:root {
  --safe-top: max(12px, env(safe-area-inset-top, 0px));
  --safe-left: max(12px, env(safe-area-inset-left, 0px));
  --safe-right: max(12px, env(safe-area-inset-right, 0px));
}

html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  min-height: 100dvh;
  overflow: hidden; /* ⛔ Disable scrolling */
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #111;
}

canvas {
  position: fixed;
  inset: 0;
  width: 100dvw;
  height: 100dvh;
  display: block;
}

#ui-overlay {
  position: fixed;
  inset: 0;
  pointer-events: none; /* Do not block 3D by default */
  z-index: 10;
}

.global-hint {
  position: fixed;
  top: 12px;
  left: 50%;
  transform: translateX(-50%);
  padding: 8px 14px;
  font-size: 1.35rem;
  font-weight: 700;
  color: #eafff0;
  text-shadow: 0 4px 12px rgba(0, 0, 0, 0.35);
  letter-spacing: 0.5px;
  text-align: center;
  pointer-events: none;
  white-space: nowrap;
}

#pop-layer {
  position: fixed;
  inset: 0;
  pointer-events: none; /* Do not block the mouse */
  z-index: 15; /* Above the three.js view */
  overflow: visible;
  font-family: "Impact", "Anton", "Archivo Black", system-ui, sans-serif;
}

.pop-effect {
  position: absolute;
  left: 0;
  top: 0;
  transform: translate(-50%, -50%) scale(0.6);
  font-weight: 900;
  letter-spacing: 0.5px;
  text-shadow:
    0 2px 6px rgba(0, 0, 0, 0.35),
    0 0 8px rgba(120, 255, 120, 0.8),
    0 0 16px rgba(170, 255, 140, 0.7);
  opacity: 0;
  will-change: transform, opacity;
  pointer-events: none;
}

@keyframes pop-burst {
  0% {
    transform: translate(-50%, -50%) scale(0.6);
    opacity: 0.95;
  }
  60% {
    transform: translate(-50%, -65%) scale(1.2);
    opacity: 1;
  }
  100% {
    transform: translate(-50%, -80%) scale(1.6);
    opacity: 0;
  }
}

/* Top-left info */
.ui-top-left {
  position: absolute;
  top: var(--safe-top);
  left: var(--safe-left);
  max-width: min(420px, 90vw);
  background: rgba(0, 0, 0, 0.35);
  backdrop-filter: blur(8px);
  padding: 16px 20px;
  border-radius: 12px;
}

.ui-top-left h1 {
  margin: 0 0 6px;
  font-size: 1.4rem;
  font-weight: 600;
  color: #fff;
}

.ui-logo {
  display: block;
  width: 260px;
  max-width: 100%;
  height: auto;
  border-radius: 10px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
  margin: 0 0 10px;
}

.ui-top-left .author {
  margin: 0;
  font-size: 0.9rem;
  opacity: 0.75;
  color: #ddd;
}

.ui-top-left .hint {
  margin-top: 8px;
  font-size: 0.85rem;
  color: #9fef9f;
}

/* Top-right contextual UI */
.ui-top-right {
  position: absolute;
  top: var(--safe-top);
  right: var(--safe-right);
  max-width: min(360px, 85vw);
  background: rgba(0, 0, 0, 0.45);
  backdrop-filter: blur(8px);
  padding: 14px 18px;
  border-radius: 12px;
  text-align: right;
  pointer-events: auto; /* 👈 Button is clickable */
}

.mode-label {
  font-size: 0.95rem;
  color: #fff;
  margin: 0 0 6px;
}

.hint-small {
  font-size: 0.8rem;
  opacity: 0.8;
  margin-bottom: 10px;
}

#back-btn {
  background: linear-gradient(135deg, #2cd86f, #18b454);
  border: 1px solid #1c8f48;
  color: #0b2d15;
  padding: 10px 18px;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 700;
  font-size: 0.95rem;
  box-shadow: 0 6px 18px rgba(24, 180, 84, 0.35);
}

#back-btn:hover {
  background: linear-gradient(135deg, #34e27a, #1fc160);
  box-shadow: 0 8px 22px rgba(31, 193, 96, 0.45);
}

.hint-small {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.78); /* Brighten */
  line-height: 1.4;
}


@media (max-width: 600px) {
  .ui-top-left, .ui-top-right {
    font-size: 0.95em;
    padding: 12px;
    max-width: 92vw;
  }

  #ui-overlay {
    inset: 0;
  }

  .global-hint {
    font-size: 1.05rem;
    padding: 8px 10px;
    white-space: normal;
    line-height: 1.3;
    max-width: 92vw;
  }

  .ui-logo {
    width: 210px;
  }

  #back-btn {
    width: 100%;
  }
}

/* Mobile-specific layout refinements (desktop unchanged) */
@media (max-width: 768px) {
  #ui-overlay {
    padding: 6px 10px;
  }

  .ui-top-left {
    top: calc(var(--safe-top) + 4px);
    left: 50%;
    transform: translateX(-50%);
    max-width: 84vw;
    padding: 12px 14px;
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.35);
  }

  .ui-logo {
    width: 180px;
  }

  .ui-top-left .author {
    font-size: 0.82rem;
  }

  .global-hint {
    top: auto;
    bottom: calc(var(--safe-top) + 8px);
    font-size: 1rem;
    padding: 8px 12px;
    max-width: 86vw;
  }

  .ui-top-right {
    top: auto;
    bottom: calc(var(--safe-top) + 72px);
    right: var(--safe-right);
    font-size: 0.9em;
  }
}