APPmy/src/app/aichat/aichat.page.scss

page-aichat {
    ion-content {
      ion-item {
        ion-avatar {
          width: 40px;
          height: 40px;
        }
        .message-time {
          font-size: 12px;
          color: #999;
        }
      }
    }
  }