<?php
include($_SERVER['DOCUMENT_ROOT'] . '/assets/Mobile_Detect.php');
$detect = new Mobile_Detect ;
if( $detect->isTablet() ){
echo '<meta name="viewport" content="width=1480">';
}else{
echo '<meta name="viewport" content="width=device-width, initial-scale=1,minimum-scale=1, maximum-scale=1, user-scalable=yes">';
}
?>
Mobile_Detect.php を使ってモバイル判定している