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 tosolve a problem
External Style Sheets can save you a lot of work
External Style Sheets are stored in CSS files
Multiple style definitions will cascade into one
Styles Solve a Common Problem
HTML tags were originally designed to define the content of a document. They were supposed to say "This is a header",
"This is a paragraph", "This is a table", by using tags like <h1>, <p>, <table>, and so on. 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 (like the <font> tag and the color attribute) 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 Sheet
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.
Syntax
The CSS syntax is made up of three parts: a selector, a property and a value:
selector {property: value}
The selector is normally the HTML element/tag you wish to define, the property is the attribute you wish to change, and each property can take a value. The property and value are separated by a colon, and surrounded by curly braces:
body {color: black}
Note: If the value is multiple words, put quotes around the value:
p {font-family: "sans serif"}
How to Insert a Style Sheet
When a browser reads a style sheet, it will format the document according to it. There are three ways of inserting a style sheet:
External Style Sheet
An external style sheet is ideal when the style is applied to many pages. With an external style sheet, you can change the look of an entire Web site by changing one file. Each page must link to the style sheet using the <link> tag. The <link> tag goes inside the head section:
<head>
<link rel="stylesheet" type="text/css"
href="mystyle.css" />
</head>
CSS Background Properties
The CSS background properties allow you to control the background color of an element, set an image as the background, repeat a background image vertically or horizontally, and position an image on a page.
