html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  overflow: hidden;
  background: #eaf4ff; /* 更明亮 */
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
}

canvas {
  display: block;
  width: 100vw;
  height: 100vh;
}

.hud {
  position: fixed;
  left: 14px;
  top: 12px;
  color: rgba(10, 30, 60, 0.92); /* 深色字，适配亮背景 */
  text-shadow: 0 1px 0 rgba(255,255,255,0.45);
  user-select: none;
  pointer-events: none;
}

.title {
  font-weight: 800;
  letter-spacing: 0.12em;
  font-size: 14px;
  opacity: 0.95;
}

.hint {
  margin-top: 6px;
  font-size: 12px;
  opacity: 0.78;
}

.info {
  margin-top: 8px;
  font-size: 12px;
  opacity: 0.9;
}