:root {
  font-family: "Segoe UI", "Noto Sans TC", sans-serif;
  color: #f2f4f8;
  background: radial-gradient(circle at top, #1d2b3a, #0b1118 60%);
}

body {
  margin: 0;
  display: grid;
  place-items: center;
  min-height: 100vh;
  gap: 12px;
}

.ui {
  text-align: center;
}

h1 {
  margin: 12px 0 4px;
  font-size: 1.6rem;
}

canvas {
  border: 2px solid #2b3b4f;
  border-radius: 12px;
  background: linear-gradient(180deg, #8ecae6 0%, #84a98c 40%, #52796f 100%);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
}

.hud {
  width: 960px;
  max-width: 92vw;
  min-height: 56px;
}

.message {
  background: rgba(16, 20, 26, 0.8);
  border: 1px solid rgba(148, 187, 233, 0.5);
  border-radius: 10px;
  padding: 12px 16px;
  font-size: 0.95rem;
  min-height: 24px;
}