.keystone {
  padding: 0 0 30px;
}
.keystone ul {
  list-style: none;
  display: grid;
  gap: 30px;
  padding: 0;
}
.keystone .right {
  grid-template-columns: 33.3% auto;
  grid-template-rows: repeat(2, auto);
}
.keystone .right li:first-child {
  grid-column: 2/3;
  grid-row: 1/span 2;
}
.keystone .left {
  grid-template-columns: auto 33.3%;
  grid-template-rows: repeat(2, auto);
}
.keystone .left li:first-child {
  grid-column: 1/2;
  grid-row: 1/span 2;
}

.keystone-tile {
  display: block;
  position: relative;
  background-size: cover;
  background-repeat: no-repeat;
  background-position: center;
  background-color: var(--black);
  width: 100%;
  height: 100%;
  padding: 30% 0;
  box-sizing: border-box;
  border-radius: 24px;
  box-shadow: rgba(0, 0, 0, 0.25) 0px 15px 25px, rgba(0, 0, 0, 0.1) 0px 5px 10px;
}
.keystone-tile:after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.3);
  border-radius: 24px;
}
.keystone-tile .content {
  position: absolute;
  top: 20px;
  left: 20px;
  right: 20px;
  bottom: 20px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-content: center;
  text-align: center;
  z-index: 2;
  border-radius: 16px;
}
.keystone-tile:hover .content, .keystone-tile:focus .content {
  border: 1px solid #FFF;
}
.keystone-tile h2, .keystone-tile h3 {
  color: #FFF !important;
  margin: 0;
  text-shadow: 1px 1px 20px rgba(0, 0, 0, 0.6);
}
.keystone-tile h2 {
  font-weight: 400;
  font-size: 32px;
  line-height: 1;
}
.keystone-tile h3 {
  font-size: 18px;
  color: #99d1d3;
  font-weight: 700;
  font-family: "Open Sans";
}

@media screen and (max-width: 990px) {
  .keystone .right,
  .keystone .left {
    grid-template-columns: repeat(2, auto);
    grid-template-rows: repeat(2, auto);
  }
  .keystone .left li:first-child,
  .keystone .right li:first-child {
    grid-column: 1/span 2;
    grid-row: 1/2;
  }
}
@media screen and (max-width: 680px) {
  .keystone ul {
    display: flex;
    flex-direction: column;
  }
}