{% css %} header { position: sticky; backdrop-filter: blur(5px); background-color: #ffffffcc; top: 0; padding: 2rem 0; } .header-container { max-width: var(--page-width); margin-left: auto; margin-right: auto; display: flex; justify-content: space-between; align-items: center; } #mainNav ul { margin: 0; padding: 0; } #mainNav li { display: inline; } {% endcss %}