Resizing canvas without changing width/height in HTML

I am trying to resize the canvas in html by NOT modifying the width and height of the gameContainer div tag which is:
<div id="gameContainer" style="width: 720px; height: 1280px; margin: auto"></div>

I set the scale of the gameContainer div to 0.5 but then the touches don't work properly. Did it this way
<div id="gameContainer" style="width: 720px; height: 1280px; transform: scale(0.5); transform-origin: 0 0; margin: auto"></div>

I tried setting the width and height of the body tag, but that doesn't seem to be working as it looks like body width and height are being override by the gameContainer div. Can anyone help out with this? Thanks!

 

There is no reason you need to do that.
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