body {
    margin: 0;
    background-color: #d3d3d3;
    font-family: Arial;
  }
  #main-container {
    display: flex;
    width: 90%;
    margin: 20px auto;
  }
  #tree-container {
    flex: 3;
    height: 600px;
    border: 2px solid #333;
    background-color: #d3d3d3;
  }
  #stack-container {
    flex: 1;
    height: 600px;
    border: 2px solid #333;
    background-color: #f0f0f0;
    margin-left: 10px;
    padding: 10px;
    box-sizing: border-box;
  }
  #stack-title {
    text-align: center;
    font-weight: bold;
    margin-bottom: 10px;
  }
  #controls {
    text-align: center;
    margin-top: 10px;
  }
  #log, #final-seq, #status {
    width: 90%;
    margin: 10px auto;
    padding: 10px;
    background-color: #fff;
    border-radius: 4px;
    font-size: 16px;
  }
  #log {
    height: 100px;
    overflow-y: auto;
  }
  button {
    padding: 10px 20px;
    font-size: 16px;
    margin: 0 10px;
  }
  .label {
    font-weight: bold;
  }