:root {
  --frame-bg: #040a18;
  --frame-glow: #132957;
  --canvas-edge: #35548e;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 12% 16%, rgba(58, 94, 160, 0.35) 0%, transparent 34%),
    radial-gradient(circle at 88% 84%, rgba(100, 70, 160, 0.22) 0%, transparent 40%),
    linear-gradient(160deg, #050d22 0%, #040914 52%, #02050c 100%);
  font-family: "Trebuchet MS", "Segoe UI", sans-serif;
  color: #dbe9ff;
}

.app-shell {
  width: 100%;
  display: grid;
  place-items: center;
  padding: 1rem;
}

#gameCanvas {
  width: min(96vw, 1220px);
  height: auto;
  aspect-ratio: 16 / 9;
  border: 2px solid var(--canvas-edge);
  border-radius: 12px;
  box-shadow:
    0 22px 54px rgba(0, 0, 0, 0.44),
    0 0 0 1px rgba(112, 149, 230, 0.22) inset;
  display: block;
  background: #02060f;
}

@media (max-width: 800px) {
  .app-shell {
    padding: 0.5rem;
  }

  #gameCanvas {
    width: 98vw;
    border-radius: 8px;
  }
}