The -moz-appearance CSS property is used in Gecko (Firefox) to display an element using a platform-native styling based on the operating system's theme.

This property is frequently used in XUL stylesheets to design custom widgets with platform-appropriate styling. It is also used in the XBL implementations of the widgets that ship with the Mozilla platform.

[Webplatform](http://docs.webplatform.org/wiki/css/properties/appearance "Webplatform")
[Mozilla docs](https://developer.mozilla.org/en/docs/Web/CSS/-moz-appearance "Mozilla")
