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The poster attribute is now supported for the video element, allowing content to specify a poster frame to be displayed until the video begins to play. This includes support for selecting multiple files using the input type="file" HTML element's new multiple attribute. Support for the new HTML5 File API has been added to Gecko, making it possible for web applications to access local files selected by the user. Windowed plugins are no longer displayed in CSS transforms, because they can't be transformed properly by the compositor.Added support for the :indeterminate pseudo-class, which matches checkbox input elements whose indeterminate attribute is true.
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Added :-moz-locale-dir(ltr) and :-moz-locale-dir(rtl) to make it easier to customize layouts based on whether the user interface is being displayed using a left-to-right or a right-to-left locale.DOM changes to elements using the table display types now work much better.image-rendering is supported for images, background images, videos and canvases.The rem length unit from CSS3 Values and Units is now supported.The pointer-events property lets content specify whether or not an element may be the target of mouse pointer events. WOFF font now supports the WOFF downloadable font file format.
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The background-size property from the CSS 3 Backgrounds and Borders draft is now supported under the name -moz-background-size. Media features have been added for Mozilla-specific system metrics, so that media queries can be used to more safely check on the availability of features such as touch support. This lets you specify multiple backgrounds that are rendered atop one another in layers. The background property (as well as background-color, background-image, background-position, background-repeat, and background-attachment) now supports multiple backgrounds.
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Firefox 3.6 adds support for the proposed -moz-linear-gradient and -moz-radial-gradient properties for background.
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