html::before {
  background: #58a6ff;
  box-shadow: 0 0 10px rgba(88, 166, 255, .75);
  content: "";
  height: 3px;
  left: 0;
  opacity: 0;
  pointer-events: none;
  position: fixed;
  top: 0;
  transform: scaleX(0);
  transform-origin: left center;
  transition: opacity .15s ease, transform .4s ease;
  width: 100%;
  z-index: 2147483647;
}

html.fs-partial-loading::before { opacity: 1; transform: scaleX(.82); }
html.fs-partial-loading .fs-inner-main { opacity: .72; pointer-events: none; transition: opacity .15s ease; }

@media (prefers-reduced-motion: reduce) {
  html::before,
  html.fs-partial-loading .fs-inner-main { transition: none; }
}