body { font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; line-height: 1.6; max-width: 720px; margin: 2rem auto; padding: 0 1rem; background: #f9f9f9; color: #333; } h1, h2, h3 { color: #2c3e50; } h1 { font-size: 2rem; margin-bottom: 1rem; border-bottom: 2px solid #3498db; padding-bottom: …