The brand row and theme toggle sit on their own background with a hairline
under it, so the header reads as an object rather than text floating on the
page. The page title and day switcher stay on the page background: they are
content, not chrome.
The colour is its own --header variable rather than a reuse of --card, so the
header can be recoloured without dragging every card along when the palette
gets overhauled. The theme-color meta tags match it, so on a phone the browser
chrome continues the header instead of butting a different shade against it;
those need literal hex, so each file points at the other.
Esa Kataja
3564d74c39