Micro Tower Defense Game Benchmark

Build a complete, polished, single-file HTML5 Canvas Tower Defense game called `index.html`.

Requirements:

1. Single File Architecture:
   - One standalone `index.html` file only.
   - Zero external dependencies: no external scripts, CDNs, fonts, images, or audio assets.
   - All CSS, JavaScript, and Canvas rendering logic must be inline in the single file.

2. Game Map & Pathing:
   - An HTML5 Canvas rendering a clear winding path from an enemy spawn portal to the player base.
   - Non-path grid tiles where the player can place defensive towers.
   - Enemies follow waypoints accurately along the path curve without drifting off track.

3. Towers & Arsenal (3 Distinct Types):
   - Gun Turret (Cost: 100g): Rapid single-target projectile attack against the nearest or first enemy in range.
   - Cannon (Cost: 175g): Slower firing rate, launches mortar shells that explode on impact dealing Area of Effect (AoE) splash damage.
   - Frost Laser (Cost: 250g): Emits a slowing beam or frost pulse that reduces target movement speed by 40% for a duration.

4. Tower Management & Upgrades:
   - Click/tap on an empty valid tile to open a build menu showing tower choices with gold costs and stats.
   - Click/tap on an existing tower to inspect its range circle, upgrade its damage and range, or sell it for 70% refund.

5. Wave System & Enemy Variety:
   - Progressive waves with countdown timer or "Start Wave" button.
   - At least 3 enemy archetypes:
     - Scout / Runner: Low HP, high movement speed.
     - Grunt: Balanced HP and speed.
     - Behemoth / Tank: High HP, slow movement, rewarding bonus gold.
   - Dynamic HP scaling per wave.

6. Audio & Visual Effects:
   - Procedural sound effects synthesized entirely in real-time via the browser's Web Audio API (shooting, impact/explosion, upgrade, game over). Include a master Mute sound toggle button.
   - Visual juice: projectile animations, muzzle flashes, floating damage numbers, and particle explosions on enemy death.

7. Economy, HUD & State Machine:
   - Top HUD displaying: Player Health / Lives (starts at 20), Current Gold (starts at 450), Current Wave, and Score.
   - Persistent High Score and Highest Wave recorded in `localStorage`.
   - Clean state management: Start / Title screen -> Wave Active -> Victory / Game Over overlay -> Restart Game.
   - Clean, modern, responsive UI overlaying the Canvas with responsive touch & mouse support.

Do not ask any clarifying questions. Build the complete, working, bug-free game file, verify it works in browser, and stop.