:root {
            /* Tema Berwarna (Default Blue) */
            --primary-dark: #1e3a8a;     /* Blue 900 */
            --primary-blue: #1d4ed8;     /* Blue 700 */
            --primary-light: #3b82f6;    /* Blue 500 */
            --text-muted: #4b5563;       /* Gray 600 */
            --bg-light: #f9fafb;         /* Gray 50 */
            --font-main: 'Poppins', sans-serif;
            --img-filter: grayscale(0%); /* Warna asli */
            --img-hover-filter: scale(1.08);
            --transition-speed: 0.5s;
        }

        /* Tema Monokrom (Hitam-Putih) */
        body.monochrome {
            --primary-dark: #000000;     /* Hitam Pekat */
            --primary-blue: #111111;     /* Hitam Sangat Gelap */
            --primary-light: #737373;    /* Abu-abu Sedang */
            --text-muted: #525252;       /* Abu-abu Teks */
            --bg-light: #f5f5f5;         /* Abu-abu Terang */
            --img-filter: grayscale(100%); /* Hitam Putih murni */
            --img-hover-filter: grayscale(0%) scale(1.08); /* Berwarna saat di-hover */
        }

        body {
            font-family: var(--font-main);
            background-color: var(--bg-light);
            color: #374151;
            overflow-x: hidden;
            transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease;
        }

        h1, h2, h3, h4 {
            font-weight: 800;
            color: var(--primary-dark);
            transition: color var(--transition-speed) ease;
        }

        /* === TRANSISI TOMBOL BOOTSTRAP === */
        .btn-primary {
            background-color: var(--primary-blue) !important;
            border-color: var(--primary-blue) !important;
            color: #ffffff !important;
            transition: all var(--transition-speed) ease-in-out;
        }
        .btn-primary:hover {
            background-color: var(--primary-dark) !important;
            border-color: var(--primary-dark) !important;
            transform: translateY(-2px);
        }

        .text-primary {
            color: var(--primary-blue) !important;
            transition: color var(--transition-speed) ease;
        }

        /* === INTERACTIVE THEME TOGGLE BUTTON === */
        .theme-toggle-btn {
            background-color: #f3f4f6;
            border: 1px solid #e5e7eb;
            color: #1f2937;
            padding: 8px 16px;
            border-radius: 50px;
            font-weight: 600;
            font-size: 0.85rem;
            cursor: pointer;
            transition: all var(--transition-speed) ease;
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }
        
        body.monochrome .theme-toggle-btn {
            background-color: #171717;
            border-color: #262626;
            color: #ffffff;
        }

        /* === NAVBAR GLASSMORPHISM === */
        .navbar {
            box-shadow: 0 4px 30px rgba(0, 0, 0, 0.03);
            border-bottom: 1px solid rgba(255, 255, 255, 0.3);
            transition: background-color var(--transition-speed) ease, border-bottom var(--transition-speed) ease;
        }
        .navbar-brand span {
            color: var(--primary-light);
            transition: color var(--transition-speed) ease;
        }
        .navbar-brand svg {
            stroke: var(--primary-blue);
            transition: stroke var(--transition-speed) ease;
        }

        /* === HERO CAROUSEL RESPONSIVE === */
        .hero-carousel .carousel-item {
            height: 100vh;
            min-height: 550px;
            background-position: center;
            background-repeat: no-repeat;
            background-size: cover;
            position: relative;
        }
        
        /* Overlay gelap agar teks mudah dibaca di segala layar */
        .hero-carousel .carousel-item::before {
            content: '';
            position: absolute;
            inset: 0;
            background: linear-gradient(to right, rgba(15, 23, 42, 0.9) 0%, rgba(30, 58, 138, 0.5) 100%);
            z-index: 1;
            transition: background var(--transition-speed) ease;
        }
        
        body.monochrome .hero-carousel .carousel-item::before {
            background: linear-gradient(to right, rgba(0, 0, 0, 0.95) 0%, rgba(0, 0, 0, 0.6) 100%);
        }
        
        .carousel-container {
            position: absolute;
            top: 55%;
            left: 50%;
            transform: translate(-50%, -50%);
            z-index: 2;
            width: 100%;
            max-width: 900px;
            padding: 0 20px;
        }

        /* Fluid Typography untuk judul Hero di HP agar tidak kebesaran */
        .hero-title {
            font-size: calc(1.8rem + 2vw);
            font-weight: 800;
            line-height: 1.2;
        }
        
        @media (max-width: 768px) {
            .hero-carousel .carousel-item { 
                height: 80vh; 
                min-height: 480px;
            }
            .carousel-container {
                top: 50%;
            }
        }

        /* === ABOUT IMAGE DECOR === */
        .about-img-wrapper {
            position: relative;
            padding: 10px;
        }
        .about-img-decor {
            position: absolute;
            bottom: -10px;
            right: -10px;
            width: 90%;
            height: 90%;
            border: 4px solid var(--primary-blue);
            border-radius: 16px;
            z-index: -1;
            transition: border var(--transition-speed) ease;
        }

        /* === SERVICE CARD === */
        .service-card {
            background: #fff;
            padding: 40px 30px;
            border-radius: 20px;
            border: 1px solid #f3f4f6;
            transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }
        .service-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 20px 30px rgba(0, 0, 0, 0.05);
            border-color: var(--primary-light);
        }
        .service-icon {
            width: 65px;
            height: 65px;
            background-color: #f5f5f5;
            color: var(--primary-blue);
            border-radius: 16px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 24px;
            transition: color var(--transition-speed) ease;
        }

        /* === GLOBAL FILTER UNTUK GAMBAR === */
        img, .carousel-item {
            filter: var(--img-filter);
            transition: filter var(--transition-speed) cubic-bezier(0.165, 0.84, 0.44, 1);
        }

        /* === ASYMMETRIC PORTFOLIO GRID (RESPONSIF) === */
        .portfolio-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 20px;
        }
        
        .portfolio-item {
            position: relative;
            border-radius: 20px;
            overflow: hidden;
            height: 300px;
            box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
        }
        
        .portfolio-item img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.6s cubic-bezier(0.165, 0.84, 0.44, 1), filter var(--transition-speed) ease;
        }
        
        .portfolio-item:hover img {
            transform: var(--img-hover-filter);
        }
        
        .portfolio-overlay {
            position: absolute;
            inset: 0;
            background: linear-gradient(to top, rgba(15, 23, 42, 0.9) 0%, rgba(15, 23, 42, 0.1) 70%, transparent 100%);
            display: flex;
            flex-direction: column;
            justify-content: flex-end;
            padding: 30px;
            color: #fff;
            opacity: 0.9;
            transition: opacity 0.3s ease, background var(--transition-speed) ease;
        }

        body.monochrome .portfolio-overlay {
            background: linear-gradient(to top, rgba(0, 0, 0, 0.95) 0%, rgba(0, 0, 0, 0.2) 70%, transparent 100%);
        }
        
        .portfolio-item:hover .portfolio-overlay {
            opacity: 1;
        }

        /* Grid Asimetris Khusus untuk Desktop / Tablet Besar */
        @media (min-width: 992px) {
            .portfolio-grid {
                grid-template-columns: repeat(4, 1fr);
                grid-template-rows: repeat(2, 280px);
            }
            .item-large {
                grid-column: span 2;
                grid-row: span 2;
                height: 100%;
            }
            .item-tall {
                grid-column: span 1;
                grid-row: span 2;
                height: 100%;
            }
            .item-small {
                grid-column: span 1;
                grid-row: span 1;
                height: 100%;
            }
        }

        /* === KONTAK FORM STYLE === */
        .contact-form-card {
            background-color: #fff;
            border-radius: 24px;
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.05);
            border: 1px solid #f3f4f6;
            transition: background-color var(--transition-speed) ease, border var(--transition-speed) ease;
        }
        
        .contact-icon-box {
            width: 50px;
            height: 50px;
            background-color: #f5f5f5;
            color: var(--primary-blue);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: color var(--transition-speed) ease;
        }