(() => {
  // Game Config
  const WORLD = { width: 4200, height: 180 };
  const GRAVITY = 0.35;
  const FRICTION = 0.80;
  const MAX_FALL = 8.5;
  const PLAYER = { w: 14, h: 16, speed: 1.25, jump: 6.5, fireCooldown: 280 };
  const CAMERA = { lerp: 0.12, shake: 0 };
  const TILE = 16;

  // Colors (choose pleasing 16-bit palette)
  const COLORS = {
    sky: "#14213d",
    sky2: "#0f1a35",
    cloud: "#e9f0ff",
    cloud2: "#d6e4ff",
    hill: "#274c77",
    hill2: "#1d3a5b",
    grass: "#41a55d",
    dirt: "#6b4f3a",
    dirt2: "#5a4130",
    pipe: "#2f9e44",
    pipeDark: "#237a34",
    enemy: "#8b5e34",
    enemyDark: "#704a2a",
    playerHat: "#e63946",
    playerBody: "#1d3557",
    playerFace: "#ffe0bd",
    fire1: "#ff9f1c",
    fire2: "#ffd166",
    coin1: "#ffd166",
    coin2: "#fca311",
    uiText: "#ffffff",
    overlay: "rgba(0,0,0,0.55)"
  };

  // DOM
  const bgCanvas = document.getElementById("bg");
  const gameCanvas = document.getElementById("game");
  const bgCtx = bgCanvas.getContext("2d");
  const ctx = gameCanvas.getContext("2d");
  ctx.imageSmoothingEnabled = false;
  bgCtx.imageSmoothingEnabled = false;

  const scoreEl = document.getElementById("score");
  const coinsEl = document.getElementById("coins");
  const livesEl = document.getElementById("lives");
  const messageBox = document.getElementById("messageBox");
  const messageTitle = document.getElementById("messageTitle");
  const messageText = document.getElementById("messageText");

  // Input
  const keys = {
    left: false, right: false, up: false, fire: false,
    pause: false, mute: false
  };

  // Touch controls
  const btnLeft = document.getElementById("btnLeft");
  const btnRight = document.getElementById("btnRight");
  const btnJump = document.getElementById("btnJump");
  const btnFire = document.getElementById("btnFire");

  // Camera
  const camera = { x: 0, y: 0, w: 320, h: 180 };

  // Game State
  let state = "playing"; // playing, paused, gameover, win
  let score = 0;
  let coins = 0;
  let lives = 3;
  let time = 0;
  let muted = false;

  // Entities
  const player = {
    x: 32, y: 0, w: PLAYER.w, h: PLAYER.h,
    vx: 0, vy: 0, dir: 1, onGround: false,
    canFireAt: 0, spawnX: 32, spawnY: 0
  };

  /** Platforms and Pipes (simple AABB rectangles) */
  const solids = [
    // Ground
    { x: 0, y: 150, w: WORLD.width, h: 60 },
    // Small hills / platforms
    { x: 240, y: 136, w: 90, h: 8 },
    { x: 420, y: 122, w: 90, h: 8 },
    { x: 650, y: 142, w: 80, h: 8 },
    { x: 980, y: 120, w: 120, h: 8 },
    { x: 1270, y: 128, w: 100, h: 8 },
    { x: 1550, y: 110, w: 80, h: 8 },
    { x: 1800, y: 140, w: 140, h: 8 },
    { x: 2150, y: 118, w: 100, h: 8 },
    { x: 2450, y: 130, w: 90, h: 8 },
    { x: 2780, y: 115, w: 120, h: 8 },
    { x: 3120, y: 140, w: 120, h: 8 },
    { x: 3450, y: 120, w: 100, h: 8 },
    { x: 3720, y: 135, w: 90, h: 8 },
  ];

  // Pipes
  const pipes = [
    { x: 600, y: 150 - 24, w: 24, h: 24 },
    { x: 1320, y: 150 - 32, w: 24, h: 32 },
    { x: 2000, y: 150 - 40, w: 24, h: 40 },
    { x: 2680, y: 150 - 28, w: 24, h: 28 },
    { x: 3300, y: 150 - 36, w: 24, h: 36 },
  ];
  solids.push(...pipes);

  /** Enemies */
  const enemies = [];
  const enemySpawn = [300, 480, 700, 1060, 1300, 1700, 2100, 2450, 2890, 3230, 3600, 3920];
  enemySpawn.forEach((x, i) => {
    enemies.push({
      x, y: 0, w: 14, h: 12,
      vx: (i % 2 === 0 ? -0.6 : -0.8),
      vy: 0,
      dir: -1, onGround: false, dead: false, squash: 0
    });
  });

  /** Fireballs */
  const fireballs = [];

  /** Coins */
  const coinsArr = [];
  const coinSpawn = [
    [260, 120], [440, 108], [680, 128], [1000, 100], [1280, 110],
    [1560, 95], [1810, 120], [2160, 100], [2460, 110], [2790, 95],
    [3140, 120], [3460, 100], [3740, 116]
  ];
  coinSpawn.forEach(([x, y]) => {
    coinsArr.push({ x, y, w: 6, h: 8, t: Math.random() * Math.PI * 2, collected: false });
  });

  // Resize handling
  function resize() {
    bgCanvas.width = window.innerWidth;
    bgCanvas.height = window.innerHeight;
    gameCanvas.width = window.innerWidth;
    gameCanvas.height = window.innerHeight;

    camera.w = gameCanvas.width;
    camera.h = gameCanvas.height;
  }
  window.addEventListener("resize", resize);
  resize();

  // Input: Keyboard
  const onKey = (e, down) => {
    const k = e.key.toLowerCase();
    if (["arrowleft","arrowright","arrowup"," "].includes(e.key.toLowerCase())) e.preventDefault();
    if (k === "arrowleft" || k === "a") keys.left = down;
    if (k === "arrowright" || k === "d") keys.right = down;
    if (k === "arrowup" || k === "w" || e.key === " ") keys.up = down;
    if (k === "f") keys.fire = down;
    if (k === "p" && down) togglePause();
    if (k === "m" && down) muted = !muted;
    if (k === "r" && down) resetGame();
  };
  window.addEventListener("keydown", (e)=>onKey(e, true));
  window.addEventListener("keyup", (e)=>onKey(e, false));

  // Touch helpers
  const press = (setter) => (down) => { setter(down); };
  btnLeft.addEventListener("pointerdown", press(v => keys.left = v));
  btnLeft.addEventListener("pointerup", press(v => keys.left = v));
  btnLeft.addEventListener("pointerleave", press(v => keys.left = v));
  btnRight.addEventListener("pointerdown", press(v => keys.right = v));
  btnRight.addEventListener("pointerup", press(v => keys.right = v));
  btnRight.addEventListener("pointerleave", press(v => keys.right = v));
  btnJump.addEventListener("pointerdown", press(v => keys.up = v));
  btnJump.addEventListener("pointerup", press(v => keys.up = v));
  btnJump.addEventListener("pointerleave", press(v => keys.up = v));
  btnFire.addEventListener("pointerdown", press(v => keys.fire = v));
  btnFire.addEventListener("pointerup", press(v => keys.fire = v));
  btnFire.addEventListener("pointerleave", press(v => keys.fire = v));

  // Audio (simple blips)
  const AudioCtx = window.AudioContext || window.webkitAudioContext;
  const actx = new AudioCtx();
  function beep(freq = 440, dur = 0.06, type = "square", vol = 0.05) {
    if (muted) return;
    const o = actx.createOscillator();
    const g = actx.createGain();
    o.type = type;
    o.frequency.value = freq;
    g.gain.value = vol;
    o.connect(g).connect(actx.destination);
    o.start();
    o.stop(actx.currentTime + dur);
  }

  // Utils
  const clamp = (v, a, b) => Math.max(a, Math.min(b, v));
  function rectsOverlap(a, b) {
    return a.x < b.x + b.w && a.x + a.w > b.x && a.y < b.y + b.h && a.y + a.h > b.y;
  }
  function collideAxis(entity, dx, dy) {
    // Move X
    if (dx !== 0) {
      entity.x += dx;
      for (const s of solids) {
        if (rectsOverlap(entity, s)) {
          if (dx > 0) entity.x = s.x - entity.w;
          else entity.x = s.x + s.w;
          entity.vx = 0;
        }
      }
    }
    // Move Y
    let onGround = false;
    if (dy !== 0) {
      entity.y += dy;
      for (const s of solids) {
        if (rectsOverlap(entity, s)) {
          if (dy > 0) { // falling
            entity.y = s.y - entity.h;
            entity.vy = 0;
            onGround = true;
          } else { // jumping
            entity.y = s.y + s.h;
            entity.vy = 0;
          }
        }
      }
    }
    return onGround;
  }

  // Update player
  function updatePlayer(dt) {
    // Horizontal
    if (keys.left) player.vx -= PLAYER.speed * dt;
    if (keys.right) player.vx += PLAYER.speed * dt;
    if (!(keys.left || keys.right)) player.vx *= FRICTION;
    player.vx = clamp(player.vx, -2.4, 2.4);
    if (Math.abs(player.vx) > 0.05) player.dir = player.vx > 0 ? 1 : -1;

    // Jump
    if (keys.up && player.onGround) {
      player.vy = -PLAYER.jump;
      player.onGround = false;
      beep(600, 0.07, "square", 0.05);
      CAMERA.shake = Math.max(CAMERA.shake, 2);
    }

    // Gravity
    player.vy += GRAVITY * dt;
    player.vy = clamp(player.vy, -99, MAX_FALL);

    // Move and collide
    const onGroundNow = collideAxis(player, player.vx * dt, 0) === true;
    const prevVy = player.vy;
    const landed = collideAxis(player, 0, player.vy * dt) === true;
    if (landed) {
      player.onGround = true;
      if (prevVy > 4.5) {
        CAMERA.shake = Math.max(CAMERA.shake, prevVy * 0.3);
        beep(120, 0.05, "sawtooth", 0.03);
      }
    } else {
      player.onGround = onGroundNow;
    }

    // Fire
    if (keys.fire && performance.now() > player.canFireAt) {
      shootFireball();
      player.canFireAt = performance.now() + PLAYER.fireCooldown;
    }

    // Clamp world
    player.x = clamp(player.x, 0, WORLD.width - player.w);
    if (player.y > WORLD.height + 100) {
      // fell off world
      loseLife(true);
    }
  }

  function shootFireball() {
    const fb = {
      x: player.x + player.w / 2 + player.dir * 8,
      y: player.y + 6,
      w: 5, h: 5,
      vx: 3.2 * player.dir,
      vy: -0.2,
      life: 1400
    };
    fireballs.push(fb);
    beep(900, 0.05, "square", 0.04);
  }

  function updateFireballs(dt) {
    for (let i = fireballs.length - 1; i >= 0; i--) {
      const f = fireballs[i];
      f.vy += 0.1 * dt;
      f.x += f.vx * dt;
      f.y += f.vy * dt;
      f.life -= dt;
      let remove = false;

      // Collide with solids
      for (const s of solids) {
        if (rectsOverlap(f, s)) { remove = true; break; }
      }
      // Hit enemies
      if (!remove) {
        for (const e of enemies) {
          if (!e.dead && rectsOverlap(f, e)) {
            e.dead = true;
            e.squash = 0.3;
            addScore(100);
            beep(300, 0.06, "triangle", 0.05);
            remove = true;
            break;
          }
        }
      }
      if (remove || f.life <= 0) fireballs.splice(i, 1);
    }
  }

  function updateEnemies(dt) {
    for (const e of enemies) {
      if (e.dead) {
        e.squash -= 0.02 * dt;
        if (e.squash <= -0.2) e.y += 0.2 * dt;
        continue;
      }
      // Basic AI: walk, turn on edge or hit wall
      const ahead = { x: e.x + (e.vx > 0 ? e.w + 1 : -1), y: e.y + e.h + 1, w: 1, h: 1 };
      // Edge detection
      let onGround = false;
      for (const s of solids) {
        if (rectsOverlap(ahead, s)) { onGround = true; break; }
      }
      if (!onGround) e.vx = -e.vx;

      // Gravity
      e.vy += GRAVITY * dt;
      e.vy = clamp(e.vy, -99, MAX_FALL);

      // Move with collision
      collideAxis(e, e.vx * dt, 0);
      const landed = collideAxis(e, 0, e.vy * dt);
      if (landed) e.onGround = true;

      // Reverse on solid hit
      for (const s of solids) {
        if (rectsOverlap(e, s)) {
          if (e.x + e.w > s.x && e.x < s.x) e.vx = Math.abs(e.vx);
          else if (e.x < s.x + s.w && e.x + e.w > s.x + s.w) e.vx = -Math.abs(e.vx);
        }
      }

      // Player interaction
      if (rectsOverlap(player, e) && !e.dead) {
        // Stomp if falling and above enemy
        const playerBottom = player.y + player.h;
        const enemyTop = e.y;
        if (player.vy > 0.2 && playerBottom - enemyTop < 10) {
          e.dead = true;
          e.squash = 0.3;
          player.vy = -4.8; // bounce
          addScore(100);
          beep(340, 0.07, "triangle", 0.05);
        } else {
          // Player hit
          loseLife(false);
        }
      }
    }
  }

  function updateCoins(dt) {
    for (const c of coinsArr) {
      c.t += 0.05 * dt;
      if (!c.collected && rectsOverlap(player, c)) {
        c.collected = true;
        coins += 1;
        addScore(200);
        beep(880, 0.05, "sine", 0.05);
      }
    }
  }

  function addScore(n) {
    score += n;
    scoreEl.textContent = score.toString().padStart(6, "0");
  }

  function loseLife(fell) {
    if (state !== "playing") return;
    lives -= 1;
    livesEl.textContent = lives.toString();
    beep(160, 0.25, "sawtooth", 0.08);
    CAMERA.shake = 10;
    if (lives < 0) {
      state = "gameover";
      showMessage("GAME OVER", "Press R to Restart");
    } else {
      // Respawn
      player.x = player.spawnX;
      player.y = player.spawnY;
      player.vx = 0;
      player.vy = 0;
    }
  }

  function checkWin() {
    if (player.x > WORLD.width - 220 && state === "playing") {
      state = "win";
      showMessage("YOU WIN!", "Press R to Play Again");
      addScore(1000);
    }
  }

  function showMessage(title, text) {
    messageTitle.textContent = title;
    messageText.textContent = text;
    messageBox.classList.remove("hidden");
  }
  function hideMessage() {
    messageBox.classList.add("hidden");
  }
  function togglePause() {
    if (state === "playing") {
      state = "paused";
      showMessage("PAUSED", "Press P to Resume");
    } else if (state === "paused") {
      state = "playing";
      hideMessage();
    }
  }
  function resetGame() {
    // Reset state
    score = 0; coins = 0; lives = 3; time = 0;
    player.x = 32; player.y = 0; player.vx = 0; player.vy = 0;
    enemies.forEach((e, i) => {
      e.dead = false; e.squash = 0;
      e.x = enemySpawn[i]; e.y = 0; e.vx = (i % 2 === 0 ? -0.6 : -0.8); e.vy = 0;
    });
    coinsArr.forEach(c => c.collected = false);
    fireballs.length = 0;
    scoreEl.textContent = "000000";
    coinsEl.textContent = "0";
    livesEl.textContent = "3";
    state = "playing";
    hideMessage();
  }

  // Camera follows player with easing
  function updateCamera(dt) {
    const targetX = clamp(player.x + player.w / 2 - camera.w / 2, 0, WORLD.width - camera.w);
    camera.x += (targetX - camera.x) * CAMERA.lerp * dt;
    // Parallax background offset
  }

  // Background drawing (parallax)
  function drawBackground() {
    // Sky gradient is via CSS; draw clouds/hills on bg canvas
    const w = bgCanvas.width, h = bgCanvas.height;
    bgCtx.clearRect(0, 0, w, h);

    // Parallax offsets
    const camX = camera.x * 0.3;
    const hillX = camera.x * 0.5;

    // Clouds
    function cloud(x, y, s, c1, c2) {
      bgCtx.fillStyle = c1;
      bgCtx.beginPath();
      bgCtx.ellipse(x, y, 18*s, 12*s, 0, 0, Math.PI*2);
      bgCtx.ellipse(x+16*s, y+2*s, 16*s, 10*s, 0, 0, Math.PI*2);
      bgCtx.ellipse(x-16*s, y+3*s, 14*s, 9*s, 0, 0, Math.PI*2);
      bgCtx.fill();
      bgCtx.fillStyle = c2;
      bgCtx.beginPath();
      bgCtx.ellipse(x+2, y+5, 14*s, 8*s, 0, 0, Math.PI*2);
      bgCtx.fill();
    }
    for (let i=0;i<6;i++){
      const cx = ((i*280 - camX*0.8) % (w+300)) - 150;
      cloud(cx, 80 + (i%2)*12, 1 + (i%3)*0.2, COLORS.cloud, COLORS.cloud2);
    }

    // Hills
    function hill(x, baseY, r, color) {
      bgCtx.fillStyle = color;
      bgCtx.beginPath();
      bgCtx.arc(x, baseY, r, Math.PI, 0);
      bgCtx.lineTo(x+r, baseY+200);
      bgCtx.lineTo(x-r, baseY+200);
      bgCtx.closePath();
      bgCtx.fill();
    }
    for (let i=0;i<8;i++) {
      const hx = ((i*280 - hillX) % (w+400)) - 200;
      hill(hx, h-40, 140 + (i%3)*20, COLORS.hill);
      hill(hx+140, h-36, 120 + ((i+1)%3)*16, COLORS.hill2);
    }
  }

  // Draw entities and tiles
  function draw() {
    // Camera shake
    if (CAMERA.shake > 0) CAMERA.shake *= 0.9;

    const shakeX = (Math.random() - 0.5) * CAMERA.shake;
    const shakeY = (Math.random() - 0.5) * CAMERA.shake;

    // Clear
    ctx.clearRect(0, 0, gameCanvas.width, gameCanvas.height);

    ctx.save();
    ctx.translate(-Math.floor(camera.x) + shakeX, -Math.floor(camera.y) + shakeY);

    // Ground tiles
    for (let x = 0; x < WORLD.width; x += TILE) {
      const baseY = 150;
      ctx.fillStyle = COLORS.dirt;
      ctx.fillRect(x, baseY, TILE, WORLD.height - baseY);
      // top grass
      ctx.fillStyle = COLORS.grass;
      ctx.fillRect(x, baseY - 2, TILE, 2);
      // speckles
      ctx.fillStyle = COLORS.dirt2;
      for (let i = 0; i < 3; i++) {
        const sx = x + (i * 5 % 12) + 2;
        const sy = baseY + 6 + (i * 7 % 10);
        ctx.fillRect(sx, sy, 2, 2);
      }
    }

    // Platforms
    for (const s of solids) {
      if (s.y < 150) {
        ctx.fillStyle = COLORS.dirt;
        ctx.fillRect(s.x, s.y, s.w, s.h);
        ctx.fillStyle = COLORS.grass;
        ctx.fillRect(s.x, s.y - 2, s.w, 2);
      }
    }

    // Pipes
    for (const p of pipes) {
      ctx.fillStyle = COLORS.pipe;
      ctx.fillRect(p.x, p.y, p.w, p.h);
      ctx.fillStyle = COLORS.pipeDark;
      ctx.fillRect(p.x + 2, p.y + 2, p.w - 4, p.h - 4);
      // lip
      ctx.fillStyle = COLORS.pipe;
      ctx.fillRect(p.x - 4, p.y - 4, p.w + 8, 4);
    }

    // Coins
    for (const c of coinsArr) {
      if (c.collected) continue;
      const bob = Math.sin(c.t) * 2;
      ctx.fillStyle = COLORS.coin2;
      ctx.fillRect(c.x, c.y + bob, c.w, c.h);
      ctx.fillStyle = COLORS.coin1;
      ctx.fillRect(c.x + 1, c.y + 1 + bob, c.w - 2, c.h - 2);
      // highlight
      ctx.fillStyle = "rgba(255,255,255,0.5)";
      ctx.fillRect(c.x + 1, c.y + 2 + bob, 1, c.h - 4);
    }

    // Enemies
    for (const e of enemies) {
      if (e.dead) {
        // Squash effect
        ctx.fillStyle = COLORS.enemyDark;
        ctx.fillRect(e.x, e.y + e.h - 4, e.w, 4);
        continue;
      }
      ctx.fillStyle = COLORS.enemy;
      ctx.fillRect(e.x, e.y, e.w, e.h);
      ctx.fillStyle = COLORS.enemyDark;
      ctx.fillRect(e.x + 2, e.y + e.h - 3, e.w - 4, 3);
      // Eyes
      ctx.fillStyle = "#111";
      ctx.fillRect(e.x + 3, e.y + 3, 2, 2);
      ctx.fillRect(e.x + e.w - 5, e.y + 3, 2, 2);
    }

    // Fireballs
    for (const f of fireballs) {
      ctx.fillStyle = COLORS.fire1;
      ctx.fillRect(f.x - 2, f.y - 2, 4, 4);
      ctx.fillStyle = COLORS.fire2;
      ctx.fillRect(f.x - 1, f.y - 1, 2, 2);
    }

    // Player
    drawPlayer();

    // Goal flag near end
    const flagX = WORLD.width - 160, flagY = 110;
    ctx.fillStyle = "#444";
    ctx.fillRect(flagX, flagY - 40, 3, 60);
    ctx.fillStyle = "#e63946";
    ctx.fillRect(flagX + 3, flagY - 38, 18, 12);
    ctx.fillStyle = "#fff";
    ctx.fillRect(flagX + 9, flagY - 35, 6, 3);

    ctx.restore();

    // HUD update
    coinsEl.textContent = coins.toString();
  }

  function drawPlayer() {
    const p = player;
    // Shadow
    ctx.fillStyle = "rgba(0,0,0,0.25)";
    ctx.fillRect(p.x - 2, p.y + p.h - 2, p.w + 4, 3);

    // Body
    ctx.fillStyle = COLORS.playerBody;
    ctx.fillRect(p.x, p.y + 4, p.w, p.h - 4);
    // Hat
    ctx.fillStyle = COLORS.playerHat;
    ctx.fillRect(p.x, p.y, p.w, 4);
    // Face
    ctx.fillStyle = COLORS.playerFace;
    ctx.fillRect(p.x + 3, p.y + 5, 8, 6);
    // Eye
    ctx.fillStyle = "#111";
    if (p.dir >= 0) ctx.fillRect(p.x + 8, p.y + 6, 2, 2);
    else ctx.fillRect(p.x + 4, p.y + 6, 2, 2);
    // Shoes
    ctx.fillStyle = "#3d3d3d";
    ctx.fillRect(p.x + 2, p.y + p.h - 2, 4, 2);
    ctx.fillRect(p.x + p.w - 6, p.y + p.h - 2, 4, 2);
  }

  // Main loop
  let last = performance.now();
  function loop(now) {
    const dtMs = now - last;
    last = now;
    const dt = clamp(dtMs / (1000 / 60), 0.2, 3); // normalize to 60fps units

    time += dtMs;
    if (state === "playing") {
      updatePlayer(dt);
      updateFireballs(dt);
      updateEnemies(dt);
      updateCoins(dt);
      checkWin();
      updateCamera(dt);
    }

    // Redraw bg and fg
    drawBackground();
    draw();

    requestAnimationFrame(loop);
  }
  requestAnimationFrame(loop);

  // Initialize
  resetGame();

  // Prevent context menu on touch
  window.addEventListener("contextmenu", e => e.preventDefault(), { passive: false });

})();