#sbg {
      font-family: Arial, sans-serif;
      padding: 20px;
      background: #f4f4f4;
    }
    #sbg .block, #sbg .drop-zone {
      display: inline-block;
      padding: 10px 15px;
      margin: 5px;
      border-radius: 5px;
      font-weight: bold;
      cursor: move;
      user-select: none;
    }
    #sbg .block {
      background-color: #007bff;
      color: white;
    }
    #sbg .drop-zone {
      border: 2px dashed #999;
      min-height: 60px;
      background-color: #fff;
      padding: 10px;
      border-radius: 6px;
      width: 100%;
    }
    #sbg .drop-zone span {
      margin-right: 5px;
    }
    #sbg #output {
      margin-top: 20px;
      font-size: 18px;
      background: #e0ffe0;
      padding: 10px;
      border-radius: 5px;
      white-space: pre-wrap;
    }
    #sbg button {
      margin-top: 15px;
      padding: 10px 20px;
      background: #28a745;
      border: none;
      color: white;
      font-size: 16px;
      border-radius: 4px;
      cursor: pointer;
      margin-right: 10px;
    }
    #sbg button:hover {
      background: #218838;
    }
    #sbg .removable {
      background-color: #dc3545 !important;
    }
    #sbg .level-box {
      background: #fff;
      padding: 10px;
      margin-bottom: 10px;
      border-left: 5px solid #007bff;
    }
    #sbg table {
      width: 100%;
      margin-top: 20px;
      border-collapse: collapse;
      background: white;
    }
    #sbg table, th, td {
      border: 1px solid #aaa;
    }
    #sbg th, td {
      padding: 8px;
      text-align: center;
    }
    #sbg #buttons {
      margin-top: 20px;
    }