There are a few elementary-specific style elements. They are as follows:

"GraniteWidgetsPopOver" [DEPRECATED]: Granite Popover widget. Accepts proprietary properties:
    -GraniteWidgetsPopOver-arrow-width
    -GraniteWidgetsPopOver-arrow-height
    -GraniteWidgetsPopOver-border-radius
    -GraniteWidgetsPopOver-border-width
    -GraniteWidgetsPopOver-shadow-size

"GraniteWidgetsThinPaned" [DEPRECATED]: Granite ThinPaned widget handle.

"GraniteWidgetsWelcome": Granite Welcome widget as seen in Scratch, Photos, Noise.

"MarlinViewChromeLocationBar": Files Pathbar widget

".back-button": Shaped back buttons as seen in Switchboard

".category-label" [DEPRECATED] Please use ".h4"

".composited-indicator": An indicator menubar item in Wingpanel

".content-view" [DEPRECATED]: "light" app areas; overriding a grey background color. Should no longer be necessary in this stylesheet

".dynamic-notebook": Tab bar widget as seen in Scratch, Terminal, Files, etc.

".gala-notification": Notifications in Gala

".h1": Large primary text as seen in Welcome

".h2": Large secondary text as seen in Welcome

".h3": Small primary text as seen in dialogs

".h4": Typically used for category labels

".help_button": Simple (?) buttons.

".pathbar": Files Pathbar widget

".panel": Wingpanel

".panel-shadow": Shadow below wingpanel

".overlay-bar": Overlay statusbar as seen in Files.

".secondary-toolbar": Used in Midori's Bookmarks bar.

".seek-bar": Used for media playback position controls

".source-list": Granite SourceList widget
