block7.ts

methods: {
  // ...

  getScrollPercentage(startMarker: HTMLElement, endMarker: HTMLElement): void {
    const offsetFromTop = this.getPosRelativeToBody(startMarker)
    const total = this.getPosRelativeToBody(endMarker) - offsetFromTop - window.innerHeight
    const progress = (((window.scrollY - offsetFromTop) / total) * 100)
    this.percent = progress
  }

  // ...
}