button { outline: thick solid }
	

	:focus  { outline: thick solid black }
	:active { outline: thick solid red }
	

Offsetting the Outline: the 'outline-offset' property

Name: outline-offset
Value: <>
Initial: 0
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: absolute length
Animation Type: by computed value

	:focus,:active  { outline-offset: 2px }
	

Negative values must cause the outline to shrink into the border box. Both the height and the width of the outside of the shape drawn by the outline should not become smaller than twice the computed value of the 'outline-width' property to make sure that an outline can be rendered even with large negative values. User agents should apply this constraint independently in each dimension. If the outline is drawn as multiple disconnected shapes, this constraint applies to each shape separately.

Resizing

Resizing Boxes: the 'resize' property

Name: resize
Value: none | both | horizontal | vertical | block | inline
Initial: none
Applies to: elements with 'overflow' other than visible,
 and optionally replaced elements such as images, videos, and iframes
Inherited: no
Percentages: N/A
Computed value: specified keyword
Animation type: discrete

none

The UA does not present a resizing mechanism on the element, and the user is given no direct manipulation mechanism to resize the element.

both

The UA presents a bidirectional resizing mechanism to allow the user to adjust both the height and the width of the element.

horizontal

The UA presents a unidirectional horizontal resizing mechanism to allow the user to adjust only the width of the element.

vertical

The UA presents a unidirectional vertical resizing mechanism to allow the user to adjust only the height of the element.

block

The UA presents a unidirectional [=block-axis=] resizing mechanism to allow the user to adjust only the [=block size=] of the element.

inline

The UA presents a unidirectional [=inline-axis=] resizing mechanism to allow the user to adjust only the [=inline size=] of the element.

• Replaced elements representing images or videos, such as <{img}>, <{video}>, <{picture}>, <{svg}>, <{object}>, or <{canvas}>.
• The <{iframe}> element.

	iframe,object[type^="text/"],
	object[type$="+xml"],object[type="application/xml"]
	{
	  overflow:auto;
	  resize:both;
	}
	

Pointing Devices and Keyboards

Pointer interaction

Styling the Cursor: the 'cursor' property

Name: cursor
Value: [ [<> [<x> <y>]?,]* 

 [ auto | default | none |

 context-menu | help | pointer | progress | wait | 

 cell | crosshair | text | vertical-text | 

 alias | copy | move | no-drop | not-allowed | grab | grabbing | 

 e-resize | n-resize | ne-resize | nw-resize | s-resize | se-resize | sw-resize | w-resize |
 ew-resize | ns-resize | nesw-resize | nwse-resize |
 col-resize | row-resize |
 all-scroll |

 zoom-in | zoom-out 

 ] ]
Initial: auto
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: as specified, except with any relative URLs converted to absolute
Animation type: discrete

image cursors

<>

The user agent retrieves the cursor from the resource designated by the URI. If the user agent cannot handle the first cursor of a list of cursors, it must attempt to handle the second, etc. If the user agent cannot handle any user-defined cursor, it must use the cursor keyword at the end of the list. Conforming user agents may, instead of <>, support <> which is a superset. The UA must support the following image file formats:

• PNG, as defined in [[!PNG]]
• SVG, as defined in [[!SVG11]], in secure static mode [[!SVG2]], if it has a [=natural size=].
• any other non-animated image file format that they support for <> in other properties, such as the 'background-image' property

In addition, the UA should support the following image file formats:

• SVG, as defined in [[!SVG11]], in secure animated mode [[!SVG2]], if it has a [=natural size=].
• any other animated image file format that they support for <> in other properties, such as the 'background-image' property

The UA may also support additional file formats, including SVG, as defined in [[!SVG11]], in secure static mode or secure animated mode [[!SVG2]], even if it does not have a [=natural size=]. Note: The CSS Working Group initially intended support for all SVG, naturally sized or not. Support for non-naturally sized SVG was downgraded from mandatory to optional due to lack of implementations. Note: At the time of writing this specification (spring 2015), the only file formats supported for cursors in common desktop browsers are the .ico and .cur file formats, as designed by Microsoft. For compatibility with legacy content, UAs are encouraged to support these, even though the lack of an open specification makes it impossible to have a normative requirement about these formats. Some information on these formats can be found on Wikipedia. The default object size for cursor images is a UA-defined size that should be based on the size of a typical cursor on the UA's operating system. The concrete object size is determined using the default sizing algorithm. If an operating system is incapable of rendering a cursor above a given size, cursors larger than that size must be shrunk to within the OS-supported size bounds, while maintaining the cursor image's [=natural aspect ratio=], if any. The optional <x> and <y> coordinates identify the exact position within the image which is the pointer position (i.e., the hotspot).

<x>

<y>

Each is a <>. The x-coordinate and y-coordinate of the position in the cursor's coordinate system (left/top relative) which represents the precise position that is being pointed to. Note: This specification does not define how the coordinate systems of the various types of <> are established, and defers these definitions to [[CSS4-IMAGES]]. If the values are unspecified, then the natural hotspot defined inside the image resource itself is used. If both the values are unspecific and the referenced cursor has no defined hotspot, the effect is as if a value of "0 0" was specified. If the coordinates of the hotspot, as specified either inside the image resource or by <x> and <y> values, fall outside of the cursor image, they must be clamped (independently) to fit.

general purpose cursors

auto

The UA determines the cursor to display based on the current context. Specifically, ''cursor/auto'' behaves as ''cursor/text'' over selectable text or editable elements, and ''cursor/default'' otherwise. Note: When over selectable text or editable elements, as it does with ''cursor/text'', the UA must use a vertical or horizontal text cursor, as appropriate for the [=writing mode=] of the element, and may take transforms and other visual effects into account as well.

default

The platform-dependent default cursor. Often rendered as an arrow.

none

No cursor is rendered for the element.

links and status cursors

context-menu

A context menu is available for the object under the cursor. Often rendered as an arrow with a small menu-like graphic next to it.

help

Help is available for the object under the cursor. Often rendered as a question mark or a balloon.

pointer

The cursor is a pointer that indicates a link. Often rendered as the backside of a hand with the index finger extended. Unless otherwise specified, UAs must apply ''cursor: pointer'' to hyperlinks for all supported document formats via the UA stylesheet, using a normal (i.e. not ''!important'') declaration. Authors should use pointer on links and may use on other interactive elements.

progress

A progress indicator. The program is performing some processing, but is different from ''wait'' in that the user may still interact with the program. Often rendered as a spinning beach ball, or an arrow with a watch or hourglass.

wait

Indicates that the program is busy and the user should wait. Often rendered as a watch or hourglass.

selection cursors

cell

Indicates that a cell or set of cells may be selected. Often rendered as a thick plus-sign with a dot in the middle.

crosshair

A simple crosshair (e.g., short line segments resembling a "+" sign). Often used to indicate a two dimensional bitmap selection mode.

text

Indicates text that may be selected. Often rendered as an I-beam. User agents must automatically display a vertical I-beam/cursor over elements with a horizontal [=writing mode=], and a horizontal I-beam/cursor (e.g. same as the ''vertical-text'' keyword) over elements in a vertical [=writing mode=]. Additionally, user agents may take transforms (see [[CSS-TRANSFORMS-1]]) or other visual effects such as text on a path (See [[SVG2/text#TextLayoutPath]]), when choosing between the horizontal or vertical text cursor, and may display any angle of I-beam/cursor for text that is rendered at any particular angle.

vertical-text

Indicates vertical-text that may be selected. Often rendered as a horizontal I-beam.

drag and drop cursors

alias

Indicates an alias of/shortcut to something is to be created. Often rendered as an arrow with a small curved arrow next to it.

copy

Indicates something is to be copied. Often rendered as an arrow with a small plus sign next to it.

move

Indicates something is to be moved.

no-drop

Indicates that the dragged item cannot be dropped at the current cursor location. Often rendered as a hand or pointer with a small circle with a line through it.

not-allowed

Indicates that the requested action will not be carried out. Often rendered as a circle with a line through it.

grab

Indicates that something can be grabbed (dragged to be moved). Often rendered as the backside of an open hand.

grabbing

Indicates that something is being grabbed (dragged to be moved). Often rendered as the backside of a hand with fingers closed mostly out of view.

resizing and scrolling cursors

e-resize, n-resize, ne-resize, nw-resize, s-resize, se-resize, sw-resize, w-resize

Indicates that some edge is to be moved. For example, the ''se-resize'' cursor is used when the movement starts from the south-east corner of the box.

ew-resize, ns-resize, nesw-resize, nwse-resize

Indicates a bidirectional resize cursor.

col-resize

Indicates that the item/column can be resized horizontally. Often rendered as arrows pointing left and right with a vertical bar separating them.

row-resize

Indicates that the item/row can be resized vertically. Often rendered as arrows pointing up and down with a horizontal bar separating them.

all-scroll

Indicates that the something can be scrolled in any direction. Often rendered as arrows pointing up, down, left, and right with a dot in the middle.

zooming cursors

zoom-in, zoom-out

Indicates that something can be zoomed (magnified) in or out, and often rendered as a magnifying glass with a "+" or "-" in the center of the glass, for ''zoom-in'' and ''zoom-out'' respectively.

	:link,:visited {
	    cursor: url(example.svg#linkcursor),
		    url(hyper.cur),
		    url(hyper.png) 2 3,
		    pointer
	}
	

Cursor of the canvas

Insertion caret

Coloring the Insertion Caret: the 'caret-color' property

Name: caret-color
Value: auto | <>
Initial: auto
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: The computed value for ''caret-color/auto'' is ''caret-color/auto''.
 For <> values, see [[!CSS-COLOR-4#resolving-color-values]] in [[!CSS-COLOR-4]].
Animation Type: by computed value

auto

User agents should use ''currentColor''. User agents may automatically adjust the color of caret to ensure good visibility and contrast with the surrounding content, possibly based on the currentColor, background, shadows, etc. Note: When 'caret-shape' is ''caret-shape/block'', ensuring good visibility and contrast is best achieved with a UA determined color other than ''currentColor''.

<>

The insertion caret is colored with the specified color.

Shape of the insertion caret: 'caret-shape'

Name: caret-shape
Value: auto | bar | block | underscore
Initial: auto
Applies to: elements that accept input
Inherited: yes
Percentages: N/A
Computed value: specified keyword
Animation type: by computed value

auto

The UA determines the shape of the caret. It should match platform conventions, and may be adjusted based on context. For example, if a UA switches between insert mode and overtype mode when the user presses the insert key on their keyboard, it may show a ''caret-shape/bar'' caret in insert mode, and a ''caret-shape/block'' caret in overtype mode.

bar

The UA must render the text insertion caret as a thin bar placed at the insertion point. This means it is between, before, or after characters, not over them. It should be perpendicular to the inline progression direction, although UAs may render it slanted when inserting italic or oblique text.

block

The UA must render the text insertion caret as a rectangle overlapping the next visible character following the insertion point. If there is no visible character after the insertion point, the UA must render the caret after the last visible character. UAs may render it as a slanted rectangle when inserting italic or oblique text.

underscore

The UA must render the text insertion caret as a thin line under (as defined in [[!CSS-WRITING-MODES-3]] the next visible character following the insertion point. If there is no visible character after the insertion point, the UA must render the caret after the last visible character.

• The caret must not be obscured by the background of the element.
• UAs must render ''caret-shape/block'' carets so that the character it overlaps with is not obscured by the caret.

	.console {
		caret-shape: underscore;
		background: black;
		color: white;
		font-family: monospace;
		padding: 1ex;
	}
	

	user@host:css-ui-4 $ ls -a
	. .. Overview.bs Overview.html
	user@host:css-ui-4 $  
	

	user@host:css-ui-4 $ ls -a
	. .. Overview.bs Overview.html
	user@host:css-ui-4 $
	

Insertion caret shorthand: 'caret'

Name: caret
Value: <<'caret-color'>> || <<'caret-shape'>>
Initial: auto
Applies to: elements that accept input
Inherited: yes
Percentages: N/A

Keyboard control

Directional Focus Navigation: the 'nav-up', 'nav-right', 'nav-down', 'nav-left' properties

Name: nav-up , nav-right , nav-down , nav-left
Value: auto | <> [ current | root | <> ]?
Initial: auto
Applies to: all enabled elements
Inherited: no
Percentages: N/A
Computed value: as specified
Animation type: discrete

auto

The user agent automatically determines which element to navigate the focus to in response to directional navigational input.

<>

The <> value is an ID selector [[SELECT]]. In response to directional navigation input corresponding to the property, the focus is navigated to the first element in tree order matching the selector. If this refers to the currently focused element, the directional navigation input respective to the nav- property is ignored — there is no need to refocus the same element. If no element matches the selector, the user agent automatically determines which element to navigate the focus to. If the focus is navigated to an element that was not otherwise focusable, it becomes focusable only as the result of this directional navigation, and the '':focus'' pseudo-class matches the element while it is focused as such. Note: there were other options under consideration for such "not otherwise focusable" elements, including focus to the next otherwise focusable element in the document tree (including descendants of such a not otherwise focusable element). Input on such other options is welcome and explicitly solicited, especially from implementation experiences and author experience using the directional navigation properties in their content.

<>

The <target-name> parameter indicates the target frame for the focus navigation. It is a <> and it MUST NOT start with the underscore "_" character. Error handling: if it does start with an underscore, "_parent" navigates to the parent frame, "_root" is treated as ''root'', and other values navigate to a frame by that name if it exists. If the specified target frame does not exist, the parameter will be treated as the keyword ''current'', which means to simply use the frame that the element is in. The keyword ''root'' indicates that the user agent should target the full window.

	button { position:absolute }

	button#b1 {
		top:0; left:50%;
		nav-right:#b2; nav-left:#b4;
		nav-down:#b2; nav-up:#b4;
	}

	button#b2 {
		top:50%; left:100%;
		nav-right:#b3; nav-left:#b1;
		nav-down:#b3; nav-up:#b1;
	}

	button#b3 {
		top:100%; left:50%;
		nav-right:#b4; nav-left:#b2;
		nav-down:#b4; nav-up:#b2;
	}

	button#b4 {
		top:50%; left:0;
		nav-right:#b1; nav-left:#b3;
		nav-down:#b1; nav-up:#b3;
	}
	

	button#foo { nav-left: #bar "sidebar"; }
	

Obsolete: the ime-mode property

input[type=password] {
		ime-mode: auto !important;
	}
	

User Interaction

Controlling content selection

	Name: user-select
	Value: auto | text | none | contain | all
	Initial: auto
	Inherited: no
	Applies to: all elements, and optionally to the ''::before'' and ''::after'' pseudo-elements
	Computed value: specified keyword
	Animation type: discrete

1. on editable elements where the [=used value=] is always ''user-select/contain'' regardless of the [=computed value=]
2. when the [=computed value=] is ''user-select/auto'', in which case the [=used value=] one of the other values as defined below

auto

The [=used value=] of ''user-select/auto'' is determined as follows:

• On the ''::before'' and ''::after'' pseudo-elements, the used value is ''user-select/none''
• If the element is an editable element, the [=used value=] is ''user-select/contain''
• Otherwise, if the [=used value=] of 'user-select' on the parent of this element is ''all'', the [=used value=] is ''all''
• Otherwise, if the [=used value=] of 'user-select' on the parent of this element is ''user-select/none'', the [=used value=] is ''user-select/none''
• Otherwise, the [=used value=] is ''user-select/text''

Note: This unusual combination of a non-inherited property with an initial value of ''user-select/auto'' whose used value depends on the parent element makes it possible to create what is effectively selective inheritance. This was initially proposed by Microsoft in IE to introduce a behavior similar to inheritance except that the ''user-select/contain'' value does not inherit.

text

The element imposes no constraint on the selection.

none

The UA must not allow selections to be started in this element. A selection started outside of this element must not end in this element. If the user attempts to create such a selection, the UA must instead end the selection range at the element boundary. Note: As of the time of writing, experimental implementations do not all behave like this. Firefox does. Chrome and Safari almost do: for a selection started after the element and trying to go backwards into the element they behave as specified here, but for a selection started before the element and trying to go into the element they behave as if the element has ''all'' and select it entirely. IE does not restrict selections started outside of the element from going into it at all. Another difference is that in Chrome and Safari, if the user attempts to start a selection inside a ''user-select: none'', and to end the selection out of it, a selection will be created from the boundary of the element to the user-designated end-point. Firefox and Internet explorer behave as prescribed in this specification and do not create a selection at all. However, if this element has descendants on which the [=used value=] of 'user-select' is not ''user-select/none'', selections that start and end within these descendants are allowed. The UA must allow selections to extend across this element, and must exclude this element from such a selection. An exception is made for UAs which do not support multiple ranges per selection, and they may include this element. If the element has descendants on which the [=used value=] of 'user-select' is not ''user-select/none'', these descendants must be included in a selection extending across the element. This specification makes no normative requirement about the behavior of the clipboard. however, UAs are encouraged to keep the visual selection consistent with what would get copied to the clipboard when copying. Copying text that does not appear to be selected, or vice versa, is highly confusing to users. Attempting to start a selection in an element where 'user-select' is ''user-select/none'', such as by clicking in it or starting a drag in it, must not cause a pre-existing selection to become unselected or to be affected in any way. As 'user-select' is a UI convenience mechanism, not a copy protection mechanism, the UA may provide an alternative way for the user to explicitly select the text even when 'user-select' is ''user-select/none''. Note: ''user-select/none'' is not a copy protection mechanism, and using it as such is ineffective: user agents are allowed to provide ways to bypass it, it will have no effect on legacy user agents that do not support it, and the user can disable it through the user style sheet or equivalent mechanisms on UAs that do anyway. Instead, ''user-select/none'' is meant to make it easier for the user to select the content they want, by letting the author disable selection on UI elements that are not useful to select. Tools such as CSS validators, linters or in-browser developer tools are encouraged to use heuristics to detect and warn against incorrect or abusive usage that would hamper usability or violate common user expectations.

Authors should be careful about not constraining the user unnecessarily. For example, setting ''user-select: none'' on the root element, and relaxing that restriction on a handful of elements the author judges useful to select can be frustrating to users: * Clicking in empty areas to undo the current selection will no longer be effective * The author may have overlooked some areas which should be selectable * Areas may be added later to the page without remembering to make them selectable * The user may want to select pieces of text other than the main content, for instance to look them up in a dictionary or in some translation tool, or to look for warnings and error messages in a search engine… Instead, a good practice is for authors is to selectively apply ''user-select: none'' to elements which seem likely to be accidentally selected when doing so would interfere with the more likely intended action. Accidentally leaving parts of the page that are unlikely to be interacted with selectable will likely cause much less frustration to users than the opposite.

contain

UAs must not allow a selection which is started in this element to be extended outside of this element. A selection started outside of this element must not end in this element. If the user attempts to create such a selection, the UA must instead end the selection range at the element boundary. The UA must allow selections to extend across this element, and such selections must include the content of the element. Note: At the time of writing, experimental implementations behave differently from each other about selections started outside and selections going into the element. The behavior can be observed even on browsers that do not explicitly support ''user-select/contain'' by trying to select into a <{textarea}> or a contenteditable element. Note: This was initially introduced as an experimental feature in Internet Explorer, under the name user-select: element.

all

The content of the element must be selected atomically: If a selection would contain part of the element, then the selection must contain the entire element including all its descendants. If the element is selected and the [=used value=] of 'user-select' on its parent is ''all'', then the parent must be included in the selection, recursively. If this element has descendants on which the [=used value=] of 'user-select' is not ''all'' and if a selection is entirely contained in these descendants, then the selection is not extended to include this whole element.

button, meter, progress, select { user-select: none; }

Exclusion from Hit-testing: the 'pointer-events' property

Name: pointer-events
Value: auto | none
Initial: ''pointer-events/auto''
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: specified keyword
Canonical order: per grammar
Animation type: by computed value type

auto

[=Hit-testing=] occurs normally.

none

[=Hit-testing=] acts as if the boxes generated by the element (see [[CSS-DISPLAY-3]]) were not there, effectively causing the element behind the ''pointer-events: none'' element to become the target of [=hit-testing=] based events instead. Issue: The statement above needs to be be qualified; for some purposes, hit-testing continues to take the element into account. For instance, clicking and dragging to start a text selection will continue to work as usual. What is the precise set of things for which hit-testing is affected by 'pointer-events'?

Styling Widgets

Widget Accent Colors: the 'accent-color' property

Name: accent-color
Value: auto | <>
Initial: ''accent-color/auto''
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: the keyword ''accent-color/auto'' or a computed color
Canonical order: per grammar
Animation type: by computed value type

auto

Represents a UA-chosen color, which should match the [=accent color=] of the platform, if any.

<>

Specifies the color to be used as the [=accent color=].

A radio button is typically composed of a circle, potentially overlaid by a “dot” representing the checked state. Certain visual styles use an [=accent color=] for the checked state: some of these use it for the background of the circle, others for its foreground. In both cases, the 'accent-color' property styles the affected parts of the control. For visual styles that do not use an [=accent color=] for radio buttons, 'accent-color' will have no effect. The following are all examples of radio buttons conformantly rendered with a blue 'accent-color':

Platform	Sample	Notes
Firefox 79 / Win		No use of [=accent color=].
Chrome 81 / Win		No use of [=accent color=].
Safari / Snow Leopard		Accent color used to generate checked-state “background” gradient.
Safari 13 / Mac / Light		Accent color as checked-state “foreground”.
Safari 13 / Mac / Dark		Accent color as checked-state “foreground”.
Chrome 83 / Win / Light		Accent color as checked-state “foreground”.
Chrome 83 / Win / Dark		Accent color as checked-state “foreground”, contrast-adjusted for dark mode backgrounds.

Switching appearance: the 'appearance' property

Name: appearance
Value: ''appearance/none'' | ''auto'' | ''textfield'' | ''menulist-button'' | <>
Initial: none
Applies To: all elements
Inherited: no
Computed value: specified keyword
Animation type: discrete

	input { appearance: none; }
	input[type=checkbox] { appearance: checkbox; }
	

none

The element is rendered following the usual rules of CSS. Replaced elements other than widgets are not affected by this and remain replaced elements. Widgets must not have their native appearance. See [[#appearance-decorative]] and [[#appearance-semantics]] for details.

auto

Widgets may have their native appearance. Elements other than widgets must be rendered as if ''appearance/none'' had been specified.

textfield

For <{input}> elements where the <{input/type}> attribute is in the Search state, the element is rendered as a "normal" text entry widget, similar to an <{input}> element where the <{input/type}> attribute is in the Text state. For all other elements, this value has the same effect as ''appearance/auto''.

menulist-button

For drop-down box <{select}> elements, the element is rendered as a drop-down box, including a "drop-down button", but not necessarily using a native control of the host operating system. For such elements, CSS properties such as 'color', 'background-color', and 'border' (that can be disregarded for ''appearance/auto'') should not be disregarded. For all other elements, this value has the same effect as ''appearance/auto''.

<compat-auto>

These values exist for compatibility of content developed for earlier non-standard versions of this property. They all have the same effect as ''appearance/auto''.

<> =  searchfield | textarea | push-button | slider-horizontal | checkbox | radio | square-button | menulist | listbox | meter | progress-bar | button 

Issue: When ''appearance/auto'' is widely supported, recommend using it instead. Issue: If any of these values are not needed for web compat, they should be dropped from this list; conversely, any value needed for compat not included in this list should be added. Issue: It is possible that for compat reasons some of these values need to be promoted to being full blown values with effects on arbitrary elements, or that some of these values need to have some side effects on some widgets.

	input[type=checkbox] {
		all: unset; /* this shorthand includes resetting appearance to none */
		width: 1em;
		height: 1em;
		display: inline-block;
		background: red;
	}
	input[type=checkbox]:checked {
		border-radius: 50%;
		background: green;
	}
	input[type=checkbox]:focus-visible {
		outline: auto;
	}
	

Name: input-security
Value: auto | none
Initial: ''input-security/auto''
Applies to: [=sensitive text inputs=]
Inherited: no
Percentages: N/A
Computed Value: as specified
Canonical order: per grammar
Animation type: by computed value type

	input[type=password] {
		input-security: auto;
	}

	<input type=password value=MySecret794>