Technique C22:Using CSS to control visual presentation of text

Applicability

All technologies that support CSS.

This technique relates to:

Description

The objective of this technique is to demonstrate how CSS can be used to control the visual presentation of text. This will allow users to modify, via the user agent, the visual characteristics of the text to meet their requirement. The text characteristics include aspects such as size, color, font family and relative placement.

CSS benefits accessibility primarily by separating document structure from presentation. Style sheets were designed to allow precise control - outside of markup - of character spacing, text alignment, object position on the page, audio and speech output, font characteristics, etc. By separating style from markup, authors can simplify and clean up the markup in their content, making it more accessible at the same time.

Text within images has several accessibility problems, including the inability to:

  • be scaled according to settings in the browser
  • be displayed in colors specified by settings in the browser or rules in user-defined style sheets
  • honor operating system settings, such as high contrast

It is better to use real text for the text portion of these elements, and a combination of semantic markup and style sheets to create the appropriate visual presentation. For this to work effectively, choose fonts that are likely to be available on the user's system and define fallback fonts for users who may not have the first font that is specified. Newer machines and user agents often smooth or anti-alias all text, so it is likely that your headings and buttons will look nice on these systems without resorting to images of text.

The following CSS properties are useful to style text and avoid the need for text in images:

  • The font-family property is used to display the code aspect in a monospace font family.
  • The text-align property is used to display the text to the right of the viewport.
  • The font-size property is used to display the text in a larger size.
  • The font-style property is used to display text in italics.
  • The font-weight property is used to set how thick or thin characters in text should be displayed.
  • The color property is used to display the color of text or text containers.
  • The line-height property is used to display the line height for a block of text.
  • The text-transform property is used to control the case of letters in text.
  • The letter-spacing property is used to control the spacing of letters in text.
  • The background-image property can be used to display text on a non-text background.
  • The :first-line pseudo-element can be used to modify the presentation of the first line in a block of text.
  • The ::first-letter pseudo-element can be used to modify the presentation of the first letter in a block of text.
  • The ::before and ::after pseudo-elements can be used to insert decorative non-text content before or after blocks of text.

Examples

Example 1: Using CSS font-family to control the font family for text

The XHTML component:

<p>The Javascript method to convert a string to uppercase is <code>toUpperCase()</code>.</p>

The CSS component:

code { font-family:"Courier New", Courier, monospace }

Example 2: Using CSS text-align to control the placement (alignment) of text

The XHTML component:

<p class="right">This text should be to the right of the viewport.</p>

The CSS component:

.right { text-align: right; }

Example 3: Using CSS font-size to control the size of text

The XHTML component:

<p>09 <strong class="largersize">March</strong> 2008</p>

The CSS component:

strong.largersize { font-size: 1.5em; }

Example 4: Using CSS color to control the color of text

The style used in this example is not used to convey information, structure or relationships.

The XHTML component:

<p>09 <em class="highlight">March</em> 2008</p>

The CSS component:

.highlight{ color: red; }

Example 5: Using CSS font-style to italicize text

The style used in this example is not used to convey information, structure or relationships.

The XHTML component:

<p>The article is available in the <a href="http://www.example.com" class="featuredsite">Endocrinology 
Blog</a>.</p>

The CSS component:

.featuredsite{ font-style:italic; }

Example 6: Using CSS font-weight to control the font weight of the text

The style used in this example is not used to convey information, structure or relationships.

The XHTML component:

<p>This deal is available <span class="highlight">now!</span></p>

The CSS component:

.highlight { font-weight:bold; color:#990000; }

Example 7: Using CSS text-transform to control the case of text

The style used in this example is not used to convey information, structure or relationships.

The XHTML component:

<p>09 <span class="caps">March</span> 2008</p>

The CSS component:

.caps { text-transform:uppercase; }

Example 8: Using CSS line-height to control spacing between lines of text

The CSS line-height property is used to display the line height for the paragraph at twice the height of the font.

The XHTML component:

<p>Concern for man and his fate must always form the<br />  
chief interest of all technical endeavors. <br />
Never forget this in the  midst of your diagrams and equations. </p>

The CSS component:

p { line-height:2em; }

The CSS line-height property is used to display the line height for the text at less than the height of the font. The second line of text is positioned after the first line of text and visually appears as though the text is part of the first line but dropped a little.

The XHTML component:

<h1 class="overlap"><span class="upper">News</span><br />
<span class="byline">today</span></h1>

The CSS component:

.overlap { line-height:0.2em;  }
.upper { text-transform:uppercase; }
.byline { color:red; font-style:italic; font-weight:bold; padding-left:3em; }

Example 9: Using CSS letter-spacing to space text

The CSS letter-spacing property is used to display the letters farther apart in the heading.

The XHTML component:

<h1 class="overlap"><span class="upper">News</span><br />
<span class="byline">today</span></h1>

The CSS component:

.overlap { line-height:0.2em;  }
.upper { text-transform:uppercase; }
.byline { color:red; font-style:italic; font-weight:bold; padding-left:3em; letter-spacing:-0.1em; }

The CSS letter-spacing property is used to display the letters closer together in the second line of text.

The XHTML component:

<h1 class="upper2">News</h1>

The CSS component:

.upper2 { text-transform:uppercase; letter-spacing:1em; }

Example 10: Using CSS background-image to layer text and images

The CSS font-style property is used to display the textual component of a banner and background-image property is used to display a picture behind the text.

The XHTML component:

<div id="banner"><span id="bannerstyle1">Welcome</span> 
<span id="bannerstyle2">to your local city council</span></div>

The CSS component:

#banner { 
  color:white; 
  background-image:url(banner-bg.gif); 
  background-repeat:no-repeat; 
  background-color:#003399; 
  width:29em; 
}

#bannerstyle1 { 
  text-transform:uppercase; 
  font-weight:bold; 
  font-size:2.5em;
}

#bannerstyle2 { 
  font-style:italic; 
  font-weight:bold; 
  letter-spacing:-0.1em;
  font-size:1.5em; 
}

Example 11: Using CSS first-line to control the presentation of the first line of text

The CSS ::first-line pseudo-element is used to display the first line of text in a larger, red font.

The XHTML component:

<p class="startline">Once upon a time...<br />
...in a land far, far away...  </p>

The CSS component:

.startline::first-line { font-size:2em; color:#990000; }

Example 12: Using CSS first-letter to control the presentation of the first letter of text

The CSS ::first-letter pseudo-element is used to display the first letter in a larger font size, red and vertically aligned in the middle.

The XHTML component:

<p class="startletter">Once upon a time...</p>

The CSS component:

.startletter::first-letter { font-size:2em; color:#990000; vertical-align:middle; }

Other sources

No endorsement implied.

Tests

Procedure

  1. Check whether CSS properties were used to control the visual presentation of text

Expected Results

  • Check #1 is true.