:root {
  color-scheme: light;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f1f5f9;
  color: #1f2933;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.app-container {
  background: #ffffff;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.12);
  padding: 24px;
  max-width: 720px;
  width: 100%;
}

.app-header h1 {
  margin: 0 0 8px;
  font-size: 1.8rem;
}

.app-header p {
  margin: 0 0 20px;
  font-size: 1rem;
  color: #475569;
}

.game-section {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.game-canvas {
  border-radius: 12px;
  border: 2px solid #cbd5f5;
  background: #bde0fe;
  max-width: 100%;
  touch-action: manipulation;
}

.game-instruction {
  margin: 0;
  font-weight: 600;
  color: #1d4ed8;
}