html,body{color:#111827;background-color:#f9fafb;margin:0;padding:0;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Noto Sans,Ubuntu,Cantarell,Helvetica Neue,sans-serif;line-height:1.6}main{max-width:800px;min-height:calc(100vh - 120px);margin:0 auto;padding:40px 20px}header{background-color:#111827;padding:16px 20px}header nav{justify-content:center;gap:24px;display:flex}header nav a{color:#f9fafb;font-size:15px;font-weight:600;text-decoration:none}header nav a:hover{color:#60a5fa}h1,h2,h3{color:#111827;margin-bottom:16px;font-weight:700}p{color:#374151;margin-bottom:14px;font-size:16px}a{color:#2563eb;text-decoration:none}a:hover{text-decoration:underline}footer{color:#6b7280;text-align:center;background-color:#f3f4f6;padding:20px;font-size:14px}