:root {
  --bg-dark: #111520;
  --card-dark: #282e37;
  --text-light: #f8fafc;
  --text-subtle: #94a3b8;
  --accent: #8b5cf6;
  --accent-hover: #7c3aed;
  --border: #334155;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

body {
  background: var(--bg-dark);
  color: var(--text-light);
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 100vh;
}

header {
  color: var(--text-light);
  text-align: center;
  padding: 1rem 0;
}

header h1 {
  font-size: 1.5rem;
  font-weight: 500;
  letter-spacing: 1.25px;
}

header p {
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-subtle);
  margin-top: 0.25rem;
}

main {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  justify-content: center;
  align-items: center;
}

#startBtn {
  padding: 0.4rem 0.75rem;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 12px;
  background: var(--accent);
  color: var(--bg-dark);
  cursor: pointer;
}
#startBtn:disabled {
  background: #888;
  color: #ddd;
}
#startBtn:hover {
  background: var(--accent-hover);
}

canvas {
  background: var(--card-dark);
  border: 3px solid var(--border);
}

footer {
  margin-top: 3rem;
  color: var(--text-subtle);
  font-size: 0.85rem;
}

footer a {
  color: var(--text-subtle);
}