@media only screen and (max-width: 600px) {
...your css here and you're good to go!
}
@media (min-width:320px) {
/* smartphones, iPhone, portrait 480x320 phones */
}
@media (min-width:481px) {
/* portrait e-readers (Nook/Kindle), smaller tablets @ 600 or @ 640
wide. */
}
@media (min-width:641px) {
/* portrait tablets, portrait iPad, landscape e-readers,
landscape 800x480 or 854x480 phones */
}
@media (min-width:961px) {
/* tablet, landscape iPad, lo-res laptops ands desktops */
}
@media (min-width:1025px) {
/* big landscape tablets, laptops, and desktops */
}
@media (min-width:1281px) {
/* hi-res laptops and desktops */
}