body, html {
  margin: 0;
  padding: 0;
  overflow: hidden; /* 防止出现滚动条 */
  background-color: #080c1a; /* 统一底色，防止页面加载时闪白 */
}

#sleep-guide {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  
  /* 新增：限制宽度，强制长文本换行 */
  width: 85%; 
  max-width: 600px; 
  line-height: 2.0; /* 新增：增加行高，看起来更舒缓 */
  
  color: rgba(160, 180, 210, 0.7);
  font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 22px; /* 稍微调小一点字号，更适合长段落 */
  letter-spacing: 4px; /* 字间距稍微收紧一点 */
  text-align: center;
  pointer-events: none;
  opacity: 0;
  transition: opacity 3s ease-in-out;
}