discourse/plugins/chat/assets/stylesheets/common/chat-index.scss

.btn-floating.open-new-message-btn {
  position: fixed;
  background: var(--tertiary);
  bottom: 2rem;
  right: 2rem;
  border-radius: 50%;
  font-size: var(--font-up-4);
  padding: 1rem;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  z-index: z("usercard");
  box-shadow: 0px 5px 5px -1px rgba(0, 0, 0, 0.25);

  .d-icon {
    color: var(--primary-very-low);
  }

  &:active {
    box-shadow: 0px 0px 5px -1px rgba(0, 0, 0, 0.25);
    transform: scale(0.9);
  }

  &:focus {
    @include default-focus;
    border-color: var(--quaternary);
    outline-color: var(--quaternary);
  }
}

.channels-list {
  overflow-y: auto;
  overscroll-behavior: contain;
  height: 100%;
  padding-bottom: env(safe-area-inset-bottom);
  position: relative;
  @include chat-scrollbar();

  @include breakpoint(mobile-large) {
    @include chat-scrollbar();
  }

  .open-browse-page-btn,
  .open-draft-channel-page-btn,
  .chat-channel-leave-btn {
    position: relative;
    padding: 0;
    background: transparent;
    color: var(--primary-medium);
    font-size: var(--font-0-rem);

    &:after {
      content: "";
      position: absolute;
      top: -50%;
      left: -50%;
      width: 200%;
      height: 200%;
    }

    &:hover {
      background: transparent;

      .d-icon {
        color: var(--primary);
      }
    }
  }

  .public-channel-empty-message {
    margin: 0 0.5em 0.5em 0.5em;
    padding: 0 1em;
  }

  .chat-channel-divider {
    padding: 2.5rem 1.5rem 0.5rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-weight: bold;
    font-family: var(--heading-font-family);
    font-size: var(--font-down-1);
    color: var(--quaternary);

    .channel-title {
      line-height: var(--line-height-medium);
    }

    &:first-of-type {
      padding-top: 1rem;
    }
  }
}