Happy Pi Day 2026 Retro Minimal Math Design Poster 招待状

Clean retro-style Pi Day 2026 design featuring bold geometric bars, warm vintage colors, and elegant pi symbols in a minimalist layout. Inspired by mid-century graphic design with a soft distressed texture and a warm beige and golden palette. Perfect for Pi Day celebrations, math classrooms, STEM events, and gifts for math lovers, teachers, and students. Works beautifully on cards, posters, stickers, notebooks, and other printable products. A stylish and modern vintage look that keeps math fun and visually elegant.