css different sreen size

1/* For Mobile */
2@media screen and (max-width: 540px) {
3    .view {
4        width: 400px;
5    }
6}
7
8/* For Tablets */
9@media screen and (min-width: 540px) and (max-width: 780px) {
10    .view {
11        width: 600px;
12    }
13}