CSS tutorial chapter 1

What is CSS?
• CSS stands for Cascading Style Sheets
• CSS describes how HTML elements are to be
displayed on screen, paper, or in other media
• CSS saves a lot of work. It can control the
layout of multiple web pages all at once
• External stylesheets are stored in CSS files

Why Use CSS?
CSS is used to define styles for your web
pages, including the design, layout and
variations in display for different devices and
screen sizes.

CSS Solved a Big Problem
• HTML was NEVER intended to contain tags for formatting a web
page!
• HTML was created to describe the content of a web page, 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 websites, 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.
• CSS removed the style formatting from the HTML page!

CSS Saves a Lot of Work!
• The style definitions are normally saved in
external .css files.
• With an external stylesheet file, you can
change the look of an entire website by
changing just one file!

CSS Syntax
• A CSS rule-set consists of a selector and a declaration
block:
• The selector points to the HTML element you want to
style.
• The declaration block contains one or more
declarations separated by semicolons.
• Each declaration includes a CSS property name and a
value, separated by a colon.
• A CSS declaration always ends with a semicolon, and
declaration blocks are surrounded by curly braces.

CSS Selectors
• CSS selectors are used to "find" (or select)
HTML elements based on their element name,
tag,id, class, attribute, and more.

The element Selector
• The element selector selects elements based on
the element name.
• You can select all <p> elements on a page like this
(in this case, all <p> elements will be center-
aligned, with a red text color):
Example
p {
text-align: center;
color: red;
}

Selector
The id Selector
The class Selector
The class selector selects elements with a specific class
attribute.
• You can also specify that only specific HTML elements
should be affected by a class.
• In the example below, only <p> elements with
class="center" will be center-aligned:
• Example
• p.center {
text-align: center;
color: red;
}

More than one class
HTML elements can also refer to more than one
class.
the <p> element will be styled according to
class="center" and to class="large":
Example
<p class="center large">This paragraph refers to
two classes.</p>
Note: A class name cannot start with a number!

Grouping Selectors
• If you have elements with the same style definitions, like this:
• h1 {
text-align: center;
color: red;
}
h2 {
text-align: center;
color: red;
}
p {
text-align: center;
color: red;
}
• It will be better to group the selectors, to minimize the code.
• To group selectors, separate each selector with a comma.
• In the example below we have grouped the selectors from the code above:
Example
h1, h2, p {
text-align: center;
color: red;
}

CSS Comments
• Comments are used to explain the code, and
may help when you edit the source code at a
later date.
• Comments are ignored by browsers.
• A CSS comment starts with /* and ends with
*/. Comments can also span multiple lines:

CSS How To...
Three Ways to Insert CSS
There are three ways of inserting a style
sheet:
External style sheet
Internal style sheet
Inline style

External Style Sheet
With an external style sheet, you can change the look of an
entire website by changing just one file!
Each page must include a reference to the external style sheet
file inside the <link> element. The <link> element goes inside
the <head> section:
<head>
<link rel="stylesheet" type="text/css" href="mystyle.css">
</head>
An external style sheet can be written in any text
editor. The file should not contain any html tags. The
style sheet file must be saved with a .css extension.

Example
body {
background-color: lightblue;
}
h1 {
color: navy;
margin-left: 20 px;
}
Note: Do not add a space between the property value
and the unit (such as margin-left: 20 px;). The correct
way is: margin-left: 20px;

Internal Style Sheet
An internal style sheet may be used if one single
page has a unique style.
Internal styles are defined within the <style>
element, inside the <head> section of an HTML
page:

Inline Styles
An inline style may be used to apply a unique style
for a single element.
To use inline styles, add the style attribute to the
relevant element. The style attribute can contain
any CSS property.
**Tip: An inline style loses many of the advantages
of a style sheet (by mixing content with
presentation). Use this method sparingly

CSS Colors
• Colors in CSS are most often specified by:
• a valid color name - like "red"
• an RGB value - like "rgb(255, 0, 0)"
• a HEX value - like "#ff0000“
• Follow exam[les

CSS Backgrounds
CSS background properties:
• background-color
• background-image
• background-repeat
• background-attachment
• background-position

Background Color
body {
background-color: lightblue;
}
Background Image
body {
background-image: url("paper.gif");
}

Background Image - Repeat Horizontally or
Vertically
• Please try to understand the example:
• Please be attentive.
• Background Image - Set position and no-
repeat
• Ex::
• We want to change the position of the image,
so that it does not disturb the text too much.

Background Property
• Background Image - Fixed position
• Background - Shorthand property
When using the shorthand property the order of
the property values is:
• background-color
• background-image
• background-repeat
• background-attachment
• background-position

Text Color
body {
color: blue;
}
h1 {
color: green;
}
****DO YOURSELF
Note: For W3C compliant CSS: If you define the
color property, you must also define the
background-color.

Text Alignment
• The text-align property is used to set the horizontal
alignment of a text.
• A text can be left or right aligned, centered, or justified.
h1 {
text-align: center;
}
h2 {
text-align: left;
}
h3 {
text-align: right; ///// ** Do yourself please
}

Text Decoration
• The text-decoration property is used to set or
remove decorations from text.
• The value text-decoration: none; is often used
to remove underlines from links:
Example
a {
text-decoration: none;
}

Text Decoration Example
• The other text-decoration values are used to decorate text:
Example
• h1 {
text-decoration: overline;
}
h2 {
text-decoration: line-through;
}
h3 {
text-decoration: underline;
}

Text Transformation
• The text-transform property is used to specify
uppercase and lowercase letters in a text.
• ////Try yourself

Text Indentation
• The text-indent property is used to specify the
indentation of the first line of a text:
Example
p {
text-indent: 50px;
}

Letter Spacing
• The letter-spacing property is used to specify
the space between the characters in a text.
• Check the EXAMPLE

Line Height
• The line-height property is used to specify the
space between lines:
• Check example::

Text Direction
• The direction property is used to change the
text direction of an element:
• Example: --------------

Word Spacing
The word-spacing property is used to specify
the space between the words in a text.
The example demonstrates how to increase or
decrease the space between words:

Text Shadow
• The text-shadow property adds shadow to
text.
• Check The example

CSS Lists
HTML Lists and CSS List Properties
• In HTML, there are two main types of lists:
• unordered lists (<ul>) - the list items are marked with
bullets
• ordered lists (<ol>) - the list items are marked with
numbers or letters
• The CSS list properties allow you to:
• Set different list item markers for ordered lists
• Set different list item markers for unordered lists
• Set an image as the list item marker
• Add background colors to lists and list items

Different List Item Markers
• The list-style-type property specifies the type
of list item marker.
• Example

An Image as The List Item Marker
• The list-style-image property specifies an
image as the list item marker:
• Example: 

Position The List Item Markers
• The list-style-position property specifies
whether the list-item markers should appear
inside or outside the content flow:
• Ex 

List - Shorthand property
• When using the shorthand property, the order of the
property values are:
• list-style-type (if a list-style-image is specified, the
value of this property will be displayed if the image for
some reason cannot be displayed)
• list-style-position (specifies whether the list-item
markers should appear inside or outside the content
flow)
• list-style-image (specifies an image as the list item
marker)
• If one of the property values above are missing, the
default value for the missing property will be inserted,
if any.

CSS tutorial chapter 1

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