h1 { color: blue; }       /* Tag selector - targets ALL h1 elements */
.highlight { color: red; } /* Class selector - targets elements with class="highlight" */
#logo { width: 100px; }    /* ID selector - targets the element with id="logo" */

a:link { color: blue; }      /* Unvisited link */
a:visited { color: purple; } /* Visited link */
a:hover { color: red; }      /* Mouse hovering */
a:active { color: orange; }  /* Being clicked */
li:first-child { font-weight: bold; }
li:last-child { border: none; }
li:nth-child(odd) { background: #f5f5f5; }