CSS documentation status

This page tries to track ongoing documentation work in the MDN CSS section. Feel free to contribute!


Pages No tags Needs* tags Missing tags Editorial reviews Technical reviews Outdated pages Dev-doc-needed bugs Documentation requests Missing pages
1007 3 (1%) 112 (12%) 3 (1%) 155 (16%) 246 (25%) 4 (1%) 138 (14%) 35 (4%) 5 (1%)

See also localization status of this section.

No tags

Found 3 pages. Learn more about how to tag pages.

Needs* tags

Found 112 pages. Learn more about how to deal with meta-tags.

Missing tags

At least missing one of the following:

Found 3 pages. Learn more about how to tag pages.

Editorial reviews

Found 155 pages. Learn more about how to do an editorial review.

Technical reviews

Found 246 pages. Learn more about how to do a technical review.

Outdated pages

Found 4 pages. These pages haven't been updated in over a year. Outdated pages can have problems with both content and format. Look at these pages and consider: Is this page talking about the Web of today? Does it look consistent with newer pages in this topic area? If not, make any needed changes.

Dev-doc-needed bugs

Found 138 bugs. Learn more about how to resolve a dev-doc-needed bug.

Bug Summary Release
1617600 Prototype focus-visible behind a flag. mozilla75
1613746 Implement CSSStyleSheet Replace() Functionality mozilla75
1221416 Add support for styling the disclosure triangle of the <details> element using summary::marker ---
1265666 Implement missing SVG 2 values of vector-effect property ---
956573 calc() CSS function doesn't work with all data types (units) that it should, such as times ---
1055385 implement font-variant descriptor for @font-face rules ---
1358327 implement image-orientation:none ---
1258270 Support calc() on stroke-width, stroke-dasharray and stroke-dashoffset ---
1337174 Implement `@media (width < 600px)` syntax from MQ Level 4 ---
1176496 Drop support for -moz-prefixed gradients (-moz-linear-gradient, -moz-radial-gradient) ---
1239218 Implement SVGUnknownElement interface ---
1351745 Disable -moz-appearance for non-UA/chrome sheets ---
700926 Unify CSS image-value rendering ---
1178895 Implement CSS 'contain: layout' (2015 version) ---
736431 Inline <svg> is given the CSS default height of 150px when the height is not explicitly specified ---
1256575 Support calc() in media queries ---
1436061 Update font-{style,weight,stretch} @font-face descriptors to accept additional values per CSS Fonts 4 ---
747754 Implement @viewport at-rule ---
912434 text-overflow: ellipsis does not work, when specified on an element that has "display: flex" ---
590468 Reduce size of chrome document layer due to status bar ---
1172087 Implement CSS 'contain: style' (2015 version) ---
1348208 Consider removing -moz-force-broken-image-icon property ---
1177032 Implement SVG 1.2 Tiny/SVG 2 solidColor paint server ---
1366146 Disable moz-prefixed gradient functions for beta and release ---
879275 Consider turning off -moz-box display types in untrusted stylesheets ---
1592389 Support unprefixed field and fieldtext css colors ---
426447 hasFeature broken for SVG 1.1 style SVG detection - regression. ---
1607308 wrong text-underline-offset zero position with text-underline-position:under mozilla74
1606997 Let CSS text-underline-position property ride the train to release mozilla74
1031664 Enable rendering of outline-style:auto by default mozilla74
1607534 `text-underline-offset` and `text-decoration-thickness` should accept percentage values mozilla74
770780 Implement CSS3 text module text-underline-position mozilla73
1424900 Enable "layout.css.individual-transform.enabled" by default mozilla72
1576946 Implement <stack> using CSS Grid and remove nsStackFrame mozilla72
371787 Support the 'letter-spacing' and 'word-spacing' properties in SVG mozilla72
1597642 [css-transforms] Have scale function and scale property accept percentage value mozilla72
1559074 Enable shadow parts for release and beta channels. mozilla72
1548718 support multiple part names in ::part() mozilla71
1569474 dispatch cut, copy and paste events to SVG graphics elements mozilla70
1554150 Remove -webkit-appearance keywords that are removed in Chromium 75 mozilla69
1513643 Enable @supports selector() by default. mozilla69
1383650 Implement SVG geometry properties in CSS mozilla69
1505489 Implement CSS Shadow Parts (and enable it for chrome callers) mozilla69
1520020 Filter functions, e.g. blur(), brightness(), contrast(), ..., could be used without arguments mozilla68
1540093 Unship line-height: -moz-block-height. mozilla68
1532471 Let CSS Containment ride the trains to early beta mozilla68
1133175 remove SVGTests.hasExtension mozilla68
1541959 The text-transform property should support `full-width` and/or `full-size-kana` in combination with one of the case transforms mozilla68
1529389 add a test for IntersectionObserverEntry.isIntersecting mozilla67
1475033 Add initial support of scrollbar-width mozilla63
1460456 Add some scrollbar color properties mozilla62
1427419 convert inIDOMUtils to Web IDL mozilla59
265894 Support SVG CSS selector matching rules for <svg:use> mozilla56
1243846 Implement Intersection Observer API mozilla55
1319137 (intersection-observer) Add isIntersecting property to IntersectionObserverEntry mozilla55
1340309 [css-align] Implement the updated spec language for interactions between "align-items" & "align-self", "justify-items" & "justify-self" mozilla54
418833 can't define the style of input when the type is set to "checkbox" or "radio" with CSS mozilla53
1216893 Add pref to optionally disable SVG (Tor 12827) mozilla53
1151204 [css-grid] Implement Grid container Baselines mozilla52
1259345 Let layout.css.prefixes.webkit ride the trains mozilla49
1258657 Update the default style of summary element to match the html spec mozilla48
1241750 Enable <details> and <summary> on Nightly/Aurora mozilla48
1260366 first-letter doesn't apply on dash [maybe another punctuation symbols] mozilla48
1243734 Have a pref to enable/ disable all new mask CSS properties added in bug 686281 mozilla48
1236979 Send 'webkitTransitionEnd', 'webkitAnimationEnd' etc. events instead of their standard equivalents, if listeners only exist for prefixed event name mozilla47
1250342 rename text-align(/-last): true to unsafe mozilla47
1218706 Make unicode-bidi: isolate the default for elements with a dir attribute mozilla47
1251999 [css-grid] Update <fixed-size> parsing to the latest spec mozilla47
1230207 [css-grid][css-flexbox] Implement grid/flex layout for <fieldset> mozilla46
1157064 experimental implementation of font-display CSS @font-face descriptor mozilla46
1213126 Enable layout.css.prefixes.webkit by default (though this was later restricted to non-release builds, in bug 1238827) mozilla46
1233106 implement changes to css-align property computation mozilla46
1118820 [css-grid] Implement auto-fill, auto-fit in the repeat() function mozilla46
1230478 [css-grid][css-align]Rename 'true' to 'unsafe' mozilla46
1239128 Implement LinkStyle for SVGStyleElement interface mozilla46
1176782 [css-grid][css-align] Implement full support for the CSS Box Alignment spec in the style system. mozilla45
1224424 mask-mode must not have a value called 'auto' mozilla45
1000592 Enable CSS Grid by default in non-release channels mozilla45
1221677 [css-grid] Put the 'subgrid' support behind a pref, disabled by default mozilla45
1151214 [css-grid] Implement align-content and justify-content mozilla45
1126230 Use top layer for Fullscreen API mozilla44
920734 support window.orientation and orientationchange event mozilla44
1215484 Figure out how high contrast / "ignore author colors" should apply to SVGs mozilla44
1149381 enable the preference for the CSS Font Loading API in release builds mozilla41
1152033 expose CSS tokenizer to javascript mozilla40
1028716 update values of -moz-orient for <progress> and <meter> to remove 'auto', and add 'inline' (new initial value) and 'block' values with writing-mode support mozilla40
1072101 implement the remaining Set-like API of FontFaceSet mozilla40
1125455 rewrite cascading of CSS Transitions and Animations to match current spec mozilla39
960465 rewrite starting of CSS transitions to match current spec mozilla38
1107584 ship <marker orient="auto-start-reverse"> mozilla37
1087562 Enable CSSOM-View scroll behavior CSS property by default (Except for Fennec) mozilla36
886390 Assigning to innerHTML on an SVG element should create elements in the SVG namespace mozilla36
1045754 Implement alternative to CSSOM-View scroll-behavior Element.scrollTop and Element.scrollLeft extensions mozilla36
1087559 Enable CSSOM-View scroll behavior DOM method extensions by default (Except for Fennec) mozilla36
1022818 Implement CSSOM-View smooth scrolling DOM Methods mozilla34
975744 enable font-variant-* / font-feature in release by default mozilla34
1015474 Update min-width:auto/min-height:auto support to match updated flexbox spec language mozilla34
1041951 convert font-variant to a shorthand and parse font-variant subproperty values mozilla34
1024707 Add API to register style sheets but without loading them mozilla33
1035106 Add new APIs to DOMUtils: colorToRGBA, IsValidCSSColor & cssPropertyIsValid mozilla33
966166 Implement @counter-style rule mozilla33
1006595 Add domUtils.GetCSSSubPropertiesForProperty, getCSSPropertyIsShorthand, CSSPropertySupportsType (Color, Gradient etc.) mozilla33
1008455 Avoid loading the xul.css UA style sheet when possible mozilla32
999964 Implementation Proposal for 'clipped' option of SVG 2 getBBox method. mozilla32
918189 Implement Node.convertPoint/Rect/QuadFromNode mozilla31
983528 enable paint-order property by default mozilla31
917755 Implement Node.getBoxQuads mozilla31
850805 Implement DOMPoint (aka WebKitPoint) mozilla31
964200 Implement Filter Effects Module feDropShadow filter mozilla30
966992 Implement overflow-clip-box: content-box mozilla30
943249 The overflow property on an <iframe> is propagated to the viewport of the inner document (unlike other UAs) mozilla29
773296 implement CSS3 variables mozilla29
956513 SVG text is drawn with wrong position mozilla29
939784 Provide a notification when the applicable state of a style sheet changes mozilla28
947728 Provide a way for content to hide <input type=number>'s spinner mozilla28
798843 change value names for -moz-objectFill to context-fill etc., and put them behind opentype SVG pref mozilla26
835048 Figure out if SVGElement.ownerSVGElement should throw mozilla26
569722 Firefox SVG support does not implement the textLength and lengthAdjust attribute functionality of <text> elements mozilla25
879659 implement <marker orient="auto-start-reverse"> from SVG 2 mozilla25
887741 Allow CSS at-rules in declaration lists mozilla25
453650 mechanism for tracking reflows in debugger mozilla24
549861 implement parsing of font feature properties mozilla24
771551 Add CSS Media Query media feature for device hardware buttons mozilla24
851379 Make flex item vertical margin/padding resolve percentages against height of the flex container mozilla23
785606 Consider implementing viewBox="none" from SVG 1.2 Tiny mozilla22
804944 add preferences for sets of CSS prefixed properties mozilla19
737003 Offer a way to apply user agent stylesheet on a given document mozilla18
732209 Allow access to the rules of cross-origin sheets that have undergone a CORS check mozilla18
745025 Implement CanvasElement.mozPrintCallback mozilla18
774122 limit CSS parser hashless-color and unitless-length quirks to only the properties that need them mozilla17
619964 Implement FillPaint and StrokePaint filter sources mozilla17
528332 Feature Request: Implement non-scaling-stroke mozilla15
512514 Implement hyperlink targeting of animation elements mozilla15
759124 Implement useCurrentView mozilla15
721920 Honor the 'lang' attribute on SVG as we do in HTML mozilla13
665597 Include margin calculations in FinishAndStoreOverflow mozilla12
589640 (ietestcenter) HTML5 Foreign Content 14/24: <altGlyphDef> is not an SVGElement mozilla11
611099 remove handling of percentages as intrinsic widths/heights (SVG height="100%" width="100%" defaults) mozilla11

Browse as bug list.

Documentation requests

Found 35 bugs. Documentation request bugs can contain various kinds work related to MDN pages. Read through the bug and ask questions in the bug if in doubt.

Bug Summary
848308 We need MDC to better document the styling of form controls using pseudo elements
904680 Document CSS Inline Formatting Context
963742 @font-face example font Bitstream Vera Bold is broken in IE9-10 (tested) possibly others.
1071549 Explanation about multiple selectors (comma)
1133414 Add page for deprecated media types and groups
1180569 HTML of example output in selectors guide does not reflect the code
1238322 Document WebVTT's :current, :past, :future CSS pseudo-classes
1240279 Document Mozilla-specific pseudo-classes and pseudo-elements for the <meter> element
1252853 Collapsing margins and flexbox
1256335 Correct entry for max-height in mdn/data css/properties.json to use "regardingHeightOfGeneratedBoxContainingBlockPercentagesRelativeToContainingBlock"
1276323 min-height, min-width default should be 'auto', not 0
1276893 Group items in CSS reference by category
1283378 Describe CSS type combinations of percentages
1288492 Broken links on webkit-inner-spin-button page
1307698 The line-height documentation needs to explain how to use it in a font shorthand
1312712 Split filter functions out into their own pages
1335106 Documentation for the CSS Box Alignment properties
1337867 Color picker tool, lumilance is not updated when entering a hex color
1357747 Add screenshot showing visual difference in text-rendering examples, from browser where there is a difference
1367282 Style attribute vs style element specificity distinction
1367534 For the text-justify style, page says that "distribute" is deprected and that it's the same as inter-word. I don't think it's deprecated and it is not inter-word.
1371361 The Marvelous Dogmas of Nobody
1387588 Example doesn't work because the corresponding .ttf is running into CORS
1428478 Document <an-plus-b> CSS syntax
1431288 Lack of clarity in Computed Value
1439959 Document the :target-within pseudo-class
1443884 scroll-snap-type documentation is out of date
1450141 Add glossary entries for the terms "device pixels" and "CSS pixels"
1470583 Move border-image generator into a GitHub repo
1470689 MDN doesn't document that @counter-style prefixes and suffixes aren't used inside counter() functions
1481494 Document web content design support for reader mode in barious browsers
1487969 There's a wrong description about the docs link.
1490204 MDN Docs: ::-moz-color-swatch page needs to be finished, webkit added
1491509 sectionTemplateExecutionError on viewport-fit MDN page
1514213 Results for example is empty

Browse as bug list.


Please help us to localize this documentation into different languages. Read more about how to translate.

Language Pages Translated Translations up to date
bn 984 12 (1%) 0 (0%)
de 984 415 (42%) 192 (46%)
es 984 460 (46%) 82 (17%)
fa 984 22 (2%) 4 (18%)
fr 1006 999 (99%) 661 (66%)
it 984 46 (4%) 2 (4%)
ja 1006 796 (79%) 234 (29%)
kab 984 2 (0%) 0 (0%)
ko 1006 274 (27%) 118 (43%)
nl 984 16 (1%) 0 (0%)
pl 984 153 (15%) 15 (9%)
pt-BR 984 200 (20%) 32 (16%)
pt-PT 984 85 (8%) 7 (8%)
ru 994 297 (29%) 82 (27%)
tr 984 18 (1%) 2 (11%)
uk 984 28 (2%) 2 (7%)
vi 990 18 (1%) 2 (11%)
zh-CN 984 480 (48%) 117 (24%)
zh-TW 984 61 (6%) 9 (14%)

Missing pages

Learn more about how to document a CSS property.


Tagging standards

  • Every page should have the tag "CSS".
  • CSS properties belonging to a group should have the tag of that group, e.g., "CSS Flexible Boxes".


Ideas for future projects or things the ideal CSS documentation should have:

  • Compatibility summary list
  • CSS variables
  • CSS to style forms (non-standard, including Chrome and IE specific styling)
  • Better CSS flexbox documentation


These macros are maintained and actively used in the MDN CSS area. If you want to create and use a new macro, please talk to MDN admins and the CSS topic driver.

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