1 css syntax sample configure a web page to display blue text and yellow background. body { color:...

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CSSSyntax Sample

Configure a Web page to display blue text and yellow background.

body { color: blue; background-color: yellow; }

This could also be written using hexadecimal color values as shown below.

body { color: #0000FF; background-color: #FFFF00; }

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Configuring Color with Inline CSS (1)

Inline CSS Configured in the body of the Web page Use the style attribute of an XHTML tag Apply only to the specific element

The Style Attribute Value: one or more style declaration property and value

pairs

Example: configure red color text in an <h1> element:<h1 style="color:#ff0000">Heading text is red</h1>

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Configuring Color with Inline CSS (2)

Example 2: configure the red text in the heading configure a gray backgroundin the heading

Separate style rule declarations with ;

<h1 style="color:#FF0000;background-color:#cccccc">This is displayed as a red heading with gray background</h1>

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CSS Embedded Styles

Configured in the header section of a Web page.

Use the XHTML <style> element Apply to the entire Web page document Style declarations are contained between the

opening and closing <style> tags The type attribute indicates the MIME type of

text/css Example: Configure a Web page with white

text on a black background<style type ="text/css">body { background-color: #000000; color: #FFFFFF;}</style>

Configuring Text with CSS

CSS properties for configuring text: font-weight

Configures the boldness of text font-style

Configures text to an italic style font-size

Configures the size of the text font-family

Configures the font typeface of the text

The font-size Property

Accessibility Recommendation: Use em or percentage font sizes – these can be easily enlarged in all browsers by users

The font-family Property

Not everyone has the same fonts installed in their computer

Configure a list of fonts and include a generic family name

p {font-family: Arial,Verdana, sans-serif;}

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XHTML <div> element

A block-level element Purpose: configure a specially formatted

division or area of a Web page There is a line break before and after the division. Can contain other block-level and inline elements

Useful to define an area that will contain other block-level tags (such as paragraphs or spans) within it.

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XHTML <div> Element Example

Configure a page footer area Embedded CSS:

<style type="text/css">.footer { font-size: small; text-align: center; }</style>

XHTML:<div class=“footer">Copyright &copy; 2009</div>

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XHTML<span> element

An inline-level element Purpose:

configure a specially formatted area displayed in-line with other elements, such as within a paragraph.

There is no line break before and after the span.

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XHTML <span> Element Example Embedded CSS:

<style type="text/css">

.companyname { font-weight: bold;

font-family: Georgia, "Times New Roman", serif;

font-size: 1.25em;

}

</style>

XHTML:<p>Your needs are important to us at <span

class=“companyname">Acme Web Design</span>.We will work with you to build your Web site.</p>

Using anExternal Style Sheet

To link to the external style sheet called color.css, the XHTML code placed in the header section is:

<link rel="stylesheet" href="color.css" type="text/css" />

body { background-color: #0000FF; color: #FFFFFF;}

External Style Sheet color.css

Centering Page Content with CSS#container { margin-left: auto;

margin-right: auto;

width:80%; }

CSS Troubleshooting Tips Verify you are using the : and ; symbols in the right

spots—they are easy to confuse.

Check that you are not using = signs instead of : between each property and its value.

Verify that the { and } symbols are properly placed

Check the syntax of your selectors, their properties, and property values for correct usage.

If part of your CSS works, and part doesn’t: Review your CSS Determine the first rule that is not applied.

Often the error is in the rule above the rule that is not applied.

Validate your CSS at http://jigsaw.w3.org/css-validator

The CSS border Property

Configures a border on the top, right, bottom, and left sides of an element

Consists of border-width border-style border-color

h2 { border: 2px solid #ff0000 }

CSS Borders: Block / Inline Elements

Block element default width of element content extends

to browser margin (or specified width) Inline element

Border closely outlines the element content

h2 { border: 2px solid #ff0000; }

a { border: 2px solid #ff0000; }

Browser Display Can Vary

Configuring Specific Sides of a Border

Use CSS to configure a line on one or more sides of an element border-bottom border-left border-right border-top

h2 { border-bottom: 2px solid #ff0000 }

The CSS padding Property

Configures empty space between the content of the XHTML element and the border

Set to 0px by default

h2 { border: 2px solid #ff0000;

padding: 5px; }

No padding configured:

Configuring Padding on Specific Sides of an

Element Use CSS to configure padding on one or

more sides of an element padding-bottom padding-left padding-right padding-top

h2 { border: 2px solid #ff0000;

background-color: #cccccc;

padding-left: 5px;

padding-bottom: 10px;

padding-top: 10px;}

CSS padding Property Shorthand: two values

Two numeric values or percentages first value configures top and bottom padding the second value configures left and right

padding

h2 { border: 2px solid #ff0000;

background-color: #cccccc;

padding: 20px 10px;

}

CSS padding Property Shorthand: four values

Four numeric values or percentages Configure top, right, bottom, and left

padding

h2 { border: 2px solid #ff0000;

width: 250px;

background-color: #cccccc;

padding: 30px 10px 5px 20px;

}

Hands-On Practice

h1 { background-color:#191970;

color:#E6E6FA;

padding: 15px;

font-family: Georgia, "Times New Roman", serif; }

h2 { background-color:#AEAED4;

color:#191970;

font-family: Georgia, "Times New Roman", serif;

border-bottom: 2px dashed #191970; }

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Types of Graphics

Graphic types commonly used on Web pages: GIF JPG PNG

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GIF

Graphics Interchange Format Best used for line art and logos Maximum of 256 colors One color can be configured as transparent Can be animated Uses lossless compression Can be interlaced

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JPEG

Joint Photographic Experts Group Best used for photographs Up to 16.7 million colors Use lossy compression Cannot be animated Cannot be made

transparent Progressive JPEG – similar to

interlaced display

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PNG

Portable Network Graphic Support millions of colors Support multiple levels of transparency

(but browsers do not -- so limit to one transparent color for Web display)

Support interlacing Use lossless compression Combines the best of GIF & JPEG Browser support is growing

CSS background-image Property

Configures a background-image By default, background images tile

(repeat)

body { background-image: url(background1.gif); }

CSS background-repeat Property

Using background-repeat

h2 { background-color: #d5edb3;

color: #5c743d;

font-family: Georgia, "Times New Roman", serif;

padding-left: 30px;

background-image: url(trilliumbullet.gif);

background-repeat: no-repeat;

}

trilliumbullet.gif:

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OrganizingYour Site

<img src=“images/home.gif” alt=“Home” height=“100” width=“200”/>

• Place images in their own folder

• Code the path to the file in the src atttribute

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ImageMaps

<map> element Defines the map

<area> element Defines a specific area on a map Can be set to a rectangle, circle, or

polygon href Attibute shape Attribute coords Attribute

Sample Image Map

<map name="boat" id="boat">

<area href="http://boat.com" shape="rect" coords="24, 188, 339, 283" alt=“fishing boat" />

</map>

<img src="boat.jpg" usemap="#boat" alt=“Lake Michigan" width="416" height="350" />

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Overall Design Is Related to the Site Purpose

Consider the target audienceof these sites.

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Web SiteOrganization

Hierarchical Linear Random

(sometimes called Web Organization)

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HierarchicalOrganization

A clearly defined home page

Navigation links to major site sections

Often used for commercial and corporate Web sites

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Hierarchical Too Shallow

Be careful that the organization is not too shallow. Too many choices a confusing and less usable web site Information Chunking

“seven plus or minus two” principle George A. Miller found that humans can store only five to nine chunks of information at a

time in short-term memory

Many web designers try not to place more than nine major navigation links on a page or in a well-defined page area.

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Hierarchical Too Deep

Be careful that the organization is not too deep.

This results in many “clicks” needed to drill down to the needed page.

User Interface “Three Click Rule” A web page visitor should be able to

get from any page on your site to any other page on your site with a maximum of three hyperlinks.

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LinearOrganization

A series of pages that provide a tutorial, tour, or presentation.

Sequential viewing

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RandomOrganization

Sometimes called “Web” Organization

Usually there is no clear path through the site

May be used with artistic or concept sites

Not typically used for commercial sites.

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Web Site NavigationBest Practices(1)

Make your site easy to navigate Provide clearly labeled navigation in the same

location on each page Most common – across top or down left side Provide “breadcrumb” navigation

Types of Navigation Graphics-based Text-based Interactive Navigation Technologies

Image Roll-overs Java Applet Flash DHTML fly-out or dropdown menus

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Web Site NavigationBest Practices(2)

Accessibility Tip Provide plain text links in the

page footer when the main navigation is non-text media such as images, Flash, Java Applet or DHTML.

http://www.fdic.gov/consumers/consumer/alerts/

Text Based Navigation: http://www.usdoj.gov/

Graphic Based Navigation: http://www.dot.gov/index.cfm

Flash Navigation: http://www.loc.gov/wiseguide/sept08/index-flash.html

DHTML: https://www.weber.edu/

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Web Site NavigationBest Practices(3)

Use a Table of Contents (with links to other parts of the page) for long pages.

Consider breaking long pages in to multiple shorter pages using Linear Organization.

Large sites may benefit from a site map or site search feature

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Design Principles

Repetition Repeat visual elements

throughout design Contrast

Add visual excitement and draw attention

Proximity Group related items

Alignment Align elements to create

visual unity

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Web Page DesignBest Practices

Page layout design Text design Graphic design Accessibility considerations

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Web Page DesignLoad Time

Watch the load time of your pages

Try to limit web page document and associated media to under 60K on the home page

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Web Page DesignTarget Audience

Design for your target audience Appropriate reading level of text Appropriate use of color Appropriate use of animation

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Web Page DesignColors & Animation

Use colors and animation that appeal to your target audience Kids

Bright, colorful, tons of animation

Generation X,Y,Z,etc. Dark, often low contrast, more subtle animation

Everyone: Good contrast between background and text Easy to read Avoid animation if it makes the page load too slowly

Accessibility Tip: Many individuals are unable to distinguish between certain colors.

See http://www.vischeck.com/showme.shtml

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Web Page Design Browser Compatibility

Web pages do NOT look the same in all the major browsers

Test with current and recent versions of: Internet Explorer Firefox, Mozilla Opera Mac versions

Design to look best in one browser and degrade gracefully (look OK) in others

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Web Page Design Screen Resolution

Test at various screen resolutions Most widely used: 1024x768, 1280x1024,

and 800x600

Design to look good at various screen resolutions Centered page content Set to either a fixed or percentage width

Wireframe

A sketch of blueprint of a Web page

Shows the structure of the basic page elements, including: Logo Navigation Content Footer

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Web Page DesignPage Layout(1)

Place the most important information "above the fold"

Use adequate "white" or blank space Use an interesting page layout

This is usable, but a little boring. See the next slide for improvements in page layout.

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Web Page DesignPage Layout(2)

Better

Best

Columns make the page more interesting and it’s easier to read this way.

Columns of different widths interspersed with graphics and headings create the most interesting, easy to read page.

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Text DesignBest Practices

Avoid long blocks of text Use bullet points Use short paragraphs

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Text Design“Easy to Read” Text (1)

Use common fonts: Arial, Helvetica, Verdana, Times New Roman

Use appropriate text size: medium, 1em, 16px, 12 pt, 100

Use strong contrast between text & background

Use columns instead of wide areas of horizontal text

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Text Design“Easy to Read” Text (2)

Bold text as needed

Avoid “click here”

Hyperlink key words or phrases, not entire sentences

Separate text with “white space” or empty space.

Chek yur spellin (Check your spelling)

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Graphic DesignBest Practices(1)

Be careful with large graphics! Remember 60k recommendation

Use the alt attribute to supply descriptive alternate text

Be sure your message gets across even if images are not displayed. If using images for navigation provide plain text links at

the bottom of the page.

Use animation only if it makes the page more effective and provide a text description.

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Graphic DesignRecommended Practices(2)

Choose colors on the web palette if consistency across older Windows/Mac platforms is needed

Use anti-aliased text in images

Use only necessary images

Reuse images

Goal: image file size should be as small as possible