adjust font sizes and spacing
- use 1.0625rem (17px) for most paragraph text
- use 1.5 for line height
- increase padding above CTA buttons
- make hero title and text larger
- remove left padding on CTA button on mobile
- align hero title center on mobile
- use text-decorate instead of border bottom to call attention to text
- increase letter spacing in last button
- remove some unnecessary overrides