Elegant, Responsive Disney-Inspired Invitation Design

I need to change the design of a birthday invitation based on a Mickey and friends invitation. Here is what I need to be done:

Use the attached/reference invitation image as the main inspiration. I want a cleaner, soft, elegant Disney-inspired birthday invitation style: mostly white background, pastel accents, centered layout, playful but polished typography, and a responsive-first design.

Important requirements:

1. Layout and responsiveness
- Build the design mobile-first.
- Keep the invitation centered and visually balanced.
- Text must remain readable on mobile, tablet, and desktop.
- Use proper spacing, alignment, and hierarchy.
- Avoid fixed sizes that break on small screens.

2. Images and decorative elements
- Add a large outline Mickey ears shape in the background behind the main image if possible using CSS/SVG.
- Add pastel Mickey-head decorative icons around the card.
- Add balloons around the design. Subtle animation is welcome, but keep it tasteful and not distracting.
- Prefer CSS/SVG decorative shapes where possible so colors can be easily changed later.

3. Code quality
Act as a senior frontend developer.
Use best practices.
Keep the code clean and easy to modify.