.scroll-progress {
  position: fixed;
  inset: 0 0 auto;
  z-index: 1000;
  height: 3px;
  overflow: hidden;
  background: rgba(255, 255, 255, .045);
  pointer-events: none;
}

.scroll-progress__bar {
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, #b8f45d 0%, #68c6ff 52%, #b99cff 100%);
  box-shadow: 0 0 12px rgba(104, 198, 255, .4);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 80ms linear;
  will-change: transform;
}

@media (max-width: 720px) {
  .scroll-progress {
    height: 4px;
    background: rgba(8, 16, 24, .78);
    box-shadow: 0 2px 9px rgba(0, 0, 0, .32);
  }

  .scroll-progress__bar {
    box-shadow:
      0 0 8px rgba(104, 198, 255, .68),
      0 1px 4px rgba(184, 244, 93, .34);
  }
}

@media (prefers-reduced-motion: reduce) {
  .scroll-progress__bar { transition: none; }
}