Act as an expert web developer. Help me build a website for a digital marketing agency. We offer social media growth, web design, and email ads. <tech_stack> - Next.js 15 (App Router) - Tailwind CSS - Lucide React for icons </tech_stack> <task> Build the site in these steps. First, explain your thinking for the site flow. Then: 1. Create a site map. List all pages we need. 2. Create a clean homepage. Include a hero section (big top part) and a services list. 3. Build pages for our three main services. </task> <rules> - Use a modern style like the Apple or Stripe websites. - Use a blue and white color theme. - Make sure the site works well on tiny phones and huge monitors. - If a user goes to a page that does not exist, show a nice error page. - Ask me questions about style or content before you write code. </rules> Please show me the site map first. Do not write code until I approve the map.