* {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    }

    body {
      background-color: #0a0a0a;
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 100vh;
      padding: 20px;
    }

    .login-card {
      background: #141414;
      padding: 40px;
      border-radius: 12px;
      border-top: 4px solid #D4AF37; 
      border-bottom: 4px solid #D4AF37;
      border-left: 4px solid #D4AF37;
      border-right: 4px solid #D4AF37;
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
      width: 100%;
      max-width: 420px;
    }

    .login-card h2 {
      text-align: center;
      margin-bottom: 8px;
      font-size: 28px;
      color: #D4AF37;
    }

    .login-card p.subtitle {
      text-align: center;
      color: #ffffff;
      font-size: 14px;
      margin-bottom: 24px;
    }

    .form-group {
      margin-bottom: 18px;
    }

    .form-group label {
      display: block;
      margin-bottom: 6px;
      font-weight: 600;
      color: #D4AF37;
      font-size: 14px;
    }

    .form-group input {
      width: 100%;
      padding: 12px;
      border: 1px solid #cccccc;
      border-radius: 6px;
      font-size: 14px;
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
    }

    .form-group input:focus {
      outline: none;
      border-color: #0066ff;
      box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.15);
    }

    .btn-submit {
      width: 100%;
      padding: 12px;
      background-color: #D4AF37;
      color: #ffffff;
      border: none;
      border-radius: 6px;
      font-size: 16px;
      font-weight: 600;
      cursor: pointer;
      transition: background-color 0.2s ease;
    }

    .btn-submit:hover {
      background-color: #b6921d;
    }

    .alert {
      padding: 10px;
      border-radius: 6px;
      margin-bottom: 18px;
      font-size: 14px;
      display: none;
    }

    .alert-error {
      background-color: #ffe6e6;
      color: #cc0000;
      border: 1px solid #ffcccc;
    }

    .alert-success {
      background-color: #e6ffe6;
      color: #008000;
      border: 1px solid #ccffcc;
    }

    .register-link {
      text-align: center;
      margin-top: 20px;
      font-size: 14px;
      color: #666666;
    }

    .register-link a {
      color: #D4AF37;
      text-decoration: none;
      font-weight: 600;
    }

    .register-link a:hover {
      text-decoration: underline;
    }