/*屏幕大于等于1200样式*/
@media screen and (min-width: 1240px) {

}
/*屏幕大于等于1200px,小于等于1239px样式*/
@media (min-width: 1200px) and (max-width: 1239px){

}
/*屏幕大于等于992px,小于等于1199px样式*/
@media (min-width: 992px) and (max-width: 1200px){

}
/*屏幕大于等于992px,小于等于1199px样式*/
@media (min-width: 750px) and (max-width: 991px){


}
/*屏幕大于等于992px,小于等于1199px样式*/
@media (min-width: 0px) and (max-width: 749px){

}