/* button grid for "open in" links; shared by index.html and at.html */
.open {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5em;
}
.open a,
.open button {
  display: block;
  padding: 0.8em;
  border: 0;
  border-radius: 0.4em;
  text-align: center;
  text-decoration: none;
  font: inherit;
  color: #fff;
  background: #333;
  cursor: pointer;
}
.open a:active,
.open button:active {
  background: #39f;
}