CSS3 Responsive Media File Template - Plantilla de archivo CSS3 para hacer una web responsiva

/*********************** RESPONSIVE *************************/
/******************** POR DISPOSITIVOS **********************/

/* Smartphones (portrait and landscape) ----------- */
@media only screen
 and (min-device-width : 320px)
 and (max-device-width : 480px) {



}

/* Smartphones (landscape) ----------- */
@media only screen
 and (min-width : 321px) {


}

/* Smartphones (portrait) ----------- */
@media only screen
 and (max-width : 320px) {


}

/* iPads (portrait and landscape) ----------- */
@media only screen
 and (min-device-width : 768px)
 and (max-device-width : 1024px) {


}

/* iPads (landscape) ----------- */
@media only screen
 and (min-device-width : 768px)
 and (max-device-width : 1024px)
 and (orientation : landscape) {


}

/* iPads (portrait) ----------- */
@media only screen
 and (min-device-width : 768px)
 and (max-device-width : 1024px)
 and (orientation : portrait) {


}

/* Desktops and laptops ----------- */
@media only screen
 and (min-width : 1224px) {


}

/* Large screens ----------- */
@media only screen
 and (min-width : 1824px) {


}

/* iPhone 4 ----------- */
@media only screen
 and (-webkit-min-device-pixel-ratio : 1.5),
 only screen and (min-device-pixel-ratio : 1.5) {



}