codesnips

pseudo-classes

css 
/* Interactive pseudo-classes */
a:link { color: blue; }
a:visited { color: purple; }
a:hover { text-decoration: underline; }
a:active { color: red; }
a:focus { outline: 2px solid orange; }

CSS pseudo-classes and pseudo-elements for advanced styling

css pseudo-classes pseudo-elements
by Alex Chang 2 tabs
css 
/* Specificity: 0,0,0,1 - Element selector */
p {
  color: black;
}

/* Specificity: 0,0,1,0 - Class selector */

CSS selectors and specificity calculation rules

css selectors specificity
by Alex Chang 1 tab