body{margin:0;font-family:Arial,Helvetica,sans-serif;line-height:1.6;background-color:#f4f4f4;color:#333}header,footer{background-color:#1f1f1f;color:#fff;text-align:center;padding:1.5rem}main{padding:1.5rem}.content-section{background-color:#fff;padding:1rem;margin-bottom:2rem;border-radius:8px}.content-section h2{margin-top:0}.content-section img{width:100%;height:auto;border-radius:6px}@media(min-width:768px){main{display:grid;grid-template-columns:repeat(3,1fr);gap:2rem}}