TODO

Fix: Tooltips cause horizontal scroll on less-wide screens. Investigate.
Fix: Tooltip flicker on page load, initially positioned in the top left
Fix: Tooltips positioned incorrectly after animating back to Home
Move routing logic from Home into Calculator
Responsiveness:
- Tooltips on mobile need different UX
Tooltips:
- Support multiple positions for tooltip (currently only top-right with fallbacks based on viewport)
Move icons back under /src when https://github.com/facebook/create-react-app/pull/6060 is released as part of 3.0.2