bigbluebutton-Github/bigbluebutton-html5/imports/ui/components/audio/audio-controls/styles.scss

.container {
  display: flex;
  flex-flow: row;

  > * {
    margin: 0 1rem;

    span:first-child {
      box-shadow: 0 2px 5px 0 rgb(0, 0, 0);
    }
  }

  > :last-child {
    margin-right: 0;
  }
}