Premium Landing Page Development for Heavy Equipment Rental with Advanced Ui/Ux and Seo

We are seeking a skilled freelancer to enhance and finalize a one-page website for a heavy equipment rental company. The site features a dark theme with gold accents and is already mobile responsive. The goal is to elevate the existing site to a premium level with advanced ui/ux, interactive elements, and robust backend integrations.

What's already done:
- Main sections: hero, catalog, advantages, contacts.
- Browser-based 3D model preview with auto-rotate and zoom functionality.
- Scroll animations and stat counters.
- Mobile responsiveness implemented.

What needs to be done:
1. Design & UI enhancements:
- Polish the overall design to a premium level.
- Implement micro-animations and hover effects.
- Develop a custom cursor.
- Replace the current preloader spinner with a branded preloader.
- Create a dynamic hero section with particles or a gradient mesh background.

2. 3D preview section improvements:
- Replace the existing spinner with a real progress bar displaying percentage for 3D model loading.
- Implement switch buttons to toggle between three different 3D models (bulldozer, excavator, grader).
- Fine-tune the auto-rotation functionality of the 3D models.

3. Forms & leads management:
- Develop a callback request form.
- Implement client-side validation for phone number and name fields.
- Integrate server-side form submission using a Python endpoint.
- Configure Telegram notifications for new lead submissions.

4. Catalog functionality:
- Add filtering options for equipment by type and price.
- Develop a detail modal for each equipment item, displaying comprehensive information.
- Implement data loading for the catalog from a JSON source.

5. Map integration:
- Integrate a branch map with markers using Leaflet.
- Add a "Nearest to me" button for location-based services.

6. English version implementation:
- Develop a language switcher for English and the existing language.
- Implement translations for all content, loading data from a JSON source.

7. SEO optimization:
- Implement Schema.org markup for improved search engine visibility.
- Configure Open Graph tags for social media previews.
- Implement lazy loading for all images and content to enhance performance.