This single-file solution provides a high-performance, responsive PPFD heatmap calculator. It utilizes pure HTML5 Canvas for real-time physics-based light intensity visualization, standard Tailwind CSS for a premium SaaS interface, and no external dependencies other than standard CDNs. ```html Free PPFD Heatmap & Grow Light Footprint Calculator

Free PPFD Heatmap & Grow Light Footprint Calculator

Visualize light intensity distribution using physics-based inverse-square modeling.

Configuration

100 1000 2000
10 45 150
30 90 140

Physics-based simulation. Real-world results may vary based on optics and reflections.

0 Low Intensity High Intensity Peak