/* Distinct backs for the two independently designed decks. */
body.td-page .td-back,
.tf-slot[data-deck="thongdiep"] .flip-back {
  background: radial-gradient(ellipse at 50% 35%, #fffaf1, #eee0cb);
  border-color: #c39883;
  color: #8a6453;
}
body.td-page .td-back { position: relative; }
body.td-page .td-back::before,
.tf-slot[data-deck="thongdiep"] .flip-back::before,
.tf-slot[data-deck="oracle"] .flip-back::before {
  content: "";
  position: absolute;
  inset: 8%;
  border: 1px solid currentColor;
  border-radius: 8px;
  opacity: .65;
}
body.td-page .td-back::after,
.tf-slot[data-deck="thongdiep"] .flip-back::after {
  content: "✉︎";
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font: 38px Georgia, serif;
}
body.td-page .td-back::after { font-size: 25px; }
.tf-slot[data-deck="oracle"] .flip-back {
  background: radial-gradient(circle at center, transparent 24%, #b6985855 25%, transparent 26%),
              radial-gradient(ellipse at 50% 40%, #1d4b52, #0c1e2b 75%);
  border-color: #b69858;
  color: #d5b873;
}
.tf-slot[data-deck="oracle"] .flip-back::after {
  content: "✦";
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font: 55px Georgia, serif;
}