:root {
            --bg-color: #ffffff;
            --text-main: #1d1d1f;
            --text-muted: #86868b;
            --card-bg: rgba(255, 255, 255, 0.75);
            --border-color: rgba(0,0,0,0.06);
            --nav-bg: rgba(255, 255, 255, 0.8);
            --accent: #000;
            --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            --ref-card-bg: #0d0d0e;
            --success: #34c759;
            --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
            --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
            --shadow-lg: 0 16px 48px rgba(0,0,0,0.12);
        }

        [data-theme="dark"] {
            --bg-color: #0b0b0c;
            --text-main: #f5f5f7;
            --text-muted: #a1a1a6;
            --card-bg: rgba(28, 28, 30, 0.7);
            --border-color: rgba(255,255,255,0.1);
            --nav-bg: rgba(11, 11, 12, 0.8);
            --accent: #fff;
            --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            --ref-card-bg: #050505;
            --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
            --shadow-md: 0 8px 24px rgba(0,0,0,0.4);
            --shadow-lg: 0 16px 48px rgba(0,0,0,0.5);
        }

        * { margin: 0; padding: 0; box-sizing: border-box; scroll-behavior: smooth; }

        body {
            font-family: 'Inter', sans-serif;
            background-image: url('https://teklifz.com/images/bg-grid.png');
            background-size: contain; 
            background-repeat: no-repeat;
            background-color: var(--bg-color); 
            color: var(--text-main);
            line-height: 1.6; 
            overflow-x: hidden;
            transition: background-color 0.5s ease, color 0.5s ease;
        }

        /* Scroll Progress Bar */
        .progress-bar {
            position: fixed;
            top: 0;
            left: 0;
            height: 3px;
            background: var(--accent-gradient);
            width: 0%;
            z-index: 9999;
            transition: width 0.1s ease;
        }

        /* Navbar */
        .navbar {
            position: fixed; top: 0; left: 0; right: 0; height: 80px;
            background: var(--nav-bg); 
            backdrop-filter: blur(20px); 
            -webkit-backdrop-filter: blur(20px);
            z-index: 1000; 
            border-bottom: 1px solid var(--border-color);
            display: flex; 
            align-items: center;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        .navbar.hidden { transform: translateY(-100%); }
        .navbar.scrolled { box-shadow: var(--shadow-md); }
        
        .nav-container {
            max-width: 1200px; width: 100%; margin: 0 auto;
            padding: 0 30px; display: flex; justify-content: space-between; align-items: center;
        }
        .logo { 
            font-size: 22px; 
            font-weight: 900; 
            text-decoration: none; 
            color: var(--text-main); 
            letter-spacing: -1.5px;
            transition: transform 0.3s ease;
        }
        .logo:hover { transform: scale(1.05); }
        
        .nav-right { display: flex; align-items: center; gap: 30px; }
        .nav-links { display: flex; gap: 30px; }
        .nav-links a { 
            text-decoration: none; 
            color: var(--text-main); 
            font-size: 14px; 
            font-weight: 500; 
            opacity: 0.6;
            position: relative;
            transition: opacity 0.3s ease;
        }
        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: -5px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--accent);
            transition: width 0.3s ease;
        }
        .nav-links a:hover { opacity: 1; }
        .nav-links a:hover::after { width: 100%; }
        
        #theme-toggle { 
            cursor: pointer; 
            font-size: 18px; 
            color: var(--text-main); 
            z-index: 1100;
            transition: transform 0.3s ease;
        }
        #theme-toggle:hover { transform: rotate(20deg) scale(1.1); }

        .menu-toggle {
            display: none;
            flex-direction: column;
            gap: 6px;
            cursor: pointer;
            z-index: 1100;
            padding: 5px;
        }
        .menu-toggle span {
            width: 25px;
            height: 2px;
            background: var(--text-main);
            transition: 0.3s;
            border-radius: 2px;
        }

        .nav-overlay {
            position: fixed; top: 0; left: 0; width: 100%; height: 100vh;
            background: var(--bg-color);
            display: flex; flex-direction: column; align-items: center; justify-content: center;
            gap: 30px; z-index: 1050;
            transform: translateY(-100%);
            transition: transform 0.5s cubic-bezier(0.77, 0, 0.175, 1);
        }
        .nav-overlay.active { transform: translateY(0); }
        .nav-overlay a {
            font-size: 28px; font-weight: 700; text-decoration: none;
            color: var(--text-main); opacity: 0; transform: translateY(20px);
            transition: 0.4s;
        }
        .nav-overlay.active a { opacity: 1; transform: translateY(0); transition-delay: 0.3s; }

        .menu-toggle.active span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
        .menu-toggle.active span:nth-child(2) { opacity: 0; }
        .menu-toggle.active span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

        /* Hero Section */
        .hero { 
            padding: 180px 20px 80px; 
            max-width: 1000px; 
            margin: 0 auto; 
            text-align: center;
            position: relative;
        }
        .hero h1 {
            font-size: clamp(40px, 7vw, 72px); 
            font-weight: 900; 
            letter-spacing: -0.04em; 
            line-height: 1.1; 
            margin-bottom: 25px;
            background: linear-gradient(180deg, var(--text-main) 0%, var(--text-muted) 100%);
            -webkit-background-clip: text; 
            -webkit-text-fill-color: transparent;
            animation: fadeInUp 0.8s ease;
        }
        .hero p { 
            font-size: clamp(18px, 2vw, 21px); 
            color: var(--text-muted); 
            max-width: 700px; 
            margin: 0 auto 40px;
            animation: fadeInUp 0.8s ease 0.2s both;
        }
        .rating-badge {
            display: inline-flex; align-items: center; gap: 8px; 
            background: var(--card-bg); 
            border: 1px solid var(--border-color);
            padding: 8px 16px; 
            border-radius: 100px; 
            font-size: 13px; 
            font-weight: 600; 
            margin-bottom: 32px;
            animation: fadeInUp 0.8s ease 0.1s both;
            box-shadow: var(--shadow-sm);
        }
        .rating-badge i { color: #ffb400; }
        
        .cta-buttons {
            display: flex;
            gap: 15px;
            justify-content: center;
            flex-wrap: wrap;
            margin-bottom: 60px;
            animation: fadeInUp 0.8s ease 0.3s both;
        }
        .btn-primary, .btn-secondary {
            padding: 16px 36px;
            border-radius: 100px;
            text-decoration: none;
            font-weight: 600;
            font-size: 15px;
            transition: all 0.3s ease;
            display: inline-flex;
            align-items: center;
            gap: 10px;
        }
        .btn-primary {
            background: var(--accent);
            color: var(--bg-color);
            box-shadow: var(--shadow-md);
        }
        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: var(--shadow-lg);
        }
        .btn-secondary {
            background: transparent;
            color: var(--text-main);
            border: 1px solid var(--border-color);
        }
        .btn-secondary:hover {
            background: var(--card-bg);
            border-color: var(--text-main);
        }

        .tech-stack { 
            display: flex; 
            justify-content: center; 
            gap: 40px; 
            flex-wrap: wrap; 
            padding-bottom: 80px; 
            opacity: 0.5;
            animation: fadeInUp 0.8s ease 0.4s both;
        }
        .tech-stack i { 
            font-size: 32px;
            transition: all 0.3s ease;
            filter: grayscale(1);
        }
        .tech-stack i:hover {
            transform: scale(1.2) translateY(-5px);
            filter: grayscale(0);
            opacity: 1;
        }

        /* Stats Section */
        .stats-section {
            max-width: 1200px;
            margin: 0 auto 100px;
            padding: 60px 30px;
            background: var(--card-bg);
            border-radius: 32px;
            backdrop-filter: blur(10px);
            border: 1px solid var(--border-color);
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 40px;
            text-align: center;
        }
        .stat-item {
            opacity: 0;
            transform: translateY(20px);
            transition: opacity 0.6s ease, transform 0.6s ease;
        }
        .stat-item.visible {
            opacity: 1;
            transform: translateY(0);
        }
        .stat-number {
            font-size: 48px;
            font-weight: 900;
            background: var(--accent-gradient);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            margin-bottom: 8px;
        }
        .stat-label {
            color: var(--text-muted);
            font-size: 14px;
            font-weight: 500;
        }

        /* Services Section */
        .services-section { 
            max-width: 1200px; 
            margin: 0 auto; 
            padding: 40px 20px 80px; 
        }
        .section-header {
            text-align: center;
            margin-bottom: 60px;
        }
        .section-header h2 {
            font-size: clamp(32px, 5vw, 48px);
            font-weight: 900;
            letter-spacing: -1.5px;
            margin-bottom: 15px;
        }
        .section-header p {
            color: var(--text-muted);
            font-size: 18px;
        }
        
        .grid { 
            display: grid; 
            grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); 
            gap: 20px; 
        }
        .service-card {
            background: var(--card-bg); 
            border: 1px solid var(--border-color); 
            padding: 40px; 
            border-radius: 24px;
            backdrop-filter: blur(10px); 
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
            opacity: 0;
            transform: translateY(30px);
        }
        .service-card.visible {
            opacity: 1;
            transform: translateY(0);
        }
        .service-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: var(--accent-gradient);
            opacity: 0;
            transition: opacity 0.3s ease;
        }
        .service-card:hover::before {
            opacity: 0.03;
        }
        .service-card:hover { 
            border-color: var(--text-muted); 
            box-shadow: var(--shadow-lg);
            transform: translateY(-5px);
        }
        .icon-box {
            width: 60px; 
            height: 60px; 
            background: var(--accent); 
            color: var(--bg-color);
            border-radius: 14px; 
            display: flex; 
            align-items: center; 
            justify-content: center;
            font-size: 24px; 
            margin-bottom: 25px;
            transition: transform 0.3s ease;
            position: relative;
            z-index: 1;
        }
        .service-card:hover .icon-box {
            transform: scale(1.1) rotate(5deg);
        }
        .service-card h3 {
            font-size: 20px;
            margin-bottom: 12px;
            font-weight: 700;
            position: relative;
            z-index: 1;
        }
        .service-card p {
            color: var(--text-muted);
            line-height: 1.7;
            position: relative;
            z-index: 1;
        }

        /* Process Section */
        .process-section { 
            max-width: 1200px; 
            margin: 120px auto; 
            padding: 0 30px; 
        }
        .process-steps { 
            display: grid; 
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); 
            gap: 30px; 
            position: relative; 
        }
        .process-steps::before {
            content: ""; 
            position: absolute; 
            top: 30px; 
            left: 10%; 
            right: 10%;
            height: 2px; 
            background: var(--border-color); 
            z-index: 0;
        }
        .step-card { 
            position: relative; 
            z-index: 1; 
            background: var(--bg-color); 
            border: 1px solid var(--border-color); 
            padding: 35px; 
            border-radius: 24px;
            transition: all 0.3s ease;
            opacity: 0;
            transform: scale(0.9);
        }
        .step-card.visible {
            opacity: 1;
            transform: scale(1);
        }
        .step-card:hover {
            box-shadow: var(--shadow-lg);
            transform: translateY(-5px);
        }
        .step-num { 
            width: 60px; 
            height: 60px; 
            background: var(--accent); 
            color: var(--bg-color);
            border-radius: 50%; 
            display: flex; 
            align-items: center; 
            justify-content: center;
            font-weight: 900; 
            font-size: 20px; 
            margin-bottom: 24px; 
            border: 6px solid var(--bg-color);
            box-shadow: var(--shadow-md);
            transition: transform 0.3s ease;
        }
        .step-card:hover .step-num {
            transform: rotate(360deg);
        }
        .step-card h4 {
            font-size: 18px;
            margin-bottom: 12px;
            font-weight: 700;
        }
        .step-card p {
            color: var(--text-muted);
            line-height: 1.6;
        }

        /* References Section */
        .references-section { 
            max-width: 1200px; 
            margin: 0 auto 100px; 
            padding: 60px 30px; 
            position: relative; 
            overflow: hidden; 
        }
        .references-header { 
            text-align: center; 
            margin-bottom: 60px; 
            position: relative; 
            z-index: 2; 
        }
        .filter-buttons {
            display: flex;
            justify-content: center;
            gap: 12px;
            flex-wrap: wrap;
            margin-bottom: 40px;
        }
        .filter-btn {
            padding: 10px 24px;
            background: var(--card-bg);
            border: 1px solid var(--border-color);
            border-radius: 100px;
            color: var(--text-main);
            font-weight: 600;
            font-size: 14px;
            cursor: pointer;
            transition: all 0.3s ease;
        }
        .filter-btn:hover, .filter-btn.active {
            background: var(--accent);
            color: var(--bg-color);
            border-color: var(--accent);
        }
        
        .references-grid { 
            display: grid; 
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); 
            gap: 20px; 
            position: relative; 
            z-index: 2; 
        }
        .ref-card {
            background: var(--ref-card-bg); 
            padding: 28px; 
            border-radius: 18px; 
            border: 1px solid rgba(255, 255, 255, 0.04); 
            position: relative; 
            overflow: hidden;
            transition: all 0.3s ease;
            opacity: 0;
            transform: scale(0.95);
        }
        .ref-card.visible {
            opacity: 1;
            transform: scale(1);
        }
        .ref-card::after {
            content: ""; 
            position: absolute; 
            top: -50%; 
            left: -50%; 
            width: 200%; 
            height: 200%;
            background: conic-gradient(transparent, transparent, transparent, rgba(255,255,255,0.1));
            animation: rotate-border 6s linear infinite; 
            z-index: 1;
            opacity: 0;
            transition: opacity 0.3s ease;
        }
        .ref-card:hover::after {
            opacity: 1;
        }
        .ref-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 40px rgba(0,0,0,0.3);
        }
        @keyframes rotate-border { 100% { transform: rotate(360deg); } }
        .ref-content { position: relative; z-index: 2; }
        .ref-name { 
            color: #ffffff; 
            font-size: 17px; 
            display: block; 
            margin-bottom: 14px; 
            font-weight: 700; 
        }
        .ref-tag {
            display: inline-flex; 
            align-items: center; 
            gap: 6px; 
            background: rgba(255, 255, 255, 0.08);
            backdrop-filter: blur(10px); 
            -webkit-backdrop-filter: blur(10px); 
            border-radius: 6px;
            border: 1px solid rgba(255, 255, 255, 0.1); 
            color: rgba(255, 255, 255, 0.9);
            padding: 6px 12px; 
            font-size: 12px; 
            font-weight: 500;
        }

        /* FAQ Section */
        .faq-section {
            max-width: 900px;
            margin: 100px auto;
            padding: 0 30px;
        }
        .faq-item {
            background: var(--card-bg);
            border: 1px solid var(--border-color);
            border-radius: 16px;
            margin-bottom: 16px;
            overflow: hidden;
            transition: all 0.3s ease;
        }
        .faq-item:hover {
            box-shadow: var(--shadow-md);
        }
        .faq-question {
            padding: 24px;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-weight: 600;
            font-size: 16px;
            user-select: none;
        }
        .faq-question i {
            transition: transform 0.3s ease;
            color: var(--text-muted);
        }
        .faq-item.active .faq-question i {
            transform: rotate(180deg);
        }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease, padding 0.3s ease;
            color: var(--text-muted);
            line-height: 1.7;
        }
        .faq-item.active .faq-answer {
            max-height: 500px;
            padding: 0 24px 24px;
        }

        /* Footer */
        footer { 
            padding: 100px 20px; 
            text-align: center; 
            border-top: 1px solid var(--border-color); 
            background: var(--card-bg);
            backdrop-filter: blur(10px);
        }
        .footer-social {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin: 30px 0;
        }
        .social-link {
            width: 48px;
            height: 48px;
            border-radius: 50%;
            background: var(--accent);
            color: var(--bg-color);
            display: flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            font-size: 20px;
            transition: all 0.3s ease;
        }
        .social-link:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-lg);
        }
        .btn-contact {
            background: var(--accent); 
            color: var(--bg-color); 
            padding: 18px 45px;
            border-radius: 100px; 
            text-decoration: none; 
            font-weight: 600; 
            display: inline-block; 
            margin-top: 20px;
            transition: all 0.3s ease;
            box-shadow: var(--shadow-md);
        }
        .btn-contact:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-lg);
        }

        /* Scroll to Top Button */
        .scroll-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background: var(--accent);
            color: var(--bg-color);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s ease;
            z-index: 999;
            box-shadow: var(--shadow-lg);
        }
        .scroll-top.visible {
            opacity: 1;
            visibility: visible;
        }
        .scroll-top:hover {
            transform: translateY(-5px);
        }

        /* Animations */
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        /* Responsive */
        @media (max-width: 900px) { 
            .process-steps { grid-template-columns: 1fr; } 
            .process-steps::before { display: none; }
            .stats-section { grid-template-columns: repeat(2, 1fr); }
        }

        @media (max-width: 768px) {
            .nav-links { display: none; }
            .menu-toggle { display: flex; }
            .nav-container { padding: 0 20px; }
            .hero { padding: 140px 20px 40px; }
            .tech-stack { gap: 20px; }
            .cta-buttons { flex-direction: column; }
            .btn-primary, .btn-secondary { width: 100%; justify-content: center; }
            .grid { grid-template-columns: 1fr; }
            .references-grid { grid-template-columns: 1fr; }
            .testimonial-card { min-width: 280px; }
            .stats-section { grid-template-columns: 1fr; }
            .scroll-top { bottom: 20px; right: 20px; }
        }