HTML - CSS - Mr. Hamlin

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HTML - CSS

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

CSS Demo

Learn 3 different ways to insert CSS into your website.

Use CSS for background image.

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 (W3C) created CSS.

In HTML 4.0, 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!

CSS (Cascading Style Sheets) is used to style HTML elements.

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Styling HTML with CSS

CSS was introduced together with HTML 4, to provide a better way to style HTML elements.

CSS can be added to HTML in the following ways:

Inline - using the style attribute in HTML elements
Internal - using the <style> element in the <head> section
External - using an external CSS file

The preferred way to add CSS to HTML, is to put CSS syntax in separate CSS files.

However, in this HTML tutorial we will introduce you to CSS using the style attribute. This is done to simplify the examples. It also makes it easier for you to edit the code and try it yourself.

Inline Styles

An inline style can be used if a unique style is to be applied to one single occurrence of an element.

To use inline styles, use the style attribute in the relevant tag. The style attribute can contain any CSS property. The example below shows how to change the text color and the left margin of a paragraph:

<p style="color:blue;margin-left:20px;">This is a paragraph.</p>

HTML Style Example - Background Color

The background-color property defines the background color for an element:

<!DOCTYPE html>
<html>

<body style="background-color:yellow;">
<h2 style="background-color:red;">This is a heading</h2>
<p style="background-color:green;">This is a paragraph.</p>
</body>

</html>

* The background-color property makes the "old" bgcolor attribute obsolete.

HTML Style Example - Font, Color and Size

The font-family, color, and font-size properties defines the font, color, and size of the text in an element:

<!DOCTYPE html>
<html>

<body>
<h1 style="font-family:verdana;">A heading</h1>
<p style="font-family:arial;color:red;font-size:20px;">A paragraph.</p>
</body>

</html>

* The font-family, color, and font-size properties make the old <font> tag obsolete.

HTML Style Example - Text Alignment

The text-align property specifies the horizontal alignment of text in an element:

<!DOCTYPE html>
<html>

<body>
<h1 style="text-align:center;">Center-aligned heading</h1>
<p>This is a paragraph.</p>
</body>

</html>

* The text-align property makes the old <center> tag obsolete.

Internal Style Sheet

An internal style sheet can be used if one single document has a unique style. Internal styles are defined in the <head> section of an HTML page, by using the <style> tag, like this:

<head>

body {background-color:yellow;}
p {color:blue;}
</style>
</head>

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: