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Text of the page (random words):
onsortium resulted in the first w3c css recommendation css1 26 being released in 1996 in particular a proposal by bert bos was influential he became co author of css1 and is regarded as co creator of css 27 style sheets have existed in one form or another since the beginnings of standard generalized markup language sgml in the 1980s and css was developed to provide style sheets for the web 28 one requirement for a web style sheet language was for style sheets to come from different sources on the web therefore existing style sheet languages like dsssl and fosi were not suitable css on the other hand let a document s style be influenced by multiple style sheets by way of cascading styles 28 as html grew it came to encompass a wider variety of stylistic capabilities to meet the demands of web developers this evolution gave the designer more control over site appearance at the cost of more complex html variations in web browser implementations such as violawww and worldwideweb 29 made consistent site appearance difficult and users had less control over how web content was displayed the browser editor developed by tim berners lee had style sheets that were hard coded into the program the style sheets could therefore not be linked to documents on the web 25 robert cailliau also of cern wanted to separate the structure from the presentation so that different style sheets could describe different presentation for printing screen based presentations and editors 29 improving web presentation capabilities was a topic of interest to many in the web community and nine different style sheet languages were proposed on the www style mailing list 28 of these nine proposals two were especially influential on what became css cascading html style sheets 24 and stream based style sheet proposal ssp 27 30 two browsers served as testbeds for the initial proposals lie worked with yves lafon to implement css in dave raggett s arena browser 31 32 33 bert bos implemented his own ssp proposal in the argo browser 27 thereafter lie and bos worked together to develop the css standard the h was removed from the name because these style sheets could also be applied to other markup languages besides html 25 lie s proposal was presented at the mosaic and the web conference later called www2 in chicago illinois in 1994 and again with bert bos in 1995 25 around this time the w3c was already being established and took an interest in the development of css it organized a workshop toward that end chaired by steven pemberton this resulted in w3c adding work on css to the deliverables of the html editorial review board erb lie and bos were the primary technical staff on this aspect of the project with additional members including thomas reardon of microsoft participating as well in august 1996 netscape communication corporation presented an alternative style sheet language called javascript style sheets jsss 25 the spec was never finished and is deprecated 34 by the end of 1996 css was ready to become official and the css level 1 recommendation was published in december development of html css and the dom had all been taking place in one group the html editorial review board erb early in 1997 the erb was split into three working groups html working group chaired by dan connolly of w3c dom working group chaired by lauren wood of softquad and css working group chaired by chris lilley of w3c the css working group began tackling issues that had not been addressed with css level 1 resulting in the creation of css level 2 on november 4 1997 it was published as a w3c recommendation on may 12 1998 css level 3 which was started in 1998 is still under development as of 2014 update in 2005 the css working groups decided to enforce the requirements for standards more strictly this meant that already published standards like css 2 1 css 3 selectors and css 3 text were pulled back from candidate recommendation to working draft level difficulty with adoption edit the css 1 specification was completed in 1996 microsoft s internet explorer 3 25 was released that year featuring some limited support for css ie 4 and netscape 4 x added more support but it was typically incomplete and had many bugs that prevented css from being usefully adopted it was more than three years before any web browser achieved near full implementation of the specification internet explorer 5 0 for the macintosh shipped in march 2000 was the first browser to have full better than 99 percent css 1 support 35 surpassing opera which had been the leader since its introduction of css support fifteen months earlier other browsers followed soon afterward and many of them additionally implemented parts of css 2 however even when later version 5 web browsers began to offer a fairly full implementation of css they were still incorrect in certain areas they were fraught with inconsistencies bugs and other quirks microsoft internet explorer 5 x for windows as opposed to the very different ie for macintosh had a flawed implementation of the css box model as compared with the css standards such inconsistencies and variation in feature support made it difficult for designers to achieve a consistent appearance across browsers and platforms without the use of workarounds termed css hacks and filters the ie windows box model bugs were so serious that when internet explorer 6 was released microsoft introduced a backward compatible mode of css interpretation quirks mode alongside an alternative corrected standards mode other non microsoft browsers also provided mode switch capabilities it therefore became necessary for authors of html files to ensure they contained special distinctive standards compliant css intended marker to show that the authors intended css to be interpreted correctly in compliance with standards as opposed to being intended for the now long obsolete ie5 windows browser without this marker web browsers with the quirks mode switching capability will size objects in web pages as ie 5 on windows would rather than following css standards problems with the patchy adoption of css and errata in the original specification led the w3c to revise the css 2 standards into css 2 1 which moved nearer to a working snapshot of current css support in html browsers some css 2 properties that no browser successfully implemented were dropped and in a few cases defined behaviors were changed to bring the standard into line with the predominant existing implementations css 2 1 became a candidate recommendation on february 25 2004 but css 2 1 was pulled back to working draft status on june 13 2005 36 and only returned to candidate recommendation status on july 19 2007 37 in addition to these problems the css extension was used by a software product used to convert powerpoint files into compact slide show files 38 so some web servers served all css 39 as mime type application x pointplus 40 rather than text css vendor prefixes edit individual browser vendors occasionally introduced new parameters ahead of standardization and universalization to prevent interfering with future implementations vendors prepended unique names to the parameters such as moz for mozilla firefox webkit named after the browsing engine of apple safari o for opera browser and ms for microsoft internet explorer and early versions of microsoft edge that use edgehtml occasionally the parameters with vendor prefixes such as moz radial gradient and webkit linear gradient have slightly different syntax as compared to their non vendor prefix counterparts 41 prefixed properties are rendered obsolete by the time of standardization programs are available to automatically add prefixes for older browsers and to point out standardized versions of prefixed parameters since prefixes are limited to a small subset of browsers removing the prefix allows other browsers to see the functionality an exception is certain obsolete webkit prefixed properties which are so common and persistent on the web that other families of browsers have decided to support them for compatibility 42 css snapshot 2021 css has various levels and profiles each level of css builds upon the last typically adding new features and typically denoted 43 as css 1 css 2 css 3 and css 4 profiles are typically a subset of one or more levels of css built for a particular device or user interface currently there are profiles for mobile devices printers and television sets profiles should not be confused with media types which were added in css 2 css 1 edit the first css specification to become an official w3c recommendation is css level 1 published on 17 december 1996 håkon wium lie and bert bos are credited as the original developers 44 45 among its capabilities are support for font properties such as typeface and emphasis color of text backgrounds and other elements text attributes such as spacing between words letters and lines of text alignment of text images tables and other elements margin border padding and positioning for most elements unique identification and generic classification of groups of attributes the w3c no longer maintains the css 1 recommendation 46 css 2 edit css level 2 specification was developed by the w3c and published as a recommendation in may 1998 a superset of css 1 css 2 includes a number of new capabilities like absolute relative and fixed positioning of elements and z index the concept of media types support for aural style sheets which were later replaced by the css 3 speech modules 47 and bidirectional text and new font properties such as shadows the w3c no longer maintains the css 2 recommendation 48 css 2 1 edit css level 2 revision 1 often referred to as css 2 1 fixes errors in css 2 removes poorly supported or not fully interoperable features and adds already implemented browser extensions to the specification to comply with the w3c process for standardizing technical specifications css 2 1 went back and forth between working draft status and candidate recommendation status for many years css 2 1 first became a candidate recommendation on 25 february 2004 but it was reverted to a working draft on 13 june 2005 for further review it returned to candidate recommendation on 19 july 2007 and then updated twice in 2009 however because changes and clarifications were made it again went back to last call working draft on 7 december 2010 css 2 1 went to proposed recommendation on 12 april 2011 49 after being reviewed by the w3c advisory committee it was finally published as a w3c recommendation on 7 june 2011 50 css 2 1 was planned as the first and final revision of level 2 but low priority work on css 2 2 began in 2015 css 3 edit css3 redirects here for other uses see css3 disambiguation unlike css 2 which is a large single specification defining various features css 3 is divided into several separate documents called modules each module adds new capabilities or extends features defined in css 2 preserving backward compatibility work on css level 3 started around the time of publication of the original css 2 recommendation the earliest css 3 drafts were published in june 1999 51 due to the modularization different modules have different stability and statuses 52 some modules have candidate recommendation cr status and are considered moderately stable at cr stage implementations are advised to drop vendor prefixes 53 summary of main module specifications 54 module specification title status date css3 background css backgrounds and borders module level 3 candidate rec feb 2023 css box 3 css box model module level 3 recommendation apr 2023 css cascade 3 css cascading and inheritance level 3 recommendation feb 2021 css color 3 css color module level 3 recommendation jan 2022 css3 content css generated content module level 3 working draft aug 2019 css fonts 3 css fonts module level 3 recommendation sep 2018 css3 gcpm css generated content for paged media module working draft may 2014 css3 layout css template layout module note mar 2015 css3 mediaqueries media queries recommendation jun 2012 mediaqueries 4 media queries level 4 candidate rec dec 2021 css3 multicol multi column layout module level 1 candidate rec oct 2021 css3 page css paged media module level 3 working draft and part migrated to css3 break oct 2018 css3 break css fragmentation module level 3 candidate rec dec 2018 selectors 3 selectors level 3 recommendation nov 2018 selectors 4 selectors level 4 working draft nov 2022 css3 ui css basic user interface module level 3 css3 ui recommendation jun 2018 css 4 edit css4 redirects here for other uses see css4 disambiguation jen simmons discussing the state of css in 2019 as several css 4 modules were being advanced there is no css4 specification 55 56 because css has been split into many separate modules which level independently modules that build on things from css level 2 started at level 3 some of them have already reached level 4 or are already approaching level 5 other modules that define entirely new functionality such as flexbox 57 have been designated as level 1 and some of them are approaching level 2 the css working group sometimes publishes snapshots a collection of whole modules and parts of other drafts that are considered stable enough to be implemented by browser developers so far five such best current practices documents have been published as notes in 2007 58 2010 59 2015 60 2017 61 and 2018 62 since these specification snapshots are primarily intended for developers there has been a growing demand for a similar versioned reference document targeted at authors which would present the state of interoperable implementations as meanwhile documented by sites like can i use 63 and the mdn web docs 64 a w3c community group has been established in early 2020 in order to discuss and define such a resource 65 the actual kind of versioning is also up to debate which means that the document once produced might not be called css4 browser support edit each web browser uses a layout engine to render web pages and support for css functionality is not consistent between them because browsers do not parse css perfectly multiple coding techniques have been developed to target specific browsers with workarounds commonly known as css hacks or css filters the adoption of new functionality in css can be hindered by a lack of support in major browsers for example internet explorer was slow to add support for many css 3 features which slowed the adoption of those features and damaged the browser s reputation among developers additionally a proprietary syntax for the non vendor prefixed filter property was used in some versions 66 in order to ensure a consistent experience for their users web developers often test their sites across multiple operating systems browsers and browser versions increasing development time and complexity tools such as browserstack have been built to reduce the complexity of maintaining these environments in addition to these testing tools many si...