Build a Markdown Previewer - Browser Compatibility

Tell us what’s happening:

Styling works in chrome, but breaks in Edge. Best way for you to see this is to open the demo in both chrome and edge. Edge is ok until the content overflows, if you delete some of the initial content from the editor you’ll see what I mean.

I realise this isn’t very descriptive. If anyone has the patience to help me, it will be much appreciated!

Your code so far

It’s a lot to paste in to this post, (although I can do that if necessary). I think the best way to see the code is to go here.

In this file the Wrapper element contains the styles for the grid. The EditorHeader and PreviewHeader elements contain the styles for the headers, and the Editor and Preview elements contain the styles for the editor and preview panes.

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.121 Safari/537.36.

Link to the challenge: