:root { color-scheme: dark; }
* { box-sizing: border-box; }
html, body {
  margin: 0; height: 100%;
  background: #07090d;
  color: #e9eef2;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  overscroll-behavior: none;
  -webkit-tap-highlight-color: transparent;
}
#stage {
  display: flex; align-items: center; justify-content: center;
  height: 100dvh; width: 100vw;
}
#c {
  touch-action: none;
  border-radius: 14px;
  box-shadow: 0 0 80px rgba(230,159,0,0.08), 0 10px 40px rgba(0,0,0,0.6);
  background: #0b0f14;
}
#help {
  position: fixed; left: 12px; bottom: 12px; max-width: 320px;
  font-size: 13px; line-height: 1.45; color: #9aa6b1; z-index: 5;
}
#help summary {
  cursor: pointer; color: #56B4E9; font-weight: 600;
  list-style: none; user-select: none; padding: 6px 0;
}
#help summary::-webkit-details-marker { display: none; }
#help details[open] {
  background: rgba(11,15,20,0.92);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 10px; padding: 10px 14px;
  backdrop-filter: blur(6px);
}
#help p { margin: 8px 0; }
#help b { color: #cdd6df; }
@media (max-height: 560px) { #help { display: none; } }