body {
  background: #111;
  color: #fff;
  font-family: "Press Start 2P", monospace, Arial, sans-serif;
  margin: 0;
  overflow: hidden;
}
#ui {
  position: absolute;
  width: 100%;
  top: 0;
  left: 0;
  z-index: 2;
  text-align: center;
}
.screen {
  background: rgba(0, 0, 0, 0.85);
  border: 2px solid #0f0;
  border-radius: 8px;
  display: inline-block;
  margin-top: 80px;
  padding: 32px 48px;
  box-shadow: 0 0 24px #0f0;
}
#hud {
  position: absolute;
  top: 8px;
  left: 0;
  width: 100%;
  display: flex;
  justify-content: space-around;
  font-size: 18px;
  letter-spacing: 2px;
  z-index: 3;
}
canvas {
  display: block;
  margin: 0 auto;
  background: #222;
  border: 4px solid #0f0;
  box-shadow: 0 0 32px #0f0;
}
button {
  font-family: inherit;
  font-size: 18px;
  background: #0f0;
  color: #111;
  border: none;
  border-radius: 4px;
  padding: 12px 32px;
  margin-top: 16px;
  cursor: pointer;
  box-shadow: 0 0 8px #0f0;
  transition: background 0.2s;
}
button:hover {
  background: #fff;
  color: #0f0;
}
@media (max-width: 900px) {
  canvas {
    width: 100vw !important;
    height: 70vh !important;
  }
  .screen {
    margin-top: 32px;
    padding: 16px 8px;
    font-size: 14px;
  }
  #hud {
    font-size: 14px;
  }
}