The use of REM is simply to add the following code:
Use the following code for a maximum width of 480px
<script >var html = document.getelementsbytagname ("html") [0];var rootresize = function () {var winclient = Docume Nt.documentElement.clientWidth; var fontSize = WinClient < 480? winclient/16:30; if (FontSize <) {fontSize = 20; } html.style.fontSize = fontSize + "px";} Rootresize (); window.onresize = function () {rootresize ()} </script> use the following code for a maximum width of 640px
<script>var html = document.getelementsbytagname ("html") [0];var rootresize = function () {var winclient = Document.documentelement.clientwidth;var fontSize = WinClient < 640? Winclient/16:40;if (FontSize <) {fontSize = 20;} Html.style.fontSize = fontSize + "px";} Rootresize (); window.onresize = function () {rootresize ();} </script>
Edit Mobile page Use of REM