Hi richardbkk,
You can do different headers by using media queries.
Your header for mobile
@media only screen and (min-width : 320px) and (max-width : 480px) {
/* style here */
}
Your header for tablet
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px){
/* style here */
}
thanks