Shifts colors to pass WebAIM contrast checker and adds media
query so that body padding is smaller at smaller widths.
Body padding responsiveness will help on StackBlitz and small
screens.
PR Close#40890
https://developer.mozilla.org/en-US/docs/Web/CSS/font-family
"You should always include at least one generic family name in a font-family list,
since there's no guarantee that any given font is available. This lets the browser
select an acceptable fallback font when necessary."
PR Close#40254
