text: export default function () {
    // function to scroll up to page top
    const PageTopBtn = document.getElementById('js-scroll-top')
    if (!PageTopBtn) return
  
    PageTopBtn.addEventListener('click', (e) => {
      window.scrollTo({
        top: 0,
        behavior: 'smooth'
      })
    })
  
    // show scroll button only when display is scroll down
    window.addEventListener('scroll', function () {
      const y = document.documentElement.scrollTop // get the height from page top
      if (y < 100) {
        PageTopBtn.classList.remove('show')
      } else if (y >= 100) {
        PageTopBtn.classList.add('show')
      }
    })
  }
  