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Cascading Style Sheets


Notes:


CSS Cascading Style Sheets (CSS2) are provided for specifying the look of XHTML content. There are some minor limitations, such as support for an aural style sheet is not required. The immaturity of CSS implementations and lack of use is likely to be more of a problem for implementations than limits to the standard. Also current implementations for conventional (static) web pages appear to take a perceptible time to render a CSS controlled page and so performance with video may be a problem. A dvb-tv media type is defined for TV-type devices with small screens. Some additional properties suiting TVs are: Opacity: Allows object to be rendered semi-transparent (as used to place semi-transparent text over a video image). Clip-video: Allows an arbitrary portion of a video image to be displayed. Focus traversal and short-cuts: Defines the order of navigation of elements using the navigation keys, and short cut keys. Viewports: The MHP standard includes a detailed, but unclear, description of how coordinate space used to define a video window on the screen. The resulting complexity appears due to a difference in terminology used in DVB and CSS standards.