body {
    font-family: sans-serif;
    margin: 0;
    padding: 0;
    background: #111;
    color: #fff;
  }
  
  header, footer {
    background: #000;
    padding: 1em;
    text-align: center;
  }
  
  nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
  }
  
  nav ul li {
    display: inline-block;
    margin: 0 10px;
  }
  
  nav ul li a {
    color: #fff;
    text-decoration: none;
  }
  
  main {
    padding: 2em;
  }
  
  .error {
    color: red;
  }
  
  form input {
    display: block;
    margin: 1em 0;
    padding: 0.5em;
  }
  
  button {
    background: #333;
    color: #fff;
    border: none;
    padding: 0.5em 1em;
  }
  
  .redeem-container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem;
    background: #ffffff;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: 1.5rem;
    position: relative;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #333;
}

.form-group input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
}

.button-group {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.submit-btn {
    background: #0066cc;
    color: white;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s;
}

.submit-btn:hover {
    background: #0052a3;
}

.instructions-btn {
    background: #ffffff;
    color: #0066cc;
    padding: 0.75rem 1.5rem;
    border: 1px solid #0066cc;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s;
}

.instructions-btn:hover {
    background: #f0f7ff;
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    max-width: 500px;
    width: 90%;
}

.modal-btn {
    background: #0066cc;
    color: white;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 5px;
    margin-top: 1rem;
    cursor: pointer;
}

.error-message {
    color: #dc3545;
    font-size: 0.875rem;
    margin-top: 0.25rem;
    display: block;
}