.parallax-image {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: auto;
  z-index: 1;
  pointer-events: none;
  will-change: transform;
  backface-visibility: hidden;
  border-top-style: solid;
  border-top-color: #000;
  border-top-width: 135px;
}

@media (min-width: 1024px) and (max-width: 1281px) {
  .parallax-image { border-top-width: calc(340px - 19.53vw); }
}
@media (min-width: 1281px) and (max-width: 1899px) {
  .parallax-image { border-top-width: calc(101.6px - 4.03vw); }
}
@media (min-width: 1899px) {
  .parallax-image { border-top-width: 25px; }
}

@supports (animation-timeline: scroll()) {
  .parallax-image {
    animation: parallax-move linear both;
    animation-timeline: scroll(root block);
    animation-range: 0 300vh;
    --parallax-end: -150vh;
  }

  @media (max-width: 768px) {
    .parallax-image { --parallax-end: -60vh; }
  }

  @keyframes parallax-move {
    to { transform: translate3d(0, var(--parallax-end), 0); }
  }
}