*{box-sizing:border-box}body{margin:0;font-family:Arial,sans-serif;background:#f4fff4;color:#222}
header{padding:40px;text-align:center;background:linear-gradient(135deg,#006400,#2ecc71,#7ed957);color:#fff}
nav{margin-top:20px}nav a{color:#fff;text-decoration:none;margin:0 10px;font-weight:bold}
section{max-width:900px;margin:25px auto;padding:20px;background:#fff;border-radius:12px;box-shadow:0 2px 8px rgba(0,0,0,.1)}
footer{text-align:center;padding:20px;background:#006400;color:#fff}