.nav-guide {
    font-style: italic;
    font-size: +1.2em;
}

@media (min-width: 768px) { /* Apply only for non-mobile views */
    nav.col-md-3 {
        position: sticky;
        top: 0; /* Distance from the top of the viewport */
        height: calc(100vh - 1rem); /* Full height minus some padding */
        overflow-y: auto; /* Add scroll if content overflows */
    }
}