message: front/app/SideBar: fixed sidebar
diff: @@ -158,7 +158,7 @@ const useStyles = makeStyles(theme => ({
  display: 'flex',
  flexFlow: 'column nowrap',
  alignItems: 'flex-start',
  - position: 'absolute',
  + position: 'fixed',
  left: 0,
  top: 0,
  bottom: 0,
  