/* normal (non-FS) layout frame */
.game-frame {
  max-width: 1100px;
  margin: clamp(1rem, 4vw, 2rem) auto;
  aspect-ratio: 16/9;
  background: #000;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(0,0,0,.15);
}
.game-frame iframe {
  width: 100%;
  height: 100%;
  border: 0;
  display: block;
}

/* when the iframe is in fullscreen, drop all constraints */
iframe:fullscreen {
  width: 100vw !important;
  height: 100vh !important;
  border-radius: 0 !important;
}
:-webkit-full-screen iframe { /* older Safari fallback */
  width: 100vw !important;
  height: 100vh !important;
  border-radius: 0 !important;
}