:root {
  --red: #E63946;
  --yellow: #F4A261;
  --blue: #264653;
  --black: #1D1D1D;
  --white: #F1FAEE;
  --gray: #8D99AE;
  --bauhaus-red: #DC3023;
  --bauhaus-yellow: #F7C548;
  --bauhaus-blue: #2059A8;
  --font-display: 'Space Grotesk', 'Impact', sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html, body {
  width: 100%; height: 100%;
  overflow: hidden;
  background: var(--black);
  touch-action: none;
  -webkit-user-select: none;
  user-select: none;
}

canvas {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--black);
  cursor: none;
}

#fullscreen-btn {
  position: fixed;
  top: 12px;
  right: 12px;
  z-index: 1000;
  width: 44px;
  height: 44px;
  border: 2px solid var(--white);
  background: rgba(29, 29, 29, 0.7);
  color: var(--white);
  font-family: var(--font-display);
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, transform 0.15s;
  opacity: 0.6;
}
#fullscreen-btn:hover {
  background: var(--bauhaus-red);
  opacity: 1;
  transform: scale(1.1);
}
#fullscreen-btn:active {
  transform: scale(0.9);
}

@media (max-width: 768px) {
  #fullscreen-btn {
    top: 8px;
    right: 8px;
    width: 38px;
    height: 38px;
    font-size: 16px;
  }
}