html, body {
      margin: 0;
      padding: 0;
      height: 100%;
      width: 100%;
      font-family: Arial, sans-serif;
      background: #f4f4f4;
      overflow: hidden;
    }

    #menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100vw;
      height: 100vh;
      background: rgba(255, 255, 255, 0.97);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      z-index: 9999;
      transition: opacity 0.6s ease;
    }

    #menu.hidden {
      opacity: 0;
      pointer-events: none;
    }

    #menu-box {
      background: #ffffff;
      padding: 30px 40px;
      border-radius: 10px;
      box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
      text-align: center;
    }

    #menu-box h2 {
      margin-bottom: 20px;
    }

    #menu-box input {
      padding: 10px;
      font-size: 16px;
      margin: 10px 0;
      width: 200px;
      border: 1px solid #ccc;
      border-radius: 5px;
    }

    #menu-box button {
      padding: 10px 20px;
      font-size: 16px;
      cursor: pointer;
      background-color: #007bff;
      border: none;
      border-radius: 5px;
      color: #fff;
      transition: background-color 0.3s ease;
    }

    #menu-box button:hover {
      background-color: #0056b3;
    }

    #message {
      color: red;
      margin-top: 10px;
      min-height: 20px;
    }

    #content {
      opacity: 0;
      visibility: hidden;
      transition: opacity 0.6s ease;
      text-align: center;
      padding-top: 100px;
    }

    #content.visible {
      opacity: 1;
      visibility: visible;
    }