.header .dropdown-helper {
  position: absolute;
  z-index: 1;
  top: 0;
  right: 0;
  width: 100vw;
  max-width: 640px;
  height: 100%;
  background-color: red;
  opacity: 0.3;
  transform-origin: bottom center;
  transition: transform 300ms ease 200ms;
}

.header .nav-section:hover .dropdown-helper {
  transform: scaleY(0);
}

.header .nav-section-title:hover + .dropdown-helper {
  transform: scaleY(1);
}

.header .nav-section-title {
  position: relative;
  z-index: 2;
}