CSS Selectors

div.red  // and
div, red  // or
div li  // Descendent aka child (any level)
div > li  direct child
li.red - li  every li sibling after li.red
li.red + li  first li sibling after li.red
li:hover  every li when hovered
input:focus  every input focused
li:first-child  first child
li:nth-child(3n)  every 3rd element
li:nth-child(2n-1)  start at first
li:nth-last-child(2n-1)  start w last
li:only-child  if only child
span:first-of-type  first span
li.last-of-type  last li
etc. nth-type and only-of-type
li:not(.green)  every li wo green
[data-red]  data attributes 
[data-red=“true”]  red and true
[data-red^=“12”]  starts with
[data-red$=“12”]  ends with
[data-red*=“12”]  any