Learn about Cascading Style Sheets LACUNY Web Management Roundtable October 21, 2005

Learn about Cascading Learn about Cascading Style SheetsStyle Sheets

LACUNY Web Management Roundtable

October 21, 2005

http://www.lehman.edu/provost/library/CSS/CSS.ppt

October 21, 2005 LACUNY Web Roundtable [email protected]

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CSS Separate Style From CSS Separate Style From Structure of a Web PageStructure of a Web Page

• Specify point size and font of text;• Set margins within a web page;• Create a distinctive style for individual web

pages or sets of web pages;• Format style to one element of a web page or to a

numerous pages;• Control color of different elements of a web

page;• Etc.


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Font Appearance of an ElementFont Appearance of an Element

• HTML code<H3 align="center"> <font face="times

new roman, times, serif" color="#800000">SPECIAL COLLECTION</a></font></h3>

• CSS ruleH3

{

Font-family: times new roman, 'serif';

Color: #800000;

Text-align: center;

}


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Understanding Style RulesUnderstanding Style Rules

• The style characteristics for an HTML element are expressed by Style Rules Style Rules .

• A set of style rules is called a Style SheetStyle Sheet.

• Style rules are contained in the <STYLE> element in the document’s <HEAD> section.

<Head><Style type=“text/css”>P {color:blue; font-size: 24pt;}</Style></Head>


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• A Style RuleStyle Rule is composed of two parts: a selector and a declaration.

TH {color: red;}.• The SelectorSelector indicates the element to which the

rule is applied.• The DeclarationDeclaration determines the property values

of a selector.

Selector Declaration


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• The PropertyProperty specifies a characteristic, such as color, font-family, position, and is followed by a colon (:).

• The ValueValue expresses specification of a property, such as red for color, arial for font family, 12 pt for font-size, and is followed by a semicolon (;).

P {color: red;}

Property Value


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Using the <STYLE> ElementUsing the <STYLE> Element

• The <STYLE> element is always positioned in the <HEAD> section of the document.

• The <STYLE> element always contains <TYPE> attribute. The value “text/css” defines the style language as Cascading Style Sheets.

<Head><Style type=“text/css”>P {color:blue; font-size: 24pt;}</Style></Head>


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Using External Style SheetUsing External Style Sheet

• Style Rules can be expressed in an external Style Sheet - a text document that doesn’t contain any HTML code. There is no <STYLE> element in an external style sheet.

• External Style Sheet has a .css extension.http://www.lehman.edu/provost/library/CSS/style_1.htm

h1, h2, h3{font-family: verdana, arial, 'sans serif'; color: #9933FF; text-align: center;}


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Linking to an External Style Linking to an External Style SheetSheet

• To link a Web page to an external style sheet a <LINK> element should be added within <HEAD> element of a document with the URL to a style sheet. It tells the browser to find a specified style sheet.

<Head><Title>Demo_1</Title><Style type=“text/css”><Link href=“style_1.css” Rel=“stylsheet”></Style></Head>


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Linking to an External Style Linking to an External Style SheetSheet

<Head><Title>Demo_1</Title><Style type=“text/css”>

<Link href=“style1.css” Rel=“stylsheet”></Style></Head>

HREF attribute states the relative URL to the style

sheet

The REL attribute describes the relationship between the

current document and the document identified by the

href attribute


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Using the Class Attribute Using the Class Attribute SelectorSelector

• CLASS is an HTML attribute that assigns a class name to any HTML element on a Web page.

• Can be used to identify which style sheet rules should be applied for the particular element of a Web page

A.nav:link {color:#FF3300; text-decoration: none;}

Class Selector

Element


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Using the Class Attribute Using the Class Attribute SelectorSelector

• A class name is created by declaring a style rule and adding (.) flag character indicating that the selector is a class selector.

• Add it to HTML code of a Web page by using the CLASS attribute.

A.nav:link {color:#FF3300; text-decoration: none;}

<a href="http://www.eric.org" class="nav">ERIC</a>


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Example 1Example 1http://www.lehman.edu/provost/library/CSS/demo_1.htmhttp://www.lehman.edu/provost/library/CSS/demo_1.htm

CSS Style Sheet

http://www.lehman.edu/provost/library/CSS/style_1.htm


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Example 2Example 2http://www.lehman.edu/provost/library/CSS/demo_2.htm

CSS Style Sheet



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Example 3Example 3http://www.lehman.edu/provost/library/CSS/demo_3.htm

CSS Style Sheet



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Lehman College Library Web Site http://www.lehman.edu/provost/library//

http://www.lehman.edu/provost/library/CSS/style.htm


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Lehman College Library Web SiteLehman College Library Web Site

CSSA.nav:link { color: #990000; font-size: 12px; line-height: 14px; font-family:

arial, verdana, geneva, helvetica; text-decoration: none; } A.nav:visited { color: #CC3333; font-size: 12px; line-height: 14px; font-family: arial, verdana, geneva, helvetica; text-decoration: none; }

HTMLIn the <Head> element<link rel="stylesheet" href="Welcome_files/style" type="text/css">In the <Body> element<td align="center" height="25"><a class="nav"

href="http://mail.lehman.edu">Check your Lehman e-mail account</a>

</td>


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Useful ResourcesUseful Resources

• Schengili-Roberts, Keith. Core CSS Cascading Style Sheets. 2nd ed. Upper Saddle River, NJ: Prentice Hall PTR, 2004.

• Sklar, Joel. Designing Web Pages with Cascading Style Sheets. Course Technology, Incorporated, 2001.

• W3C http://www.w3.org/Style/CSS/• WDG Web Design Group

<http://www.htmlhelp.com/reference/css/>

Documents

Learn about Cascading Style Sheets LACUNY Web Management Roundtable October 21, 2005