I'll create a basic layout for a WhatsApp Web clone using React and Tailwind CSS. This will include a sidebar with a list of chats and a main chat area. Let's break it down into components:

This code creates a basic WhatsApp Web clone with the following features:

1. A sidebar with a header, search input, and a scrollable list of chats.
2. A main chat area with a header, scrollable message list, and an input area for new messages.
3. Placeholder data for chats and messages to demonstrate the layout.
4. Responsive design using Tailwind CSS classes.
5. Use of shadcn/ui components like Input, Button, and ScrollArea for consistent styling.
6. Icons from the Lucide React library for various UI elements.

To use this code, you'll need to make sure you have the necessary dependencies installed, including the shadcn/ui components and Lucide React icons.

You can further enhance this clone by adding more interactivity, such as:

1. Implementing state management to switch between chats.
2. Adding functionality to send and receive messages.
3. Implementing real-time updates using WebSockets or a similar technology.
4. Adding more features like file attachments, voice messages, or emoji pickers.

Let me know if you want to expand on any specific part of this WhatsApp Web clone!