discourse/plugins/chat/assets/stylesheets/mobile/chat-thread-list-header.scss

.chat-thread-list-header {
  padding-inline: 0 0.5rem;
  align-items: flex-start;

  &__label {
    padding-top: 0.35em;
  }

  &__label-channel {
    line-height: var(--line-height-small);
  }
}