@media (max-width:640px){.site-header{align-items:flex-start;flex-direction:column;padding:20px}.site-header nav{gap:12px 16px;font-size:.95rem}.page-shell{padding:20px}.site-footer{align-items:flex-start;flex-direction:column;padding:20px}.site-footer span:last-child{gap:16px}}