10,000 Particles Morph Between Sphere, Heart, and Text

A Three.js particle animation page: about 12,000 glowing particles morph every 4 seconds among three shapes: a sphere, a heart, and the text "HI". Each shape gets a color gradient, additive blending creates the glow, and the whole scene slowly rotates and responds to mouse parallax. The prompt is five numbered technical requirements, including importmap loading and offscreen canvas text sampling. Good for confession pages, event openers, or web background effects.