:root {
          --primary: #2563eb;
          --primary-dark: #1e40af;
          --secondary: #0f172a;
          --text-main: #334155;
          --text-light: #64748b;
          --bg-light: #f8fafc;
          --white: #ffffff;
          --border: #e2e8f0;
          --whatsapp: #25D366;
          --whatsapp-dark: #128C7E;
        }

        * {
          margin: 0;
          padding: 0;
          box-sizing: border-box;
          font-family: 'Inter', sans-serif;
        }

        body {
          color: var(--text-main);
          background-color: var(--white);
          line-height: 1.6;
        }

        a {
          text-decoration: none;
          color: inherit;
        }

        /* Navbar */
        header {
          background: var(--white);
          border-bottom: 1px solid var(--border);
          position: sticky;
          top: 0;
          z-index: 1000;
          padding: 15px 5%;
          display: flex;
          justify-content: space-between;
          align-items: center;
        }

        .logo {
          display: flex;
          align-items: center;
          gap: 10px;
          font-size: 24px;
          font-weight: 800;
          color: var(--primary);
        }

        .logo i {
          background: var(--primary);
          color: white;
          padding: 8px;
          border-radius: 8px;
          font-size: 18px;
        }

        .nav-links {
          display: flex;
          gap: 30px;
          font-weight: 500;
        }

        .nav-links a:hover {
          color: var(--primary);
        }

        .nav-buttons {
          display: flex;
          gap: 15px;
        }

        .btn {
          padding: 10px 24px;
          border-radius: 8px;
          font-weight: 600;
          cursor: pointer;
          transition: all 0.3s ease;
          border: none;
          display: inline-flex;
          align-items: center;
          justify-content: center;
          gap: 8px;
        }

        .btn-primary {
          background: var(--primary);
          color: white;
        }

        .btn-primary:hover {
          background: var(--primary-dark);
          transform: translateY(-2px);
          box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
        }

        .btn-outline {
          background: transparent;
          border: 2px solid var(--primary);
          color: var(--primary);
        }

        .btn-outline:hover {
          background: var(--primary);
          color: white;
        }

        .btn-whatsapp {
          background: var(--whatsapp);
          color: white;
        }

        .btn-whatsapp:hover {
          background: var(--whatsapp-dark);
          transform: translateY(-2px);
          box-shadow: 0 4px 12px rgba(37, 211, 102, 0.3);
        }

        /* Hero Section */
        .hero {
          padding: 80px 5% 60px;
          background: linear-gradient(135deg, #f0f7ff 0%, #ffffff 100%);
          text-align: center;
        }

        .hero h1 {
          font-size: 48px;
          font-weight: 800;
          color: var(--secondary);
          margin-bottom: 20px;
          line-height: 1.2;
        }

        .hero h1 span {
          color: var(--primary);
        }

        .hero p {
          font-size: 18px;
          color: var(--text-light);
          max-width: 700px;
          margin: 0 auto 30px;
        }

        .hero-buttons {
          display: flex;
          justify-content: center;
          gap: 15px;
          margin-bottom: 50px;
        }

        .hero-image {
          max-width: 1000px;
          margin: 0 auto;
          border-radius: 12px;
          box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
          border: 1px solid var(--border);
          overflow: hidden;
        }

        .hero-image img {
          width: 100%;
          display: block;
        }

        /* Stats */
        .stats {
          background: var(--primary);
          color: white;
          padding: 40px 5%;
          display: flex;
          justify-content: space-around;
          text-align: center;
          flex-wrap: wrap;
          gap: 20px;
        }

        .stat-item h3 {
          font-size: 36px;
          font-weight: 800;
        }

        .stat-item p {
          font-size: 14px;
          opacity: 0.9;
        }

        /* Features Section */
        .section-title {
          text-align: center;
          margin-bottom: 50px;
        }

        .section-title h2 {
          font-size: 36px;
          color: var(--secondary);
          margin-bottom: 15px;
        }

        .section-title p {
          color: var(--text-light);
          max-width: 600px;
          margin: 0 auto;
        }

        .features {
          padding: 80px 5%;
          background: var(--bg-light);
        }

        .features-grid {
          display: grid;
          grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
          gap: 30px;
          max-width: 1200px;
          margin: 0 auto;
        }

        .feature-card {
          background: var(--white);
          padding: 30px;
          border-radius: 12px;
          border: 1px solid var(--border);
          transition: all 0.3s ease;
        }

        .feature-card:hover {
          transform: translateY(-5px);
          box-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
          border-color: var(--primary);
        }

        .feature-icon {
          width: 50px;
          height: 50px;
          background: #eff6ff;
          color: var(--primary);
          border-radius: 10px;
          display: flex;
          align-items: center;
          justify-content: center;
          font-size: 24px;
          margin-bottom: 20px;
        }

        .feature-card h3 {
          font-size: 20px;
          margin-bottom: 10px;
          color: var(--secondary);
        }

        .feature-card p {
          color: var(--text-light);
          font-size: 15px;
        }

        /* Screenshots Section */
        .screenshots {
          padding: 80px 5%;
          background: var(--white);
        }

        .screenshot-item {
          display: flex;
          align-items: center;
          gap: 50px;
          max-width: 1100px;
          margin: 0 auto 80px;
        }

        .screenshot-item.reverse {
          flex-direction: row-reverse;
        }

        .screenshot-content {
          flex: 1;
        }

        .screenshot-content h3 {
          font-size: 28px;
          color: var(--secondary);
          margin-bottom: 15px;
        }

        .screenshot-content p {
          color: var(--text-light);
          margin-bottom: 20px;
        }

        .screenshot-content ul {
          list-style: none;
        }

        .screenshot-content ul li {
          margin-bottom: 10px;
          display: flex;
          align-items: center;
          gap: 10px;
          font-weight: 500;
        }

        .screenshot-content ul li i {
          color: #10b981;
        }

        .screenshot-image {
          flex: 1;
          border-radius: 12px;
          box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
          border: 1px solid var(--border);
          overflow: hidden;
        }

        .screenshot-image img {
          width: 100%;
          display: block;
        }

        /* Contact Section (WhatsApp) */
        .contact-section {
          padding: 80px 5%;
          background: var(--bg-light);
          text-align: center;
        }

        .contact-card {
          background: var(--white);
          padding: 50px;
          border-radius: 16px;
          border: 1px solid var(--border);
          box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
          max-width: 700px;
          margin: 0 auto;
        }

        .contact-card .whatsapp-icon {
          width: 80px;
          height: 80px;
          background: #dcfce7;
          color: var(--whatsapp);
          border-radius: 50%;
          display: flex;
          align-items: center;
          justify-content: center;
          font-size: 40px;
          margin: 0 auto 25px;
        }

        .contact-card h3 {
          font-size: 28px;
          color: var(--secondary);
          margin-bottom: 15px;
        }

        .contact-card p {
          color: var(--text-light);
          margin-bottom: 30px;
          font-size: 16px;
        }

        .contact-card .btn-whatsapp {
          font-size: 18px;
          padding: 16px 40px;
          border-radius: 10px;
        }

        .contact-info {
          margin-top: 30px;
          display: flex;
          justify-content: center;
          gap: 30px;
          flex-wrap: wrap;
          font-size: 15px;
          color: var(--text-light);
        }

        .contact-info span {
          display: flex;
          align-items: center;
          gap: 8px;
        }

        /* CTA Section */
        .cta {
          padding: 80px 5%;
          background: var(--secondary);
          text-align: center;
          color: white;
        }

        .cta h2 {
          font-size: 36px;
          margin-bottom: 20px;
        }

        .cta p {
          color: #94a3b8;
          margin-bottom: 30px;
          max-width: 600px;
          margin-left: auto;
          margin-right: auto;
        }

        /* Footer */
        footer {
          background: #0b1120;
          color: #94a3b8;
          padding: 60px 5% 20px;
        }

        .footer-grid {
          display: grid;
          grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
          gap: 40px;
          max-width: 1200px;
          margin: 0 auto 40px;
        }

        .footer-col h4 {
          color: white;
          margin-bottom: 20px;
        }

        .footer-col ul {
          list-style: none;
        }

        .footer-col ul li {
          margin-bottom: 10px;
        }

        .footer-col ul li a:hover {
          color: white;
        }

        .footer-bottom {
          text-align: center;
          border-top: 1px solid #1e293b;
          padding-top: 20px;
          font-size: 14px;
        }

        .footer-bottom .demsoft {
          color: #94a3b8;
          font-size: 13px;
          margin-top: 5px;
        }

        .footer-bottom .demsoft strong {
          color: white;
        }

        /* Responsive */
        @media (max-width: 768px) {
          .hero h1 {
            font-size: 32px;
          }

          .nav-links {
            display: none;
          }

          .nav-buttons {
            display: none;
          }

          .screenshot-item,
          .screenshot-item.reverse {
            flex-direction: column;
            gap: 30px;
          }

          .hero-buttons {
            flex-direction: column;
          }

          .btn {
            width: 100%;
            text-align: center;
          }

          .contact-card {
            padding: 30px 20px;
          }
        }

        /* --- LIGHTBOX (BÜYÜTME) İÇİN EKLENEN CSS --- */

        /* SADECE screenshot-image içindeki görseller tıklanabilir ve hover efektli */
        .screenshot-image img {
          cursor: zoom-in;
          transition: transform 0.3s ease, box-shadow 0.3s ease;
        }

        .screenshot-image img:hover {
          transform: scale(1.02);
          box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
        }

        /* Hero resmi normal kalsın, tıklanabilir imleci olmasın */
        .hero-image img {
          cursor: default;
          transition: none;
        }

        /* Modal (Lightbox) Arka Planı */
        .lightbox-modal {
          display: none;
          /* Varsayılan olarak gizli */
          position: fixed;
          z-index: 9999;
          left: 0;
          top: 0;
          width: 100%;
          height: 100%;
          background-color: rgba(15, 23, 42, 0.9);
          /* Koyu yarı saydam arka plan */
          backdrop-filter: blur(5px);
          /* Arka planı bulanıklaştır */
          align-items: center;
          justify-content: center;
          opacity: 0;
          transition: opacity 0.3s ease;
        }

        /* Modal aktif olduğunda */
        .lightbox-modal.active {
          display: flex;
          opacity: 1;
        }

        /* Büyütülmüş Resim */
        .lightbox-modal img {
          max-width: 90%;
          max-height: 90%;
          border-radius: 8px;
          box-shadow: 0 25px 50px rgba(0, 0, 0, 0.5);
          transform: scale(0.8);
          transition: transform 0.3s ease;
          cursor: default;
        }

        .lightbox-modal.active img {
          transform: scale(1);
        }

        /* Kapatma Butonu (X) */
        .lightbox-close {
          position: absolute;
          top: 20px;
          right: 35px;
          color: #fff;
          font-size: 40px;
          font-weight: bold;
          cursor: pointer;
          transition: color 0.3s;
          z-index: 10000;
        }

        .lightbox-close:hover {
          color: #ef4444;
          /* Kırmızı hover */
        }