While CSS is used mainly to style HTML, it can also be used in combination with other markup languages, such as XML (extensible markup language). Style sheets can exist internally (embedded or
inline) within the HTML or externally, attached as
a separate file. An internal style sheet only affects
the HTML document in which it is embedded.
Classes and IDs are case-sensitive, start with letters, and can include alphanumeric characters, hyphens, and underscores. In addition to HTML, other markup languages support the use of CSS including XHTML, plain XML, SVG, and XUL. This module provides links to sections of content explaining how to use CSS to solve common problems when creating a web page. A thistle background color and paragraphs with 20 point, medium blue font will now be applied to this single page. The class selector is used to select elements that have some class attributes.
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For example, it can present a printer-friendly version of the page when requested. CSS3 took this a step further by introducing query capabilities to respond to the dimensions of a viewport or a device, the portrait or landscape orientation of the device and the screen resolution. For these sites, the owner often desires a cohesive look with the different pages. In this regard, CSS files can specify how specific components will look on each page; they can be considered a “dress code” for the website. For example, links may always have the same font, text size, and color when activated.
Styles may be found within a webpage’s HTML file or in a separate document referenced by multiple webpages. The following box contains an example of using CSS code to define fonts, the color of hyperlinks, and the color of a link when the mouse cursor hovers over. In this specific example, we are only changing the HTML (hypertext markup language) tags and , rather than creating any new class or id selectors. It describes to the user how to display HTML elements on the screen in a proper format. In simple words, cascading style sheets are a language used to simplify the process of making a webpage. The invention of HTML by computer scientist Tim Berners-Lee in the early 1990s allowed content to be displayed on websites.
Internal CSS:
These same basic principles can be applied to change font sizes, background colors, margin indentations, and more on your web page by choosing the specific selector. In this case, “p” (the paragraph) is called the “selector” — it’s the part of Cascading Style Sheets code specifying which HTML element the CSS styling will affect. In CSS, the selector is written to the left of the first curly bracket. The information between curly brackets is called a declaration, and it contains properties and values that are applied to the selector. CSS2, an evolution of CSS, incorporated media queries to allow developers to specify triggers for certain styles to take effect.
CSS defines the font, font size, font weight, position, and other visual settings. One of the goals of CSS is to allow users greater control over presentation. Someone who finds red italic headings difficult to read may apply a different style sheet.
Selector
This further decouples the styling from the HTML document and makes it possible to restyle multiple documents by simply editing a shared external CSS file. At this point we’ve already looked at CSS fundamentals, how to style text, and how to style and manipulate the boxes that your content sits inside. Now it’s time to look at how to place your boxes in the right place in relation to the viewport, and to each other. Instead of versioning the CSS specification, W3C now periodically takes a snapshot of the latest stable state of the CSS specification and individual modules progress.
Each has its primary advantages, and many websites will use all three. The choice of which kind of style sheet to use depends upon web development css cascading the level and consistency of customization desired. A more thorough discussion will follow the brief overview that is next.
Browser support information
An external style
sheet, on the other hand, is independent and can be attached or linked to
many HTML documents. With external style sheets, one can change the entire appearance
of a website by altering just one file. CSS was first proposed in 1994, by Norwegian technologist Håkon Wium Lie, who was then working at the European Organization for Nuclear Research (CERN) with Berners-Lee. Two years later the World Wide Web Consortium (W3C) adopted the first standardized specifications for CSS, called CSS1.
Declarations not set in the highest priority source are passed on to a source of lower priority, such as the user agent style. This module carries on where CSS first steps left off — now you’ve gained familiarity with the language and its syntax, and got some basic experience with using it, it’s time to dive a bit deeper. This module looks at the cascade and inheritance, all the selector types we have available, units, sizing, styling backgrounds and borders, debugging, and lots more. Although CSS standards were issued by the World Wide Web Consortium, there
is still inconsistent browser support. Support
of CSS style sheets, beginning in Netscape Navigator 4.0x and Internet
Explorer 3, varies widely among browsers and among different versions
of the same browser. The newer versions of browsers tend to offer better
support than older ones.
The CSS layout cookbook aims to bring together recipes for common layout patterns, things you might need to implement in your sites. In addition to providing code you can use as a starting point in your projects, these recipes highlight the different ways layout specifications can be used and the choices you can make as a developer. CSS is among the core languages of the open web and is standardized across Web browsers according to W3C specifications.
- The following box contains an example of using CSS code to define fonts, the color of hyperlinks, and the color of a link when the mouse cursor hovers over.
- CSS provides developers and designers with powerful control over the presentation of HTML elements.
- If you would like to reference this page or cite this definition, please use the green citation links above.
- The aim here is to provide you with a toolkit for writing competent CSS and help you understand all the essential theory, before moving on to more specific disciplines like text styling and CSS layout.
Short for cascading style sheets, CSS describes reusable styles for presenting documents written in a markup language. In December 1996, CSS was made a specification by the W3C, and today allows web developers to alter the layout and appearance of their web pages. For example, CSS can change the font used in certain HTML elements and their size and color.
CSS Grid Layout
CSS is essential for creating visually appealing and maintainable web pages. It enhances the website look and feel and user experience by allowing precise control over the presentation of HTML elements. Mastering CSS is crucial for effective web design and development. The specific instruction set in CSS uses some of the same words as HTML, but most individual properties are unique.
