/* Marco común del juego: diseño original 750 × 1334, sin estirar sus ejes. */
:root { color-scheme: dark; }
html, body { margin: 0; width: 100%; height: 100%; background: #080a0e; overflow: hidden; }
#viewport-juego {
  position: absolute;
  left: 50%; top: 50%;
  transform: translate(-50%, -50%);
  width: min(100vw, calc(100vh * 750 / 1334));
  height: min(100vh, calc(100vw * 1334 / 750));
  width: min(100vw, calc(100dvh * 750 / 1334));
  height: min(100dvh, calc(100vw * 1334 / 750));
  overflow: hidden;
  background: #000;
}
#viewport-juego canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; touch-action: none; }
#carga { position: absolute; inset: 0; display: grid; place-items: center; color: #9fd3ff;
  font: 14px "Segoe UI", system-ui, sans-serif; background: #050a14; }