Make App Responsive

[sunnymui]

Currently, everything is mostly formatted for desktop or large screens. We'll need to add some responsive styles to make it mobile friendly.

This would involve deciding how we want the UI to look on mobile and the navigation design. Most of the content can just use a single column design for mobile. Some basic UI prototyping in Sketch or on paper would be useful.

After the design decisions, we'd just need to add the appropriate media queries and styling in the CSS to make it happen.