body{font-family:Arial,sans-serif;margin:0;background:#f4fff4;color:#234}header{background:#2e7d32;color:#fff;padding:40px;text-align:center}.btn{display:inline-block;padding:10px 16px;background:#2e7d32;color:#fff;text-decoration:none;border-radius:6px}main{padding:20px;max-width:800px;margin:auto}section{background:#fff;padding:18px;margin:15px 0;border-radius:10px}footer{text-align:center;padding:20px}