body { font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif; line-height: 1.6; color: #333; max-width: 800px; margin: 0 auto; padding: 20px; } h1 { font-size: 28px; color: #1a1a1a; border-bottom: 2px solid #4CAF50; padding-bottom: 10px; } h2 { font-s…