Use this code below for your mobile CSS. With this, you can manage the CSS for every devices breakpoints.
/*################# mobile CSS #####################################*/
@media only screen and (min-width: 250px) and (max-width: 999px) {
}
@media only screen and (device-width: 768px) {
/* For general iPad layouts */
}
@media only screen and (min-device-width: 481px) and (max-device-width: 1024px) and (orientation:portrait) {
/* For portrait layouts only */
}
@media only screen and (min-device-width: 481px) and (max-device-width: 1024px) and (orientation:landscape) {
/* For landscape layouts only */
}
/* Medium devices (desktops, 1024px and up to 1199px) */
@media (min-width: 1025px) and (max-width: 1199px) {
}
/* Large devices (large desktops, 1200px and up) */
@media (min-width: 1200px) {
}
/*################# END mobile CSS #################################*/