ctx.clearRect(0, 0, canvas.width, canvas.height); 
 
 if (increasing) { 
 rectScale += 0.02; 
 if (rectScale >= 2) { 
 increasing = false; 
 } 
 } else { 
 rectScale -= 0.02; 
 if (rectScale <= 1) { 
 increasing = true; 
 } 
 } 
 
 const scaledWidth = rectWidth * rectScale; 
 const scaledHeight = rectHeight * rectScale; 
 rectX = (canvas.width - scaledWidth) / 2; 
 rectY = (canvas.height - scaledHeight) / 2; 
 
 ctx.fillStyle = 'blue'; 
 ctx.fillRect(rectX, rectY, scaledWidth, scaledHeight); 
 
 requestAnimationFrame(animate);
 }