CSS: Media Queries
/* Smartphones */
@media (max-width: 480px) { ... }
/* Smartphones to Tablets */
@media (min-width: 481px) and (max-width: 767px) { ... }
/* Tablets */
@media (min-width: 768px) and (max-width: 959px) { ... }
/* Desktop */
@media (min-width: 960px) and (max-width: 1199px) { ... }
/* Large Display */
@media (min-width: 1200px) { ... }