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.

 

Do not use this property on Web sites: not only is it non-standard, but its behavior changes from one browser to another. Even the keyword none does not have the same behavior on each form element across different browsers, and some do not support it at all.

Initial value none (but this value is overriden in the user agent CSS)
Applies to all elements
Inherited no
Media visual
Computed value as specified
Animatable no
Canonical order the unique non-ambiguous order defined by the formal grammar

SyntaxEDIT

/* Partial list of available values in Gecko */
-moz-appearance: none;
-moz-appearance: button;
-moz-appearance: checkbox;
-moz-appearance: scrollbarbutton-up;

/* Partial list of available values in WebKit/Blink */
-webkit-appearance: none;
-webkit-appearance: button;
-webkit-appearance: checkbox;
-webkit-appearance: scrollbarbutton-up;