Wednesday, October 24, 2012

CSS Class Selector


Chapter 6

The class Selector

The class selector is used to specify a style for a group of elements. Unlike the id selector, the class selector is most often used on several elements.
This allows you to set a particular style for many HTML elements with the same class.
The class selector uses the HTML class attribute, and is defined with a "."
In the example below, all HTML elements with class="center" will be center-aligned:

Example :4

<!By using class selector >

<html>
<head>
<style>
.center
{
text-align:center;
}
</style>
</head>

<body>
<h1 class="center">Center-aligned heading</h1>
<p class="center">Center-aligned paragraph.</p>
</body>
</html>

Output is:

Center-aligned heading

Center-aligned paragraph.

CSS Id


Chapter 5

The id and class Selectors

In addition to setting a style for a HTML element, CSS allows you to specify your own selectors called "id" and "class".



The id Selector

The id selector is used to specify a style for a single, unique element.
The id selector uses the id attribute of the HTML element, and is defined with a "#".
The style rule below will be applied to the element with id="para1":

Example :3

<!By using ID >

<html>
<head>
<style>
#para1
{
text-align:center;
color:red;
}
</style>
</head>
<body>
<p id="para1">Hello World!</p>
<p>This paragraph is not affected by the style.</p>
</body>
</html>

Output is:

Hello World!
This paragraph is not affected by the style.


CSS Link




Chapter 4



Example :2

<html>
<head>
<style>
body {background-color:tan;}
h1   {color:maroon;font-size:20pt;}
hr   {color:navy;}
p    {font-size:11pt;margin-left:15px;}
a:link    {color:green;}
a:visited {color:yellow;}
a:hover   {color:black;}
a:active  {color:blue;}
</style>
</head>

<body>

<h1>This is a header 1</h1>
<hr>

<p>You can see that the style
sheet formats the text</p>

<p><a href="http://atoz4tutorials.blogspot.in/"
target="_blank">This is a link</a></p>

</body>
</html>

Output is:

This is a header 1

You can see that the style sheet formats the text


CSS Head



Chapter 3



Example :1

<head>
<style>
body {background-color:yellow;}
h1   {font-size:36pt;}
h2   {color:blue;}
p    {margin-left:50px;}
</style>
</head>

<body>

<h1>This header is 36 pt</h1>
<h2>This header is blue</h2>

<p>This paragraph has a left margin of 50 pixels</p>

</body>
</html>

Output is:

This header is 36 pt

This header is blue

This paragraph has a left margin of 50 pixels

CSS Syntax


Chapter 2


CSS Syntax

A CSS rule has two main parts: a selector, and one or more declarations:




The selector is normally the HTML element you want to style.
Each declaration consists of a property and a value.
The property is the style attribute you want to change. Each property has a value.

CSS Introducation


Chapter 1



CSS


What You Should Already Know
Before you continue you should have a basic understanding HTML.

What is What You Should Already Know
Before you continue you should have a basic understanding of the following:
  • HTML

What is CSS?
  • CSS stands for Cascading Style Sheets
  • Styles define how to display HTML elements
  • Styles were added to HTML 4.0 to solve a problem
  • External Style Sheets can save a lot of work
  • External Style Sheets are stored in CSS files


Styles Solved a Big Problem
HTML was never intended to contain tags for formatting a document.
HTML was intended to define the content of a document, like:

<h1>This is a heading</h1>
<p>This is a paragraph.</p>

When tags like <font>, and color attributes were added to the HTML 3.2 specification, it started a nightmare for web developers. Development of large web sites, where fonts and color information were added to every single page, became a long and expensive process.

To solve this problem, the World Wide Web Consortium created CSS.
In HTML , all formatting could be removed from the HTML document, and stored in a separate CSS file.
All browsers support CSS today.


CSS Saves a Lot of Work!
CSS defines HOW HTML elements are to be displayed.
Styles are normally saved in external .css files. External style sheets enable you to change the appearance and layout of all the pages in a Web site, just by editing one single file!

HTML Colors

Chapter 18

Web Safe Colors?

Some years ago, when computers supported max 256 different colors, a list of 216 "Web Safe Colors" was suggested as a Web standard, reserving 40 fixed system colors.

The 216 cross-browser color palette was created to ensure that all computers would display the colors correctly when running a 256 color palette.



0000000000330000660000990000CC0000FF
0033000033330033660033990033CC0033FF
0066000066330066660066990066CC0066FF
0099000099330099660099990099CC0099FF
00CC0000CC3300CC6600CC9900CCCC00CCFF
00FF0000FF3300FF6600FF9900FFCC00FFFF
3300003300333300663300993300CC3300FF
3333003333333333663333993333CC3333FF
3366003366333366663366993366CC3366FF
3399003399333399663399993399CC3399FF
33CC0033CC3333CC6633CC9933CCCC33CCFF
33FF0033FF3333FF6633FF9933FFCC33FFFF
6600006600336600666600996600CC6600FF
6633006633336633666633996633CC6633FF
6666006666336666666666996666CC6666FF
6699006699336699666699996699CC6699FF
66CC0066CC3366CC6666CC9966CCCC66CCFF
66FF0066FF3366FF6666FF9966FFCC66FFFF
9900009900339900669900999900CC9900FF
9933009933339933669933999933CC9933FF
9966009966339966669966999966CC9966FF
9999009999339999669999999999CC9999FF
99CC0099CC3399CC6699CC9999CCCC99CCFF
99FF0099FF3399FF6699FF9999FFCC99FFFF
CC0000CC0033CC0066CC0099CC00CCCC00FF
CC3300CC3333CC3366CC3399CC33CCCC33FF
CC6600CC6633CC6666CC6699CC66CCCC66FF
CC9900CC9933CC9966CC9999CC99CCCC99FF
CCCC00CCCC33CCCC66CCCC99CCCCCCCCCCFF
CCFF00CCFF33CCFF66CCFF99CCFFCCCCFFFF
FF0000FF0033FF0066FF0099FF00CCFF00FF
FF3300FF3333FF3366FF3399FF33CCFF33FF
FF6600FF6633FF6666FF6699FF66CCFF66FF
FF9900FF9933FF9966FF9999FF99CCFF99FF
FFCC00FFCC33FFCC66FFCC99FFCCCCFFCCFF
FFFF00FFFF33FFFF66FFFF99FFFFCCFFFFFF