Outlook button and spacing issues

[Tommy Holm Jakobsen]

I'm wondering if this is intentional, or if there's an error on my end somewhere. Using the default example_config.json, and default templates, compiled using npm run build, I'm seeing the following differences between Firefox (left) and Outlook 2016 (right):

Obviously, I'd like the Outlook version to look identical to the browser. Is this possible?