In https://en.wiktionary.org in Special:Preferences the background color of the tabs is missing. So i cannot see which of the tabs is currently selected. This also happens in https://de.wiktionary.org and in Special:GlobalPreferences
BTW in Special:GlobalPreferences in the tab "Appearance" the first item of selection lists jumps to the right side of the window depending on the width of the window.
Happens in IE and Firefox.