I need a web-based user interface developed in HTML, CSS, and JavaScript to connect with the ComfyUI API. The primary functionality required is enabling users to send inputs or commands to the API. Specifically, these commands should be managed through a drag-and-drop interface for intuitive interaction. The interface should be clean, functional, and designed to enhance user experience. Please ensure the UI effectively communicates with the API and provides seamless interaction for the end-users.