Animated Product Launch Landing Page

Build a complete one-page product launch site in a single HTML file. Sticky shrinking header, floating SVG hero, count-up stats, logo marquee, an interactive demo panel, a draggable before/after comparison, monthly/annual pricing, a testimonial carousel, FAQ accordion and a validating waitlist form. Light and dark themes, full keyboard access, 320px to 2560px with no horizontal scroll. Five bracket variables re-skin the whole site for any product. No frameworks, no CDN, no build step.