CSS Tutorial

CSS is the acronym for "Cascading Style Sheet". It's a style sheet language used for describing the presentation of a document written in a markup language like HTML. CSS helps the web developers to control the layout and other visual aspects of the web pages. CSS plays a crucial role in modern web development by providing the tools necessary to create visually appealing, accessible, and responsive websites.

CSS Versions

Since the inception of CSS, several versions have came into existence. Some of the notable versions include:

• CSS1 (Cascading Style Sheets Level1) - The initial version of CSS, released in December 1996. CSS1 provided basic styling capabilities for HTML documents, including properties for text, colors, backgrounds, margins, and borders.

• CSS2 (Cascading Style Sheets Level2) - Released in May 1998, CSS2 introduced new features such as positioning, z-index, media types, and more advanced selectors like attribute selectors and child selectors.

• CSS2.1 - The version 2.1, published as a W3C Recommendation in June 2011, clarified and refined CSS2, addressing inconsistencies and ambiguities in the specification. CSS2.1 focused on improving interoperability among web browsers.

• CSS3 (Cascading Style Sheets Level 3) - CSS3 is a collection of modules that extend the capabilities of CSS. It introduces numerous new features and enhancements, including advanced selectors, multiple column layouts, animations, transformations, gradients, shadows, and more.

• CSS4 (Cascading Style Sheets Level 4) - CSS4 is an ongoing effort to extend CSS3 with new features and enhancements.

Each version of CSS builds upon the previous ones, adding new features and refining existing capabilities to meet the evolving needs of web developers and designers. CSS is referred as just CSS now, without a version number.

Advantages of CSS

• Responsive design - CSS offers features like media queries that enable developers to create responsive layouts that adapt to different screen sizes and devices, ensuring a consistent user experience.

• Flexibility and Control - CSS provides precise control over the presentation of HTML elements, allowing developers to customize layout, typography, colors, and other visual properties.

• Consistency and Reusability - Developers can ensure consistency across the entire website, by defining styles in a central CSS file. Styles can be reused across multiple pages, reducing redundancy and making updates easier.

• Search Engine Optimization (SEO) - CSS can be used to structure content in a way that improves search engine visibility.

• Ease of Maintenance - Centralized CSS files make it easier to maintain and update styles across a website. Changes can be applied globally, ensuring uniformity and reducing the risk of inconsistencies.

• Faster Page Loading - External CSS files can be cached by browsers, resulting in faster page loading times for subsequent visits to a website. This caching mechanism reduces server load and bandwidth consumption.

Prerequisites

Before using CSS extensively, it is essential to have a baisc understanding of the following prerequisites:

• HTML - A fundamental understanding of HTML markup is necessary. This includes knowledge of HTML elements, attributes, tags, and their hierarchical structure.

• Text Editors or Integrated Development Environments (IDEs) - In order to write to write your CSS code, a text editor or an IDE is required. Popular choices include Visual Studio Code, Sublime Text, Atom, or integrated editors within IDEs like IntelliJ IDEA or Eclipse.

• Browser Developer Tools - Familiarizing yourself with browser developer tools can help you understand how styles are applied and troubleshoot layout issues.

• Basic Environment Setup - Basic understanding of creating and managing files, along with saving and organizing them on your computer.

If you are new to HTML and XHTML, then we would suggest you to go through our HTML or XHTML Tutorial first.

Components of CSS

CSS works by associating rules with HTML elements. A CSS rule contains two main parts:

• a selector which specifies the HTML element(s) to style.

• a declaration block which contains one or more declarations separated by semicolons.

Each declaration includes a property name and a value, specifying the aspect of the element's presentation to control.

Sample Code

Just to give you a little excitement about CSS, here is a sample CSS snippet for your reference.

<html>
<head>
   <title>CSS Tutorial</title>
   <style>
      h1 {
         color: #36CFFF; 
      }
      p {
         font-size: 1.5em;
         color: white;
      }
      div {
         border: 5px inset gold;
         background-color: black;
         width: 300px;
         text-align: center;
      }
   </style>
</head>	
<body>
   <div>
      <h1>Hello World!</h1>
      <p>This is a sample CSS code.</p>
   </div>
</body>	
</html>

In the above CSS snippet:

• h1, p, and div are the selectors that target the <h1>, <p>, and <div> elements.

• color, font-size, border, background-color, width, and text-align are the properties.

• #36CFFF, 1.5em, white, 5px inset gold, black, 300px, and center are the corresponding values passed to these properties.

For a quick glance of CSS properties and features, check our CSS Reference page.