Cascading Style Sheets - Tutorials

As we are getting ready to launch into our CSS class (following the conclusion of HTML), I thought I'd post this link to w3Schools. They have great tutorials and a WYSIWYG editor (what you see is what you get) that you can practice with.

What is CSS?

• CSS Stands for Cascading Style Sheets
• Styles define how to display HTML elements
• Styles are normally stored in Style Sheets
• Styles were added to HTML 4.0 to solve a problem
• External Style Sheets are stored in CSS files
• Multiple style definitions will cascade into one

HTML tags were originally designed to define the content of a document. The layout of the document was supposed to be taken care of by the browser, without using any formatting tags.

As the two major browsers - Netscape and Internet Explorer - continued to add new HTML tags and attributes to the original HTML specification, it became more and more difficult to create Web sites where the content of HTML documents was clearly separated from the document's presentation layout.

To solve this problem, the World Wide Web Consortium (W3C) - the non profit, standard setting consortium, responsible for standardizing HTML - created STYLES in addition to HTML 4.0.

All major browsers support Cascading Style Sheets.

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Style Sheets Can Save a Lot of Work

Styles sheets define HOW HTML elements are to be displayed, just like the font tag and the color attribute in HTML 3.2.

Styles are normally saved in external .css files. External style sheets enable you to change the appearance and layout of all the pages in your Web, just by editing one single CSS document!

CSS is a breakthrough in Web design because it allows developers to control the style and layout of multiple Web pages all at once. As a Web developer you can define a style for each HTML element and apply it to as many Web pages as you want. To make a global change, simply change the style, and all elements in the Web are updated automatically.

Multiple Styles Will Cascade Into One

Style sheets allow style information to be specified in many ways. Styles can be specified inside a single HTML element, inside the head element of an HTML page, or in an external CSS file.

Even multiple external style sheets can be referenced inside a single HTML document.


Cascading Order
What style will be used when there is more than one style specified for an HTML element?

Generally speaking we can say that all the styles will "cascade" into a new "virtual" style sheet by the following rules, where number four has the highest priority:

Browser default
External style sheet
Internal style sheet (inside the head tag)
Inline style (inside an HTML element)

So, an inline style (inside an HTML element) has the highest priority, which means that it will override a style declared inside the head tag, in an external style sheet, or in a browser (a default value).

Read more here...