:root {
            /* Copied from index.html */
            --void-black: #000000;
            --carbon-black: #0a0a0a;
            --obsidian: #111111;
            --charcoal-deep: #1a1a1a;
            --graphite: #242424;
            --ash-gray: #383838;
            --smoke: #4d4d4d;
            --pewter: #595959;
            --steel: #737373;
            --mist: #808080;
            --whisper: #9a9a9a;
            --pearl-gray: #a7a7a7;
            --glass-black: rgba(0, 0, 0, 0.3);
            --glass-charcoal: rgba(26, 26, 26, 0.4);
            --glass-smoke: rgba(77, 77, 77, 0.2);
            --glass-border-dark: rgba(255, 255, 255, 0.08);
            --glass-border-subtle: rgba(255, 255, 255, 0.05);
            --card-background: var(--glass-charcoal);
            --card-border: var(--glass-border-dark);
            --text-primary: var(--pearl-gray);
            --text-secondary: var(--mist);
            --text-accent: var(--whisper);
            --link-hover-background: rgba(55, 55, 55, 0.5);
            --space-xs: 0.25rem;
            --space-sm: 0.5rem;
            --space-md: 1rem;
            --space-lg: 1.5rem;
            --space-xl: 2rem;
            --space-2xl: 3rem;
            --radius-md: 0.75rem;
            --radius-lg: 1rem;
            --radius-xl: 1.25rem;
            --radius-full: 9999px;
            --duration-normal: 250ms;
            --ease-out: cubic-bezier(0.19, 1, 0.22, 1);
            --gradient-depth: linear-gradient(145deg, var(--obsidian) 0%, var(--void-black) 50%, var(--carbon-black) 100%);
        }

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

        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
            background: var(--gradient-depth);
            color: var(--text-secondary);
            min-height: 100vh;
            padding: var(--space-xl) var(--space-lg);
            overflow-x: hidden;
        }

        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            animation: fadeIn 0.8s var(--ease-out) forwards;
            opacity: 0;
        }
        
        @keyframes fadeIn {
            to { opacity: 1; }
        }

        /* Header */
        .page-header {
            text-align: left;
            margin-bottom: var(--space-2xl);
            display: flex;
            align-items: center;
            gap: var(--space-lg);
        }
        
        .back-link {
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-secondary);
            background: var(--glass-smoke);
            border: 1px solid var(--glass-border-dark);
            border-radius: var(--radius-full);
            width: 44px;
            height: 44px;
            transition: all var(--duration-normal) var(--ease-out);
        }

        .back-link:hover {
            background: var(--link-hover-background);
            color: var(--text-primary);
            transform: scale(1.05);
        }

        .page-header h1 {
            font-size: 2.5rem;
            font-weight: 700;
            color: var(--text-primary);
        }

        .page-header h1 .accent-text {
            color: var(--text-accent);
        }
        
        /* Skills Slider */
        .skills-section {
            margin-bottom: var(--space-2xl);
        }
        
        .section-header {
            font-size: 2rem;
            font-weight: 700;
            color: var(--text-primary);
            margin-bottom: var(--space-lg);
        }

        .section-header .accent-text {
             color: var(--text-accent);
        }

        .skills-slider {
            position: relative;
            background: rgba(0,0,0,0.2);
            border-radius: var(--radius-lg);
            padding: var(--space-lg) 0;
            overflow: hidden;
            width: 100%;
        }

        .skills-slider::before,
        .skills-slider::after {
            content: '';
            position: absolute;
            top: 0;
            bottom: 0;
            width: 150px;
            z-index: 2;
            pointer-events: none;
        }

        .skills-slider::before {
            left: 0;
            background: linear-gradient(to right, var(--charcoal-deep) 20%, transparent 100%);
        }

        .skills-slider::after {
            right: 0;
            background: linear-gradient(to left, var(--charcoal-deep) 20%, transparent 100%);
        }

        .skills-slide-track {
            display: flex;
            width: calc(150px * 20); /* item-width * total-items */
            animation: scroll 40s linear infinite;
        }

        @keyframes scroll {
            0% { transform: translateX(0); }
            100% { transform: translateX(calc(-150px * 10)); } /* item-width * number-of-original-items */
        }

        .skill-item {
            width: 150px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: var(--space-sm);
            color: var(--text-secondary);
            transition: all var(--duration-normal) var(--ease-out);
            cursor: default;
        }

        .skill-item i {
            font-size: 3rem;
        }

        .skill-item span {
            font-weight: 500;
            font-size: 0.9rem;
        }

        .skill-item:hover {
            transform: scale(1.1);
            color: var(--text-primary);
        }

        /* Filter Navigation */
        .filter-nav {
            display: flex;
            gap: var(--space-sm);
            margin-bottom: var(--space-2xl);
            flex-wrap: wrap;
        }
        
        .filter-btn {
            background: var(--glass-smoke);
            border: 1px solid var(--glass-border-subtle);
            color: var(--text-secondary);
            padding: var(--space-sm) var(--space-lg);
            border-radius: var(--radius-full);
            cursor: pointer;
            font-weight: 500;
            transition: all var(--duration-normal) var(--ease-out);
        }
        
        .filter-btn:hover {
            background: var(--link-hover-background);
            border-color: var(--glass-border-dark);
            color: var(--text-primary);
        }

        .filter-btn.active {
            background: var(--text-accent);
            color: var(--void-black);
            border-color: var(--text-accent);
        }

        /* Certificates Grid */
        .certificates-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: var(--space-xl);
        }

        .certificate-card {
            background: var(--card-background);
            backdrop-filter: blur(20px) saturate(150%);
            -webkit-backdrop-filter: blur(20px) saturate(150%);
            border: 1px solid var(--card-border);
            border-radius: var(--radius-lg);
            overflow: hidden;
            transition: all var(--duration-normal) var(--ease-out);
            box-shadow: 0 10px 30px -10px rgba(0,0,0,0.4);
        }

        .certificate-card:hover {
            transform: translateY(-8px) scale(1.03);
            box-shadow: 0 20px 40px -10px rgba(0,0,0,0.5);
            border-color: var(--glass-border-dark);
        }

        .certificate-card img {
            width: 100%;
            height: 200px;
            object-fit: cover;
            display: block;
            border-bottom: 1px solid var(--card-border);
        }

        .card-content {
            padding: var(--space-lg);
            display: flex;
            justify-content: space-between;
            align-items: center;
            gap: var(--space-md);
        }

        .card-details {
            flex-grow: 1;
        }

        .card-content h3 {
            font-size: 1.25rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: var(--space-xs);
        }

        .card-content p {
            font-size: 0.9rem;
            color: var(--text-secondary);
        }

        .download-btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            background: var(--glass-smoke);
            border: 1px solid var(--glass-border-subtle);
            border-radius: var(--radius-full);
            color: var(--text-secondary);
            text-decoration: none;
            transition: all var(--duration-normal) var(--ease-out);
            flex-shrink: 0;
        }

        .download-btn:hover {
            background: var(--link-hover-background);
            color: var(--text-primary);
            transform: scale(1.1);
        }

        /* Responsive */
        @media (max-width: 768px) {
            body {
                padding: var(--space-lg) var(--space-md);
            }
            .page-header h1 {
                font-size: 2rem;
            }
            .certificates-grid {
                grid-template-columns: 1fr;
            }
        }

        .section-footer {
            text-align: center;
            margin-top: var(--space-2xl);
        }
        .btn-secondary { background: var(--glass-smoke); color: var(--text-primary); }
        .btn-secondary:hover { background: var(--link-hover-background); }
        .btn {
            display: inline-flex;
            align-items: center;
            gap: var(--space-sm);
            padding: var(--space-md) var(--space-xl);
            border-radius: var(--radius-full);
            font-weight: 500;
            text-decoration: none;
            border: 1px solid var(--glass-border-subtle);
            transition: all var(--duration-normal) var(--ease-out);
        }