Nope, you can do it centrally, just add:
--header-mobile-bookend: 40px;
to my code, like this:
@media screen and (max-width: 749px) {
.header__columns {
--header-template-columns: 1fr var(--header-mobile-bookend) var(--header-mobile-bookend) var(--header-mobile-bookend) var(--header-mobile-bookend);
--header-mobile-bookend: 40px; /* default is 44px */
grid-template-areas: "center leftA leftB rightA rightB";
}
.header__columns .header-logo {
justify-content: flex-start;
padding: 0 1rem;
}
}
But fat fingers!