body {
  margin: 0;
  padding: 0;
  overflow: hidden;
  font-family: 'Arial', sans-serif;
  background: linear-gradient(to bottom, #0077be, #004466);
  color: #fff;
}

canvas {
  display: block;
  background: linear-gradient(to bottom, #0077be, #004466);
}

.hud {
  position: absolute;
  top: 10px;
  left: 10px;
  right: 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 100;
  font-size: 16px;
  background: rgba(0,0,0,0.3);
  padding: 8px 12px;
  border-radius: 8px;
}

button {
  background: #00f9ff;
  border: none;
  color: #000;
  font-weight: bold;
  padding: 6px 10px;
  border-radius: 5px;
  cursor: pointer;
  transition: 0.2s;
}

button:hover {
  background: #00ffff;
  box-shadow: 0 0 10px #00ffff;
}