text: 
  // Scroll up
  
  document.getElementById("button-up").addEventListener("click", scrollUp);
  
  function scrollUp(){
  
      var currentScroll = document.documentElement.scrollTop;
  
      if (currentScroll > 0){
          window.requestAnimationFrame(scrollUp);
          window.scrollTo (0, currentScroll - (currentScroll / 10));
      }
  }
  
  ///
  
  buttonUp = document.getElementById("button-up");
  
  window.onscroll = function(){
  
      var scroll = document.documentElement.scrollTop;
  
      if (scroll > 500){
          buttonUp.style.transform = "scale(1)";
      }else if(scroll < 500){
          buttonUp.style.transform = "scale(0)";
      }
  
  }
  
  
  
  
  
  