:root {
  --oracle-background-current: url("/assets/oracle-sanctum-large-underlit-d.png");
  --oracle-background-next: url("/assets/oracle-sanctum-large-underlit-d.png");
}

body .mansion-art-backdrop {
  isolation: isolate;
  background-image:
    linear-gradient(180deg, rgba(2, 5, 5, 0.02), rgba(2, 5, 5, 0.06) 58%, rgba(2, 4, 4, 0.34)),
    var(--oracle-background-current);
}

body .mansion-art-backdrop::before {
  content: "";
  position: absolute;
  z-index: 1;
  inset: -1%;
  opacity: 0;
  background:
    linear-gradient(180deg, rgba(2, 5, 5, 0.02), rgba(2, 5, 5, 0.06) 58%, rgba(2, 4, 4, 0.34)),
    var(--oracle-background-next) center / cover no-repeat;
  transform: scale(1.01);
  transition: opacity 700ms cubic-bezier(0.22, 0.72, 0.2, 1);
  pointer-events: none;
}

body[data-background-transitioning="true"] .mansion-art-backdrop::before { opacity: 1; }

.background-quick-switch {
  position: relative;
  margin: 0 0.62rem 0.5rem;
  padding: 0.42rem 0.46rem 0.5rem;
  border: 1px solid rgba(105, 191, 182, 0.27);
  border-left: 0.18rem solid rgba(121, 212, 203, 0.82);
  background:
    linear-gradient(100deg, rgba(8, 37, 34, 0.88), rgba(12, 15, 14, 0.94) 56%, rgba(44, 10, 16, 0.64)),
    rgba(2, 8, 7, 0.92);
  box-shadow: inset 0 0 1.4rem rgba(0, 0, 0, 0.38), 0 0.35rem 0.9rem rgba(0, 0, 0, 0.3);
}

.background-switch-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.34rem;
}

.background-switch-heading > span {
  color: rgba(150, 224, 215, 0.74);
  font: 700 0.43rem/1 var(--oracle-font-code, "Cascadia Code", Consolas, monospace);
  letter-spacing: 0.06em;
}

.background-state {
  color: #eaf4ed;
  font: 700 0.54rem/1 var(--oracle-font-ui, "Yu Gothic UI", Meiryo, sans-serif);
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.background-selector {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 0.28rem;
}

.game-command-menu .background-option {
  --background-thumbnail: none;
  min-width: 0;
  display: grid;
  grid-template-rows: auto auto;
  gap: 0.18rem;
  height: auto;
  padding: 0.12rem 0.12rem 0.18rem;
  overflow: hidden;
  border: 1px solid rgba(109, 192, 183, 0.22);
  border-bottom: 0.12rem solid rgba(88, 154, 147, 0.3);
  border-radius: 0;
  background: rgba(2, 11, 10, 0.78);
  color: rgba(216, 228, 221, 0.7);
  text-align: left;
  cursor: pointer;
  transition: border-color 180ms ease, background-color 180ms ease, color 180ms ease, transform 180ms ease;
}

.background-option[data-background-id="oracle-sanctum"] { --background-thumbnail: url("/assets/oracle-sanctum-large-underlit-d.png"); }
.background-option[data-background-id="shrine-hall"] { --background-thumbnail: url("/assets/sanctum-shrine-hall-v2.png"); }
.background-option[data-background-id="abandoned-platform"] { --background-thumbnail: url("/assets/sanctum-abandoned-platform-v2.png"); }
.background-option[data-background-id="oracle-archive"] { --background-thumbnail: url("/assets/sanctum-oracle-archive-v2.png"); }
.background-option[data-background-id="flooded-approach"] { --background-thumbnail: url("/assets/sanctum-flooded-approach-v2.png"); }
.background-option[data-background-id="descent-junction"] { --background-thumbnail: url("/assets/sanctum-descent-junction-v2.png"); }

.background-option > i {
  width: 100%;
  aspect-ratio: 16 / 9;
  display: block;
  border: 1px solid rgba(133, 215, 205, 0.18);
  background: var(--background-thumbnail) center / cover no-repeat;
  filter: saturate(0.82) contrast(1.06) brightness(0.76);
  box-shadow: inset 0 0 1rem rgba(0, 0, 0, 0.48);
  transition: filter 180ms ease, transform 180ms ease;
}

.background-option > strong {
  overflow: hidden;
  font-family: var(--oracle-font-ui, "Yu Gothic UI", Meiryo, sans-serif);
  font-size: 0.42rem;
  line-height: 1.15;
  text-align: center;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.game-command-menu .background-option:hover,
.game-command-menu .background-option:focus-visible {
  border-color: rgba(151, 239, 228, 0.72);
  background: rgba(8, 37, 34, 0.92);
  color: #eff9f2;
  outline: 0;
  transform: translateY(-1px);
}

.background-option:hover > i,
.background-option:focus-visible > i,
.background-option[aria-pressed="true"] > i { filter: saturate(1.02) contrast(1.04) brightness(1.02); }

.game-command-menu .background-option[aria-pressed="true"] {
  border-color: rgba(175, 255, 244, 0.9);
  border-bottom-color: #d34b52;
  background: rgba(10, 45, 41, 0.96);
  color: #f5fbf4;
  box-shadow: 0 0 0.8rem rgba(92, 225, 210, 0.14);
}

@media (max-width: 780px) {
  .background-quick-switch {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  body .mansion-art-backdrop::before,
  .background-option,
  .background-option > i { transition: none; }
}