:root {
      --primary-color: #0056b3;
      --accent-color: #00d2ff;
      --bg-light: #f4f7f6;
    }

    body {
      font-family: 'Poppins', sans-serif;
      background-color: var(--bg-light);
    }

    /* Navbar Moderno */
    .main-header {
      border-bottom: none !important;
      padding: 0.8rem 0;
    }
    .navbar-brand img {
      transition: transform 0.3s;
    }
    .navbar-brand img:hover {
      transform: scale(1.05);
    }

    /* Contenedores de Tarjetas */
    .content-header h1 {
      font-weight: 700;
      color: #2c3e50;
      letter-spacing: -1px;
    }

    .card {
      border: none;
      border-radius: 15px;
      box-shadow: 0 10px 30px rgba(0,0,0,0.05) !important;
      margin-bottom: 2rem;
    }

    .card-primary.card-outline {
      border-top: 5px solid var(--primary-color);
    }

    .card-header {
      background-color: transparent;
      border-bottom: 1px solid #eee;
      padding: 1.25rem;
    }

    .card-title {
      font-weight: 600 !important;
      color: #444;
      display: flex;
      align-items: center;
    }

    .card-title i {
      margin-right: 10px;
      color: var(--primary-color);
    }

    /* Formulario */
    .form-control, .select2-container--bootstrap4 .select2-selection {
      border-radius: 10px !important;
      border: 1px solid #e0e0e0;
      padding: 0.6rem 1rem;
      height: auto !important;
      transition: all 0.3s;
    }

    .form-control:focus {
      border-color: var(--primary-color);
      box-shadow: 0 0 0 0.2rem rgba(0,86,179,0.1);
    }

    .input-group-text {
      border-radius: 0 10px 10px 0 !important;
      background-color: var(--primary-color);
      color: white;
      border: none;
    }

    /* Alertas y Boxes */
    .alert-info-custom {
      background: white;
      border-left: 5px solid var(--primary-color);
      border-radius: 10px;
      padding: 20px;
    }

    /* Botones */
    .btn-primary {
      background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
      border: none;
      border-radius: 10px;
      padding: 12px 25px;
      font-weight: 600;
      transition: all 0.3s;
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 5px 15px rgba(0,86,179,0.3);
    }

    /* Secciones de carga de archivos (Dropzone) */
    .fileinput-button {
      background-color: #28a745 !important;
      border: none !important;
      border-radius: 10px !important;
    }

    .preview img {
      border-radius: 8px;
    }

    .footer-custom {
      background: white;
      padding: 20px 0;
      margin-top: 50px;
      border-top: 1px solid #eee;
    }