PUBLIC MARKS from decembre with tags web & xul

When editing userChrome.css, you must add CSS selectors based on the element names and IDs/classes of the XUL user interface. There is no comprehensive listing of every single possible selector to use when styling the user interface (just as it would be silly to create such a comprehensive list for a web page), but a few of the more common and interesting selectors are listed below. The best way to discover how to select an element in the user interface is to use the DOM Inspector.

You can inspect the Firefox user interface directly with DOM Inspector. (Which is not the same Inspector as in the Web Developer menu.) [addons.mozilla.org] https://addons.mozilla.org/en-US/firefox/addon/dom-inspector-6622/Click the icon in the upper-left corner of DOMi, the one with a pointer on it, then click anywhere in the browser to select an element; that element will be highlighted in the left column. Right-click the highlighted entry to display a context menu: "Copy Selector" suggests selectors for the element, "Set Pseudo-classes..." lets you switch on :hover. Notice that the browser itself is a document with its own URI, chrome://browser/content/browser.xul, Most of the browser chrome is XUL, but some, such as the Stylish editor, is HTML embedded in XUL. https://developer.mozilla.org/en-US/docs/XUL

The DOM Inspector (also known as DOMi) is a developer tool used to inspect, browse, and edit the Document Object Model of documents - usually web pages or XUL windows. The DOM hierarchy can be navigated using a two-paned window that allows for a variety of different views on the document and all nodes within.