:root {
            /* Color Palette - Crisp White & Slate Accents */
            --bg-body: #f8fafc;
            --bg-surface: #ffffff;
            --bg-subtle: #f1f5f9;
            --bg-muted: #e2e8f0;
            
            --text-main: #0f172a;
            --text-secondary: #475569;
            --text-muted: #94a3b8;
            --text-on-primary: #ffffff;

            /* Brand & Accent Colors */
            --primary: #2563eb;
            --primary-hover: #1d4ed8;
            --primary-light: #eff6ff;
            --primary-border: #bfdbfe;

            --success: #10b981;
            --success-light: #ecfdf5;
            --success-border: #a7f3d0;

            --warning: #f59e0b;
            --warning-light: #fffbeb;
            --warning-border: #fde68a;

            --danger: #ef4444;
            --danger-light: #fef2f2;
            --danger-border: #fecaca;

            /* Neutral Borders */
            --border-light: #f1f5f9;
            --border-medium: #e2e8f0;
            --border-strong: #cbd5e1;

            /* Typography */
            --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
            --font-mono: 'JetBrains Mono', Consolas, Monaco, monospace;

            /* Shadows - Soft White-Theme Depth */
            --shadow-xs: 0 1px 2px 0 rgba(15, 23, 42, 0.03);
            --shadow-sm: 0 1px 3px 0 rgba(15, 23, 42, 0.06), 0 1px 2px -1px rgba(15, 23, 42, 0.06);
            --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.05), 0 2px 4px -2px rgba(15, 23, 42, 0.05);
            --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, 0.04), 0 4px 6px -4px rgba(15, 23, 42, 0.04);
            --shadow-xl: 0 20px 25px -5px rgba(15, 23, 42, 0.05), 0 8px 10px -6px rgba(15, 23, 42, 0.03);

            /* Border Radii */
            --radius-sm: 0.375rem; /* 6px */
            --radius-md: 0.5rem;   /* 8px */
            --radius-lg: 0.75rem;  /* 12px */
            --radius-xl: 1rem;     /* 16px */
            --radius-full: 9999px;

            /* Transitions */
            --transition-fast: 0.15s ease;
            --transition-normal: 0.25s ease;
            --transition-slow: 0.35s ease;

            /* Spacing Scale */
            --space-1: 0.25rem;
            --space-2: 0.5rem;
            --space-3: 0.75rem;
            --space-4: 1rem;
            --space-6: 1.5rem;
            --space-8: 2rem;
            --space-12: 3rem;
            --space-16: 4rem;
        }

        *, *::before, *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        html {
            font-size: 16px;
            scroll-behavior: smooth;
            -webkit-text-size-adjust: 100%;
        }

        body {
            font-family: var(--font-sans);
            background-color: var(--bg-body);
            color: var(--text-main);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        img, picture, video, canvas, svg {
            display: block;
            max-width: 100%;
            height: auto;
        }

        input, button, textarea, select {
            font: inherit;
        }

        a {
            color: var(--primary);
            text-decoration: none;
            transition: color var(--transition-fast);
        }

        a:hover {
            color: var(--primary-hover);
        }

        .container {
            width: 100%;
            max-width: 1200px;
            margin-left: auto;
            margin-right: auto;
            padding-left: var(--space-4);
            padding-right: var(--space-4);
        }

        .header {
            background-color: rgba(255, 255, 255, 0.85);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--border-medium);
            position: sticky;
            top: 0;
            z-index: 1000;
            padding: var(--space-4) 0;
        }

        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .brand {
            display: flex;
            align-items: center;
            gap: var(--space-3);
            font-weight: 700;
            font-size: 1.25rem;
            color: var(--text-main);
        }

        .brand-icon {
            width: 36px;
            height: 36px;
            background: linear-gradient(135deg, var(--primary), #3b82f6);
            color: white;
            border-radius: var(--radius-md);
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: var(--shadow-sm);
        }

        .nav-list {
            display: flex;
            list-style: none;
            gap: var(--space-6);
            align-items: center;
        }

        .nav-link {
            color: var(--text-secondary);
            font-weight: 500;
            font-size: 0.95rem;
            padding: var(--space-2) 0;
            position: relative;
        }

        .nav-link:hover, .nav-link.active {
            color: var(--primary);
        }

        .nav-link.active::after {
            content: '';
            position: absolute;
            bottom: -4px;
            left: 0;
            right: 0;
            height: 2px;
            background-color: var(--primary);
            border-radius: var(--radius-full);
        }

        .main-layout {
            display: grid;
            grid-template-columns: 240px 1fr;
            gap: var(--space-8);
            padding: var(--space-8) 0;
        }

        .sidebar {
            position: sticky;
            top: 5rem;
            height: fit-content;
        }

        .sidebar-menu {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: var(--space-1);
        }

        .sidebar-link {
            display: flex;
            align-items: center;
            gap: var(--space-3);
            padding: var(--space-2) var(--space-3);
            color: var(--text-secondary);
            border-radius: var(--radius-md);
            font-weight: 500;
            font-size: 0.9rem;
            transition: all var(--transition-fast);
        }

        .sidebar-link:hover {
            background-color: var(--bg-subtle);
            color: var(--text-main);
        }

        .sidebar-link.active {
            background-color: var(--primary-light);
            color: var(--primary);
            font-weight: 600;
        }

        .grid {
            display: grid;
            gap: var(--space-6);
        }

        .grid-2 { grid-template-columns: repeat(2, 1fr); }
        .grid-3 { grid-template-columns: repeat(3, 1fr); }
        .grid-4 { grid-template-columns: repeat(4, 1fr); }

        .flex { display: flex; }
        .flex-wrap { flex-wrap: wrap; }
        .items-center { align-items: center; }
        .justify-between { justify-content: space-between; }
        .gap-2 { gap: var(--space-2); }
        .gap-4 { gap: var(--space-4); }

        .card {
            background-color: var(--bg-surface);
            border: 1px solid var(--border-medium);
            border-radius: var(--radius-lg);
            padding: var(--space-6);
            box-shadow: var(--shadow-xs);
            transition: box-shadow var(--transition-normal), border-color var(--transition-normal);
        }

        .card:hover {
            box-shadow: var(--shadow-md);
            border-color: var(--border-strong);
        }

        .card-header {
            margin-bottom: var(--space-4);
            padding-bottom: var(--space-3);
            border-bottom: 1px solid var(--border-light);
        }

        .card-title {
            font-size: 1.15rem;
            font-weight: 600;
            color: var(--text-main);
        }

        .card-subtitle {
            font-size: 0.875rem;
            color: var(--text-muted);
            margin-top: 2px;
        }

        .section-block {
            margin-bottom: var(--space-12);
            scroll-margin-top: 6rem;
        }

        h1, h2, h3, h4, h5, h6 {
            color: var(--text-main);
            font-weight: 700;
            line-height: 1.25;
            letter-spacing: -0.02em;
        }

        h1 { font-size: 2.25rem; margin-bottom: var(--space-4); }
        h2 { font-size: 1.75rem; margin-bottom: var(--space-3); }
        h3 { font-size: 1.35rem; margin-bottom: var(--space-3); }
        h4 { font-size: 1.1rem; margin-bottom: var(--space-2); }

        p {
            color: var(--text-secondary);
            margin-bottom: var(--space-4);
            font-size: 0.975rem;
        }

        p.lead {
            font-size: 1.125rem;
            font-weight: 400;
            color: var(--text-secondary);
            line-height: 1.6;
        }

        blockquote {
            border-left: 4px solid var(--primary);
            background-color: var(--bg-subtle);
            padding: var(--space-4) var(--space-6);
            border-radius: 0 var(--radius-md) var(--radius-md) 0;
            margin-bottom: var(--space-4);
            font-style: italic;
            color: var(--text-main);
        }

        code {
            font-family: var(--font-mono);
            background-color: var(--bg-subtle);
            color: var(--text-main);
            padding: 0.2rem 0.4rem;
            border-radius: var(--radius-sm);
            font-size: 0.875em;
            border: 1px solid var(--border-medium);
        }

        pre {
            background-color: #0f172a;
            color: #f8fafc;
            padding: var(--space-4);
            border-radius: var(--radius-md);
            overflow-x: auto;
            margin-bottom: var(--space-4);
        }

        pre code {
            background: none;
            color: inherit;
            padding: 0;
            border: none;
        }

        ul, ol {
            margin-bottom: var(--space-4);
            padding-left: var(--space-6);
            color: var(--text-secondary);
        }

        li { margin-bottom: var(--space-1); }

        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: var(--space-2);
            font-weight: 500;
            font-size: 0.9rem;
            padding: 0.55rem 1.1rem;
            border-radius: var(--radius-md);
            border: 1px solid transparent;
            cursor: pointer;
            transition: all var(--transition-fast);
            white-space: nowrap;
            user-select: none;
            box-shadow: var(--shadow-xs);
        }

        .btn:active {
            transform: translateY(1px);
        }

        .btn-primary {
            background-color: var(--primary);
            color: var(--text-on-primary);
            border-color: var(--primary);
        }

        .btn-primary:hover {
            background-color: var(--primary-hover);
            border-color: var(--primary-hover);
            box-shadow: var(--shadow-sm);
        }

        .btn-secondary {
            background-color: var(--bg-surface);
            color: var(--text-main);
            border-color: var(--border-strong);
        }

        .btn-secondary:hover {
            background-color: var(--bg-subtle);
            border-color: var(--text-secondary);
        }

        .btn-subtle {
            background-color: var(--bg-subtle);
            color: var(--text-main);
            border-color: transparent;
            box-shadow: none;
        }

        .btn-subtle:hover {
            background-color: var(--bg-muted);
        }

        .btn-danger {
            background-color: var(--danger);
            color: white;
        }

        .btn-danger:hover {
            background-color: #dc2626;
        }

        .btn-sm {
            padding: 0.35rem 0.75rem;
            font-size: 0.8rem;
            border-radius: var(--radius-sm);
        }

        .btn-lg {
            padding: 0.75rem 1.5rem;
            font-size: 1rem;
            border-radius: var(--radius-lg);
        }

        .btn-icon-only {
            padding: 0.55rem;
            border-radius: var(--radius-md);
        }

        .form-group {
            margin-bottom: var(--space-4);
            display: flex;
            flex-direction: column;
            gap: var(--space-1);
        }

        .form-label {
            font-size: 0.875rem;
            font-weight: 500;
            color: var(--text-main);
        }

        .form-control {
            width: 100%;
            padding: 0.55rem 0.85rem;
            font-size: 0.925rem;
            color: var(--text-main);
            background-color: var(--bg-surface);
            border: 1px solid var(--border-strong);
            border-radius: var(--radius-md);
            outline: none;
            transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
        }

        .form-control:focus {
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
        }

        .form-control::placeholder {
            color: var(--text-muted);
        }

        .form-hint {
            font-size: 0.8rem;
            color: var(--text-muted);
            margin-top: 2px;
        }

        .form-check {
            display: flex;
            align-items: center;
            gap: var(--space-2);
            cursor: pointer;
            user-select: none;
        }

        .form-check-input {
            width: 1.1rem;
            height: 1.1rem;
            accent-color: var(--primary);
            cursor: pointer;
        }

        /* Toggle Switch */
        .switch {
            position: relative;
            display: inline-block;
            width: 44px;
            height: 24px;
        }

        .switch input {
            opacity: 0;
            width: 0;
            height: 0;
        }

        .slider {
            position: absolute;
            cursor: pointer;
            top: 0; left: 0; right: 0; bottom: 0;
            background-color: var(--bg-muted);
            transition: .2s;
            border-radius: var(--radius-full);
            border: 1px solid var(--border-strong);
        }

        .slider:before {
            position: absolute;
            content: "";
            height: 18px;
            width: 18px;
            left: 2px;
            bottom: 2px;
            background-color: white;
            transition: .2s;
            border-radius: 50%;
            box-shadow: var(--shadow-xs);
        }

        input:checked + .slider {
            background-color: var(--primary);
            border-color: var(--primary);
        }

        input:checked + .slider:before {
            transform: translateX(20px);
        }

        .badge {
            display: inline-flex;
            align-items: center;
            padding: 0.2rem 0.6rem;
            font-size: 0.75rem;
            font-weight: 600;
            border-radius: var(--radius-full);
            line-height: 1;
        }

        .badge-primary { background-color: var(--primary-light); color: var(--primary); border: 1px solid var(--primary-border); }
        .badge-success { background-color: var(--success-light); color: var(--success); border: 1px solid var(--success-border); }
        .badge-warning { background-color: var(--warning-light); color: var(--warning); border: 1px solid var(--warning-border); }
        .badge-danger { background-color: var(--danger-light); color: var(--danger); border: 1px solid var(--danger-border); }
        .badge-neutral { background-color: var(--bg-subtle); color: var(--text-secondary); border: 1px solid var(--border-medium); }

        .alert {
            display: flex;
            align-items: flex-start;
            gap: var(--space-3);
            padding: var(--space-4);
            border-radius: var(--radius-lg);
            border: 1px solid;
            margin-bottom: var(--space-4);
            font-size: 0.9rem;
        }

        .alert-info { background-color: var(--primary-light); border-color: var(--primary-border); color: #1e40af; }
        .alert-success { background-color: var(--success-light); border-color: var(--success-border); color: #065f46; }
        .alert-warning { background-color: var(--warning-light); border-color: var(--warning-border); color: #92400e; }
        .alert-danger { background-color: var(--danger-light); border-color: var(--danger-border); color: #991b1b; }

        .table-container {
            width: 100%;
            overflow-x: auto;
            border: 1px solid var(--border-medium);
            border-radius: var(--radius-lg);
            background-color: var(--bg-surface);
        }

        .table {
            width: 100%;
            border-collapse: collapse;
            text-align: left;
            font-size: 0.9rem;
        }

        .table th {
            background-color: var(--bg-subtle);
            color: var(--text-main);
            font-weight: 600;
            padding: var(--space-3) var(--space-4);
            border-bottom: 1px solid var(--border-medium);
        }

        .table td {
            padding: var(--space-3) var(--space-4);
            border-bottom: 1px solid var(--border-light);
            color: var(--text-secondary);
        }

        .table tr:last-child td {
            border-bottom: none;
        }

        .table tr:hover td {
            background-color: var(--bg-subtle);
        }

        .progress-bar {
            width: 100%;
            height: 8px;
            background-color: var(--bg-muted);
            border-radius: var(--radius-full);
            overflow: hidden;
        }

        .progress-fill {
            height: 100%;
            background-color: var(--primary);
            border-radius: var(--radius-full);
            transition: width var(--transition-normal);
        }

        /* Modal Overlay Placeholder */
        .modal-backdrop {
            position: fixed;
            top: 0; left: 0; right: 0; bottom: 0;
            background-color: rgba(15, 23, 42, 0.4);
            backdrop-filter: blur(4px);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 2000;
            opacity: 0;
            pointer-events: none;
            transition: opacity var(--transition-fast);
        }

        .modal-backdrop.active {
            opacity: 1;
            pointer-events: auto;
        }

        .modal {
            background-color: var(--bg-surface);
            border-radius: var(--radius-xl);
            width: 100%;
            max-width: 500px;
            padding: var(--space-6);
            box-shadow: var(--shadow-xl);
            border: 1px solid var(--border-medium);
            transform: translateY(10px);
            transition: transform var(--transition-fast);
        }

        .modal-backdrop.active .modal {
            transform: translateY(0);
        }

        @media (max-width: 768px) {
            .main-layout {
                grid-template-columns: 1fr;
            }

            .sidebar {
                display: none; /* Mobile Navigation Toggle can be added */
            }

            .grid-2, .grid-3, .grid-4 {
                grid-template-columns: 1fr;
            }

            .nav-list {
                gap: var(--space-3);
            }
        }