A quick refresher on CSS selectors

.question {font-weight: bold } (solitary class selector)
p.question {font-weight: bold} (regular class selector)
body {font-weight: bold} (element selector)
p#question { font-weight: bold} (ID selector)
ul li strong  {font-weight: bold} (descendent selector)
ul.mylist li strong {font-weight: bold} (descendent selector for a class)
ul#mylist li strong {font-weight: bold} (descendent selector for an ID)
div>p {} (child selector)
a {}
a:link {} (psuedo selector)
a:visited{}
a:hover{}
a:active{}
p:first-letter {} (psuedo selector)
p:first-line {}
h1:before {}
h1:after {}
h1, h2, h3 {} (Group selectors)
p.introduction:active, hover,  focus {} (Dynamic psuedo selector)
p:first-child {}
strong + em {} (adjacent selector)
(some-selector) a[title] (attribute selector)
(some-selector) a[title="somevalue"] (attribute selector)

For an explanation of each of these elements click on the following link

>1. Additional notes on the above items

>2. Additional notes on CSS