They can even be set in motion to create animation-like effects. Layers can hold images, text, frames, or any other sort of element. A layer's clipping area can be adjusted to show part of a layer at a time, slowly reveal the layer to the user, or slowly make it disappear. You can accomplish all of these tricks with a simple set of attributes. A style sheet is a standard format all pages on a site follow for colors, fonts, margins, and other layout details.
Users can also create style sheets for their browsers, so every page they visit has the same look.
Even with CSS, users can still dictate how pages look in their browsers by setting preferences. Dynamic cascading style sheets make styles interactive. When a user moves the pointer over a certain spot, words might change, menus might pop open, or columns might be sorted. Font characteristics can change based on user actions, such as moving a pointer over an area or clicking a word. Designers can use style sheets to change the look of cells, and cells can change according to the data a user types in.