* { margin: 0; padding: 0; box-sizing: border-box; }

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #b8d8d0;
}

#cam { display: none; }

#base, #scene {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
}

/* ---------- 开场卡片 ---------- */
#overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(184, 216, 208, 0.3);
  z-index: 10;
  transition: opacity 0.8s ease;
}

#overlay.hide {
  opacity: 0;
  pointer-events: none;
}

.card {
  background: #f2efe8;
  padding: 48px 56px;
  border-radius: 14px;
  box-shadow: 0 20px 60px rgba(80, 70, 50, 0.15);
  text-align: center;
  max-width: 420px;
}

.card .en {
  font: 400 11px/1 -apple-system, "PingFang SC", sans-serif;
  letter-spacing: 0.3em;
  color: rgba(90, 80, 65, 0.5);
  margin-bottom: 20px;
}

.card h1 {
  font: 300 38px/1.2 -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #4a4438;
  letter-spacing: 0.15em;
  margin-bottom: 16px;
}

.card .sub {
  font: 300 13px/1.8 Georgia, serif;
  color: rgba(90, 80, 65, 0.6);
  font-style: italic;
  margin-bottom: 32px;
}

.gestures {
  text-align: left;
  margin-bottom: 28px;
}

.row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 0;
  font: 300 13px/1 -apple-system, "PingFang SC", sans-serif;
  color: #5a5040;
}

.row .g { font-size: 18px; width: 24px; }
.row .lbl { width: 48px; color: #4a4438; }
.row .arr { color: rgba(90, 80, 65, 0.4); }
.row .desc { color: rgba(90, 80, 65, 0.65); }

.tip {
  font: 300 11px/1.6 -apple-system, "PingFang SC", sans-serif;
  color: rgba(90, 80, 65, 0.45);
  margin-bottom: 24px;
}

#enter {
  background: #6b7a5e;
  color: #f2efe8;
  border: none;
  padding: 12px 36px;
  border-radius: 8px;
  font: 300 13px/1 -apple-system, "PingFang SC", sans-serif;
  letter-spacing: 0.1em;
  cursor: pointer;
  transition: background 0.3s ease;
}

#enter:hover { background: #5a6a4e; }

/* ---------- 底部提示 ---------- */
#hint {
  position: fixed;
  left: 50%;
  bottom: 36px;
  transform: translateX(-50%);
  font: 300 13px/1.8 -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: rgba(70, 105, 100, 0.75);
  letter-spacing: 0.25em;
  text-indent: 0.25em;
  pointer-events: none;
  transition: opacity 1s ease;
  z-index: 5;
}

#hint.fade { opacity: 0; }