body {
  font-family: Arial, sans-serif;
  background-color: #f5f5f5;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
}

header {
  background-color: #333;
  color: #fff;
  padding: 20px;
  width: 50%;
  text-align: center;
}

main {
  width: 80%;
  margin-top: 20px;
}
  h1, h2 {
    text-align: center;
  }
  form {
    max-width: 400px;
    margin: 0 auto;
    text-align: center;
  }
  label {
    display: block;
    margin-bottom: 10px;
  }
  select, input[type="submit"] {
    width: 100%;
    padding: 10px;
    margin-bottom: 10px;
    border: 1px solid #ccc;
    border-radius: 5px;
    box-sizing: border-box;
  }
  .cards {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    max-width: 800px;
    margin: 20px auto;
  }
  .card {
    width: 197px;
    /* height: 342px; */ 
    margin: 10px;
    border-radius: 5px;
    overflow: visible;
    box-shadow: 0 4px 6px;
    background-color: #fff;
    transition: transform 0.3s;
  }
  
  .card:hover {
    transform: translateY(-5px);
  }
  .card img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.3s;
  }
  .card p {
    text-align: center;
    margin: 10px 0;
    display: block;
  }  
  #downloadLink {
    text-align: center;
    margin-top: 40px;
  }
  #downloadButton {
    padding: 10px 20px;
    background-color: #007bff;
    color: #fff;
    text-decoration: none;
    border-radius: 5px;
    transition: background-color 0.3s;
  }

  #downloadButton:hover {
    background-color: #0056b3;
  }

  #chatWindow {
    text-align: center;
    padding: 30px;
    width: 100%;
    height: 50%;
  }

  footer {
    padding: 12px;
    text-align: center;
  }

  input[type="text"] {
    width: 100%;
    padding: 10px;
    margin-bottom: 20px;
    font-size: 16px;
  }

  input[type="submit"] {
    padding: 10px 20px;
    background-color: #333;
    color: #fff;
    border: none;
    font-size: 16px;
    width: 106%;
  }

  input[type="submit"]:hover {
    background-color: #222;
  }

  input:invalid{
    border:2px solid red;
  }