/* Desktop only. On a phone the corner is where the thumb already is, and the
   header is never far away. */

.back-to-top {
  display: none;
}

@media (min-width: 60em) {
  .back-to-top {
    display: block;
    position: fixed;
    right: var(--page-margin);
    bottom: var(--page-margin);
  }
}

/* Set by the script while any of the header is in view. Out-specifies the
   rule above, so it holds inside the media query too. */
.back-to-top[hidden] {
  display: none;
}