Get the width of a browser scrollbar

get-scrollbar-width.js

// from: https://davidwalsh.name/detect-scrollbar-width

function getScrollbarWidth() {
  const div = document.createElement("div")

  div.style = `
    width: 100px;
    height: 100px;
    overflow: scroll;
    position: absolute;
    top: -9999px;
  `

  document.body.appendChild(div)
  const out = div.offsetWidth - div.clientWidth
  document.body.removeChild(div)
  return out
}