Firefox rendering issues

The site - leanhire.co that I'm working on seems to render perfectly on Chrome but it seems to be a mess when I view the site via Firefox.

What do you think is missing and what is the best way to debug the issue?

Hmm, you're right. I would check a couple things:

1. Make sure you're including any of the browser specific tags that you might be using for newer css styles. Make sure you include any of the -moz ones just in case https://developer.mozilla.org/en-US/docs/Web/CSS/Mozilla_Extensions
2. Verify your CSS isn't missing any curly braces or anything. For example it looks like .tab-container .etabs works just fine in Chrome but on Firefox that's not getting matched. Seems odd, so maybe the CSS for that specific tag has some error that causes it not to get parsed properly in Firefox.