text: const boxesContainer = document.getElementById('boxes');
  const btn = document.getElementById('btn');
  
  btn.addEventListener('click', toggleBoxAnimation);
  function createBoxes() {
      for (let i = 0; i < 4; i++) {
          for (let j = 0; j < 4; j++) {
              const box = document.createElement('div');
              box.classList.add('box');
              box.style.backgroundPosition = `${j*-125}px ${i*-125}px`
              boxesContainer.appendChild(box);
          }   
      }
  }
  function toggleBoxAnimation() {
      boxesContainer.classList.toggle('big');
  }
  createBoxes();