body {
    margin: 0;
    font-family: 'Segoe UI', sans-serif;
    background-color: var(--biru1);
    color: var(--putih);
  }
  
  .container {
    max-width: 800px;
    margin: 40px auto;
    background-color: var(--biru2);
    padding: 30px;
    border: 3px solid var(--kuning);
    border-radius: 10px;
  }
  
  h1 {
    font-size: 2em;
    text-align: center;
    color: var(--kuning);
  }
  
  p {
    text-align: center;
    margin-bottom: 25px;
  }
  
  .referral-box {
    background-color: var(--biru1);
    padding: 20px;
    border-radius: 10px;
    border: 2px solid var(--kuning);
    display: flex;
    flex-direction: column;
    gap: 10px;
  }
  
  .referral-box input {
    padding: 10px;
    font-size: 1em;
    border: none;
    border-radius: 5px;
    background-color: var(--putih);
    text-align: center;
    font-weight: bold;
  }
  
  .hint {
    font-size: 0.9em;
    color: var(--hijau1);
    text-align: center;
  }
  
  .reward-info {
    margin-top: 30px;
    background-color: var(--biru2);
    padding: 20px;
    border-radius: 10px;
    border: 2px solid var(--kuning);
  }
  
  .reward-info h2 {
    color: var(--kuning);
    margin-bottom: 15px;
  }
  
  .reward-info ul {
    list-style: none;
    padding: 0;
  }
  
  .reward-info li {
    margin: 10px 0;
    padding-left: 1em;
    position: relative;
  }
  
  .reward-info li::before {
    content: "✔";
    position: absolute;
    left: 0;
    color: var(--hijau1);
  }
  
  footer {
    margin-top: 40px;
    text-align: center;
    font-size: 0.9em;
    color: var(--putih);
  }