• Sequence of rules that define how specific elements in XHTML are styled
  • Paragraphs should have a font-size of 16pt
  • First paragraph after a header should have first letter of first word capitalised and colour green
  • Paragraphs should start on a newline and have extra space before next element
  • I am old so all the font-sizes should be increased by 2pts on the screen
  • Don't add that coloured background when you print it on paper

selector { property : value }
selector1 , selector2 { property1 : value1  ; property2 : value2  }
         

• Rule has two parts: Selector and Declaration, which consists of Property : Value
• Selector defines which set of XHTML elements it applies to

• Declaration defines properties to be applied to that set

  h1 { color: red }  All h1 elements should be coloured red
                 

• Also defines flow for an element

  h1 {display:block} Starts with a newline
  em {display:inline} Continues on current line