:root {
  --bg: #0e0f13;
  --tile: #1b1d24;
  --ring: #7dd3fc;
  --ink: #e6e8ee;
  --muted: #8b90a0;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--ink);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  overflow: hidden;
}

#stage {
  position: fixed;
  inset: 0;
  overflow: hidden;
  touch-action: none;
  user-select: none;
}

#world {
  position: absolute;
  left: 0;
  top: 0;
  transform: translate(0, 0);
  transition: transform .5s cubic-bezier(.22, 1, .36, 1);
  will-change: transform;
}

.tile {
  position: absolute;
  border-radius: 6px;
  overflow: hidden;
  background: var(--tile);
  box-shadow: 0 2px 10px rgba(0, 0, 0, .45);
  cursor: pointer;
  transition: box-shadow .2s;
}
.tile img { width: 100%; height: 100%; object-fit: cover; display: block; }
.tile.lock { animation: lock .5s cubic-bezier(.22, 1, .36, 1); }

@keyframes lock {
  0%   { transform: scale(.2); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

.tile.current {
  box-shadow: 0 0 0 2px var(--ring), 0 0 26px 2px rgba(125, 211, 252, .4);
}

.nav {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0;
  transition: opacity .15s;
}
.tile.current:hover .nav { opacity: 1; }

.nav-btn {
  position: absolute;
  pointer-events: auto;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, .25);
  background: rgba(14, 15, 19, .85);
  color: var(--ink);
  font-size: 15px;
  line-height: 1;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: transform .12s, border-color .12s;
}
.nav-btn:hover { border-color: var(--ring); transform: scale(1.12); }
.nav-btn[data-dir="N"] { top: 0; left: 50%; translate: -50% -50%; }
.nav-btn[data-dir="E"] { top: 50%; right: 0; translate: 50% -50%; }
.nav-btn[data-dir="S"] { bottom: 0; left: 50%; translate: -50% 50%; }
.nav-btn[data-dir="W"] { top: 50%; left: 0; translate: -50% -50%; }

.nav-label {
  position: absolute;
  left: 50%;
  translate: -50%;
  white-space: nowrap;
  font-size: 11px;
  letter-spacing: .04em;
  color: var(--ink);
  background: rgba(14, 15, 19, .92);
  border: 1px solid rgba(255, 255, 255, .18);
  border-radius: 4px;
  padding: 2px 7px;
  opacity: 0;
  transition: opacity .12s;
  pointer-events: none;
}
.nav-btn[data-dir="N"] .nav-label { bottom: calc(100% + 8px); }
.nav-btn[data-dir="S"] .nav-label { top: calc(100% + 8px); }
.nav-btn[data-dir="E"] .nav-label { top: 50%; left: calc(100% + 10px); translate: 0 -50%; }
.nav-btn[data-dir="W"] .nav-label { top: 50%; right: calc(100% + 10px); translate: 0 -50%; }
.nav-btn:hover .nav-label { opacity: 1; }

#flash {
  position: fixed;
  top: 18px;
  left: 50%;
  translate: -50%;
  font-size: 14px;
  letter-spacing: .06em;
  color: var(--ink);
  background: rgba(14, 15, 19, .88);
  border: 1px solid rgba(255, 255, 255, .22);
  border-radius: 6px;
  padding: 6px 14px;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s;
}
#flash.show { opacity: 1; }

#splash {
  position: fixed;
  inset: 0;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 14px;
  text-align: center;
  background: var(--bg);
  z-index: 10;
  transition: opacity .4s, visibility .4s;
}
#splash.hide { opacity: 0; visibility: hidden; pointer-events: none; }
#splash h1 { margin: 0; font-size: 44px; font-weight: 300; letter-spacing: .18em; }
#splash h1 .dot { color: var(--ring); }
#splash p { max-width: 34ch; color: var(--muted); margin: 0; font-size: 15px; line-height: 1.6; }
#start {
  margin-top: 10px;
  padding: 10px 34px;
  font-size: 15px;
  letter-spacing: .12em;
  border: 1px solid rgba(255, 255, 255, .3);
  border-radius: 999px;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  transition: border-color .15s, background .15s;
}
#start:hover { border-color: var(--ring); background: rgba(125, 211, 252, .08); }

@media (prefers-reduced-motion: reduce) {
  #world { transition: none; }
  .tile.lock { animation: none; }
  #flash { transition: none; }
}