insert a meta tag in the head section of your main .php file
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=0, minimum-scale=1.0, maximum-scale=1.0">
include CSS and input the following code:
<link rel="stylesheet" href="your_css.css">
/* ---------------------------------------------------------------------- */
/* Styling for Medium Devices Up To Larger Devices
/* ---------------------------------------------------------------------- */
@media (min-width: 980px) and (max-width: 1199px) {
/* ---------------------------------------------------------------------- */
/* Styling for Only larger Devices
/* ---------------------------------------------------------------------- */
@media (min-width: 1200px) {
}
/* ---------------------------------------------------------------------- */
/* Styling from Small Devices Up To Medium Devices
/* ---------------------------------------------------------------------- */
@media (min-width: 768px) and (max-width: 979px) {
}
/* ---------------------------------------------------------------------- */
/* Styling for Extra Small Devices Only
/* ---------------------------------------------------------------------- */
@media (max-width: 767px) {
}
/* ---------------------------------------------------------------------- */
/* Styling for Extra Small Devices Only
/* ---------------------------------------------------------------------- */
@media (max-width: 480px) {
/***
}
/* ---------------------------------------------------------------------- */
/* Styling for Up To Medium Devices
/* ---------------------------------------------------------------------- */
@media (max-width: 979px) {
/***
general body settings
***/
}
/* ---------------------------------------------------------------------- */
/* Styling for Up To Medium Devices
/* ---------------------------------------------------------------------- */
@media (min-width: 768px) {
}