:root {
  color-scheme: light;
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  background: #a9dce2;
  color: #224132;
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  overflow: hidden;
}

body {
  background:
    radial-gradient(circle at 50% 38%, rgba(255, 255, 255, 0.65), transparent 38%),
    linear-gradient(180deg, #9dd8e3 0%, #d9f0de 100%);
}

button {
  font: inherit;
}

#scene,
#scene canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}

#scene canvas {
  cursor: crosshair;
  touch-action: none;
}

.brand {
  position: fixed;
  top: max(22px, env(safe-area-inset-top));
  left: max(24px, env(safe-area-inset-left));
  z-index: 2;
  pointer-events: none;
  text-shadow: 0 1px 0 rgba(255, 255, 255, 0.55);
}

.eyebrow {
  margin: 0 0 5px;
  color: rgba(34, 65, 50, 0.62);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.16em;
}

h1 {
  margin: 0;
  font-family: "STKaiti", "KaiTi", "Songti SC", serif;
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 700;
  letter-spacing: 0.02em;
}

.hint,
.home-button {
  position: fixed;
  z-index: 2;
  bottom: max(22px, env(safe-area-inset-bottom));
  border: 1px solid rgba(255, 255, 255, 0.72);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.74);
  box-shadow: 0 10px 28px rgba(42, 77, 55, 0.14);
  color: #294936;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.hint {
  left: max(24px, env(safe-area-inset-left));
  padding: 11px 16px;
  font-size: 0.875rem;
  line-height: 1.2;
  pointer-events: none;
}

.home-button {
  right: max(24px, env(safe-area-inset-right));
  min-height: 44px;
  padding: 10px 18px;
  cursor: pointer;
  transition: transform 160ms ease, background-color 160ms ease;
}

.home-button:hover {
  background: rgba(255, 255, 255, 0.92);
  transform: translateY(-2px);
}

.home-button:focus-visible {
  outline: 3px solid rgba(40, 105, 69, 0.35);
  outline-offset: 3px;
}

.mobile-hint {
  display: none;
}

.loading {
  position: fixed;
  inset: 0;
  z-index: 5;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 13px;
  background: #b8e0d0;
  color: #294936;
  font-size: 1rem;
  transition: opacity 360ms ease, visibility 360ms ease;
}

.loading.is-hidden {
  opacity: 0;
  visibility: hidden;
}

.loading-dot {
  width: 30px;
  height: 30px;
  border: 4px solid rgba(255, 255, 255, 0.62);
  border-top-color: #dd8c2a;
  border-radius: 50%;
  animation: spin 800ms linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

@media (max-width: 680px) {
  .brand {
    top: max(16px, env(safe-area-inset-top));
    left: max(17px, env(safe-area-inset-left));
  }

  .eyebrow {
    font-size: 0.64rem;
  }

  .hint {
    left: 50%;
    bottom: max(18px, env(safe-area-inset-bottom));
    width: max-content;
    max-width: calc(100vw - 140px);
    padding: 10px 14px;
    transform: translateX(-50%);
    text-align: center;
  }

  .desktop-hint {
    display: none;
  }

  .mobile-hint {
    display: inline;
  }

  .home-button {
    top: max(16px, env(safe-area-inset-top));
    right: max(14px, env(safe-area-inset-right));
    bottom: auto;
    padding-inline: 14px;
  }
}

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

  .home-button {
    transition: none;
  }
}