CSS: The Definitive Guide, 3rd Edition (75 page)
Read CSS: The Definitive Guide, 3rd Edition Online
Authors: Eric A. Meyer
Tags: #COMPUTERS / Web / Page Design
This property affects the height of peaks in the intonation of a speaking voice.
These peaks are in turn generated by stress marks within a language.
- Values:
| inherit- Initial value:
50- Applies to:
All elements
- Inherited:
Yes
- Computed value:
As specified
This property
is used to define a list of voice families that can be used in the audio rendering of
an element's content, and is comparable tofont-family. The permitted generic voices aremale,female, andchild.
- Values:
[[
| ],]*
[| ] | inherit- Initial value:
User agent-dependent
- Applies to:
All elements
- Inherited:
Yes
- Computed value:
As specified
This sets the median volume level for the waveform of the audibly rendered
content. Thus, a waveform with large peaks and valleys may go well above or below the
volume level set with this property. Note that0is not the same assilent.
- Values:
| | silent|x-soft|soft|medium|loud|x-loud|inherit- Initial value:
medium- Applies to:
All elements
- Inherited:
Yes
- Computed value:
An absolute number
This selector matches any element name in the document's language. If a rule does
not have an explicit selector, then the universal selector
is inferred.
Pattern:*
Examples:
* {color: red;}
div * p {color: blue;}
This selector matches the name of an element in the document's language. Every
instance of the element name is matched. (CSS1 referred to these as
element
selectors
.)
Pattern:element1
Examples:
body {background: #FFF;}
p {font-size: 1em;}
This allows the author to select an element based on its status as a descendant of
another element. The matched element can be a child, grandchild, great-grandchild,
etc., of the ancestor element. (CSS1 referred to these as contextual selectors.)
Pattern:element1 element2
Examples:
body h1 {font-size: 200%;}
table tr td div ul li {color: purple;}
This type of selector
is used to match an element based on its status as a child of another element. This
is more restrictive than a descendant element, since only a child will be matched.
Pattern:element1 > element2
Examples:
div > p {color: cyan;}
ul > li {font-weight: bold;}
This allows the author to select an element that is the following adjacent sibling
of another element. Any text between the two elements is ignored; only elements and
their positions in the document tree are considered.
Pattern:element1 + element2
Examples:
table + p {margin-top: 2.5em;}
h1 + * {margin-top: 0;}
In languages that permit it, such as HTML, SVG, and MathML, a class selector using
"dot notation" can be used to select elements that have a class containing a specific
value or values. The name of the class value must immediately follow the dot.
Multiple class values can be "chained" together. If no element name precedes the dot,
the selector matches all elements containing that class value.
Patterns:element1.classname
element1.classname1.classname2
Examples:
p.urgent {color: red;}
a.external {font-style: italic;}
.example {background: olive;}
In languages that permit it,
such as HTML, an ID selector using "hash notation" can be used to select elements
that have an ID containing a specific value or values. The name of the ID value must
immediately follow the octothorpe (#). If no
element name precedes the octothorpe, the selector matches all elements containing
that ID value.
Pattern:element1#idname
Examples:
h1#page-title {font-size: 250%;}
body#home {background: silver;}
#example {background: lime;}
This allows authors to select any element based on the presence of an attribute,
regardless of the attribute's value.
Pattern:element1[attr]
Examples:
a[rel] {border-bottom: 3px double gray;}
p[class] {border: 1px dotted silver;}
This allows authors to select any element based on the precise complete value of
an attribute.
Pattern:element1[attr="value"]
Examples:
a[rel="Home"] {font-weight: bold;}
p[class="urgent"] {color: red;;}
This allows authors to select any element based on a portion of the
space-separated value of an attribute. Note that[class~="value"]is equivalent to.value(see above).
Pattern:element1[attr~="value"]
Examples:
a[rel~="friend"] {text-transform: uppercase;}
p[class~="warning"] {background: yellow;}
This allows authors to select any element based on a substring at the very
beginning of an attribute's value.
Pattern:element1[attr^="substring"]
Examples:
a[href^="/blog"] {text-transform: uppercase;}
p[class^="test-"] {background: yellow;}
This allows authors to
select any element based on a substring at the very end of an attribute's value.
Pattern:element1[attr$="substring"]
Example:
a[href$=".pdf"] {font-style: italic;}
This allows authors to select any element based on a substring found anywhere
within an attribute's value.
Pattern:element1[attr*="substring"]
Examples:
a[href*="oreilly.com"] {font-weight: bold;}
div [class*="port"] {border: 1px solid red;}
This allows authors to select any element with alangattribute whose value is a hyphen-separated list of values, starting
with the value provided in the selector.
Pattern:element1[lang|="lc"]
Examples:
html[lang|="en"] {color: gray;}
This applies to an element during the period in which it is activated. The most
common example of this is clicking on a hyperlink in an HTML document: during the
time that the mouse button is held down, the link is active. There are other ways to
activate elements, and other elements can in theory be activated, although CSS
doesn't define this.
Type: Pseudo-class
Applies to: An element that is being activated
Examples:
a:active {color: red;}
*:active {background: blue;}
This allows the author to insert generated
content at the end of an element's content. By default, the pseudo-element is inline,
but this can be changed using the propertydisplay.
Type: Pseudo-element
Generates: A pseudo-element containing generated content placed after the content
in the element
Examples:
a.external:after {content: " " url(/icons/globe.gif);}
p:after {content: " | ";}
This allows the author to insert generated content at the beginning of an
element's content. By default, the pseudo-element is inline, but this can be changed
using the propertydisplay.
Type: Pseudo-element
Generates: A pseudo-element containing generated content placed before the content
in the element
Examples:
a[href]:before {content: "[LINK] ";}
p:before {content: attr(class);}
With this pseudo-class, an element is matched only when it is the first child of
another element. For example,p:first-childwill
select anypelement that is the first child of
some other element. It does
not
, as is commonly assumed, select
whatever element is the first child of a paragraph; for that, an author would writep > *:first-child.
Type: Pseudo-class
Applies to: Any element that is the first child of another element
Examples:
body *:first-child {font-weight: bold;}
p:first-child {font-size: 125%;}
This is used to style the first letter of an element.
Any leading punctuation should be styled along with the first letter. Some languages
have letter combinations that should be treated as a single character, and a user
agent may apply the first-letter style to both. Prior to CSS2.1,:first-lettercould be attached only to block-level
elements. CSS2.1 expands its scope to include all elements. There is a limited set of
properties that can apply to a first letter.
Type: Pseudo-element
Generates: A pseudo-element that contains the first letter of an element
Examples:
h1:first-letter {font-size: 166%;}
a:first-letter {text-decoration: underline;}
This is used to style the first line of text in an element, no matter how many or
how few words may appear in that line.:first-linecan be attached only to block-level elements. There is a limited set of properties
that can apply to a first line.
Type: Pseudo-element
Generates: A pseudo-element that contains the first formatted line of an element
Examples:
p.lead:first-line {font-weight: bold;}
This applies to an element during the period in which it has focus. One example
from HTML is an input box that has the text-input cursor within it; that is, when the
user starts typing, text will be entered into that box. Other elements, such as
hyperlinks, can also have focus, although CSS does not define which ones.
Type: Pseudo-class
Applies to: An element that has focus
Examples:
a:focus {outline: 1px dotted red;}
input:focus {background: yellow;}
This applies to an element during the period in which it
is "hovered." Hovering is defined as the user designating an element without
activating it. The most common example of this is moving the mouse pointer inside the
boundaries of a hyperlink in an HTML document. Other elements can in theory be
hovered, although CSS doesn't define which ones.
Type: Pseudo-class
Applies to: An element in a hovered state
Examples:
a[href]:hover {text-decoration: underline;}
p:hover {background: yellow;}
This matches elements based on their human language encoding. Such language
information must be contained within or otherwise associated with the document; it
cannot be assigned from CSS. The handling of:langis the same as for|=attribute selectors.
Type: Pseudo-class
Applies to: Any element with associated language-encoding information
Examples:
html:lang(en) {background: silver;}
*:lang(fr) {quotes: '« ' ' »';}
This applies to a link to a URI that has not been visited; that is, the URI to
which the link points does not appear in the user agent's history. This state is
mutually exclusive with the:visitedstate.
Type: Pseudo-class
Applies to: A link to another resource that has not been visited
Examples:
a:link {color: blue;}
*:link {text-decoration: underline;}
This applies to a link to a URI that
has been visited; that is, the URI to which the link points appears in the user
agent's history. This state is mutually exclusive with the:linkstate.
Type: Pseudo-class
Applies to: A link to another resource that has already been visited
Examples:
a:visited {color: purple;}
*:visited {color: gray;}