/* ---- Reset & base ---- */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            background: linear-gradient(145deg, #0a4b8c, #0d6efd, #0a4b8c);
            background-size: 400% 400%;
            animation: gradientMove 10s ease infinite;
            font-family: 'Segoe UI', Roboto, system-ui, -apple-system, sans-serif;
            padding: 1rem;
        }

        @keyframes gradientMove {
            0% {
                background-position: 0% 50%;
            }
            50% {
                background-position: 100% 50%;
            }
            100% {
                background-position: 0% 50%;
            }
        }

        /* ---- Tarjeta principal ---- */
        .login-card {
            border: none;
            border-radius: 28px;
            background: rgba(255, 255, 255, 0.85);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35), 0 0 0 1px rgba(255, 255, 255, 0.15) inset;
            width: 100%;
            max-width: 440px;
            transition: transform 0.25s ease;
        }

        .login-card:hover {
            transform: translateY(-4px);
        }

        .login-card .card-body {
            padding: 2.8rem 2.5rem;
        }

        /* ---- Header ---- */
        .login-header {
            text-align: center;
            margin-bottom: 2rem;
        }

        .login-header .icon-wrapper {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 80px;
            height: 80px;
            border-radius: 50%;
            background: linear-gradient(135deg, #0d6efd, #0a58ca);
            box-shadow: 0 8px 24px rgba(13, 110, 253, 0.35);
            margin-bottom: 1rem;
        }

        .login-header .icon-wrapper i {
            font-size: 3rem;
            color: #fff;
            filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
        }

        .login-header h4 {
            font-weight: 700;
            font-size: 1.4rem;
            color: #0b2b4a;
            letter-spacing: -0.3px;
        }

        .login-header .subtitle {
            font-size: 0.9rem;
            color: #5e6f8d;
            font-weight: 400;
        }

        /* ---- Campos ---- */
        .form-label {
            font-weight: 600;
            font-size: 0.85rem;
            color: #1e2f4a;
            margin-bottom: 0.35rem;
        }

        .input-group {
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
            transition: box-shadow 0.2s;
        }

        .input-group:focus-within {
            box-shadow: 0 0 0 3px rgba(13, 110, 253, 0.25), 0 2px 8px rgba(0, 0, 0, 0.06);
        }

        .input-group-text {
            background: #f8faff;
            border: 1px solid #dce3ef;
            border-right: none;
            padding: 0.6rem 0.9rem;
            color: #6b7d9c;
        }

        .form-control {
            border: 1px solid #dce3ef;
            border-left: none;
            padding: 0.6rem 0.9rem;
            font-size: 0.95rem;
            background: #ffffff;
            color: #0b2b4a;
            transition: border-color 0.2s;
        }

        .form-control:focus {
            border-color: #0d6efd;
            box-shadow: none;
        }

        .form-control.is-invalid {
            border-color: #dc3545;
        }

        .input-group .btn-outline-secondary {
            border: 1px solid #dce3ef;
            border-left: none;
            background: #fff;
            color: #6b7d9c;
            padding: 0.6rem 0.9rem;
        }

        .input-group .btn-outline-secondary:hover {
            background: #f0f4ff;
            color: #0d6efd;
        }

        /* ---- Checkbox ---- */
        .form-check-input {
            border-radius: 6px;
            border: 2px solid #cdd7e6;
            margin-top: 0.2rem;
            cursor: pointer;
            transition: all 0.15s;
            width: 1.1rem;
            height: 1.1rem;
        }

        .form-check-input:checked {
            background-color: #0d6efd;
            border-color: #0d6efd;
            box-shadow: 0 0 0 2px rgba(13, 110, 253, 0.2);
        }

        .form-check-label {
            font-size: 0.85rem;
            color: #3e526f;
            font-weight: 500;
        }

        /* ---- Botón ---- */
        .btn-primary {
            background: linear-gradient(135deg, #0d6efd, #0a58ca);
            border: none;
            padding: 0.75rem;
            border-radius: 14px;
            font-weight: 600;
            font-size: 1rem;
            letter-spacing: 0.3px;
            box-shadow: 0 6px 18px rgba(13, 110, 253, 0.3);
            transition: all 0.2s;
            color: #fff;
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 28px rgba(13, 110, 253, 0.4);
            background: linear-gradient(135deg, #0b5ed7, #084298);
        }

        .btn-primary:active {
            transform: translateY(0);
            box-shadow: 0 4px 12px rgba(13, 110, 253, 0.25);
        }

        /* ---- Alert ---- */
        .alert {
            border-radius: 14px;
            background: rgba(220, 53, 69, 0.08);
            border: 1px solid rgba(220, 53, 69, 0.2);
            color: #b02a37;
            font-weight: 500;
            padding: 0.7rem 1rem;
        }

        .alert i {
            font-size: 1.1rem;
        }

        /* ---- Footer extra ---- */
        .login-footer {
            text-align: center;
            margin-top: 1.8rem;
            font-size: 0.8rem;
            color: #7a8aa8;
        }

        .login-footer a {
            color: #0d6efd;
            text-decoration: none;
            font-weight: 500;
        }

        .login-footer a:hover {
            text-decoration: underline;
        }

        /* ---- Responsive ---- */
        @media (max-width: 480px) {
            .login-card .card-body {
                padding: 2rem 1.5rem;
            }

            .login-header .icon-wrapper {
                width: 64px;
                height: 64px;
            }

            .login-header .icon-wrapper i {
                font-size: 2.2rem;
            }

            .login-header h4 {
                font-size: 1.2rem;
            }
        }