Selectors Reference Part 3

/*
  CSS Selectors
  - :first-child
  - :last-child
  - :first-of-type
  - :last-of-type
  - :only-child
*/

* {
  box-sizing: border-box;
  margin: 0;
}
body {
  font-family: Arial, Helvetica, sans-serif;
}