The mobile terminal page uses REM for adaptation

index.html Add this code

fnResize()
        window.onresize = function() {
            fnResize()
        }

        function fnResize() {
            var deviceWidth = document.documentElement.clientWidth || window.innerWidth
            if (deviceWidth >= 750) {
                deviceWidth = 750
            }
            if (deviceWidth <= 320) {
                deviceWidth = 320
        }
        document.documentElement.style.fontSize = (deviceWidth / 7.5) + 'px'
}
   

according to UI 750 The proportion 100px = 1rem