Fonts 
Google fonts:
- Free fonts
 - Google uses it to track users
 - Might be a bit slower
 
You can self host Google fonts in your server, use this link Google web-fonts helper
You can use system fonts if you want to not load a separate font:
- Fast: No network request, no time to parse a font, no flash of an incorrect font.
 - Styles & Unicode: System fonts have lots of styles and broad language coverage, unlike many web-fonts.
 - Familiarity: Web apps feel more native when they use system font faces.
 
css
/*Sans-serif*/
font-family:
  -apple-system,
  BlinkMacSystemFont,
  avenir next,
  avenir,
  segoe ui,
  helvetica neue,
  helvetica,
  Ubuntu,
  roboto,
  noto,
  arial,
  sans-serif;
/*Serif*/
font-family:
  Iowan Old Style,
  Apple Garamond,
  Baskerville,
  Times New Roman,
  Droid Serif,
  Times,
  Source Serif Pro,
  serif,
  Apple Color Emoji,
  Segoe UI Emoji,
  Segoe UI Symbol;
/*Mono*/
font-family:
  Menlo,
  Consolas,
  Monaco,
  Liberation Mono,
  Lucida Console,
  monospace;- Reference SYSTEM FONT STACK
 
Preload 
html
<link
  rel="preload"
  href="fonts/Roboto.woff2"
  as="font"
  type="font/woff2"
  crossorigin
/>
<link
  rel="preload"
  href="fonts/Noto.woff2"
  as="font"
  type="font/woff2"
  crossorigin
/>Hierarchy 
- Sub-headers: 24px
 - Primary heading: 48px
 - Secondary heading: 32px
 - Body: 16px
 
Font Choices 
- Two font type if needed, avoid using more
 
Typeface 
Whitespace 
Color & Contrast 
- Heading: black
 - Body text: dark gray
 
Letter Spacing 
Optimal Line Length 
- Short lines
 - Keep lines between 60-80 characters long
 
