message: refactor: switch css classes
diff: position: fixed;
  }
  -.PopoutWrapper:not(.PopoutWrapper--fixed) .PopoutWrapper__overlay {
  - position: fixed;
  -}
  -
  .PopoutWrapper--masked .PopoutWrapper__overlay {
  background: rgba(0, 0, 0, .4);
  }
  }
  .PopoutWrapper__overlay {
  - position: absolute;
  + position: fixed;
  left: 0;
  top: 0;
  width: 100%;
  opacity: 1;
  }
  +.PopoutWrapper--fixed .PopoutWrapper__overlay {
  + position: absolute;
  +}
  +
  .PopoutWrapper__container {
  width: 100%;
  height: 100%;
  