CSS Object Model (CSSOM) - MDN Web Docs Glossary: Definitions of Web-related terms
the css object model (cssom) is a map of all css selectors and relevant properties for each selector in the form of a tree, with a root node, sibling, descendant, child, and other relationship.
... the cssom is very similar to the document object model (dom).
... the cssom, together with the dom, to build the render tree, which is in turn used by the browser to layout and paint the web page.
... cssom api the css object model is also a set of apis allowing the manipulation of css from javascript.

CSSOMString - Web APIs
cssomstring is used to denote string data in cssom specifications and can refer to either domstring or usvstring.
... when a specification says cssomstring, it depends on the browser vendors to choose whether to use domstring or usvstring.
... while browser implementations that use utf-8 internally to represent strings in memory can use usvstring when the specification says cssomstring, implementations that already represent strings as 16-bit sequences might choose to use domstring instead.
... implementation differences browser domstring or usvstring for cssomstring firefox (gecko) usvstring chrome (blink) usvstring safari (webkit) usvstring edge (edgehtml) - opera (blink) usvstring specifications specification status comment css object model (cssom)the definition of 'cssomstring' in that specification.

CSS Object Model (CSSOM) - Web APIs
cssrulelist cssstyledeclaration cssstylesheet cssstylerule csssupportsrule cssvariablesmap cssviewportrule elementcssinlinestyle fontface fontfaceset fontfacesetloadevent geometryutils getstyleutils linkstyle medialist mediaquerylist mediaquerylistevent mediaquerylistlistener screen stylesheet stylesheetlist transitionevent several other interfaces are also extended by the cssom-related specifications: document, window, element, htmlelement, htmlimageelement, range, mouseevent, and svgelement.
...oduct cssmathsum cssmathvalue cssmatrixcomponent cssnumericarray cssnumericvalue cssperspective csspositionvalue cssrotate cssscale cssskew cssskewx cssskewy cssstylevalue csstransformcomponent csstransformvalue csstranslate cssunitvalue cssunparsedvalue cssvariablereferencevalue stylepropertymap stylepropertymapreadonly obsolete cssom interfaces cssprimitivevalue cssvalue cssvaluelist tutorials determining the dimensions of elements (it needs some updating as it was made in the dhtml/ajax era).
... css object model (cssom) view module working draft defined the screen and mediaquerylist interfaces and the mediaquerylistevent event and mediaquerylistlistener event listener.
... css object model (cssom) working draft extended the css interface and provides the base for the modern cssom specification.

CSSOM View - CSS: Cascading Style Sheets
cssom view is a module of css that lets you manipulate the visual view of a document, in particular its scrolling behavior.
... specifications specification status comment css object model (cssom) view module working draft initial definition.

Index - Web APIs
87 animationevent() api, animationevent, cssom, constructor, experimental, reference, web animations the animationevent() constructor returns a newly created animationevent, representing an event in relation with an animation.
... 88 animationevent.animationname api, animationevent, cssom, experimental, property, reference, web animations the animationevent.animationname read-only property is a domstring containing the value of the animation-name css property associated with the transition.
... 89 animationevent.elapsedtime api, animationevent, cssom, experimental, property, reference, web animations the animationevent.elapsedtime read-only property is a float giving the amount of time the animation has been running, in seconds, when this event fired, excluding any time the animation was paused.
...And 132 more matches

Populating the page: how browsers work - Web Performance
parsing is the step the browser takes to turn the data it receives over the network into the dom and cssom, which is used by the renderer to paint a page to the screen.
... building the cssom the second step in the critical rendering path is processing css and building the cssom tree.
...the dom and cssom are both trees.
...And 8 more matches

FontFace - Web APIs
fontface.display a cssomstring that determines how a font face is displayed based on whether and when it is downloaded and ready to use.
... fontface.family a cssomstring that retrieves or sets the family of the font.
... fontface.featuresettings a cssomstring that retrieves or sets infrequently used font features that are not available from a font's variant properties.
...And 5 more matches

Critical rendering path - Web Performance
optimizing the critical render path improves render performance.the critical rendering path includes the document object model (dom), css object model (cssom), render tree and layout.
...with the dom and cssom complete, the browser builds the render tree, computing the styles for all the visible content.
...the cssom contains all the styles of the page; information on how to style that dom.
...And 4 more matches

Houdini - MDN Web Docs Glossary: Definitions of Web-related terms
houdini gives developers access to the css object model (cssom), enabling developers to write code the browser can parse as css.
... while many of the features houdini enables can be created with javascript, interacting directly with the cssom before javascript is enabled provides for faster parse times.
... browsers create the cssom — including layout, paint, and composite processes — before applying any style updates found in scripts: layout, paint, and composite processes are repeated for updated javascript styles to be implemented.
... see also houdini houdini: an introduction cssom css paint api css typed om ...

MouseEvent.pageX - Web APIs
the cssom view module redefined it as a double float.
... this property was originally specified in the touch events specification as a long integer, but was redefined in the cssom view module to be a double-precision floating-point number to allow for subpixel precision.
... .box { width: 400px; height: 250px; border: 2px solid darkblue; background-color: blue; color: white; font: 16px "zilla", "open sans", "helvetica", "arial", sans-serif; } result try this out here: specifications specification status comment css object model (cssom) view modulethe definition of 'pagex' in that specification.
... prior to being added to the cssom view specification, pagex and pagey were available on the uievent interface in a limited subset of browsers for a short time.

Index - MDN Web Docs Glossary: Definitions of Web-related terms
56 css object model (cssom) css, cssom, dom, glossary, web performance the css object model (cssom) is a map of all css selectors and relevant properties for each selector in the form of a tree, with a root node, sibling, descendant, child, and other relationship.
... the cssom is very similar to the document object model (dom).
...houdini gives developers access to the css object model (cssom), enabling developers to write code the browser can parse as css.

CSS.escape() - Web APIs
the css.escape() static method returns a cssomstring containing the escaped string passed as parameter, mostly for use as part of a css selector.
... syntax escapedstr = css.escape(str); parameters str the cssomstring to be escaped.
...scape() method can be used: var element = document.queryselector('#' + css.escape(id) + ' > img'); the escape() method can also be used for escaping strings, although it escapes characters that don't strictly need to be escaped: var element = document.queryselector('a[href="#' + css.escape(fragment) + '"]'); specification specification status comment css object model (cssom)the definition of 'css.escape()' in that specification.

Using dynamic styling information - Web APIs
the css object model (cssom), part of the dom, exposes specific interfaces allowing manipulation of a wide amount of information regarding css.
... initially defined in the dom level 2 style recommendation, these interfaces forms now a specification, css object model (cssom) which aims at superseding it.
... modify a stylesheet rule with cssom <html> <head> <title>modifying a stylesheet rule with cssom</title> <style type="text/css"> body { background-color: red; } </style> <script type="text/javascript"> var stylesheet = document.stylesheets[0]; stylesheet.cssrules[0].style.backgroundcolor="blue"; </script> </head> <body> the stylesheet declaration for the body's background color is modified via javascript.

CSS reference - CSS: Cascading Style Sheets
also included is a brief dom-css / cssom reference.
...note that css rule definitions are entirely (ascii) text-based, whereas dom-css / cssom (the rule management system) is object-based.
...scade comments descriptor inheritance shorthand properties specificity value definition syntax css unit and value types values actual value computed value initial value resolved value specified value used value layout block formatting context box model containing block layout mode margin collapsing replaced elements stacking context visual formatting model dom-css / cssom major object types documentorshadowroot.stylesheets stylesheets[i].cssrules cssrules[i].csstext (selector & style) cssrules[i].selectortext htmlelement.style htmlelement.style.csstext (just style) element.classname element.classlist important methods cssstylesheet.insertrule() cssstylesheet.deleterule() ...

CSS Houdini
houdini is a group of apis that give developers direct access to the css object model (cssom), enabling developers to write code the browser can parse as css, thereby creating new css features without waiting for them to be implemented natively in browsers.
...browsers parse the cssom — including layout, paint, and composite processes — before applying any style updates found in scripts.
... css properties and values api reference css properties and values api guide css typed om converting cssom value strings into meaningfully typed javascript representations and back can incur a significant performance overhead.