Interactive 2D HP lattice model of protein folding. Residues classified as Hydrophobic (H, dark green) or Polar (P, blue) are placed on a square lattice. Monte Carlo pivot moves explore the conformational space; simulated annealing gradually reduces temperature to converge toward the minimum-energy fold where H residues cluster together to minimise contact with water. Visualises the energy landscape of protein folding and the hydrophobic collapse driving force.