discourse/plugins/discourse-calendar/assets/stylesheets/mobile/discourse-post-event.scss

.discourse-post-event {
  .discourse-post-event-widget {
    border-width: 1px;
  }

  .event-dates {
    .date {
      max-width: 75vw;
    }
  }

  .event-actions {
    .event-status {
      width: 100%;
      display: flex;
      justify-content: space-between;

      button {
        padding: 0 0.6em;
        height: 2.5em;
      }
    }
  }

  .event-invitees-status {
    font-size: var(--font-down-1);
  }

  .creators {
    .created-by {
      display: none;
    }
  }
}