popup.css

body {
    width: 300px;
    height: 240px;
    margin: 0;
    padding: 10px;
    font-family: Arial, sans-serif;
    background-color: #111;
    color: #eee;
  }

  h1 {
    font-size: 24px;
    font-weight: bold;
    margin-top: 0;
    margin-bottom: 10px;
    text-align: center;
  }

  p {
    font-size: 14px;
    margin-bottom: 10px;
    text-align: justify;
  }

  select {
    display: block;
    width: 100%;
    padding: 8px;
    margin-bottom: 10px;
    border: 1px solid #ccc;
    border-radius: 5px;
    background-color: #fff;
    color: #333;
    font-size: 14px;
    font-family: Arial, sans-serif;
  }

  option[selected] {
      font-weight: bold;
  }

  select::-ms-expand {
      display: none;
  }

  select:hover {
      border-color: #999;
  }

  body.dark select {
      background-color: #444;
      color: #eee;
      border-color: #666;
  }

  button {
    display: block;
    margin: 0 auto;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    background-color: #1e88e5;
    color: #fff;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
  }

  button:hover {
    background-color: #1565c0;
  }

  img {
    display: block;
    margin: 0 auto;
    margin-bottom: 10px;
    width: 80px;
    height: 80px;
  }

  .mean-score {
    font-size: 18px;
    font-weight: bold;
    margin-bottom: 10px;
    text-align: center;
  }

  body.dark {
    background-color: #333;
    color: #eee;
  }

  button.dark {
    background-color: #1e88e5;
    color: #fff;
  }

  button.dark:hover {
    background-color: #1565c0;
  }