@media only screen and (max-width: 600px) {	...your css here and you're good to go!
}

@media only screen and (max-width: 600px) { body { background-color: lightblue; }
}

/* CSS media query for mobile devices */
@media only screen and (max-width: 767px) { /* Add your mobile-specific CSS styles here */ body { background-color: #f2f2f2; font-size: 14px; } /* ... */
}

/* Styles for devices with a maximum width of 768 pixels (e.g., mobile phones) */
@media only screen and (max-width: 768px) { /* Add your CSS styles for mobile devices here */
}
/* Styles for devices with a maximum width of 480 pixels (e.g., smaller mobile phones) */
@media only screen and (max-width: 480px) { /* Add your CSS styles for smaller mobile devices here */
}

@media only screen and (max-width: 768px) { /* CSS rules specific to mobile devices */ /* Add your styles here */
}

@media screen and (orientation:landscape) and
(min-device-width: 320px) and (max-device-width: 450px) { /* Input Styles */
}

@media only screen and (max-width: 600px) { /* CSS rules for mobile devices */
}