Small changes to the midnight theme css.

Can you please add these to the midnight theme? ```CSS .volunteer_teaser {background-color: transparent;} html{overflow-x:hidden;} img[src^="https://www.themotte.org/assets/images/TheMotte/default"], img[src^="https://www.themotte.org/assets/images/default_"]{ filter: invert(1); } .container{ margin: 10px!important; } ```