text: import { TweenMax } from 'gsap'
  
  const pageTopBtnFade = () => {
    const $window = $(window)
    const $topBtn = $('.goTop')
    const addVisibleClass = () => {
      const isActive = () => !!($window.scrollTop() > 160)
      TweenMax.to($topBtn, 0.6, {
        autoAlpha: isActive() ? 1 : 0,
        display: isActive() ? 'block' : 'none',
      })
    }
  
    // 初期化
    addVisibleClass()
    $window.on('scroll', addVisibleClass)
  }
  export default pageTopBtnFade()
  