code: function getClasses(lastSegmentScrolledBy, isInSegment, parallaxData) {
    let cssClasses = null;
  
    if (lastSegmentScrolledBy === null) {
      cssClasses = 'Plx--above';
    } else if (lastSegmentScrolledBy === parallaxData.length - 1 && !isInSegment) {
      cssClasses = 'Plx--below';
    } else if (lastSegmentScrolledBy !== null && isInSegment) {
      const segmentName = parallaxData[lastSegmentScrolledBy].name || lastSegmentScrolledBy;
  
      cssClasses = `Plx--active Plx--in Plx--in-${ segmentName }`;
    } else if (lastSegmentScrolledBy !== null && !isInSegment) {
      const segmentName = parallaxData[lastSegmentScrolledBy].name || lastSegmentScrolledBy;
      const nextSegmentName = parallaxData[lastSegmentScrolledBy + 1].name || lastSegmentScrolledBy + 1;
  
      cssClasses = `Plx--active Plx--between Plx--between-${ segmentName }-and-${ nextSegmentName }`;
    }
  
    return cssClasses;
  }
docs: Returns CSS classes based on animation state