:root {
            --primary-color: #2563eb;
            --primary-dark: #1d4ed8;
            --secondary-color: #10b981;
            --secondary-dark: #059669;
            --background-dark: #0f172a;
            --background-darker: #020617;
            --background-light: #f8fafc;
            --text-dark: #e2e8f0;
            --text-light: #1e293b;
            --card-bg-dark: #1e293b;
            --card-bg-light: #ffffff;
            --nav-bg-dark: rgba(15, 23, 42, 0.95);
            --nav-bg-light: rgba(248, 250, 252, 0.95);
            --border-radius: 12px;
            --box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
        }

        :root.light-mode {
            --primary-color: #10b981;
            --primary-dark: #059669;
            --secondary-color: #2563eb;
            --secondary-dark: #1d4ed8;
            --background-dark: #f8fafc;
            --background-light: #0f172a;
            --text-dark: #1e293b;
            --text-light: #e2e8f0;
            --card-bg-dark: #ffffff;
            --card-bg-light: #1e293b;
            --nav-bg-dark: rgba(248, 250, 252, 0.95);
            --nav-bg-light: rgba(15, 23, 42, 0.95);
        }

        body {
            background: var(--background-dark);
            color: var(--text-dark);
            font-family: 'Montserrat', sans-serif;
            line-height: 1.7;
            transition: background 0.5s, color 0.5s;
        }

        /* Typography */
        h1,
        h2,
        h3,
        h4,
        h5,
        h6 {
            font-family: 'Poppins', sans-serif;
            font-weight: 600;
            line-height: 1.3;
        }

        h2 {
            font-size: 2.5rem;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
            margin-bottom: 2rem;
            position: relative;
            display: inline-block;
        }

        h2::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 0;
            width: 60px;
            height: 4px;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            border-radius: 2px;
        }

        h3 {
            font-size: 2rem;
            margin: 2.5rem 0 1.5rem;
            color: var(--text-dark);
        }

        h4 {
            font-size: 1.5rem;
            margin: 2rem 0 1rem;
        }

        p {
            font-size: 1.1rem;
            opacity: 0.9;
            margin-bottom: 1.5rem;
        }

        /* Custom Scrollbar */
        ::-webkit-scrollbar {
            width: 10px;
        }

        ::-webkit-scrollbar-track {
            background: var(--background-dark);
        }

        ::-webkit-scrollbar-thumb {
            background: var(--primary-color);
            border-radius: 5px;
        }

        /* Navbar */
        .navbar {
            background: var(--nav-bg-dark);
            backdrop-filter: blur(10px);
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            padding: 1rem 0;
            transition: var(--transition);
        }

        .navbar-brand {
            font-weight: 700;
            font-size: 1.5rem;
            color: var(--text-dark);
            transition: color 0.3s;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .navbar-brand:hover {
            color: var(--primary-color);
        }

        .navbar-brand i {
            font-size: 1.3rem;
        }

        /* Feature Cards */
        .feature-section {
            margin: 3rem 0;
        }

        .feature-card {
            background: var(--card-bg-dark);
            border-radius: var(--border-radius);
            padding: 2rem;
            height: 100%;
            transition: var(--transition);
            border: 1px solid rgba(255, 255, 255, 0.05);
            box-shadow: var(--box-shadow);
        }

        .feature-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.2);
            border-color: var(--primary-color);
        }

        .feature-card i {
            font-size: 2.5rem;
            margin-bottom: 1.5rem;
            color: var(--primary-color);
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .feature-card h4 {
            font-weight: 600;
            margin-bottom: 1rem;
        }

        .feature-card p {
            opacity: 0.8;
        }

        /* Project Highlights */
        .project-highlight {
            background: rgba(37, 99, 235, 0.1);
            border-left: 4px solid var(--primary-color);
            padding: 2rem;
            border-radius: 0 var(--border-radius) var(--border-radius) 0;
            margin: 3rem 0;
            transition: var(--transition);
        }

        .project-highlight h3 {
            margin-top: 0;
        }

        /* Images */
        .img-fluid {
            border-radius: var(--border-radius);
            transition: var(--transition);
            box-shadow: var(--box-shadow);
            margin: 1.5rem 0;
            border: 1px solid rgba(255, 255, 255, 0.1);
            max-height: 500px;
            width: auto;
            object-fit: contain;
        }

        .img-fluid:hover {
            transform: scale(1.02);
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.2);
        }

        .facebook-video {
            overflow: hidden;
            border-radius: var(--border-radius);
            background: var(--card-bg-dark);
            box-shadow: var(--box-shadow);
        }

        .facebook-video iframe {
            opacity: 0;
            transition: opacity 0.4s ease;
        }

        .facebook-video.embed-ready iframe {
            opacity: 1;
        }

        .facebook-video.embed-ready .video-fallback {
            opacity: 0;
            pointer-events: none;
            transform: scale(0.98);
        }

        .video-fallback {
            position: absolute;
            inset: 0;
            z-index: 2;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 0.55rem;
            padding: clamp(0.9rem, 4vw, 1.6rem);
            text-align: center;
            background:
                radial-gradient(circle at 20% 20%, rgba(16, 185, 129, 0.24), transparent 32%),
                radial-gradient(circle at 80% 70%, rgba(37, 99, 235, 0.22), transparent 34%),
                linear-gradient(145deg, rgba(15, 23, 42, 0.98), rgba(30, 41, 59, 0.96));
            color: #e2e8f0;
            transition: opacity 0.4s ease, transform 0.4s ease;
        }

        .light-mode .video-fallback {
            background:
                radial-gradient(circle at 20% 20%, rgba(16, 185, 129, 0.18), transparent 32%),
                radial-gradient(circle at 80% 70%, rgba(37, 99, 235, 0.16), transparent 34%),
                linear-gradient(145deg, rgba(248, 250, 252, 0.98), rgba(226, 232, 240, 0.96));
            color: #1e293b;
        }

        .signal-animation {
            position: relative;
            width: 96px;
            height: 96px;
            display: grid;
            place-items: center;
        }

        .signal-core,
        .signal-block,
        .signal-ring {
            position: absolute;
            border-radius: 50%;
        }

        .signal-core {
            width: 54px;
            height: 54px;
            display: grid;
            place-items: center;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            color: #ffffff;
            font-size: 1.6rem;
            box-shadow: 0 18px 35px rgba(37, 99, 235, 0.3);
            animation: signalPulse 2s ease-in-out infinite;
        }

        .signal-ring {
            inset: 16px;
            border: 2px solid rgba(16, 185, 129, 0.55);
            opacity: 0;
            animation: signalRing 2.4s ease-out infinite;
        }

        .ring-two {
            animation-delay: 0.45s;
        }

        .ring-three {
            animation-delay: 0.9s;
        }

        .signal-block {
            right: 5px;
            bottom: 10px;
            width: 32px;
            height: 32px;
            display: grid;
            place-items: center;
            background: #ef4444;
            color: #ffffff;
            border: 3px solid var(--card-bg-dark);
            font-size: 0.9rem;
            animation: blockPop 1.7s ease-in-out infinite;
        }

        .fallback-label {
            margin: 0;
            color: var(--secondary-color);
            font-size: 0.78rem;
            font-weight: 700;
            letter-spacing: 0.08em;
            opacity: 1;
            text-transform: uppercase;
        }

        .video-fallback h4 {
            margin: 0;
            max-width: 520px;
            font-size: clamp(1.05rem, 3vw, 1.55rem);
        }

        .video-fallback p:not(.fallback-label) {
            max-width: 560px;
            margin: 0;
            font-size: clamp(0.8rem, 2vw, 0.95rem);
            opacity: 0.86;
        }

        .fallback-link {
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            padding: 0.55rem 0.85rem;
            border-radius: 8px;
            background: rgba(255, 255, 255, 0.1);
            color: inherit;
            font-size: 0.9rem;
            font-weight: 700;
            text-decoration: none;
            border: 1px solid rgba(255, 255, 255, 0.16);
            transition: var(--transition);
        }

        .fallback-button {
            cursor: pointer;
            font-family: inherit;
        }

        .fallback-link:hover {
            color: #ffffff;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            transform: translateY(-2px);
        }

        .light-mode .fallback-link {
            background: rgba(37, 99, 235, 0.08);
            border-color: rgba(37, 99, 235, 0.36);
            box-shadow: 0 8px 20px rgba(15, 23, 42, 0.08);
        }

        .light-mode .fallback-link:hover {
            color: #ffffff;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            border-color: transparent;
        }

        @keyframes signalPulse {
            0%, 100% {
                transform: scale(1);
            }

            50% {
                transform: scale(1.08);
            }
        }

        @keyframes signalRing {
            0% {
                opacity: 0.75;
                transform: scale(0.7);
            }

            100% {
                opacity: 0;
                transform: scale(1.55);
            }
        }

        @keyframes blockPop {
            0%, 100% {
                transform: scale(1) rotate(0deg);
            }

            45% {
                transform: scale(1.1) rotate(-8deg);
            }
        }

        @media (prefers-reduced-motion: reduce) {
            .signal-core,
            .signal-ring,
            .signal-block {
                animation: none;
            }
        }

        .image-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 20px;
            margin: 2rem 0;
        }

        .image-card {
            background: var(--card-bg-dark);
            border-radius: var(--border-radius);
            padding: 1rem;
            transition: var(--transition);
            border: 1px solid rgba(255, 255, 255, 0.05);
            box-shadow: var(--box-shadow);
        }

        .image-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.2);
        }

        .image-card img {
            border-radius: var(--border-radius);
            width: 100%;
            height: auto;
            margin-bottom: 1rem;
        }

        .image-card h4 {
            font-size: 1.2rem;
            margin-bottom: 0.5rem;
        }

        .image-card p {
            font-size: 0.9rem;
            opacity: 0.8;
            margin-bottom: 0;
        }

        /* Buttons */
        .btn-primary {
            background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
            border: none;
            border-radius: var(--border-radius);
            padding: 0.75rem 1.5rem;
            font-weight: 600;
            transition: var(--transition);
            box-shadow: var(--box-shadow);
        }

        .btn-primary:hover {
            background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
            transform: translateY(-2px);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.2);
        }

        /* Floating Buttons */
        .floating-btn {
            position: fixed;
            bottom: 20px;
            right: 20px;
            display: flex;
            flex-direction: column;
            gap: 15px;
            z-index: 1000;
        }

        .back-to-top,
        .theme-toggle {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            background: var(--primary-color);
            color: white;
            border: none;
            cursor: pointer;
            transition: var(--transition);
            box-shadow: var(--box-shadow);
        }

        .back-to-top:hover,
        .theme-toggle:hover {
            transform: translateY(-5px) scale(1.1);
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
        }

        .back-to-top {
            bottom: 85px;
        }

        /* Back Button */
        .back-button {
            position: fixed;
            bottom: 40px;
            left: 20px;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            color: white;
            border: none;
            border-radius: var(--border-radius);
            padding: 12px 24px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            box-shadow: var(--box-shadow);
            display: flex;
            align-items: center;
            gap: 8px;
            z-index: 1000;
        }

        .back-button:hover {
            background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
            transform: translateY(-2px);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.2);
        }

        /* Technical Specifications */
        .specs-table {
            width: 100%;
            border-collapse: collapse;
            margin: 2rem 0;
            background: var(--card-bg-dark);
            border-radius: var(--border-radius);
            overflow: hidden;
            box-shadow: var(--box-shadow);
        }

        .specs-table th,
        .specs-table td {
            padding: 1rem;
            text-align: left;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }

        .specs-table th {
            background: rgba(37, 99, 235, 0.2);
            font-weight: 600;
        }

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

        .specs-table tr:hover {
            background: rgba(255, 255, 255, 0.05);
        }

        .light-mode .specs-table tr:hover {
            background: rgba(0, 0, 0, 0.05);
        }

        /* Footer */
        footer {
            background: var(--background-darker);
            color: var(--text-dark);
            padding: 2rem 0;
            margin-top: 4rem;
            text-align: center;
            transition: background 0.5s, color 0.5s;
        }

        footer p {
            margin: 0;
            font-size: 0.9rem;
            opacity: 0.8;
        }

        .light-mode footer {
            background: #e2e8f0;
            color: var(--text-dark);
        }

        /* Animations */
        @keyframes fadeIn {
            from {
                opacity: 0;
                transform: translateY(20px);
            }

            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .animate-fadeIn {
            animation: fadeIn 0.6s ease-out forwards;
        }

        .delay-100 {
            animation-delay: 0.1s;
        }

        .delay-200 {
            animation-delay: 0.2s;
        }

        .delay-300 {
            animation-delay: 0.3s;
        }

        .delay-400 {
            animation-delay: 0.4s;
        }

        .delay-500 {
            animation-delay: 0.5s;
        }

        /* Responsive Adjustments */
        @media (max-width: 768px) {
            h2 {
                font-size: 2rem;
            }

            h3 {
                font-size: 1.75rem;
            }

            .feature-card {
                padding: 1.5rem;
                margin-bottom: 1.5rem;
            }

            .back-button {
                bottom: 20px;
                left: 50%;
                transform: translateX(-50%);
                padding: 10px 20px;
            }

            .image-grid {
                grid-template-columns: 1fr;
            }
        }

        /* Algorithm Cards */
        .algorithm-card,
        .api-card {
            background: var(--card-bg-dark);
            border-radius: var(--border-radius);
            padding: 2rem;
            height: 100%;
            box-shadow: var(--box-shadow);
            border: 1px solid rgba(255, 255, 255, 0.1);
            transition: var(--transition);
        }

        .algorithm-card:hover,
        .api-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.2);
            border-color: var(--primary-color);
        }

        .algorithm-header,
        .api-header {
            display: flex;
            align-items: center;
            margin-bottom: 1.5rem;
            padding-bottom: 1rem;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }

        .algorithm-header i,
        .api-header i {
            font-size: 2rem;
            margin-right: 1rem;
            color: var(--primary-color);
        }

        .feature-item {
            display: flex;
            margin-bottom: 1.5rem;
            padding-bottom: 1.5rem;
            border-bottom: 1px dashed rgba(255, 255, 255, 0.05);
        }

        .feature-item:last-child {
            border-bottom: none;
            margin-bottom: 0;
            padding-bottom: 0;
        }

        .feature-icon {
            margin-right: 1rem;
        }

        .feature-icon i {
            font-size: 1.5rem;
            color: var(--secondary-color);
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .feature-content h5 {
            margin-bottom: 0.5rem;
            color: var(--text-dark);
        }

        .feature-content p {
            font-size: 0.95rem;
            opacity: 0.8;
            margin-bottom: 0.5rem;
        }

        .progress {
            height: 6px;
            background: rgba(255, 255, 255, 0.1);
            border-radius: 3px;
            margin-top: 0.5rem;
        }

        .progress-bar {
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            border-radius: 3px;
            height: 100%;
        }

        /* API Endpoints */
        .endpoint-item {
            margin-bottom: 1.5rem;
            padding-bottom: 1.5rem;
            border-bottom: 1px dashed rgba(255, 255, 255, 0.05);
        }

        .endpoint-item:last-child {
            border-bottom: none;
            margin-bottom: 0;
            padding-bottom: 0;
        }

        .endpoint-method {
            display: inline-block;
            padding: 0.25rem 0.75rem;
            border-radius: 4px;
            font-weight: 600;
            font-size: 0.8rem;
            margin-right: 0.5rem;
        }

        .endpoint-method.get {
            background: rgba(56, 161, 105, 0.2);
            color: #38a169;
        }

        .endpoint-method.post {
            background: rgba(66, 153, 225, 0.2);
            color: #4299e1;
        }

        .endpoint-path {
            display: inline-block;
            font-family: monospace;
            background: rgba(255, 255, 255, 0.05);
            padding: 0.25rem 0.5rem;
            border-radius: 4px;
            font-size: 0.9rem;
        }

        .endpoint-description {
            margin: 0.5rem 0;
            font-size: 0.95rem;
            opacity: 0.9;
        }

        .endpoint-params {
            font-size: 0.85rem;
            color: var(--text-dark);
            opacity: 0.8;
            margin-top: 0.5rem;
        }

        .param {
            font-family: monospace;
            background: rgba(255, 255, 255, 0.1);
            padding: 0.1rem 0.3rem;
            border-radius: 3px;
        }

        .endpoint-response {
            margin-top: 0.5rem;
            background: rgba(0, 0, 0, 0.2);
            padding: 0.75rem;
            border-radius: 4px;
            overflow-x: auto;
        }

        .endpoint-response pre {
            margin: 0;
            font-family: monospace;
            font-size: 0.85rem;
            color: var(--text-dark);
            white-space: pre-wrap;
            line-height: 1.5;
        }

        /* Responsive adjustments */
        @media (max-width: 992px) {

            .algorithm-card,
            .api-card {
                margin-bottom: 2rem;
            }
        }