.fixed-header {
  display: block;
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  z-index: 100;
}

.collapse {
  display: grid;
  grid-template-rows: 1fr;
  overflow: hidden;
  transition: grid-template-rows 300ms ease;
}

.is-scrolled .collapse {
  grid-template-rows: 0fr;
}

.collapse > * {
  min-height: 0;
  transition: padding 300ms ease, opacity 200ms ease;
}

.is-scrolled .collapse > * {
  padding-top: 0;
  padding-bottom: 0;
  opacity: 0;
}