DRAFT CSS Working Group Charter

The mission of the Cascading Style Sheets (CSS) Working Group is to is to develop and maintain CSS.

Join the CSS Working Group.

This proposed charter is available on GitHub. Feel free to raise issues.

Start date [dd monthname yyyy] (date of the "Call for Participation", when the charter is approved)
End date 14 Sept 2022
Charter extension See Change History.
Chairs Alan Stearns (Adobe), Rossen Atanassov (Microsoft)
Team Contacts Chris Lilley (0.44 FTE);
Fuqiao Xue (0.35 FTE)
Meeting Schedule Teleconferences: 1-hour calls will be held weekly.
Face-to-face: we will meet during the W3C's annual Technical Plenary week; additional face-to-face meetings may be scheduled by consent of the participants, usually no more than 3 per year.

Scope

Cascading Style Sheets (CSS) is a style sheet language that allows authors and users to attach style (e.g., from fonts and spacing to filter effects and style animations) to structured documents and Web applications. By separating the presentation style from the content, CSS simplifies Web authoring and site maintenance. It supports media-specific style so that authors may tailor the presentation to different devices and capabilities.

The CSS WG develops a single deliverable, the CSS specification. It consists of the following, somewhat independent technologies, all of which are in scope for the CSS Working Group:

The CSS WG not only develops CSS, but also checks that properties needed by other working groups and which could occur in a style sheet together with CSS properties, are compatible with CSS in general and consistent in their naming schemes. This affects properties such as those of SVG and Device Independence (such as media features).

Part of the work of the working group is also to develop test suites for the various specifications it publishes.

Another part is to maintain errata and, when needed, publish revised versions of the various specifications.

Deliverables

There is a single deliverable, the CSS specification. The CSS specification is large, and is divided into a series of modules.

More detailed milestones and updated publication schedules are available on the group publication status page.

Draft state indicates the state of the deliverable at the time of the charter approval. Expected completion indicates when the deliverable is projected to become a Recommendation within this charter period. Deliverables without expected completion dates are not projected to become Recommendation within this charter period.

This list of modules is not exclusive: The WG may also create new CSS modules, within its scope. Also, it may split or merge CSS modules. If no participant in the group believes a proposed module is out of scope, and the group has consensus to add it, the group may add a new module. If the participants who object sustain their objection after discussion, a re-charter to clarify the scope may be needed.

Normative Specifications

The Working Group will deliver the following W3C normative specifications:

Candidate Recommendation and above

CSS Backgrounds and Borders Module Level 3

This draft contains the features of CSS relating to borders and backgrounds.

Draft state: Candidate Recommendation

Expected completion: Q2 2021

Adopted Candidate Recommendation: CSS Backgrounds and Borders Module Level 3, W3C Candidate Recommendation, 17 October 2017

Reference Candidate Recommendation: CSS Backgrounds and Borders Module Level 3, W3C Candidate Recommendation, 17 October 2017

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Cascading and Inheritance Level 3

This CSS module describes how to collate style rules and assign values to all properties on all elements. By way of cascading and inheritance, values are propagated for all properties on all elements.

Draft state: Candidate Recommendation

Expected completion: Q3 2020

Adopted Candidate Recommendation: CSS Cascading and Inheritance Level 3, W3C Candidate Recommendation, 28 August 2018

Reference Candidate Recommendation: CSS Cascading and Inheritance Level 3, W3C Candidate Recommendation, 28 August 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Cascading and Inheritance Level 4

This CSS module describes how to collate style rules and assign values to all properties on all elements. By way of cascading and inheritance, values are propagated for all properties on all elements.

Draft state: Candidate Recommendation

Expected completion: Q1 2022

Adopted Candidate Recommendation: CSS Cascading and Inheritance Level 4, W3C Candidate Recommendation, 28 August 2018

Reference Candidate Recommendation: CSS Cascading and Inheritance Level 4, W3C Candidate Recommendation, 28 August 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Conditional Rules Module Level 3

This module contains the features of CSS for conditional processing of parts of style sheets, conditioned on capabilities of the processor or the document the style sheet is being applied to.

Draft state: Candidate Recommendation

Expected completion: Q4 2020

Adopted Candidate Recommendation: CSS Conditional Rules Module Level 3, W3C Candidate Recommendation, 4 April 2013

Reference Draft: CSS Conditional Rules Module Level 3, W3C Working Draft, 13 December 2012

Produced under Working Group Charter: http://www.w3.org/2010/09/CSSWG/charter

CSS Flexible Box Layout Module Level 1

The specification describes a CSS box model optimized for user interface design.

Draft state: Candidate Recommendation

Expected completion: Q2 2020

Adopted Candidate Recommendation: CSS Flexible Box Layout Module Level 1, W3C Candidate Recommendation, 19 November 2018

Reference Candidate Recommendation: CSS Flexible Box Layout Module Level 1, W3C Candidate Recommendation, 8 November 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Image Values and Replaced Content Module Level 3

This module contains features relating to the <image> type and replaced elements.

Draft state: Candidate Recommendation

Expected completion: Q2 2022

Adopted Candidate Recommendation: CSS Image Values and Replaced Content Module Level 3, W3C Candidate Recommendation, 17 April 2012

Reference Draft: CSS Image Values and Replaced Content Module Level 3, W3C Working Draft, 12 January 2012

Produced under Working Group Charter: http://www.w3.org/2010/09/CSSWG/charter

CSS Values and Units Module Level 3

This CSS module describes the common values and units that CSS properties accept and the syntax used for describing them in CSS property definitions.

Draft state: Candidate Recommendation

Expected completion: Q2 2020

Adopted Candidate Recommendation: CSS Values and Units Module Level 3, W3C Candidate Recommendation, 6 June 2019

Reference Draft: CSS Values and Units Module Level 3, W3C Candidate Recommendation, 6 June 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Custom Properties for Cascading Variables Module Level 1

This module introduces cascading variables as a new primitive value type that is accepted by all CSS properties, and custom properties for defining them.

Draft state: Candidate Recommendation

Expected completion: Q2 2020

Adopted Candidate Recommendation: CSS Custom Properties for Cascading Variables Module Level 1, W3C Candidate Recommendation, 03 December 2015

Reference Candidate Recommendation: CSS Custom Properties for Cascading Variables Module Level 1, W3C Candidate Recommendation, 03 December 2015

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

Media Queries Level 4

Media Queries allow authors to test and query values or features of the user agent or display device, independent of the document being rendered. They are used in the CSS @media rule to conditionally apply styles to a document, and in various other contexts and languages, such as HTML and JavaScript.

Draft state: Candidate Recommendation

Expected completion: Q2 2022

Adopted Candidate Recommendation: Media Queries Level 4, W3C Candidate Recommendation, 5 September 2017

Reference Candidate Recommendation: Media Queries Level 4, W3C Candidate Recommendation, 5 September 2017

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

Compositing and Blending Level 1

Compositing describes how shapes of different elements are combined into a single image.

Draft state: Candidate Recommendation

Expected completion: Q3 2020

Adopted Candidate Recommendation: Compositing and Blending Level 1, W3C Candidate Recommendation, 13 January 2015

Reference Candidate Recommendation: Compositing and Blending Level 1, W3C Candidate Recommendation, 13 January 2015

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Writing Modes Level 3

CSS Writing Modes Level 3 defines CSS support for various writing modes and their combinations, including left-to-right and right-to-left text ordering as well as horizontal and vertical orientations.

Draft state: Candidate Recommendation

Expected completion: Q2 2020

Adopted Candidate Recommendation: CSS Writing Modes Level 3, W3C Candidate Recommendation, 30 July 2019

Reference Candidate Recommendation: CSS Writing Modes Level 3, W3C Candidate Recommendation, 30 July 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Writing Modes Level 4

CSS Writing Modes Level 4 defines CSS support for various writing modes and their combinations, including left-to-right and right-to-left text ordering as well as horizontal and vertical orientations.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Writing Modes Level 4, W3C Candidate Recommendation, 30 July 2019

Reference Candidate Recommendation: CSS Writing Modes Level 4, W3C Candidate Recommendation, 30 July 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Fragmentation Module Level 3

This module describes the fragmentation model that partitions a flow into pages, columns, or regions. It builds on the Page model module and introduces and defines the fragmentation model. It adds functionality for pagination, breaking variable fragment size and orientation, widows and orphans.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Fragmentation Module Level 3, W3C Candidate Recommendation, 4 December 2018

Reference Draft: CSS Fragmentation Module Level 3, W3C Candidate Recommendation, 4 December 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Containment Module Level 1

This CSS module describes the contain property, which indicates that the element’s subtree is independent of the rest of the page.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Containment Module Level 1, W3C Candidate Recommendation, 30 April 2019

Reference Candidate Recommendation: CSS Containment Module Level 1, W3C Candidate Recommendation, 30 April 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Counter Styles Level 3

This module introduces the @counter-style rule, which allows authors to define their own custom counter styles for use with CSS list-marker and generated-content counters.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Counter Styles Level 3, W3C Candidate Recommendation, 14 December 2017

Reference Candidate Recommendation: CSS Counter Styles Level 3, W3C Candidate Recommendation, 14 December 2017

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Display Module Level 3

This module describes how the CSS formatting box tree is generated from the document element tree and defines the display property that controls it.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Display Module Level 3, W3C Candidate Recommendation, 11 July 2019

Reference Candidate Recommendation: CSS Display Module Level 3, W3C Candidate Recommendation, 11 July 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Easing Functions Level 1

This CSS module describes a way for authors to define a transformation that controls the rate of change of some value.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Easing Functions Level 1, W3C Candidate Recommendation, 30 April 2019

Reference Candidate Recommendation: CSS Easing Functions Level 1, W3C Candidate Recommendation, 30 April 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Grid Layout Module Level 1

This CSS module defines a two-dimensional grid-based layout system, optimized for user interface design.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Grid Layout Module Level 1, W3C Candidate Recommendation, 14 December 2017

Reference Candidate Recommendation: CSS Grid Layout Module Level 1, W3C Candidate Recommendation, 14 December 2017

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Scroll Snap Module Level 1

This module contains features to control panning and scrolling behavior with “snap positions”.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Scroll Snap Module Level 1, W3C Candidate Recommendation, 19 March 2019

Reference Candidate Recommendation: CSS Scroll Snap Module Level 1, W3C Candidate Recommendation, 31 January 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Shapes Module Level 1

CSS Shapes describe geometric shapes for use in CSS.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Shapes Module Level 1, W3C Candidate Recommendation, 20 March 2014

Reference Draft: CSS Shapes Module Level 1, W3C Last Call Working Draft, 11 February 2014

Produced under Working Group Charter: https://www.w3.org/2010/09/CSSWG/charter

CSS Syntax Module Level 3

This module describes, in general terms, the basic structure and syntax of CSS stylesheets.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Syntax Module Level 3, W3C Candidate Recommendation, 16 July 2019

Reference Draft: CSS Syntax Module Level 3, W3C Candidate Recommendation, 16 July 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Text Decoration Module Level 3

This module contains the features of CSS relating to text decoration, such as underlines, text shadows, and emphasis marks.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Text Decoration Module Level 3, W3C Candidate Recommendation, 13 August 2019

Reference Candidate Recommendation: CSS Text Decoration Module Level 3, W3C Candidate Recommendation, 13 August 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Transforms Module Level 1

CSS transforms allows elements styled with CSS to be transformed in two-dimensional space.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Transforms Module Level 1, W3C Candidate Recommendation, 14 February 2019

Reference Candidate Recommendation: CSS Transforms Module Level 1, W3C Candidate Recommendation, 14 February 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Will Change Module Level 1

This module introduces cascading variables as a new primitive value type that is accepted by all CSS properties, and custom properties for defining them.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Will Change Module Level 1, W3C Candidate Recommendation, 03 December 2015

Reference Candidate Recommendation: CSS Will Change Module Level 1, W3C Candidate Recommendation, 03 December 2015

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Masking Module Level 1

CSS Masking provides two means for partially or fully hiding portions of visual elements: masking and clipping.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Masking Module Level 1, W3C Candidate Recommendation, 26 August 2014

Reference Draft: CSS Masking Module Level 1, W3C Last Call Working Draft, 22 May 2014

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

Geometry Interfaces Module Level 1

This specification provides basic geometric interfaces to represent points, rectangles, quadrilaterals and transformation matrices that can be used by other modules or specifications.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: Geometry Interfaces Module Level 1, W3C Candidate Recommendation, 4 December 2018

Reference Candidate Recommendation: Geometry Interfaces Module Level 1, W3C Candidate Recommendation, 4 December 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Painting API Level 1

An API for allowing web developers to define a custom CSS <image> with javascript, which will respond to style and size changes.

Draft state: Candidate Recommendation

Adopted Candidate Recommendation: CSS Painting API Level 1, W3C Candidate Recommendation, 9 August 2018

Reference Candidate Recommendation: CSS Painting API Level 1, W3C Candidate Recommendation, 9 August 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

Working Draft

CSS Text Decoration Module Level 4

This module contains the features of CSS relating to text decoration, such as underlines, text shadows, and emphasis marks.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Text Decoration Module Level 4, W3C First Public Working Draft, 13 March 2018

Reference Draft: CSS Text Decoration Module Level 4, W3C First Public Working Draft, 13 March 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Box Alignment Module Level 3

This module contains the features of CSS relating to the alignment of boxes within their containers in the various CSS box layout models: block layout, table layout, flex layout, and grid layout.

Draft state: Working Draft

Adopted Working Draft: CSS Box Alignment Module Level 3, W3C Working Draft, 6 December 2018

Reference Draft: CSS Box Alignment Module Level 3, W3C Working Draft, 18 December 2014

Produced under Working Group Charter: https://www.w3.org/2010/09/CSSWG/charter

CSS Animations Level 1

This CSS module describes a way for authors to animate the values of CSS properties over time, using keyframes.

Draft state: Working Draft

Adopted Working Draft: CSS Animations Level 1, W3C Working Draft, 11 October 2018

Reference Draft: CSS Animations Module Level 3, W3C Working Draft, 20 March 2009

Produced under Working Group Charter: https://www.w3.org/Style/2008/css-charter.html

CSS Box Model Module Level 3

This specification describes the margin and padding properties.

Draft state: Working Draft

Adopted Working Draft: CSS Box Model Module Level 3, W3C Working Draft, 18 December 2018

Reference Draft: CSS3 module: The box model, W3C Working Draft, 24 October 2002

Produced under Working Group Charter: http://www.w3.org/Style/2004/css-charter-long

CSS Fragmentation Module Level 4

This module describes the fragmentation model that partitions a flow into pages, columns, or regions. It builds on the Page model module and introduces and defines the fragmentation model. It adds functionality for pagination, breaking variable fragment size and orientation, widows and orphans.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Fragmentation Module Level 3, W3C First Public Working Draft, 18 December 2018

Reference Draft: CSS Fragmentation Module Level 3, W3C First Public Working Draft, 18 December 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Color Module Level 4

This specification describes CSS <color> values, and properties for foreground color and group opacity.

Draft state: Working Draft

Adopted Working Draft: CSS Color Module Level 4, W3C Working Draft, 5 March 2019

Reference Draft: CSS Color Module Level 4, W3C First Public Working Draft, 05 July 2016

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Color Adjustment Module Level 1

This module introduces a model and controls over automatic color adjustment by the user agent to handle user preferences, such as "Dark Mode", contrast adjustment, or specific desired color schemes.

Draft state: Working Draft

Adopted Working Draft: CSS Color Adjustment Module Level 1, W3C Working Draft, 23 May 2019

Reference Draft: CSS Color Adjustment Module Level 1, W3C Working Draft, 23 May 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Generated Content Module Level 3

This module describes how to insert content in a document.

Draft state: Working Draft

Adopted Working Draft: CSS Generated Content Module Level 3, W3C Working Draft, 10 July 2019

Reference Draft: CSS3 Generated and Replaced Content Module, W3C Working Draft, 14 May 2003

Produced under Working Group Charter: https://www.w3.org/Style/2004/css-charter-long

CSS Grid Layout Module Level 2

This CSS module defines a two-dimensional grid-based layout system, optimized for user interface design.

Draft state: Working Draft

Adopted Working Draft: CSS Grid Layout Module Level 2, W3C Working Draft, 04 August 2018

Reference Draft: CSS Grid Layout Module Level 2, First Public Working Draft, 06 February 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Device Adaptation Module Level 1

This specification provides a way for an author to specify, in CSS, the size, zoom factor, and orientation of the viewport that is used as the base for the initial containing block.

Draft state: Working Draft

Adopted Working Draft: CSS Device Adaptation Module Level 1, W3C Working Draft, 29 March 2016

Reference Draft: CSS Device Adaptation Module Level 1, W3C Working Draft, 29 March 2016

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Exclusions Module Level 1

CSS Exclusions define arbitrary areas around which inline content can flow.

Draft state: Working Draft

Adopted Working Draft: CSS Exclusions Module Level 1, W3C Working Draft, 15 January 2015

Reference Draft: CSS Exclusions Module Level 1, W3C Working Draft, 15 January 2015

Produced under Working Group Charter: http://www.w3.org/2010/09/CSSWG/charter

CSS Font Loading Module Level 3

This CSS module describes events and interfaces used for dynamically loading font resources.

Draft state: Last Call Working Draft

Adopted Working Draft: CSS Font Loading Module Level 3, W3C Last Call Working Draft, 22 May 2014

Reference Draft: CSS Font Loading Module Level 3, W3C Last Call Working Draft, 22 May 2014

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Fonts Module Level 4

This module describes how font properties are specified and how font resources are loaded dynamically.

Draft state: Working Draft

Adopted Working Draft: CSS Fonts Module Level 4, W3C Working Draft, 20 September 2018

Reference Draft: CSS Fonts Module Level 4, W3C Working Draft, 11 July 2017

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Generated Content for Paged Media Module

This module defines generated content for paged media.

Draft state: Working Draft

Adopted Working Draft: CSS Generated Content for Paged Media Module, W3C Working Draft, 13 May 2014

Reference Draft: CSS3 module: Generated Content for Paged Media, W3C Working Draft, 12 June 2006

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Image Values and Replaced Content Module Level 4

This module contains features relating to the <image> type and replaced elements.

Draft state: Working Draft

Adopted Working Draft: CSS Image Values and Replaced Content Module Level 4, W3C Working Draft, 13 April 2017

Reference Draft: CSS Image Values and Replaced Content Module Level 4, W3C Working Draft, 11 September 2012

Produced under Working Group Charter: http://www.w3.org/2010/09/CSSWG/charter

CSS Inline Layout Module Level 3

The CSS formatting model provides for a flow of elements and text inside of a container to be wrapped into lines.

Draft state: Working Draft

Adopted Working Draft: CSS Inline Layout Module Level 3, W3C Working Draft, 8 August 2018

Reference Draft: CSS Inline Layout Module Level 3, W3C Working Draft, 18 December 2014

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Line Grid Module Level 1

This module contains CSS features for aligning content to a baseline grid.

Draft state: Working Draft

Adopted Working Draft: CSS Line Grid Module Level 1, W3C Working Draft, 16 September 2014

Reference Draft: CSS Line Grid Module Level 1, W3C First Public Working Draft, 3 April 2014

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Lists Module Level 3

This module contains CSS features related to list counters: styling them, positioning them, and manipulating their value.

Draft state: Working Draft

Adopted Working Draft: CSS Lists Module Level 3, W3C Working Draft, 25 April 2019

Reference Draft: CSS Lists and Counters Module Level 3, W3C Working Draft, 24 May 2011

Produced under Working Group Charter: https://www.w3.org/Style/2004/css-charter-long

CSS Logical Properties and Values Level 1

This module introduces logical properties and values that provide the author with the ability to control layout through logical, rather than physical, direction and dimension mappings.

Draft state: Working Draft

Adopted Working Draft: CSS Logical Properties and Values Level 1, W3C Working Draft, 27 August 2018

Reference Draft: CSS Logical Properties and Values Level 1, W3C First Public Working Draft, 18 May 2017

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Multi-column Layout Module Level 1

This specification describes multi-column layouts in CSS.

Draft state: Working Draft

Adopted Working Draft: CSS Multi-column Layout Module Level 1, W3C Working Draft, 28 May 2018

Reference Draft: CSS3 module: Multi-column layout, W3C Working Draft, 30 June 2009

Produced under Working Group Charter: https://www.w3.org/Style/2008/css-charter

CSS Spatial Navigation Level 1

This specification defines a general model for navigating the focus using the arrow keys, as well as related CSS, JavaScript features and Events.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Spatial Navigation Level 1, W3C First Public Working Draft, 23 April 2019

Reference Draft: CSS Spatial Navigation Level 1, W3C First Public Working Draft, 23 April 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Overflow Module Level 3

This module contains the features of CSS relating to scrollable overflow handling in visual media.

Draft state: Working Draft

Adopted Working Draft: CSS Overflow Module Level 3, W3C Working Draft, 31 July 2018

Reference Draft: CSS Overflow Module Level 3, W3C First Public Working Draft, 18 April 2013

Produced under Working Group Charter: https://www.w3.org/2010/09/CSSWG/charter

CSS Overflow Module Level 4

This module contains the features of CSS relating to new mechanisms of overflow handling in visual media (e.g., screen or paper).

Draft state: First Public Working Draft

Adopted Working Draft: CSS Overflow Module Level 4, First Public Working Draft, 13 June 2017

Reference Draft: CSS Overflow Module Level 4, First Public Working Draft, 13 June 2017

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Overscroll Behavior Module Level 1

This module defines overscroll-behavior to control the behavior when the scroll position of a scroll container reaches the edge of the scrollport.

Draft state: Working Draft

Adopted Working Draft: CSS Overscroll Behavior Module Level 1, W3C Working Draft, 31 July 2018

Reference Draft: CSS Overscroll Behavior Module Level 1, W3C First Public Working Draft, 18 April 2013

Produced under Working Group Charter: https://www.w3.org/2010/09/CSSWG/charter

CSS Paged Media Module Level 3

This CSS module specifies how pages are generated and laid out to hold fragmented content in a paged presentation.

Draft state: Working Draft

Adopted Working Draft: CSS Paged Media Module Level 3, W3C Working Draft, 18 October 2018

Reference Draft: CSS Paged Media Module Level 3, W3C Working Draft, 14 March 2013

Produced under Working Group Charter: https://www.w3.org/Style/2004/css-charter-long

CSS Page Floats

This document describes floats that move to the top or bottom of content passages.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Page Floats, W3C First Public Working Draft, 15 September 2015

Reference Draft: CSS Page Floats, W3C First Public Working Draft, 15 September 2015

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Positioned Layout Module Level 3

This module contains the features of CSS level 3 relating to positioning and stacking of elements.

Draft state: Working Draft

Adopted Working Draft: CSS Positioned Layout Module Level 3, W3C Working Draft, 17 May 2016

Reference Draft: CSS Positioned Layout Module Level 3, W3C Working Draft, 17 May 2016

Produced under Working Group Charter: https://www.w3.org/2010/09/CSSWG/charter

CSS Pseudo-Elements Module Level 4

This CSS module defines pseudo-elements, abstract elements that represent portions of the CSS render tree that can be selected and styled.

Draft state: Working Draft

Adopted Working Draft: CSS Pseudo-Elements Module Level 4, W3C Working Draft, 25 February 2019

Reference Draft: CSS Pseudo-Elements Module Level 4, W3C First Public Working Draft, 15 January 2015

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Regions Module Level 1

The CSS Regions module allows content from one or more elements to flow through one or more boxes called CSS Regions, fragmented as defined in CSS Fragmentation Module.

Draft state: Working Draft

Adopted Working Draft: CSS Regions Module Level 1, W3C Working Draft, 9 October 2014

Reference Draft: CSS Regions Module, W3C Working Draft, 09 June 2011

Produced under Working Group Charter: https://www.w3.org/Style/2008/css-charter

CSS Rhythmic Sizing

This module contains CSS features for aligning content size to multiple of unit size.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Rhythmic Sizing, W3C First Public Working Draft, 2 March 2017

Reference Draft: CSS Rhythmic Sizing, W3C First Public Working Draft, 2 March 2017

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Round Display Level 1

This document describes CSS extensions to support a round display. The extensions help web authors to build a web page suitable for a round display.

Draft state: Working Draft

Adopted Working Draft: CSS Round Display Level 1, W3C Working Draft, 22 December 2016

Reference Draft: CSS Round Display Level 1, W3C First Public Working Draft, 22 September 2015

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Ruby Layout Module Level 1

This module describes the rendering model and formatting controls related to displaying ruby annotations in CSS.

Draft state: Working Draft

Adopted Working Draft: CSS Ruby Layout Module Level 1, W3C Working Draft, 5 August 2014

Reference Draft: CSS3 Ruby Module, W3C Candidate Recommendation, 14 May 2003

Produced under Working Group Charter: https://www.w3.org/Style/2002/css-charter.html

CSS Scoping Module Level 1

This specification defines various scoping/encapsulation mechanisms for CSS.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Scoping Module Level 1, W3C First Public Working Draft, 3 April 2014

Reference Draft: CSS Scoping Module Level 1, W3C First Public Working Draft, 3 April 2014

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Scrollbars Module Level 1

CSS Scrollbars standardizes the ability to color scrollbars.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Scrollbars Module Level 1, W3C First Public Working Draft, 25 September 2018

Reference Draft: CSS Scrollbars Module Level 1, W3C First Public Working Draft, 25 September 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Shadow Parts

This specification defines the ::part() pseudo-element on shadow hosts, allowing shadow hosts to selectively expose chosen elements from their shadow tree to the outside page for styling purposes.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Shadow Parts, W3C First Public Working Draft, 15 November 2018

Reference Draft: CSS Shadow Parts, W3C Candidate Recommendation, 31 January 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Intrinsic & Extrinsic Sizing Module Level 3

This module extends the CSS sizing properties with keywords that represent content-based "intrinsic" sizes and context-based "extrinsic" sizes, allowing CSS to more easily describe boxes that fit their content or fit into a particular layout context.

Draft state: Working Draft

Adopted Working Draft: CSS Intrinsic & Extrinsic Sizing Module Level 3, W3C Working Draft, 22 May 2019

Reference Draft: CSS Intrinsic & Extrinsic Sizing Module Level 3, W3C Working Draft, 27 September 2012

Produced under Working Group Charter: https://www.w3.org/2010/09/CSSWG/charter

CSS Table Module Level 3

This CSS module defines a two-dimensional grid-based layout system, optimized for tabular data rendering.

Draft state: Working Draft

Adopted Working Draft: CSS Table Module Level 3, W3C Working Draft, 7 March 2017

Reference Draft: CSS Table Module Level 3, W3C First Public Working Draft, 25 October 2016

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Text Module Level 3

This CSS module defines properties for text manipulation and specifies their processing model.

Draft state: Working Draft

Adopted Working Draft: CSS Text Module Level 3, W3C Working Draft, 12 December 2018

Reference Draft: CSS Text Module Level 3, W3C Last Call Working Draft, 10 October 2013

Produced under Working Group Charter: https://www.w3.org/2010/09/CSSWG/charter

CSS Text Module Level 4

This module defines properties for text manipulation and specifies their processing model.

Draft state: Working Draft

Adopted Working Draft: CSS Text Module Level 4, W3C Working Draft, 20 September 2018

Reference Draft: CSS Text Module Level 4, W3C First Public Working Draft, 22 September 2015

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Transitions

CSS Transitions allows property changes in CSS values to occur smoothly over a specified duration.

Draft state: Working Draft

Adopted Working Draft: CSS Transitions, W3C Working Draft, 11 October 2018

Reference Draft: CSS Transitions Module Level 3, W3C Working Draft, 20 March 2009

Produced under Working Group Charter: https://www.w3.org/Style/2008/css-charter

CSS Basic User Interface Module Level 4

This specification describes user interface related properties and values to style HTML and XML (including XHTML). It includes and extends user interface related features from the properties and values of previous CSS levels. It uses various properties and values to style basic user interface elements in a document.

Draft state: Working Draft

Adopted Working Draft: CSS Basic User Interface Module Level 4, W3C Working Draft, 22 December 2017

Reference Draft: CSS Basic User Interface Module Level 4, W3C First Public Working Draft, 22 September 2015

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Values and Units Module Level 4

This CSS module describes the common values and units that CSS properties accept and the syntax used for describing them in CSS property definitions.

Draft state: Working Draft

Adopted Working Draft: CSS Values and Units Module Level 4, W3C Working Draft, 31 January 2019

Reference Draft: CSS Values and Units Module Level 4, W3C First Public Working Draft, 14 August 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS 2.2

CSS 2.2 is derived from and is intended to replace the CSS 2.1 and CSS2 (1998) specifications.

Draft state: First Public Working Draft

Adopted Working Draft: Cascading Style Sheets Level 2 Revision 2 (CSS 2.2) Specification, W3C First Public Working Draft, 12 April 2016

Reference Draft: Cascading Style Sheets Level 2 Revision 2 (CSS 2.2) Specification, W3C First Public Working Draft, 12 April 2016

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Object Model (CSSOM)

CSSOM defines APIs (including generic parsing and serialization rules) for Media Queries, Selectors, and of course CSS itself.

Draft state: Working Draft

Adopted Working Draft: CSS Object Model (CSSOM), W3C Working Draft, 17 March 2016

Reference Draft: CSS Object Model (CSSOM), W3C Working Draft, 17 March 2016

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSSOM View Module

The APIs introduced by this specification provide authors with a way to inspect and manipulate the visual view of a document. This includes getting the position of element layout boxes, obtaining the width of the viewport through script, and also scrolling an element.

Draft state: Working Draft

Adopted Working Draft: CSSOM View Module, W3C Working Draft, 17 March 2016

Reference Draft: CSSOM View Module, W3C Working Draft, 17 March 2016

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

Selectors Level 4

Selectors are patterns that match against elements in a tree, and as such form one of several technologies that can be used to select nodes in a document.

Draft state: Working Draft

Adopted Working Draft: Selectors Level 4, W3C Working Draft, 21 November 2018

Reference Draft: Selectors Level 4, W3C Working Draft, 29 September 2011

Produced under Working Group Charter: https://www.w3.org/Style/2008/css-charter

Web Animations

This specification defines a model for synchronization and timing of changes to the presentation of a Web page. This specification also defines an application programming interface for interacting with this model and it is expected that further specifications will define declarative means for exposing these features.

Draft state: Working Draft

Adopted Working Draft: Web Animations, W3C Working Draft, 11 October 2018

Reference Draft: Web Animations, W3C Working Draft, 7 July 2015

Produced under Working Group Charter: https://www.w3.org/2010/09/CSSWG/charter

CSS Fill and Stroke Module Level 3

This module contains the features of CSS relating to filling and stroking text and SVG shapes.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Fill and Stroke Module Level 3, W3C First Public Working Draft, 13 April 2017

Reference Draft: CSS Fill and Stroke Module Level 3, W3C First Public Working Draft, 13 April 2017

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

Filter Effects Module Level 1

Filter effects are a way of processing an element’s rendering before it is displayed in the document.

Draft state: Working Draft

Adopted Working Draft: Filter Effects Module Level 1, W3C Working Draft, 18 December 2018

Reference Draft: Filter Effects 1.0, W3C Working Draft, 25 October 2012

Produced under Working Group Charter: https://www.w3.org/2010/09/CSSWG/charter

Motion Path Module Level 1

Motion path allows authors to position any graphical object and animate it along an author specified path.

Draft state: Working Draft

Adopted Working Draft: Motion Path Module Level 1, W3C Working Draft, 18 December 2018

Reference Draft: Motion Path Module Level 1, W3C First Public Working Draft, 9 April 2015

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Animation Worklet API

The Animation Worklet API provides a method to create scripted animations that control a set of animation effects.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Animation Worklet API, W3C First Public Working Draft, 25 June 2019

Reference Draft: CSS Animation Worklet API, W3C First Public Working Draft, 25 June 2019

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Layout API Level 1

This specification describes an API which allows developers to layout a box in response to computed style and box tree changes.

Draft state: First Public Working Draft

Adopted Working Draft: CSS Layout API Level 1, W3C First Public Working Draft, 12 April 2018

Reference Draft: CSS Layout API Level 1, W3C First Public Working Draft, 12 April 2018

Produced under Working Group Charter: https://www.w3.org/Style/2016/css-2016.html

CSS Properties and Values API Level 1

This CSS module defines an API for registering new CSS properties. Properties registered using this API are provided with a parse syntax that defines a type, inheritance behaviour, and an initial value.

Draft state: Working Draft

Adopted Working Draft: CSS Properties and Values API Level 1, W3C Working Draft, 9 November 2017

Reference Working Draft: CSS Properties and Values API Level 1, W3C First Public Working Draft, 07 June 2016

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

CSS Typed OM Level 1

Converting CSSOM value strings into meaningfully typed JavaScript representations and back can incur a significant performance overhead. This specification exposes CSS values as typed JavaScript objects to facilitate their performant manipulation.

Draft state: Working Draft

Adopted Working Draft: CSS Typed OM Level 1, W3C Working Draft, 10 April 2018

Reference Working Draft: CSS Typed OM Level 1, W3C First Public Working Draft, 07 June 2016

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

Worklets Level 1

This specification defines an API for running scripts in stages of the rendering pipeline independent of the main javascript execution environment.

Draft state: First Public Working Draft

Adopted Working Draft: Worklets Level 1, W3C Working Draft, 07 June 2016

Reference Working Draft: Worklets Level 1, W3C Working Draft, 07 June 2016

Produced under Working Group Charter: https://www.w3.org/Style/2014/css-charter

Maintenance of existing CSS Recommendations (gathering of errata, publication of new editions incorporating errata) is also in scope.

Other Deliverables

css-2019

This document collects together into one definition all the specs that together form the current state of Cascading Style Sheets (CSS) as of 2019. The primary audience is CSS implementers, not CSS authors, as this definition includes modules by specification stability, not Web browser adoption rate.

Draft state: No draft, published annually.

Expected completion: Q4 2019

css-2020

This document collects together into one definition all the specs that together form the current state of Cascading Style Sheets (CSS) as of 2020. The primary audience is CSS implementers, not CSS authors, as this definition includes modules by specification stability, not Web browser adoption rate.

Draft state: No draft, published annually.

Expected completion: Q4 2020

css-2021

This document collects together into one definition all the specs that together form the current state of Cascading Style Sheets (CSS) as of 2021. The primary audience is CSS implementers, not CSS authors, as this definition includes modules by specification stability, not Web browser adoption rate.

Draft state: No draft, published annually.

Expected completion: Q4 2021

Timeline

  • Q1 2020: REC for CSS Writing Modes Level 3
  • Q2 2020: REC for CSS Values and Units Module Level 3
  • Q2 2020: REC for CSS Custom Properties for Cascading Variables Module Level 1
  • Q2 2020: REC for CSS Flexible Box Layout Module Level 1
  • Q3 2020: REC for CSS Cascading and Inheritance Level 3
  • Q3 2020: REC for Compositing and Blending Level 1
  • Q4 2020: REC for CSS Conditional Rules Module Level 3
  • Q2 2021: REC for CSS Backgrounds and Borders Module Level 3
  • Q1 2022: REC for CSS Cascading and Inheritance Level 4
  • Q2 2022: REC for CSS Image Values and Replaced Content Module Level 3
  • Q2 2022: REC for Media Queries Level 4

Success Criteria

The CSS Working Group's work is considered a success if there are multiple, independent, interoperable implementations of its modules that are widely used.

In order to advance to Proposed Recommendation, each module is expected to have at least two independent implementations of each of the features it defines, and to provide evidence for this claim based on tests. The Working Group is therefore expected to proactively work on writing, reviewing, and maintaining tests. Doing so concurrently with its work on specification text is recommended; among other benefits, it helps minimize accidental divergence between implementations and specifications, test results may also inform discussions on specifications, and failing test may stimulate implementers to update their implementations accordingly. Testing efforts should be conducted via the Web Platform Tests project.

Each specification should contain a section detailing all known security and privacy implications for implementers, Web authors, and end users.

Each specification should contain a section on accessibility that describes the benefits and impacts, including ways specification features can be used to address them, and recommendations for maximising accessibility in implementations.

Modules that reach W3C Recommendation, are considered successful when all of the following are present:

  • Production of stable documents addressing the work items listed in the Deliverables section.
  • Test suites for each module with conformance criteria.
  • Availability of multiple, independent, interoperable implementations of each feature with conformance criteria in each deliverable; as demonstrated by an implementation report (summarizing implementation status against the relevant test suite) for each testable class of product, including user agents.
  • Deployment on multiple types of platform (traditional computers, phones, tablets, accessibility aids, print formatters, and so on).
  • User community and industry adoption of the group deliverables.

Coordination

For all specifications, this Working Group will seek horizontal review for accessibility, internationalization, performance, privacy, and security with the relevant Working and Interest Groups, and with the TAG. Invitation for review must be issued during each major standards-track document transition, including FPWD. The Working Group is encouraged to engage collaboratively with the horizontal review groups throughout development of each specification. The Working Group is advised to seek a review at least 3 months before CR and is encouraged to proactively notify the horizontal review groups when major changes occur in a specification following a review.

Additional technical coordination with the following Groups will be made, per the W3C Process Document:

In addition to the above catch-all reference to horizontal review which includes accessibility review, this Working Group will work with the Accessible Platform Architectures Working Group to work on accessible navigation which needs to be addressed coherently across multiple specifications, address accessibility issues related to the features of individual specifications, and develop new CSS specifications to address accessibility use cases where appropriate. Some of this work may be carried out in the joint CSS Accessibility Task Force.

W3C Groups

Scalable Vector Graphics (SVG) Working Group
The Group coordinates closely with the SVG WG on common features (such as the CSS Animations, CSS Fonts, CSS Object Model, CSS 2D and 3D Transformations, and CSS Transitions Modules) to meet the needs of HTML/CSS, SVG, and mixed HTML/CSS/SVG content, and to ensure compatibility at the functionality level for ease of implementation and authoring.
The CSS WG is aware of normative references to CSS specifications from SVG and will endeavor to maintain their stability, for example by avoiding breaking changes to the referenced portions.
WebFonts Working Group
The Group coordinates with the WebFonts WG to enable high quality Web typography with downloadable fonts, in particular WOFF and WOFF2.
Publishing Working Group
The group coordinates closely with the Publishing WG on requirements for various aspects of CSS in all types of digital publishing, including for e-books and publications on paper.
Web Applications Working Group
The Group reviews the Selectors API specification, being developed by the Web Applications Working Group.
Web Platform Incubator Community Group
The CSS WG may adopt promising CSS work incubated in the WICG, provided that RF patent commitments are in place for such work. WICG participants working on CSS-related proposals are expected to coordinate with the CSS WG to ensure timely reviews of their work. Note: No restriction of the CSS WG's ability to adopt proposals developed elsewhere is implied.
Technical Architecture Group
The group coordinates with the TAG on architectural review of CSS specifications and to develop an extensible CSS architecture. The Houdini task force is the primary venue for this work, and those specifications are published jointly.

External Organizations

WHATWG
The group coordinates with the WHATWG to ensure that HTML only contains constructs that can be rendered with CSS.
The CSS WG is aware of normative references to CSS specifications from HTML and will endeavor to maintain their stability, for example by avoiding breaking changes to the referenced portions.

Participation

To be successful, this Working Group is expected to have 6 or more active participants for its duration, including representatives from the key implementors of this specification, and active Editors and Test Leads for each specification. The Chairs, specification Editors, and Test Leads are expected to contribute half of a working day per week towards the Working Group. There is no minimum requirement for other Participants.

The group encourages questions, comments and issues on its public mailing lists and document repositories, as described in Communication.

The group also welcomes non-Members to contribute technical submissions for consideration upon their agreement to the terms of the W3C Patent Policy.

Communication

Technical discussions for this Working Group are conducted in public: the meeting minutes from teleconference and face-to-face meetings will be archived for public review, and technical discussions and issue tracking will be conducted in a manner that can be both read and written to by the general public. Working Drafts and Editor's Drafts of specifications will be developed on a public repository and may permit direct public contribution requests. The meetings themselves are not open to public participation, however.

Information about the group (including details about deliverables, issues, actions, status, participants, and meetings) will be available from the CSS Working Group home page.

Most CSS Working Group teleconferences will focus on discussion of particular specifications, and will be conducted on an as-needed basis.

This group primarily conducts its technical work via the GitHub issues list, with more general discussion on the public mailing list www-style@w3.org (archive). The public is invited to review and discuss issues, and to post messages to this list.

The group may use a Member-confidential mailing list for administrative purposes and, at the discretion of the Chairs and members of the group, for member-only discussions in special cases when a participant requests such a discussion.

Decision Policy

This group will seek to make decisions through consensus and due process, per the W3C Process Document (section 3.3). Typically, an editor or other participant makes an initial proposal, which is then refined in discussion with members of the group and other reviewers, and consensus emerges with little formal voting being required.

However, if a decision is necessary for timely progress and consensus is not achieved after careful consideration of the range of views presented, the Chairs may call for a group vote and record a decision along with any objections.

Decisions are made by consensus of the Working Group. In addition to decisions made on teleconferences or face to face meetings, decisions may also be made by a call for consensus on the public mailing list; consensus to be determined by the chairs after some reasonable interval for objections.

All decisions made by the group should be considered resolved unless and until new information becomes available or unless reopened at the discretion of the Chairs or the Director.

This charter is written in accordance with the W3C Process Document (Section 3.4, Votes) and includes no voting procedures beyond what the Process Document requires.

Patent Policy

This Working Group operates under the W3C Patent Policy (Version of 5 February 2004 updated 1 August 2017). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis. For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.

Licensing

This Working Group will use the W3C Software and Document license for all its deliverables.

About this Charter

This charter has been created according to section 5.2 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

Charter History

The following table lists details of all changes from the initial charter, per the W3C Process Document (section 5.2.3):

Charter Period Start Date End Date Changes
Initial Charter 28 February 1997 28 February 1999
Rechartered 22 March 1999 31 March 2000
Rechartered 31 July 2001 31 July 2002
Rechartered 15 October 2002 31 August 2004
Charter Extension 22 September 2004 31 March 2005
Rechartered 28 June 2006 31 July 2008
Charter Extension 26 September 2008 31 December 2008
Rechartered 12 December 2008 30 November 2010
Charter Extension 19 November 2010 31 March 2011
Charter Extension 12 July 2011 30 August 2011
Rechartered 14 December 2011 30 September 2013
Rechartered 01 July 2014 15 June 2016
Charter Extension 11 July 2016 30 September 2016
Rechartered 16 September 2016 14 September 2019