:root {
  --night: #07090d;
  --ink: #e8e4dc;
  --dim: #8b8881;
  --cold: #8ea8b7;
  --warm: #b49b82;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --sans: "Avenir Next", "Helvetica Neue", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--night);
}

body {
  overflow: hidden;
  color: var(--ink);
  font-family: var(--sans);
}

button,
a { font: inherit; }
button { -webkit-tap-highlight-color: transparent; }

#room {
  position: relative;
  min-height: 100svh;
  overflow: hidden;
  isolation: isolate;
  background:
    radial-gradient(circle at 54% 52%, rgba(142, 168, 183, .055), transparent 26%),
    radial-gradient(circle at 28% 72%, rgba(180, 155, 130, .045), transparent 36%),
    linear-gradient(148deg, #080a0f, #05070a 55%, #0b0c10);
}

#field {
  position: absolute;
  inset: 0;
  z-index: 1;
  width: 100%;
  height: 100%;
  opacity: .88;
}

.grain {
  position: fixed;
  inset: -45%;
  z-index: 8;
  pointer-events: none;
  opacity: .035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.84' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.62'/%3E%3C/svg%3E");
  animation: grain .42s steps(2) infinite;
}

@keyframes grain {
  0% { transform: translate(-1%, 2%); }
  50% { transform: translate(2%, -1%); }
  100% { transform: translate(1%, 1%); }
}

.house-nav {
  position: fixed;
  top: max(.8rem, env(safe-area-inset-top));
  left: 50%;
  z-index: 20;
  display: flex;
  gap: .56rem;
  align-items: center;
  transform: translateX(-50%);
  padding: .55rem .75rem;
  border: 1px solid rgba(232, 228, 220, .12);
  border-radius: 999px;
  color: rgba(232, 228, 220, .76);
  background: rgba(7, 9, 13, .58);
  backdrop-filter: blur(13px);
  font-size: clamp(.58rem, 1vw, .7rem);
  letter-spacing: .07em;
  white-space: nowrap;
}

.house-nav a {
  color: rgba(232, 228, 220, .46);
  text-decoration: none;
  transition: color .6s ease;
}

.house-nav a:hover,
.house-nav a:focus-visible { color: var(--ink); }

.threshold,
.performance,
.ending {
  position: absolute;
  inset: 0;
  z-index: 4;
  min-height: 100svh;
  transition: opacity 2.4s ease, visibility 2.4s ease, filter 2.4s ease;
}

.threshold {
  display: grid;
  align-content: end;
  justify-items: start;
  padding: clamp(1.4rem, 7vw, 7rem);
  padding-bottom: max(clamp(2.6rem, 10vh, 6rem), env(safe-area-inset-bottom));
}

.eyebrow,
.rule,
.instruction,
.translation {
  margin: 0;
  color: rgba(232, 228, 220, .5);
  font: .68rem/1.65 var(--mono);
  letter-spacing: .12em;
  text-transform: lowercase;
}

.eyebrow { margin-bottom: 1.1rem; }

h1 {
  margin: 0;
  font: 300 clamp(4rem, 10vw, 9.5rem)/.78 var(--sans);
  letter-spacing: -.055em;
}

.rule { margin-top: 1.9rem; }

#enter,
#sound,
#sound-fallback,
#again,
.ending a {
  padding: .65rem 0;
  border: 0;
  border-bottom: 1px solid rgba(232, 228, 220, .26);
  color: rgba(232, 228, 220, .72);
  background: transparent;
  text-decoration: none;
  cursor: pointer;
  font-size: .72rem;
  letter-spacing: .08em;
  transition: color .8s ease, border-color .8s ease, letter-spacing 1.1s ease;
}

#enter { margin-top: 2.2rem; }

#enter:hover,
#enter:focus-visible,
#sound:hover,
#sound:focus-visible,
#sound-fallback:hover,
#sound-fallback:focus-visible,
#again:hover,
#again:focus-visible,
.ending a:hover,
.ending a:focus-visible {
  color: var(--ink);
  border-color: var(--ink);
  letter-spacing: .115em;
}

.performance {
  visibility: hidden;
  opacity: 0;
  pointer-events: none;
}

.instruction {
  position: absolute;
  left: max(1.3rem, env(safe-area-inset-left));
  bottom: max(1.25rem, env(safe-area-inset-bottom));
}

#sound,
#sound-fallback {
  position: absolute;
  right: max(1.3rem, env(safe-area-inset-right));
  bottom: max(1.25rem, env(safe-area-inset-bottom));
}

.ending {
  display: grid;
  place-content: center;
  justify-items: start;
  visibility: hidden;
  opacity: 0;
  pointer-events: none;
  padding: 1.5rem;
  background: rgba(7, 9, 13, .22);
  backdrop-filter: blur(2px);
}

.sentence {
  margin: 0;
  max-width: 19ch;
  font: 300 clamp(2.1rem, 5.5vw, 5.5rem)/1.02 var(--sans);
  letter-spacing: -.035em;
}

.translation { margin-top: 1.4rem; }

.ending-actions {
  display: flex;
  gap: 1.4rem;
  align-items: center;
  margin-top: 2.4rem;
}

[data-state="performance"] .threshold,
[data-state="ending"] .threshold {
  visibility: hidden;
  opacity: 0;
  filter: blur(8px);
  pointer-events: none;
}

[data-state="performance"] .performance {
  visibility: visible;
  opacity: 1;
  pointer-events: auto;
}

[data-state="ending"] .performance {
  visibility: hidden;
  opacity: 0;
  pointer-events: none;
}

[data-state="ending"] .ending {
  visibility: visible;
  opacity: 1;
  pointer-events: auto;
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 650px) {
  .house-nav {
    gap: .38rem;
    padding-inline: .58rem;
    font-size: .54rem;
    letter-spacing: .045em;
  }

  .threshold {
    padding: 1.35rem;
    padding-bottom: max(3.2rem, env(safe-area-inset-bottom));
  }

  h1 { font-size: clamp(4rem, 20vw, 6.4rem); }
  .sentence { font-size: clamp(2.1rem, 10vw, 3.4rem); }
  .instruction { max-width: 12ch; }
}

@media (prefers-reduced-motion: reduce) {
  .grain { animation: none; }

  *,
  *::before,
  *::after { transition-duration: .01ms !important; }
}

@media (max-width: 650px) {
  /* The pill of room names stops fitting once the house has six rooms.
     The way back to the threshold remains; the house itself is the map. */
  .house-nav a:not([href$="#rooms"]) { display: none; }
}