discourse/plugins/chat/assets/stylesheets/common/chat-threads-list.scss

.chat-thread-list {
  display: flex;
  flex-direction: column;
  position: relative;
  @include chat-height;

  &__items {
    overflow-y: scroll;
    @include chat-scrollbar();
    box-sizing: border-box;
    flex-grow: 1;
    overscroll-behavior: contain;
    display: flex;
    flex-direction: column;

    .chat-thread-list-item {
      margin: 0.75rem 0.25rem 0.75rem 0.5rem;

      & + .chat-thread-list-item {
        margin-top: 0;
      }
    }
  }

  &__no-threads {
    @include thread-list-item;
    margin: 0.5rem 0rem 0.5rem 0.5rem;
  }
}