* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: #111827;
  color: #f9fafb;
  font-family: Arial, Helvetica, sans-serif;
}

.game-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 18px;
}

h1 {
  margin: 0;
  font-size: 24px;
  text-align: center;
}

canvas {
  width: min(960px, 100%);
  aspect-ratio: 16 / 9;
  background: #76c7f2;
  border: 4px solid #f9fafb;
  border-radius: 12px;
  image-rendering: pixelated;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.45);
}

.help {
  margin: 0;
  max-width: 960px;
  line-height: 1.4;
  text-align: center;
  color: #d1d5db;
}