:root {
      --primary-color: #2d6e1b;
      --secondary-color: #29A000;
      --success-color: #4cc9f0;
      --danger-color: #f94144;
      --light-bg: #f8f9fa;
      --card-shadow: 0 4px 12px rgba(0,0,0,0.1);
      --border-radius: 12px;
    }

    body {
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      background-color: #f5f7fa;
      color: #2b2d42;
      display: flex;
      min-height: 100vh;
      align-items: center;
      justify-content: center;
      padding: 20px;
    }

    .login-container {
      max-width: 500px;
      width: 100%;
      animation: fadeIn 0.5s ease-in-out;
    }

    @keyframes fadeIn {
      from { opacity: 0; transform: translateY(-20px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .login-card {
      background: white;
      border-radius: var(--border-radius);
      box-shadow: var(--card-shadow);
      overflow: hidden;
    }

    .login-header {
      background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
      color: white;
      padding: 1.5rem;
      text-align: center;
    }

    .login-header h2 {
      margin: 0;
      font-weight: 700;
    }

    .login-header img {
      max-height: 130px;
      margin-bottom: 1rem;
    }

    .login-body {
      padding: 2rem;
    }

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

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

    .form-control {
      width: 100%;
      padding: 0.75rem 1rem;
      border: 1px solid #ddd;
      border-radius: var(--border-radius);
      font-size: 1rem;
      transition: all 0.3s ease;
    }

    .form-control:focus {
      border-color: var(--primary-color);
      box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
      outline: none;
    }

    .btn-login {
      background-color: var(--primary-color);
      color: white;
      border: none;
      border-radius: var(--border-radius);
      padding: 0.75rem;
      width: 100%;
      font-size: 1rem;
      font-weight: 600;
      cursor: pointer;
      transition: all 0.3s ease;
    }

    .btn-login:hover {
      background-color: var(--secondary-color);
      transform: translateY(-2px);
    }

    .btn-login:disabled {
      background-color: #adb5bd;
      cursor: not-allowed;
      transform: none;
    }

    .error-message {
      color: var(--danger-color);
      margin-top: 0.5rem;
      font-size: 0.9rem;
      display: none;
    }

    .login-footer {
      text-align: center;
      margin-top: 1.5rem;
      color: #6c757d;
      font-size: 0.9rem;
    }

    @media (max-width: 576px) {
      .login-body { padding: 1.5rem; }
      .form-control { padding: 0.65rem 0.9rem; }
    }