(function(){
  const buttons = document.querySelectorAll('.btn');
  let count = 0;

  buttons.forEach(function(button){
    button.addEventListener('click', function(){
      if(button.classList.contains('prevBtn')){
        count--
      }
      else if(button.classList.contains('nextBtn')){
        count++
      }
      const counter = document.querySelector("#counter");
      counter.textContent = count

      if(count < 0){
        counter.style.color = 'red'
      }
      else if(count > 0){
        counter.style.color = "green"
      }
      else{
        counter.style.color = "#333333"
      }
    })
  })
    // statements
}) ()