For example, you can create a print style sheet that will define how the web page should print out. Because web page items like navigation buttons or web forms will have no purpose on the printed page, a Print Style Sheet can be used to « turn off » those areas when a page is printed. Consider the styles applied on the CSS file to be a waterfall of sorts. The HTML document reads through the flow and applies whatever it finds along the way. However, another paragraph element was added underneath the first in the CSS file.

  • If you look at the way the style code cascades down, you can see which properties are being added and which ones are being changed along the way.
  • Using this code, the page will render with this basic appearance.
  • You should learn the basics of HTML before attempting any CSS.
  • Headings will look larger than regular text, paragraphs break onto a new line and have space between them.
  • Now that you have an answer to “what is CSS”, you might be curious as to the mention of cascading.
  • The first gives it three property values to work with, one of which is the color of sea green.

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. 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.

How to Work with CSS Style Sheets – the Basics for Beginners

A CSS stylesheet will contain many such rules, written one after the other. Presenting a document to a user means converting it into a form usable by your audience. Browsers, like Firefox, Chrome, or Edge, are designed to present documents visually, for example, on a computer screen, projector, or printer. As we have mentioned before, CSS is a language for specifying how documents are presented to users — how they are styled, laid out, etc. The main entry point for CSS documentation on MDN, where you’ll find detailed reference documentation for all features of the CSS language.

cascading style sheets

Style sheets have been used for document design for many years. 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 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.

The Cascade Example

The name cascading comes from the specified priority scheme to determine which declaration applies if more than one declaration of a property match a particular element. For beginners, Starting with HTML + CSS teaches how to create a
style sheet. For a quick introduction to CSS, try chapter 2 of Lie & Bos or Dave Raggett’s intro to CSS. If you’re new to web development, be sure to read our CSS basics article to learn what CSS is and how to use it.

cascading style sheets

Values may be keywords, such as « center » or « inherit », or numerical values, such as 200px (200 pixels), 50vw (50 percent of the viewport width) or 80% (80 percent of the parent element’s width). Pseudo-classes are used in CSS selectors to permit formatting based on information web development css cascading that is not contained in the document tree. Note how the opening tag has a type attribute of text/css, although I’m not sure how necessary that is any more. The browser support status is shown on every MDN CSS property page in a table named « Browser compatibility ».

What is CSS? Cascading Style Sheets Explained

The creative ability in programming is allowing people to do even more with their ideas. If you want to advance your career,  take the first steps by learning to code. Having these skills can help you open doors to those new professional possibilities. Enroll in Udacity’s Intro to Programming Nanodegree today to start the journey. Now that you have an answer to “what is CSS”, you might be curious as to the mention of cascading.

CSS lets you stylize everything on a different file, thus creating the design there and later on integrating the CSS files on top of the HTML markup. This makes the actual HTML markup much cleaner and easier to maintain. CSS was developed by W3C (World Wide Web Consortium) in 1996 for a rather simple reason. HTML element was not designed to have tags that would help format the page.


Where HTML provides the bones or structure to a document, CSS injects the style for it. CSS allows you to manipulate HTML elements in various ways such as size, shapes, colors, or even interactions from the end-users. Think of CSS as a toolbox that you can reference when trying to fine-tune the website appearance to your needs. 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.

In our example, we have the color property, which can take various color values. It is also recommended that you work through Getting started with the web before proceeding with this topic, especially if you are completely new to web development. However, much of what is covered in its CSS basics article is also covered in our CSS first steps module, albeit in a lot more detail. An external style sheet is used to define the style for many HTML pages. That example uses the stylesheet attribute to point to a CSS file called main.css that’s in the web root directory on its server. Beyond managing formatting, CSS also lets you modularize resources across complex websites, providing uniform presentation across multiple web pages.

Introducing the CSS Cascade

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. Because the specificity values do not carry over as in the decimal system, commas are used to separate the « digits »[18] (a CSS rule having 11 elements and 11 classes would have a specificity of 11,11, not 121). CSS is one of the most powerful tools a web designer can learn because with it you can affect the entire visual appearance of a website. The final coloring and font-size values were taken from the last entry on the stylesheet. The font-family and font-weight properties were added along the way and kept on the final render as well.

cascading style sheets

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. As there are so many things that you could style using CSS, the language is broken down into modules.

User-agent stylesheets

If you want links to be blue and underlined, you do not need to do anything since that is the default, but if your site’s CSS file says that links should be green, that color will override the default blue. The underline will remain in this example since you did not specify otherwise. CSS, or Cascading Style Sheets, offers a flexible way to style web content, with styles originating from browser defaults, user preferences, or web designers. These styles can be applied inline, within an HTML document, or through external .css files for broader consistency.

cascading style sheets