Vibrant magical third-grade T-shirt design on a blue background. A cute dynamic white unicorn with a flowing rainbow mane and tail, bright pink, turquoise, purple and yellow highlights, standing in a playful energetic pose surrounded by colorful stars, hearts, confetti and school-themed doodles. At the top, bold colorful uppercase lettering reads exactly: "I'M READY TO". The dominant center headline reads exactly: "CRUSH". Beneath the unicorn, large multicolored block lettering reads exactly: "3RD GRADE". Add playful colorful paint-splash accents behind the artwork, high-energy elementary-school aesthetic, polished cartoon illustration, crisp outlines, saturated neon colors, strong typography hierarchy, excellent text readability, centered composition, premium screen-print-ready apparel graphic, no mockup, no person, no extra words.