Adjust text styles

[sssoz]

• Improving readability:
  • Line lengths (measure: >65 characters / line)
  • Line heights (leading)
  • Font size (consistent, and relative units, rem, based on body’s font-size instead of px)
• Improving legibility on all viewports & browsers:
  • Type colour (should it be a nuanced black?)
  • Anti-aliasing
  • Letter-spacing