:root {
            /* Palette Warna Kalem (Soft Navy & Muted Slate) */
            --bg-gradient-start: #e9ecef;
            --bg-gradient-end: #dee2e6;
            --primary-slate: #34495e;
            --primary-slate-hover: #2c3e50;
            --soft-accent: #f1f3f5;
        }

        body {
            background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);
            min-height: 100vh;
            color: #495057;
        }

        .login-card {
            border: 1px solid rgba(0, 0, 0, 0.05);
            border-radius: 1rem;
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.06);
        }

        .brand-icon {
            width: 64px;
            height: 64px;
            background-color: var(--soft-accent);
            color: var(--primary-slate);
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            font-size: 1.75rem;
        }

        /* Custom Styling Tombol Slate Kalem */
        .btn-slate {
            background-color: var(--primary-slate);
            color: #ffffff;
            border: none;
        }
        .btn-slate:hover, .btn-slate:focus {
            background-color: var(--primary-slate-hover);
            color: #ffffff;
        }

        /* Styling Tab Navigasi */
        .nav-pills .nav-link {
            color: #6c757d;
            font-weight: 500;
        }
        .nav-pills .nav-link.active {
            background-color: var(--primary-slate);
            color: #ffffff;
        }

        /* Input Focus Border Kalem */
        .form-control:focus {
            border-color: var(--primary-slate);
            box-shadow: 0 0 0 0.25rem rgba(52, 73, 94, 0.15);
        }