Technique C22:Using CSS to control visual presentation of text
About this Technique
This technique relates to:
- 1.3.1: Info and Relationships (Advisory)
- 1.4.4: Resize Text (Advisory)
- 1.4.5: Images of Text (Sufficient)
- 1.4.9: Images of Text (No Exception) (Sufficient)
This technique applies to all technologies that support CSS.
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 HTML 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 HTML 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 HTML 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
Note
The style used in this example is not used to convey information, structure or relationships.
The HTML 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
Note
The style used in this example is not used to convey information, structure or relationships.
The HTML component
<p>The article is available in the
<a href="https://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
Note
The style used in this example is not used to convey information, structure or relationships.
The HTML 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
Note
The style used in this example is not used to convey information, structure or relationships.
The HTML 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 HTML component
<p>Concern for man and his fate must always form the chief interest of all technical
endeavors. Never forget this in the midst of your diagrams and equations.</p>
The CSS component
p { line-height:2; }
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 HTML component
<h1 class="overlap"><span class="upper">News</span>
<span class="byline">today</span>
</h1>
The CSS component
.overlap { line-height:0.2;}
.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 HTML 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 HTML 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 HTML 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 HTML 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 HTML component
<p class="startletter">Once upon a time...</p>
The CSS component
.startletter::first-letter { font-size:2em; color:#990000; vertical-align:middle; }
Related Resources
No endorsement implied.
Tests
Procedure
- Check whether CSS properties were used to control the visual presentation of text
Expected Results
- Check #1 is true.