg-min) { ... }
大于等于992px是pc端,678px-991px是平板,小于678px是移动端
![](https://img2018.cnblogs.com/blog/1234710/201907/1234710-20190701183139321-516039229.jpg)