判断设备横竖屏

/* 横屏 */
@media all and (orientation :landscape) {

}

/* 竖屏 */
@media all and (orientation :portrait) {

}

判断设备宽高

/* 设备宽度大于 320px 小于 640px */
@media all and (min-width:320px) and (max-width:640px) {

}

判断设备像素比

/* 设备像素比为 1 */
@media only screen and (-webkit-min-device-pixel-ratio: 1), only screen and (min-device-pixel-ratio: 1) {

}

/* 设备像素比为 1.5 */
@media only screen and (-webkit-min-device-pixel-ratio: 1.5), only screen and (min-device-pixel-ratio: 1.5) {

}

/* 设备像素比为 2 */
@media only screen and (-webkit-min-device-pixel-ratio: 2), only screen and (min-device-pixel-ratio: 2) {

}

常用设备设置

iPhones

/* ----------- iPhone 4 and 4S ----------- */

/* Portrait and Landscape */
@media only screen
and (min-device-width: 320px)
and (max-device-width: 480px)
and (-webkit-min-device-pixel-ratio: 2) {

}

/* Portrait */
@media only screen
and (min-device-width: 320px)
and (max-device-width: 480px)
and (-webkit-min-device-pixel-ratio: 2)
and (orientation: portrait) {
}

/* Landscape */
@media only screen
and (min-device-width: 320px)
and (max-device-width: 480px)
and (-webkit-min-device-pixel-ratio: 2)
and (orientation: landscape) {

}

/* ----------- iPhone 5 and 5S ----------- */

/* Portrait and Landscape */
@media only screen
and (min-device-width: 320px)
and (max-device-width: 568px)
and (-webkit-min-device-pixel-ratio: 2) {

}

/* Portrait */
@media only screen
and (min-device-width: 320px)
and (max-device-width: 568px)
and (-webkit-min-device-pixel-ratio: 2)
and (orientation: portrait) {
}

/* Landscape */
@media only screen
and (min-device-width: 320px)
and (max-device-width: 568px)
and (-webkit-min-device-pixel-ratio: 2)
and (orientation: landscape) {

}

/* ----------- iPhone 6 ----------- */

/* Portrait and Landscape */
@media only screen
and (min-device-width: 375px)
and (max-device-width: 667px)
and (-webkit-min-device-pixel-ratio: 2) {

}

/* Portrait */
@media only screen
and (min-device-width: 375px)
and (max-device-width: 667px)
and (-webkit-min-device-pixel-ratio: 2)
and (orientation: portrait) {

}

/* Landscape */
@media only screen
and (min-device-width: 375px)
and (max-device-width: 667px)
and (-webkit-min-device-pixel-ratio: 2)
and (orientation: landscape) {

}

/* ----------- iPhone 6+ ----------- */

/* Portrait and Landscape */
@media only screen
and (min-device-width: 414px)
and (max-device-width: 736px)
and (-webkit-min-device-pixel-ratio: 3) {

}

/* Portrait */
@media only screen
and (min-device-width: 414px)
and (max-device-width: 736px)