autohide toolbox: clamp urlbar-input box block padding When the user exits customize mode, Firefox re-evaluates urlbar dimensions and the result ends up with --urlbar-height becoming 0px since the urlbar gets hidden. The input box uses --urlbar-height to calculate its block padding which in turn evaluates to full urlbar-height - thus making the contents of input-box 0px leading to "invisible" input-box. As a workaround we now clamp the padding-block calculation to 4px.