/* Mobile menu scroll lock. Shared by every page that has #nav-toggle.
   Opening the menu used to set overflow:hidden on body only. That left two
   holes: the fixed panel is not a scroll container, so links past the
   viewport are clipped and cannot be reached, and the panel paints over the
   bar, so the close control is buried while the page is locked.
   Locking html as well stops iOS from scrolling the document under the
   overlay, but overflow:hidden on html releases position:sticky, so the bar
   is pinned for as long as the menu is open. */

html.nav-scroll-lock {
  overflow: hidden;
  overscroll-behavior: none;
}

html.nav-scroll-lock body {
  overflow: hidden;
  overscroll-behavior: none;
}

.topnav.is-open {
  position: fixed;
  top: 12px;
  left: 0;
  right: 0;
}

.topnav.is-open .topnav__bar {
  position: relative;
  z-index: 100;
  touch-action: manipulation;
}

.topnav.is-open .topnav__panel {
  z-index: 1;
  overflow-y: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  touch-action: pan-y;
}