discourse/app/assets/stylesheets/common/select-kit/topic-notifications-button.scss

#topic-footer-buttons {
  .topic-notifications-button {
    min-width: auto;
    margin: 1em 0;

    .btn {
      margin: 0;
    }

    .reason {
      display: inline;
      line-height: $line-height-medium;
    }
  }
}

.topic-notifications-button .topic-notifications-options {
  min-width: auto;
}

.topic-notifications-button {
  margin: 0;

  .topic-notifications-options {
    display: inline-flex;
  }
}