body, html {
    height: 100%;
    margin: 0;
    font-family: Arial, sans-serif;
    background-image: url('img/background.png'); /* 替换为你的图片路径 */
    background-size: cover; /* 图片覆盖整个背景 */
    background-position: center; /* 图片居中 */
    background-repeat: no-repeat; /* 不重复背景图 */
  }
  #sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 250px;
    height: 100%;
    background-color: #222222c6;
    color: white;
    overflow-x: hidden;
    transition: 0.5s;
    padding-top: 60px;
  }
  #sidebar a {
    padding: 10px 15px;
    text-decoration: none;
    font-size: 25px;
    color: white;
    display: block;
  }
  #sidebar a:hover {
    color: #f1f1f1;
  }
  #main {
    transition: margin-left .5s;
    padding: 16px;
    margin-left: 250px; /* 初始状态下，主内容区域向右偏移250px */
  }
  .openbtn {
    font-size: 20px;
    cursor: pointer;
    background-color: #1111119c;
    color: white;
    padding: 10px 15px;
    border: none;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1001; /* 确保按钮在侧栏之上 */
  }
  .openbtn:hover {
    background-color: #444;
  }
  /* 聊天框 */
  #chat-container {
    background-color: rgba(255, 255, 255, 0.8);
    width: 80%;
    height: 80%; /* 占据右边区域80%的高度 */
    margin: 10vh auto;
    border: 10px solid #ff648195;
    border-radius: 20px;
    overflow: hidden;
    padding: 4px solid #ff648195;/* 内边距，确保内容与边框之间有间距 */
  }
  #messages {
    height: 60vh;
    padding: 10px;
    background-color: rgba(255, 255, 255, 0); /* 半透明背景色 */
    border-bottom: 1px solid #ccc;
    overflow-y: scroll;
  }
  .message {
    margin: 5px 0;
    padding: 10px;
    border-radius: 10px;
  }
  .message.user {
    text-align: right;
    background-color: #DCF8C6; /* 用户消息气泡颜色 */

  }
  .message.bot {
    text-align: left;
    background-color: #ECECEC; /* 机器人消息气泡颜色 */
  }
  #input-area {
    display: flex;
    background-color: rgba(255, 255, 255, 0); /* 半透明背景色 */
    margin: 5px; /* 输入框与边界有5px的距离 */
  }
  #user-input {
    height: 25px;
    flex: 1;
    padding: 5px;
    border: 2px solid #cccccc95;
    border-radius: 5px;
  }
  #send-button {
    padding: 5px 10px;
    margin-left: 5px;
    border: 2px solid #cccccc95;
    border-radius: 5px;
    background-color: #007bffb5;
    color: white;
    cursor: pointer;
  }
  @media screen and (max-height: 450px) {
    #sidebar {padding-top: 15px;}
    #sidebar a {font-size: 18px;}
  }
  .slider_box {
    width: 90%;
    margin: auto;
    overflow: hidden;
  }