Cascading Style Sheets

1
Cascading Style Sheets

• August 18, 2007

2
Background

• CSS introduced in 1994. CSS2 introduced in 1998.
• FrontPage had poor CSS support
• Dreamweaver has had excellent CSS support
• Purpose of CSS to dramatically improve
  formatting capabilities

3
Advantages of CSS over HTML

• Positioning objects and text
• Absolute positioning
• Fixed backgrounds for web pages
• Specify page layout
• Better design control
• Web sites are easier to maintain
• Specify styles at the element or page lever
• Store style info in a element, page, or external
  file
• More margin controls (left vs right and top vs
  bottom)

4
Cascading

• Cascading refers to the capability for style
  information stored in more than one location and
  then combined.
• Three types of styles
• Inline
• Embedded
• External files with a .css extension

5
Rules of CSS

• You can have multiple external style files.
• Inline styles override embedded styles.
• Embedded styles override external styles.
• Multiple external style files are processed in
  order defined on page

6
Misc

• Expression Web will usually use embedded styles.
  But you can easily move these embedded styles to
  external style files.
• CSS reports Unused styles, undefined classes,
  mismatched case