Most dark modes invert everything. This kit keeps one thing fixed: the surfaces that slide over the page are dark in both themes.
What counts as a bar
The slide-down menu panel, the Recent drawer, a fixed bottom bar and the toast. Each sits over the page for a moment, so it should look different from the page.
What it does in light mode
A dark block on cream is the strongest contrast the palette has. It makes the panel feel like a separate sheet laid on top, without a shadow or a blur. That flat contrast is what Swiss posters relied on too.
What it does in dark mode
The bars step up to a slightly raised black, so they still read as a layer above a page that is now dark itself. Labels on them use the brighter accent, which keeps its contrast on either black.