* {
    box-sizing: border-box;
    font-family: 'Segoe UI', sans-serif;
  }
  
  body {
    background: linear-gradient(to right, #1f1c2c, #928dab);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
  }
  
  .container {
    background: #fff;
    padding: 30px 40px;
    border-radius: 12px;
    width: 100%;
    max-width: 400px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
  }
  
  h2 {
    text-align: center;
    margin-bottom: 20px;
  }
  
  .form-group {
    margin-bottom: 15px;
    position: relative;
  }
  
  label {
    display: block;
    font-weight: bold;
    margin-bottom: 5px;
  }
  
  input {
    width: 100%;
    padding: 10px;
    border: 2px solid #ccc;
    border-radius: 8px;
    transition: border-color 0.3s ease;
  }
  
  input:focus {
    border-color: #6c5ce7;
    outline: none;
  }
  
  input.valid {
    border-color: #2ecc71;
  }
  
  input.invalid {
    border-color: #e74c3c;
  }
  
  .error-message {
    color: #e74c3c;
    font-size: 0.8rem;
    display: none;
    margin-top: 3px;
  }
  
  button {
    width: 100%;
    padding: 12px;
    border: none;
    background: #6c5ce7;
    color: white;
    font-size: 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.3s ease;
  }
  
  button:hover {
    background: #5a4bcf;
  }
  
  /* Popup Notifikasi */
  .popup {
    position: fixed;
    top: 20px;
    right: 20px;
    background: #2ecc71;
    color: white;
    padding: 16px 20px;
    border-radius: 10px;
    box-shadow: 0 6px 12px rgba(0,0,0,0.3);
    display: none;
    animation: fadeIn 0.4s ease;
    z-index: 999;
  }
  
  .popup p {
    margin: 0;
    margin-bottom: 10px;
  }
  
  .popup button {
    background: #27ae60;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.9rem;
  }
  
  @keyframes fadeIn {
    from {
      opacity: 0;
      transform: translateY(-10px);
    } to {
      opacity: 1;
      transform: translateY(0);
    }
  }