* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #111827;
  color: white;
  text-align: center;
}

.page {
  max-width: 950px;
  margin: 0 auto;
  padding: 24px;
}

h1 {
  margin-bottom: 20px;
}

.game-card {
  background: #1f2937;
  border-radius: 16px;
  padding: 20px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
}

canvas {
  display: block;
  margin: 0 auto;
  background: #050816;
  border: 3px solid #374151;
  border-radius: 12px;
  max-width: 100%;
  height: auto;
}

.controls {
  margin-top: 16px;
  line-height: 1.4;
}

.controls p {
  margin: 5px;
}

.teacher-note {
  margin-top: 24px;
  background: #1f2937;
  border-radius: 12px;
  padding: 16px;
}

.teacher-note h2 {
  margin-top: 0;
}