const canvas = document.getElementById('game');
const ctx = canvas.getContext('2d');

const state = {
  running: true,
  lastTs: performance.now()
};

function drawBackground() {
  ctx.fillStyle = '#88d34f';
  ctx.fillRect(0, 420, canvas.width, 120);
}

function tick(ts) {
  if (!state.running) return;
  const dt = Math.min((ts - state.lastTs) / 1000, 0.05);
  state.lastTs = ts;

  ctx.clearRect(0, 0, canvas.width, canvas.height);
  drawBackground();

  requestAnimationFrame(tick);
}

requestAnimationFrame((ts) => {
  state.lastTs = ts;
  requestAnimationFrame(tick);
});