.progress-rail span {
  transform: scaleX(0);
  animation: reading-progress linear;
  animation-timeline: scroll(root);
}

@keyframes reading-progress {
  to { transform: scaleX(1); }
}

.account {
  position: sticky;
  inset: 0 0 auto 0;
  justify-content: flex-end;
  min-height: 32px;
  padding: .25rem 1.25rem;
  border-radius: 0;
  box-shadow: none;
}

.account a { color: #fff; }
.presentation-header,
.walk-header { top: 32px; }
.progress-rail { top: 115px; }