/* ==========================================================================
           1. ROOT & DESIGN SYSTEM VARIABLES
           ========================================================================== */
        :root {
            /* Brand Colors */
            --color-primary: #182341;       /* Deep Navy Blue */
            --color-secondary: #BD9951;     /* Metallic Gold */
            --color-accent: #9C7834;        /* Dark Bronze */
            
            /* UI Neutral Colors */
            --color-background: #FAFAFC;    
            --color-surface: #FFFFFF;       
            --color-surface-dark: #111827;  
            --color-text: #1E293B;          
            --color-muted: #5F667B;         
            --color-border: #E3E1DD;        

            /* Typography */
            --font-heading: 'Plus Jakarta Sans', -apple-system, sans-serif;
            --font-body: 'Inter', -apple-system, sans-serif;

            /* Layout */
            --section-padding: 6rem 0;
            --container-max: 1280px;

            /* Micro-Interactions */
            --radius-md: 8px;
            --radius-lg: 16px;
            --shadow-premium: 0 20px 40px -15px rgba(24, 35, 65, 0.07);
            --shadow-hover: 0 30px 60px -20px rgba(24, 35, 65, 0.12);
            --transition-smooth: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
        }

        /* ==========================================================================
           2. RESET & BASE TYPOGRAPHY
           ========================================================================== */
        * { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; }
        body {
            font-family: var(--font-body);
            color: var(--color-text);
            background-color: var(--color-background);
            line-height: 1.65;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        h1, h2, h3, h4 { 
            font-family: var(--font-heading); 
            color: var(--color-primary); 
            line-height: 1.25; 
            font-weight: 700;
            letter-spacing: -0.02em;
        }

        a { text-decoration: none; color: inherit; transition: var(--transition-smooth); }
        img { max-width: 100%; height: auto; display: block; }
        ul { list-style: none; }

        .display-1 { font-size: clamp(2.4rem, 5vw, 4.2rem); font-weight: 800; letter-spacing: -0.03em; }
        .heading-2 { font-size: clamp(1.8rem, 4vw, 2.8rem); font-weight: 700; }
        .heading-3 { font-size: clamp(1.25rem, 2vw, 1.6rem); font-weight: 600; }
        .text-lead { font-size: 1.15rem; color: var(--color-muted); line-height: 1.8; font-weight: 400; }
        .text-overline { 
            font-family: var(--font-heading); 
            font-size: 0.85rem; 
            text-transform: uppercase; 
            letter-spacing: 0.15em; 
            color: var(--color-secondary); 
            font-weight: 700;
        }

        .container { width: 100%; max-width: var(--container-max); margin: 0 auto; padding: 0 1.5rem; }
        .section { padding: var(--section-padding); }
        .text-center { text-align: center; }
        .mb-1 { margin-bottom: 0.75rem; }
        .mb-2 { margin-bottom: 1.5rem; }
        .mb-3 { margin-bottom: 2.25rem; }
        .mb-4 { margin-bottom: 3.5rem; }
        
        .grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 3.5rem; align-items: center; }
        .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2.5rem; }
        .grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 2rem; }

        .btn {
            display: inline-flex; align-items: center; justify-content: center;
            padding: 1.1rem 2.2rem; font-family: var(--font-heading); font-weight: 600;
            font-size: 0.95rem; border-radius: 4px; transition: var(--transition-smooth);
            cursor: pointer; border: none; white-space: nowrap; gap: 0.6rem; letter-spacing: 0.02em;
        }
        .btn-primary { background-color: var(--color-primary); color: var(--color-surface); }
        .btn-primary:hover { background-color: var(--color-secondary); transform: translateY(-2px); box-shadow: var(--shadow-hover); }
        .btn-secondary { background-color: var(--color-secondary); color: var(--color-surface); }
        .btn-secondary:hover { background-color: var(--color-accent); transform: translateY(-2px); box-shadow: var(--shadow-hover); }
        .btn-whatsapp { background-color: #25D366; color: white; }
        .btn-whatsapp:hover { background-color: #1DA851; color: white; transform: translateY(-2px); }
        .btn-outline { background-color: transparent; border: 1px solid var(--color-border); color: var(--color-primary); }
        .btn-outline:hover { border-color: var(--color-primary); background-color: var(--color-primary); color: var(--color-surface); }
        
        .badge {
            display: inline-block; padding: 0.45rem 1.1rem; border-radius: 50px;
            background-color: rgba(189, 153, 81, 0.12); color: var(--color-accent);
            font-size: 0.85rem; font-weight: 700; font-family: var(--font-heading); letter-spacing: 0.05em;
        }

        /* Scroll Reveal Effect */
        .reveal { opacity: 0; transform: translateY(30px); transition: all 0.8s ease; }
        .reveal.active { opacity: 1; transform: translateY(0); }

        /* ==========================================================================
           3. HEADER & NAVIGATION
           ========================================================================== */
        .site-header {
            position: fixed; top: 0; left: 0; width: 100%;
            background-color: rgba(255, 255, 255, 0.98);
            backdrop-filter: blur(12px); border-bottom: 1px solid var(--color-border);
            z-index: 1000; padding: 1.25rem 0; transition: var(--transition-smooth);
        }
        .header-inner { display: flex; justify-content: space-between; align-items: center; }
        .logo-placeholder { 
            font-family: var(--font-heading); font-weight: 800; font-size: 1.55rem; 
            color: var(--color-primary); letter-spacing: 1px; display: flex; align-items: center; gap: 8px;
        }
        .logo-placeholder span { color: var(--color-secondary); }

        .site-logo {
                height: 48px; /* Masaüstü görünür yükseklik */
                width: auto;  /* Oran koruma */
                display: block;
                object-fit: contain;
                transition: var(--transition-smooth);
            }

            /* Scroll sırasında header küçüldüğünde logoyu hafifçe ölçeklemek için */
            .site-header.scrolled .site-logo {
                height: 40px;
            }

            /* Mobil Ekran Optimize */
            @media (max-width: 767px) {
                .site-logo {
                    height: 38px;
                }
            }
        
        .main-nav ul { display: flex; gap: 2.2rem; }
        .main-nav a { font-family: var(--font-heading); font-weight: 600; font-size: 0.95rem; color: var(--color-text); }
        .main-nav a:hover { color: var(--color-secondary); }
        .header-actions { display: flex; align-items: center; gap: 1rem; }
        .mobile-menu-btn { display: none; background: none; border: none; font-size: 1.8rem; color: var(--color-primary); cursor: pointer; }

        /* Mobile Drawer */
        .mobile-drawer {
            position: fixed; top: 0; right: -100%; width: 85%; max-width: 380px; height: 100vh;
            background-color: var(--color-surface); z-index: 1001; padding: 2.5rem 2rem;
            box-shadow: -10px 0 30px rgba(0,0,0,0.15); transition: var(--transition-smooth);
            display: flex; flex-direction: column; justify-content: space-between;
        }
        .mobile-drawer.active { right: 0; }
        .mobile-drawer-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 3rem; }
        .close-drawer-btn { background: none; border: none; font-size: 2rem; color: var(--color-primary); cursor: pointer; }
        .mobile-nav-links { display: flex; flex-direction: column; gap: 1.5rem; }
        .mobile-nav-links a { font-family: var(--font-heading); font-size: 1.2rem; font-weight: 600; color: var(--color-primary); }
        .drawer-overlay {
            position: fixed; top: 0; left: 0; width: 100%; height: 100vh;
            background: rgba(24, 35, 65, 0.6); z-index: 1000; opacity: 0; visibility: hidden; transition: var(--transition-smooth);
        }
        .drawer-overlay.active { opacity: 1; visibility: visible; }

        /* Mobile Bottom Bar */
        .mobile-bottom-bar {
            display: none; position: fixed; bottom: 0; left: 0; width: 100%;
            background: var(--color-surface); border-top: 1px solid var(--color-border);
            padding: 0.75rem 1rem; z-index: 999; box-shadow: 0 -5px 20px rgba(0,0,0,0.08);
        }
        .mobile-bottom-bar .grid-2 { grid-template-columns: 1fr 1fr; gap: 0.75rem; }
        .mobile-bottom-bar .btn { padding: 0.75rem 0.5rem; font-size: 0.875rem; width: 100%; }

        /* ==========================================================================
           4. SECTIONS & COMPONENTS
           ========================================================================== */
        
        /* HERO */
        .hero {
            position: relative; min-height: 92vh; display: flex; align-items: center;
            padding-top: 6rem; padding-bottom: 4rem; overflow: hidden;
        }
        .hero-bg { position: absolute; top: 0; left: 0; width: 100%; height: 100%; z-index: -1; }
        .hero-bg img { width: 100%; height: 100%; object-fit: cover; }
        .hero-bg::after {
            content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 100%;
            background: linear-gradient(90deg, rgba(24,35,65,0.95) 0%, rgba(24,35,65,0.7) 60%, rgba(24,35,65,0.3) 100%);
        }
        .hero-content { color: var(--color-surface); max-width: 820px; }
        .hero-content h1 { color: var(--color-surface); margin: 1rem 0 1.5rem; }
        .hero-content .text-lead { color: #E3E1DD; max-width: 640px; margin-bottom: 2.5rem; font-size: 1.2rem; }
        .hero-cta-group { display: flex; gap: 1rem; flex-wrap: wrap; }
        .hero-btn-outline { border-color: rgba(255,255,255,0.4); color: var(--color-surface); }
        .hero-btn-outline:hover { background-color: var(--color-surface); color: var(--color-primary); }

        /* METRICS */
        .metrics-section { background-color: var(--color-surface); border-bottom: 1px solid var(--color-border); padding: 3.5rem 0; }
        .metric-card { text-align: center; border-right: 1px solid var(--color-border); padding: 0 1rem; }
        .metric-card:last-child { border-right: none; }
        .metric-number { color: var(--color-secondary); margin-bottom: 0.25rem; font-size: 3.2rem; font-weight: 800; font-family: var(--font-heading); }
        .metric-label { font-family: var(--font-heading); font-weight: 600; color: var(--color-muted); font-size: 0.95rem; }

        /* HİZMETLERİMİZ SECTION */
        .services-section { background-color: var(--color-background); }
        .service-card {
            background-color: var(--color-surface); border: 1px solid var(--color-border);
            padding: 2.5rem 2rem; border-radius: var(--radius-md); transition: var(--transition-smooth);
            display: flex; flex-direction: column; justify-content: space-between; height: 100%;
        }
        .service-card:hover {
            transform: translateY(-6px); border-color: var(--color-secondary);
            box-shadow: var(--shadow-hover);
        }
        .service-icon {
            width: 55px; height: 55px; background: rgba(189, 153, 81, 0.12);
            color: var(--color-accent); border-radius: 8px; display: flex;
            align-items: center; justify-content: center; font-size: 1.6rem; margin-bottom: 1.5rem;
        }

        /* YATAY İLETİŞİM BANNERI (MID-PAGE CTA) */
        .quick-contact-banner {
            background: linear-gradient(135deg, var(--color-primary) 0%, #111827 100%);
            color: var(--color-surface); padding: 4rem 0; position: relative; overflow: hidden;
            border-top: 3px solid var(--color-secondary);
        }
        .banner-inner { display: flex; justify-content: space-between; align-items: center; gap: 2rem; flex-wrap: wrap; }
        .banner-text h2 { color: var(--color-surface); font-size: 2.1rem; margin-bottom: 0.75rem; }
        .banner-text p { color: rgba(255,255,255,0.85); font-size: 1.1rem; max-width: 650px; }
        .banner-actions { display: flex; gap: 1rem; flex-wrap: wrap; }

        /* ARSA FİZİBİLİTE SİMÜLATÖRÜ */
        .simulator-card {
            background-color: var(--color-surface); border-radius: var(--radius-lg);
            box-shadow: var(--shadow-premium); padding: 3rem; border: 1px solid var(--color-border);
        }
        .sim-steps { display: flex; justify-content: space-between; margin-bottom: 2rem; border-bottom: 1px solid var(--color-border); padding-bottom: 1rem; }
        .sim-step-item { font-family: var(--font-heading); font-weight: 600; font-size: 0.9rem; color: var(--color-muted); opacity: 0.5; }
        .sim-step-item.active { color: var(--color-secondary); opacity: 1; border-bottom: 2px solid var(--color-secondary); padding-bottom: 0.8rem; }
        
        .sim-box { display: none; }
        .sim-box.active { display: block; }
        
        .form-group { margin-bottom: 1.25rem; }
        .form-group label { display: block; font-family: var(--font-heading); font-weight: 600; font-size: 0.875rem; margin-bottom: 0.4rem; color: var(--color-primary); }
        .form-control, .form-select {
            width: 100%; padding: 0.9rem 1.1rem; border: 1px solid var(--color-border);
            border-radius: 4px; font-family: var(--font-body); font-size: 0.95rem; outline: none; transition: var(--transition-smooth); background: #fff;
        }
        .form-control:focus, .form-select:focus { border-color: var(--color-secondary); }

        .result-box {
            background: rgba(189, 153, 81, 0.08); border: 1px solid var(--color-secondary);
            border-radius: var(--radius-md); padding: 1.5rem; text-align: center; margin-bottom: 1.5rem;
        }
        .result-val { font-size: 1.6rem; font-weight: 700; color: var(--color-primary); margin: 0.5rem 0; font-family: var(--font-heading); }

        /* PROJELER */
        .projects-section { background-color: var(--color-surface); padding-bottom: 5rem; }

        .project-card {
            border-radius: var(--radius-md); overflow: hidden;
            box-shadow: var(--shadow-premium); background-color: var(--color-surface);
            transition: var(--transition-smooth); cursor: pointer; border: 1px solid var(--color-border);
        }
        .project-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-hover); }
        .project-img-wrapper { position: relative; height: 260px; overflow: hidden; }
        .project-img-wrapper img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.6s ease; }
        .project-card:hover .project-img-wrapper img { transform: scale(1.05); }
        .project-status {
            position: absolute; top: 1rem; left: 1rem; background: var(--color-primary); color: white;
            font-size: 0.75rem; font-weight: 600; padding: 0.35rem 0.85rem; border-radius: 4px; text-transform: uppercase; font-family: var(--font-heading);
        }
        .project-status.ongoing { background: var(--color-secondary); }
        .project-content { padding: 1.75rem; }
        .project-title { margin-bottom: 0.5rem; font-size: 1.25rem; }
        .project-location { color: var(--color-muted); font-size: 0.875rem; margin-bottom: 1rem; }
        .project-meta {
            display: flex; justify-content: space-between; border-top: 1px solid var(--color-border);
            padding-top: 1rem; font-size: 0.85rem; color: var(--color-muted); font-weight: 600; font-family: var(--font-heading);
        }

        /* NEDEN ARHAN İNŞAAT SECTION */
        .why-us-section { 
            background-color: var(--color-background); 
            border-top: 1px solid var(--color-border);
            border-bottom: 1px solid var(--color-border);
            padding: 5rem 0;
        }

        /* PROJE MODAL (HIZLI İNCELEME) */
        .modal-overlay {
            position: fixed; top: 0; left: 0; width: 100%; height: 100vh;
            background: rgba(24, 35, 65, 0.8); z-index: 2000; display: flex; align-items: center; justify-content: center;
            opacity: 0; visibility: hidden; transition: var(--transition-smooth); padding: 1.5rem;
        }
        .modal-overlay.active { opacity: 1; visibility: visible; }
        .modal-content {
            background: var(--color-surface); border-radius: var(--radius-lg); max-width: 800px; width: 100%;
            max-height: 90vh; overflow-y: auto; position: relative; padding: 2.5rem; box-shadow: var(--shadow-hover);
        }
        .modal-close { position: absolute; top: 1.5rem; right: 1.5rem; font-size: 2rem; border: none; background: none; cursor: pointer; color: var(--color-primary); }

        /* FAQ (SSS) */
        .faq-section { background-color: var(--color-background); }
        .faq-item { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md); margin-bottom: 1rem; overflow: hidden; }
        .faq-question { padding: 1.5rem 2rem; font-family: var(--font-heading); font-weight: 600; font-size: 1.1rem; color: var(--color-primary); cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
        .faq-answer { padding: 0 2rem 1.5rem 2rem; color: var(--color-muted); display: none; line-height: 1.7; }
        .faq-item.active .faq-answer { display: block; }
        .faq-item.active .faq-question { color: var(--color-secondary); }

        /* FLOATING WHATSAPP BUTTON */
        .whatsapp-float {
            position: fixed; bottom: 30px; right: 30px; width: 60px; height: 60px;
            background-color: #25D366; color: white; border-radius: 50%;
            display: flex; align-items: center; justify-content: center; font-size: 2rem;
            box-shadow: 0 10px 25px rgba(37, 211, 102, 0.4); z-index: 998; transition: var(--transition-smooth);
        }
        .whatsapp-float:hover { transform: scale(1.1); }

        /* FOOTER */
        .site-footer { background-color: var(--color-surface-dark); color: var(--color-border); padding: 5.5rem 0 2rem; }
        .site-footer h4 { color: var(--color-surface); margin-bottom: 1.5rem; font-size: 1.1rem; }
        .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1.5fr; gap: 3rem; margin-bottom: 4rem; }
        .footer-desc { color: rgba(255,255,255,0.65); margin-top: 1rem; max-width: 310px; font-size: 0.95rem; }
        .footer-links li { margin-bottom: 0.85rem; }
        .footer-links a { color: rgba(255,255,255,0.65); font-size: 0.95rem; }
        .footer-links a:hover { color: var(--color-secondary); }
        .contact-info li { display: flex; gap: 12px; margin-bottom: 1.25rem; color: rgba(255,255,255,0.65); font-size: 0.95rem; }
        .contact-info strong { color: var(--color-surface); }
        .footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 2rem; text-align: center; font-size: 0.85rem; color: rgba(255,255,255,0.4); }

        /* MEDIA QUERIES */
        @media (max-width: 991px) {
            .main-nav { display: none; }
            .mobile-menu-btn { display: block; }
            .header-actions .btn { display: none; }
            .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
            .grid-2 { grid-template-columns: 1fr; gap: 2.5rem; }
            .footer-grid { grid-template-columns: 1fr 1fr; }
            .banner-inner { flex-direction: column; text-align: center; }
            .banner-actions { justify-content: center; }
            :root { --section-padding: 5rem 0; }
        }

        @media (max-width: 767px) {
            .whatsapp-float { display: none !important; }
            body { padding-bottom: 70px; }
            .mobile-bottom-bar { display: block; }
            .grid-3, .grid-4, .footer-grid { grid-template-columns: 1fr; }
            .metric-card { border-right: none; border-bottom: 1px solid var(--color-border); padding: 1.5rem 0; }
            .metric-card:last-child { border-bottom: none; }
            :root { --section-padding: 4rem 0; }
        }

    .main-nav a.active,
    .mobile-nav-links a.active {
        color: var(--color-secondary) !important;
        font-weight: 700;
    }



    .custom-modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: rgba(24, 35, 65, 0.7);
    backdrop-filter: blur(6px);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    padding: 1.5rem;
}

.custom-modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.custom-modal-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    max-width: 440px;
    width: 100%;
    padding: 2.5rem 2rem;
    text-align: center;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    transform: translateY(20px) scale(0.95);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    border: 1px solid var(--color-border);
}

.custom-modal-overlay.active .custom-modal-card {
    transform: translateY(0) scale(1);
}

.custom-modal-icon {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.25rem auto;
    font-size: 2rem;
}

.custom-modal-icon.success {
    background: rgba(37, 211, 102, 0.12);
    color: #1DA851;
}

.custom-modal-icon.error {
    background: rgba(239, 68, 68, 0.12);
    color: #EF4444;
}

.custom-modal-title {
    font-family: var(--font-heading);
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: 0.5rem;
}

.custom-modal-text {
    font-size: 0.95rem;
    color: var(--color-muted);
    line-height: 1.6;
    margin-bottom: 1.75rem;
}

/* Proje Kartı İç Açılır Detay Alanı */
.project-details-expand {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    border-top: 1px dashed transparent;
    margin-top: 0;
    padding-top: 0;
}

.project-card.expanded .project-details-expand {
    max-height: 500px; /* İçeriğin genişlemesine imkan tanır */
    opacity: 1;
    margin-top: 0.85rem;
    padding-top: 0.85rem;
    border-top-color: var(--color-border);
}

.btn-expand-details {
    background: none;
    border: none;
    color: var(--color-secondary);
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 0.85rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    margin-top: 0.85rem;
    margin-bottom: 0.5rem;
    padding: 0;
    transition: var(--transition-smooth);
}

.btn-expand-details:hover {
    color: var(--color-accent);
}

.project-highlights-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.project-highlights-list li {
    font-size: 0.83rem;
    color: var(--color-muted);
    margin-bottom: 0.35rem;
    position: relative;
    padding-left: 1rem;
    line-height: 1.45;
}

.project-highlights-list li::before {
    content: "•";
    color: var(--color-secondary);
    font-weight: bold;
    position: absolute;
    left: 0;
}

#projectsGrid, #projectsPortfolioGrid {
    align-items: start;
}