Contents
The properties defined in the following sections affect the visual presentation of characters, spaces, words, and paragraphs.
Value: | <length> | <percentage> | inherit |
Initial: | 0 |
Applies to: | block-level elements, table cells and inline blocks |
Inherited: | yes |
Percentages: | refer to width of containing block |
Media: | visual |
Computed value: | the percentage as specified or the absolute length |
This property specifies the indentation of the first line of text in a block. More precisely, it specifies the indentation of the first box that flows into the block's first line box. The box is indented with respect to the left (or right, for right-to-left layout) edge of the line box. User agents should render this indentation as blank space.
Values have the following meanings:
The value of 'text-indent' may be negative, but there may be implementation-specific limits. If the value of 'text-indent' is either negative or exceeds the width of the block, that first box, described above, may overflow the block. The value of 'overflow' will affect whether such text that overflows the block is visible.
The following example causes a '3em' text indent.
p { text-indent: 3em }
Note: Since the 'text-indent' property inherits, when specified on
a block element, it will affect descendent inline-block elements.
For this reason, it is often wise to specify 'text-indent: 0
'
on elements that are specified 'display:inline-block
'.
Value: | left | right | center | justify | inherit |
Initial: | 'left' if 'direction' is 'ltr'; 'right' if 'direction' is 'rtl' |
Applies to: | block-level elements, table cells and inline blocks |
Inherited: | yes |
Percentages: | N/A |
Media: | visual |
Computed value: | as specified |
This property describes how inline content of a block is aligned. Values have the following meanings:
A block of text is a stack of line boxes. In the case of 'left', 'right' and 'center', this property specifies how the inline boxes within each line box align with respect to the line box's left and right sides; alignment is not with respect to the viewport. In the case of 'justify', the UA may stretch the inline boxes in addition to adjusting their positions. (See also 'letter-spacing' and 'word-spacing'.)
If the computed value of text-align is 'justify' while the computed value of white-space is 'pre' or 'pre-line', the actual value of text-align is set to the initial value.
In this example, note that since 'text-align' is inherited, all block-level elements inside DIV elements with a class name of 'important' will have their inline content centered.
div.important { text-align: center }
Note. The actual justification algorithm used depends on the user-agent and the language/script of the text.
Conforming user agents may interpret the value 'justify' as 'left' or 'right', depending on whether the element's default writing direction is left-to-right or right-to-left, respectively.
Value: | none | [ underline || overline || line-through || blink ] | inherit |
Initial: | none |
Applies to: | all elements |
Inherited: | no (see prose) |
Percentages: | N/A |
Media: | visual |
Computed value: | as specified |
This property describes decorations that are added to the text of an element using the element's color. When specified on an inline element, it affects all the boxes generated by that element; for all other elements, the decorations are propagated to an anonymous inline box that wraps all the in-flow inline children of the element, and to any block-level in-flow descendants. It is not, however, further propagated to floating and absolutely positioned descendants, nor to the contents of 'inline-table' and 'inline-block' descendants.
If an element contains no text (ignoring white space in elements
that have 'white-space' set to 'normal', 'pre-line', or 'no-wrap'),'nowrap'),
user agents must refrain from rendering text decorations on the
element. For example, elements containing only images and collapsed
white space will not be underlined.
Text decorations on inline boxes are drawn across the entire element, going across any descendant elements without paying any attention to their presence. The 'text-decoration' property on descendant elements cannot have any effect on the decoration of the element. In determining the position of and thickness of text decoration lines, user agents may consider the font sizes of and dominant baselines of descendants, but must use the same baseline and thickness on each line.
Values have the following meanings:
The color(s) required for the text decoration must be derived from the 'color' property value of the element on which 'text-decoration' is set. The color of decorations should remain the same even if descendant elements have different 'color' values.
Some user agents have implemented text-decoration by
propagating the decoration to the descendant elements as opposed to
simply drawing the decoration through the elements as described
above. This was arguably allowed by the looser wording in CSS2. SVG1,
CSS1-only, and CSS2-only user agents may implement the older model
and still claim conformance to this part of CSS2.1.CSS 2.1. (This does not
apply to UAs developed after this specification was released.)
In the following example for HTML, the text content of all A elements acting as hyperlinks (whether visited or not) will be underlined:
a:visited,a:link { text-decoration: underline }
In the following stylesheetstyle sheet and document fragment:
blockquote { text-decoration: underline; color: blue; }
em { display: block; }
cite { color: fuchsia; }
<blockquote>
<p>
<span>
Help, help!
<em> I am under a hat! </em>
<cite> —GwieF </cite>
</span>
</p>
</blockquote>
...the underlining for the blockquote element is propagated to an
anonymous inline element that surrounds the span element, causing
the text "Help, help!" to be blue, with the blue underlining from
the anonymous inline underneath it, the color being taken from the
blockquote element. The <em>text</em>
in the em block is also underlined,
as it is in an in-flow block to which the underline is propagated. The final line of text is fuchsia, but the underline
underneath it is still the blue underline from the anonymous inline
element.
This diagram shows the boxes involved in the example above. The rounded aqua line represents the anonymous inline element wrapping the inline contents of the paragraph element, the rounded blue line represents the span element, and the orange lines represent the blocks.
Value: | normal | <length> | inherit |
Initial: | normal |
Applies to: | all elements |
Inherited: | yes |
Percentages: | N/A |
Media: | visual |
Computed value: | 'normal' or absolute length |
This property specifies spacing behavior between text characters. Values have the following meanings:
Character spacing algorithms are user agent-dependent.
In this example, the space between characters in BLOCKQUOTE elements is increased by '0.1em'.
blockquote { letter-spacing: 0.1em }
In the following example, the user agent is not permitted to alter inter-character space:
blockquote { letter-spacing: 0cm } /* Same as '0' */
When the resultant space between two characters is not the same as the default space, user agents should not use ligatures.
Value: | normal | <length> | inherit |
Initial: | normal |
Applies to: | all elements |
Inherited: | yes |
Percentages: | N/A |
Media: | visual |
Computed value: | for 'normal' the value '0'; otherwise the absolute length |
This property specifies spacing behavior between words. Values have the following meanings:
Word spacing algorithms are user agent-dependent. Word spacing is
also influenced by justification (see the 'text-align' property).
When whiteWord spacing affects each space is preserved, e.g. with 'white-space:pre', all(U+0020), non-breaking space characters are affected by word-spacing.(U+00A0),
and ideographic space (U+3000) left in the text after the white space
processing rules have been applied.
In this example, the word-spacing between each word in H1 elements is increased by '1em'.
h1 { word-spacing: 1em }
Value: | capitalize | uppercase | lowercase | none | inherit |
Initial: | none |
Applies to: | all elements |
Inherited: | yes |
Percentages: | N/A |
Media: | visual |
Computed value: | as specified |
This property controls capitalization effects of an element's text. Values have the following meanings:
The actual transformation in each case is written language dependent. See RFC 3066 ([RFC3066]) for ways to find the language of an element.
Conforming user agents may consider the value of 'text-transform' to be 'none' for writing scripts for which there is no transform.
In this example, all text in an H1 element is transformed to uppercase text.
h1 { text-transform: uppercase }
Value: | normal | pre | nowrap | pre-wrap | pre-line | inherit |
Initial: | normal |
Applies to: | all elements |
Inherited: | yes |
Percentages: | N/A |
Media: | visual |
Computed value: | as specified |
This property declares how whitespace inside the element is handled. Values have the following meanings:
The following examples show what whitespace behavior is expected from the PRE and P elements, the "nowrap" attribute in HTML, and in generated content.
pre { white-space: pre }
p { white-space: normal }
td[nowrap] { white-space: nowrap }
:before,:after { white-space: pre-line }
In addition, the effect of an HTML PRE element with the non-standard "wrap" attribute is demonstrated by the following example:
pre[wrap] { white-space: pre-wrap }
Any text that is directly contained inside a block (not inside an inline) should be treated as an anonymous inline element.
For each inline (including anonymous inlines), the following steps are performed, treating bidi formatting characters as if they were not there:
Then, the entire block is rendered. Inlines are laid out, taking bidi reordering into account, and wrapping as specified by the 'white-space' property.
As each line is laid out,
Note. CSS 2.1 does not fully define where line breaking opportunities occur.
Given the following markup fragment, taking special note of spaces (with varied backgrounds and borders for emphasis and identification):
<ltr>A <rtl> B </rtl> C</ltr>
...where the <ltr>
element represents a left-to-right embedding and
the <rtl>
element represents a right-to-left embedding, and
assuming that the 'white-space' property is set to 'normal', the
above processing model would result in the following:
This would leave two spaces, one after the A in the left-to-right embedding level, and one after the B in the right-to-left embedding level. This is then rendered according to the Unicode bidirectional algorithm, with the end result being:
A BC
Note that there are two spaces between A and B, and none between B and C. This can sometimes be avoided by using the natural bidirectionality of characters instead of explicit embedding levels. Also, it is good to avoid spaces immediately inside start and end tags, as these tend to do weird things when dealing with white space collapsing.
Control characters other than U+0009 (tab), U+000A (line feed), U+0020 (space), and U+202x (bidi formatting characters) are treated as characters to render in the same way as any normal character.
Combining characters should be treated as part of the character
with which they are supposed to combine. For example, :first-letter
styles the entire glyph if you have content like
"o<span>̈</span>
"; it doesn't just
match the base character.