body {
      font-family: Arial, sans-serif;
      background-color: #f2f2f2;
      margin: 0;
      padding: 20px;
    }
    h2 {
      color: #333;
    }
    input, button {
      padding: 8px;
      margin: 5px;
      font-size: 16px;
    }
    #userList {
      margin-top: 10px;
      margin-bottom: 20px;
    }
    .user-item {
      margin: 5px 0;
    }
    .user-item span {
      font-weight: bold;
    }
    .user-item button {
      margin-left: 10px;
    }
    video {
      width: 45%;
      margin: 10px;
      border: 2px solid #ccc;
    }
    #incomingCall {
      background-color: #fff8dc;
      border: 1px solid #f0c040;
      padding: 10px;
      margin-bottom: 15px;
      display: none;
    }
    #endCallBtn {
      display: none;
      padding: 10px;
      background-color: red;
      color: white;
      border: none;
      font-size: 16px;
      cursor: pointer;
    }
    @media screen and (max-width: 600px) {
      video {
        width: 100%;
      }
      body {
        padding: 10px;
      }
      input, button {
        width: 100%;
        box-sizing: border-box;
      }
      
    }