I’m really quite lost because I’m not good at HTML. I know I need to edit the WebGL Template index.html and possibly style.css but I don’t know how.
Thank you so much!
It will maintain the aspect ratio because of height:auto? 
How can you check the browser window width? Clever idea.
Thank you! I’m working with it now but it seems that the resizing doesn’t happen anymore after the game has started?
I’m changing the browser window size during gameplay but only the black background of the game changes.