A similar situation arises if the document head Performance concerns Some people have voiced concerns over performance issues for style sheets.įor instance, retrieving an external style sheet may delay the full To select from among alternate style sheets or to switch off style sheetsĪltogether. User agents should give users the opportunity This specificationĪllows authors to specify a preferred style sheet as well as alternates that One that specifies larger fonts for increased legibility. Instance, a style sheet for rendering compact documents with small fonts, or Alternate styles Authors may wish to offer readers several ways to view a document. Languages may include features for describing media dependencies within the User agents to avoid retrieving inappropriate style sheets. This specification allows you to define theīroad categories of media a given style sheet is applicable to. Sheet intended for screen use may be applicable when printing, but is of little Style sheets, by contrast, apply to specific media or media groups. ThisĪllows users to access Web pages using a wide variety of devices and media,Į.g., graphical displays for computers running Windows, Macintosh OS, and X11,ĭevices for television sets, specially adapted phones and PDA-based portableĭevices, speech-based browsers, and braille-based tactile devices. Media dependencies HTML allows authors to specify documents in a media-independent way. Not all style sheet languages support cascading. Style sheets where rules in later sheets have greater precedence than earlier The cascade defines an ordered sequence of Separately, style sheets can be reused, simplifying authoring and making moreĮffective use of network caching. TheseĬould be, for instance, corporate style guidelines, styles common to a group ofĭocuments, and styles specific to a single document. To allow style information from several sources to be blended together. Cascading This is the capability provided by some style sheet languages such as CSS (Cascading Style Sheets) language, but other style The examples included below all use the CSS This allows for a range of such languages to be used, for instance simple onesįor the majority of users and much more complex ones for the minority of users Independence from specific style sheet languages This specification doesn't tie HTML to any particular style sheet language. The style sheets to be applied to a document. On a site basis, this specification describes how to use HTTP headers to set It's useful to include rendering instructions within the document to which theyĪpply, either grouped at the start of the document, or in attributes of theĮlements throughout the body of the document. HTML 4 provides support for the following style sheet features: Flexible placement of style information Placing style sheets in separate files makes them easy to reuse. This paragraph should have special green text. "special.css"), sets the text color of a paragraph to green and surrounds itĪuthors may link this style sheet to their source HTML document with the Indented, the colors used for the text and the backgrounds, the font size andįor example, the following short CSS style sheet (stored in the file Specify the amount of white space between text lines, the amount lines are Limited range of presentation mechanisms in HTML. Style sheets solve these problems at the same time they supersede the Limited flexibility, suffer from interoperability problems, and create These techniques considerably increase the complexity of Web pages, offer Writing a program instead of using HTML.These techniques work for some of the people, some of the time,īut not for all of the people, all of the time. Presentation of Web pages - the techniques for doing so have had unfortunate While the intentions have been good - to improve the Source of continuing frustration and authors were forced to sidestep HTML's As peopleįrom wider walks of life discovered the Web, the limitations of HTML became a Scientific environments in which the Web was conceived, people are moreĬoncerned with the content of their documents than the presentation. Style sheets represent a major breakthrough for Web page designers,Įxpanding their ability to improve the appearance of their pages. Header style information: the STYLE element.
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