For example, CSS lets you control some specifications centrally. This means that similar elements (such as all hyperlinks or images) within a single document can be recognized and formatted using a single command. The design instructions do not have to be in the form of an internal style sheet in the HTML document itself. If you save the CSS instructions in an external stylesheet, i.e., a separate file, this can also be used for other documents. The word “stylesheet” refers to the document itself (like HTML, CSS files are really just text documents that can be edited with a variety of programs). Style sheets have been used for document design for many years.

Finally, we select the .heading1 class — which is applied to the h1 tag — and give it the attributes of font-family and color. Like classes, we can also use IDs to select HTML elements and apply styling to them. The only difference between class and ID is that one ID can be assigned to only one HTML element. Another way of selecting HTML elements is by using the class attribute.

Link to External CSS

This is done by establishing one or more keyframes using the @keyframes at-rule. Each keyframe describes how the animated element should render at a given time during the animation sequence. 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. This means web developers had to separately describe the background color, font size, alignments, etc. The final coloring and font-size values were taken from the last entry on the stylesheet.

• Its evolution has contributed to the separation of concerns in web development, making it easier to create responsive, accessible, and visually appealing websites.
• Another page also has some books,
  mailing lists and similar fora, and
  links to other directories.
• It applied this to the paragraph element and gave a final render that was seen above.
• In addition to these testing tools, many sites maintain lists of browser support for specific CSS properties, including CanIUse and the MDN Web Docs.

Lists the pseudo-classes, selectors that allow the selection of elements based on state information that is not contained in the document tree, defined in the various CSS modules and HTML. In the Introduction to HTML module, we covered what HTML is and how it is used to mark up documents. Headings will look larger than regular text, paragraphs break onto a new line and have space between them. Links are colored and underlined to distinguish them from the rest of the text. In addition to these testing tools, many sites maintain lists of browser support for specific CSS properties, including CanIUse and the MDN Web Docs.

The Evolution of CSS

If you use the same external style sheet for every page of your site, you can be sure that all the pages will have the same styles. CSS (Cascading Style Sheets) is used to style and layout web pages — for example, to alter the font, color, size, and spacing of your content, split it into multiple columns, or add animations and other decorative features. This module provides a gentle beginning to your path towards CSS mastery with the basics of how it works, what the syntax looks like, and how you can start using it to add styling to HTML.

As you can see, the paragraph element has increased in size, become bold, and changed color to sea green. Now in the next example, the paragraph element will be used again in the stylesheet. Notice that the previous use of the paragraph element is still on the sheet. Many experienced developers would much rather refer to MDN documentation or other tutorials.

CSS modules

Along the way, you will amass a “bag of tricks” of styles and approaches that have worked for you in the past and which you can turn to again as you build new web pages in the future. When CSS is used effectively, in terms of inheritance and “cascading”, a global style sheet can be used to affect and style elements site-wide. If the situation arises that the styling of the elements should be changed or adjusted, these changes can be made by editing rules in the global style sheet. Before CSS, this sort of maintenance was more difficult, expensive, and time-consuming. That said, there are also very good reasons not to use external style sheets.

These workarounds—and the need to support fallback functionality—can add complexity to development projects, and consequently, companies frequently define a list of browser versions that they will and will not support. The cascade is an algorithm that defines how user agents combine property values originating from different sources. The cascade defines the origin and layer that takes precedence when declarations in more than one origin or cascade layer set a value for a property on an element. All the grouping methods that are available to CSS can be used in external style sheets, and this provides you with more control and flexibility on your pages. You can create classes of styles that can then be used on many different HTML elements.

They are the technical specifications for a layout, whether print or online. Print designers have long used style sheets to ensure that their designs are printed exactly to their what is css specifications. A style sheet for a web page serves the same purpose, but with the added functionality of also telling the web browser how to render the document being viewed.