Fix date picker UX

[Pwuts]

Multiple issues:

• When the current date is selected, its date number is obscured because the font color == background color
• When a date hasn't been selected yet, and the current date is highlighted, clicking the current date doesn't do anything
• The arrow to go to the next month overlaps with dates, making it hard to see and click
• There is no "level up" where you can skip through entire years, making it super tedious to select a date more than a few months from the current date