The toggle arrows should align with the left scan-line (see screenshot) of the layout.
currently there is a 10px gap due to margin on both sides of the chevron
What is it currently
What is expected
on RTL languages, the chevron should align on the right side
Note that mw-ui-icon adds this margin so you may need to employ a negative margin to combat this. This value is exposed in @iconGutterWidth.