body{font-family:Arial,sans-serif;margin:0;padding:0}header{display:flex;justify-content:space-between;padding:20px}main{padding:20px}@media (max-width: 768px){header{flex-direction:column;align-items:center}main{padding:10px}.container{width:100%;padding:10px}.responsive-image{width:100%;height:auto}.nav-menu{display:flex;flex-direction:column;align-items:center}.nav-menu a{padding:10px;width:100%;text-align:center}}