The HTMLDocument.getSelection() method has been moved to the Document interface so it is available to XML documents ( bugВ 718711).

The files property of the HTMLInputElement interface is now settable ( bugВ 1384030).

Document.createEvent('FocusEvent') is now supported ( bugВ 1388069).

The Selection.type property of the Selection API is now implemented ( bugВ 1359157).

The Storage API is implemented and enabled by default ( bugВ 1399038).

The AbortController and AbortSignal interfaces (known as the Abort API) have been added, allowing DOM requests (such as fetch requests) to be aborted if desired ( bugВ 1378342).

The PerformanceObserver API is now enabled by default ( bugВ 1386021).

Another Gecko bug means that the background-position property can't be transitioned between two values containing different numbers of values, for example background-position: 10px 10px and background-position: 20px 20px, 30px 30px (see bugВ 1390446).

As per spec, they shouldn't be ( bugВ 1387931).

Gecko has a bug whereby the ::before and ::after pseudo-elements are still generated even if the content property value is set to normal or none.

In Quantum CSS, calc() is supported everywhere that the spec explains it should be ( bugВ 1350857).

In Gecko, calc(1*2*3) is not parsed successfully Quantum CSS fixes this ( bugВ 1379467).

In Gecko, calc() expressions are rejected - causing the value to be invalid - when used as the radius component of a radial-gradient() function ( bugВ 1376019).

In Quantum CSS this is set as inline, as per spec ( bugВ 1374994). a created using createElement() that is not yet inserted into the DOM), the subtree's root element is set as a block-level element.

In Gecko, when you create a detached subtree (e.g.

menu), getting the font value fails to return the expected font (it returns nothing).

In Gecko, when you set a system font as the value of a canvas 2D context's font (e.g.

Quantum CSS does not use the same mechanism and it does not consider tokens invalid when they contain brackets or quotes ( bugВ 1362333).

Gecko reuses the same mechanism used when parsing a url-token when parsing the domain() or url-prefix() URL matching functions for a rule.

Gecko also deals with font-size inheritance differently from Quantum CSS, meaning that for some language settings inherited font sizes end up being smaller than expected (see bugВ 1391341).

Animations using em units are not affected by changes to the font-size on the animated element's parent in Gecko, whereas they should be ( bugВ 1254424).

with animation-fill-mode: forwards set) can trigger a transition set on the same element, although only once (see bugВ 1192592 and these test cases for more information).В In general declarative animations should not trigger transitions.

In Gecko, cancelling a filling animation (e.g.

In Gecko, transitions will not work when transitioning from a text-shadow with a color specified to a text-shadow without a color specified ( bugВ 726550).In Gecko, elements can't be made open by default using the open attribute if they have an animation active on them ( bugВ 1382124).When you animate an offscreen element onscreen but specify a delay, Gecko does not repaint on some platforms, e.g.Radial gradient values like radial-gradient(circle gold,red) will work in the old Gecko style system, even though they shouldn't because of the missing comma between circle and gold ( bugВ 1383323).This support was shipped in Firefox 54 and can no longer be disabled.ДЇollowing bugs have been fixed in Quantum:

This preference allowed disabling the support in clip-path. The preference has been removed ( bugВ 1399767).The grid-row-gap and grid-column-gap properties are no longer reset by the grid shorthand ( bugВ 1387410).

See also the Web app manifest display field.

The minimal-ui and standalone values of the display-mode media query are now supported ( bugВ 1369815).

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