Build a Snake game as a polished single-page web app in this directory: index.html, style.css, game.js (vanilla JS, no deps). Canvas grid; snake grows on eating food; dies on wall or self collision; live score and a high score persisted in localStorage; speed ramps up as the score climbs; arrow keys AND wasd; spacebar to pause; a game-over overlay with a restart button; and a sharp dark neon theme. Make it genuinely nice.