What Is CSS? Definition, vs HTML, Responsive CSS

Résumé

However, the web would be a boring place if all websites looked like that. Using CSS, you can control exactly how HTML elements look in the browser, presenting your markup using whatever design you like. Pseudo-classes are used in CSS selectors to permit formatting based on information website development css cascading that is not contained in the document tree. In CSS, selectors declare which part of the markup a style applies to by matching tags and attributes in the markup itself. In addition to HTML, other markup languages support the use of CSS including XHTML, plain XML, SVG, and XUL.

css definition

CSS lets you have multiple styles on one HTML page, therefore making the customization possibilities almost endless. Nowadays, this is becoming more a necessity than a commodity. The late 1990s and early 2000s were marked by the « Browser Wars, » where Internet Explorer and Netscape Navigator competed for web dominance.

CSS Border

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. CSS modules are used to avoid style conflicts, because, on modules, application of CSS rules is local rather than global by default. Additionally, modules help users reuse code components, because each component can have its own set of stylistic rules. The introduction of modules improved CSS safety by having CSS rules apply locally rather than globally by default.

css definition

We’ll look at this process more in the lesson How CSS works. It is unusual for all browsers to implement a feature at the same time, and so there is usually a gap where you can use some part of CSS in some browsers and not in others. For this reason, being able to check implementation status is useful. CSS properties have different allowable values, depending on which property is being specified. In our example, we have the color property, which can take various color values. This property can take various size units as a value.

Specificity

This website provides tutorials with examples, code snippets, and practical insights, making it suitable for both beginners and experienced developers. In RGBA, the first 3 parameters vary from 0 to 255, and the last varies from 0 to 1. Hex is a code that starts with # and comprises 6 numbers which are further divided into 3 groups. RGB is a combination of three colours red, green, and blue. It takes three parameters, and the value of each parameter varies from 0 to 255.

The relation between HTML and CSS is strongly tied together since HTML is the very foundation of a site and CSS is all of the aesthetics of an entire website. Each type of CSS has its own advantages and use cases. As there are so many things that you could style using CSS, the language is broken down into modules.

Inline CSS

External CSS is used to link all webpage with an external file. It is more efficient for styling an extensive webpage. After a CSS feature has been specified, then it is only useful for us in developing web pages if one or more browsers have implemented the feature. This means that the code has been written to turn the instruction in our CSS file into something that can be output to the screen.

css definition

External CSS involves creating a separate CSS file with all the styles and linking it to the HTML file using the «  element in the «  section. This approach promotes the separation of concerns and allows you to apply the same styles to multiple HTML files. The External method might be the most convenient one. This means you can do all the styling on a separate file and apply the CSS to any page you want.

The advantages of CSS and why use it

CSS lets developers and designers define how it behaves, including how elements are positioned in the browser. CSS contains rules and values that a web browser can then apply to the content of the webpage in order to correctly display its content. For example, you can use CSS to define that the body section of the page has a blue background, and that the text is displayed in white Helvetica font with a size of 18px. In contrast, website builders that use What You See is What You Get (WYSIWYG) software do not require the user to enter any description code – it’s all built in to the platform. Specificity refers to the relative weights of various rules.[17] It determines which styles apply to an element when more than one rule could apply. Based on the specification, a simple selector (e.g. H1) has a specificity of 1, class selectors have a specificity of 1,0, and ID selectors have a specificity of 1,0,0.

  • Consult the information in that table to check if the property can be used on your website.
  • That’s what web pages with only HTML look like, and I think you’d agree that that’s not very appealing.Before using CSS, all of the stylizing had to be included into the HTML markup.
  • You might have seen a website that fails to load completely and has a white background color with most of the text being blue and black.
  • In RGBA, the first 3 parameters vary from 0 to 255, and the last varies from 0 to 1.

As we all know, CSS is a powerful style sheet language used to control the HTML document to improve the webpage design. With the help of CSS, we can control the colour of text and style of fonts, and we can control the spacing between the paragraph and many more things. CSS is easy to understand but provides strong control on the Html documents.CSS is combined with HTML. Many experienced developers would much rather refer to MDN documentation or other tutorials. Nevertheless, it is worth knowing that these specs exist and understanding the relationship between the CSS you are using, the browser support (see below), and the specs. Responsive web design means the CSS uses flexible layouts, images and other techniques to style the page automatically for various screen sizes.

Example of CSS

This separation of style and content has many advantages, among them are improved accessibility, and more control over web design. CSS can be used for very basic document text styling — for example, for changing the color and size of headings and links. It can be used to create a layout — for example, turning a single column of text into a layout with a main content area and a sidebar for related information. Have a look at the links in this paragraph for specific examples. The style sheet with the highest priority controls the content display. Declarations not set in the highest priority source are passed on to a source of lower priority, such as the user agent style.

css definition

CSS styles are applied to the HTML element using selectors. CSS is easy to learn and understand, but it provides powerful control over the presentation of an HTML document. Inline CSS is used to style the elements of HTML documents. It is used in HTML to style the attributes without using the selectors. It is challenging to manage the inline function in websites compared to other types.

This era saw inconsistent CSS support across browsers, leading to the need for complex workarounds to achieve consistent designs. In the early days of the web (late 1980s and early 1990s), websites were primarily plain text with minimal formatting options. The introduction of HTML allowed for basic formatting using tags like «  and « . Visit Mozilla Corporation’s not-for-profit parent, the Mozilla Foundation.Portions of this content are ©1998–2024 by individual mozilla.org contributors. The browser support status is shown on every MDN CSS property page in a table named « Browser compatibility ».

css definition