.page-loader {
  position: fixed;
  inset: 0;
  z-index: 2000;
  overflow: hidden;
  pointer-events: none;
  isolation: isolate;
  animation: page-loader-failsafe 0s 4s forwards;
}

.page-loader__panel {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 50%;
  background: var(--signal);
  transition: transform 760ms cubic-bezier(0.76, 0, 0.24, 1);
}

.page-loader__panel--left {
  left: 0;
}

.page-loader__panel--right {
  right: 0;
}

.page-loader__line {
  position: absolute;
  inset: 0 auto 0 calc(50% - 1px);
  width: 2px;
  background: var(--ink);
  transform-origin: center;
  animation: page-loader-draw 700ms cubic-bezier(0.65, 0, 0.35, 1) both;
  transition: opacity 120ms ease-out;
}

.page-loader.is-opening .page-loader__panel--left {
  transform: translateX(-100%);
}

.page-loader.is-opening .page-loader__panel--right {
  transform: translateX(100%);
}

.page-loader.is-opening .page-loader__line {
  opacity: 0;
}

@keyframes page-loader-draw {
  from {
    transform: scaleY(0);
  }
  to {
    transform: scaleY(1);
  }
}

/* A script error must never leave the visual mask over the page. */
@keyframes page-loader-failsafe {
  to {
    visibility: hidden;
  }
}

@media (prefers-reduced-motion: reduce), print {
  .page-loader {
    display: none;
    animation: none;
  }

  .page-loader__panel,
  .page-loader__line {
    animation: none;
    transition: none;
  }
}