CSS: Separating Design and Content
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Transcript CSS: Separating Design and Content
CSS: Separating Design and
Content
Kevin Campbell
Duke University/Grouchyboy.com
Assumptions
You know HTML
You do not know CSS
You care about aesthetics and
function
You have 50 minutes to kill
What We’ll Do
What is CSS?
View some code and talk basics
Why use CSS?
Advantages to Workflow
Cost Savings
Implementations
Resources
What are Cascading Style Sheets?
Created by Hakon Wium Lie of MIT
in 1994
Has become the W3C standard for
controlling visual presentation of
web pages
Separates design elements from
structural logic
You get control and maintain the
integrity of your data
Let’s See Some Code
Sample Style sheet
Rule Structure
Selectors
Element Selectors – (refer to
HTML tags)
H1 {color: purple;}
H1, H2, P {color: purple;}
Contextual – (refer to HTML, but in
context)
LI B {color: purple;}
Selectors
Class Selectors
<H1 CLASS=“warning”>Danger!</H1>
<P CLASS=“warning”>Be careful…</P>
…….
In your HTML code H1.warning {color: red;}
OR to an entire class…
.warning {color:red;}
Applying CSS to HTML
Style rules can be applied in 3 ways:
Inline
Styles:
Embedded
style
sheets:
External
style
sheets:
<H1
STYLE=“color: blue; font-size: 20pt;”>A large purple
<HTML><HEAD><TITLE>Stylin’!</TITLE>
<HEAD>
Heading</H1>
<STYLE
TYPE=“text/css”>
<LINK REL=stylesheet”
TYPE=“text/css”
H1 {color: purple;}
HREF=“styles/mystyles.css”>
For
individual
elements
usinggray;}
the STYLE attribute
P {font-size:
10pt; color:
</HEAD>
</STYLE>
</HEAD>
This is true “separation” of style and content.
…
Keeping all your styles in an external document is
</HTML>
simpler
Why CSS?
Advantages to Workflow
Cost Savings
You WILL Be Cooler
Advantages of CSS
Workflow
Faster downloads
Streamlined site maintenance
Global control of design attributes
Precise control (Advanced)
Positioning
Fluid layouts
Advantages of CSS - Cost Savings
Cost Savings
Reduced Bandwidth Costs
One style sheet called and cached
Higher Search Engine Rankings
Cleaner code is easier for search engines
to index
Greater density of indexable content
Advantages of CSS - Cost Savings
Faster download = better usability
Web usability redesign can increase the
sales/conversion rate by 100% (source: Jakob
Nielson)
CSS requires less code
Tables require spacer images
Entire table has to render before content
CSS can control the order that elements
download (content before images)
Advantages of CSS - Cost Savings
Increased Reach
CSS website is compatible w/ many
different devices
In 2008 an est. 58 Million PDA’s will be
sold (Source: eTForecast.com)
1/3 of the world’s population will own a
wireless device by 2010
Implementations
Apply to HTML pages
Apply to dynamic data
Format or style XML
Use for layout (this is cool)
See http://www.csszengarden.com
CSS isn’t perfect (yet)
CSS support in browsers is still
uneven
Make sure your CSS properties are
supported
Resources
http://www.csszengarden.com
http://www.w3.org/Style/CSS/
The Official CSS Site
http://css.maxdesign.com.au/
This is CSS at its finest
Australian firm, very professional
http://webmonkey.wired.com/webm
onkey/reference/stylesheet_guide
Where I learned CSS and Web Design
Come and see me at 3:30pm!
“Making Your Web Site More
Appealing”