body, html {
  margin: 0; 
  height: 100%;
  overflow: hidden;
  background: linear-gradient(135deg, #2a2a2a, #181818);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-family: Arial, sans-serif;
  color: #eee;
  padding: 20px;
}

header nav {
  width: 100%;
  background: #121212;
  padding: 10px 0;
  text-align: center;
  margin-bottom: 20px;
}

header nav a {
  color: #eee;
  text-decoration: none;
  font-weight: bold;
  margin: 0 15px;
  font-size: 1.1rem;
}

#canvas-container {
  width: 80vw;
  height: 70vh;
  border-radius: 12px;
  box-shadow: 0 0 30px rgba(255, 255, 255, 0.15);
  background: #222;
}