text: let width = 130; 
  let count = 3; 
  let list = package.querySelector("ul");
  let listElems = package.querySelectorAll("li");
  let position = 0;
  
  package.querySelector(".prev").onclick = function () {
    position += width * count;
    position = Math.min(position, 0);
    list.style.marginLeft = position + "px";
  };
  
  package.querySelector(".next").onclick = function () {
    position -= width * count;
    position = Math.max(position, -width * (listElems.length - count));
    list.style.marginLeft = position + "px";
  };
  