Everything is clean, though overall is pretty basic in terms of an idle game. Needs a clearly defined goal and/or loop system, perhaps a story.

World ending meteor/monster approaching; X amount of Adamantite needed by X amount of days to protect the planet.

or a more "Cozy" approach:

Legends mention a powerful ore that would let humans live forever, sparking a race between towns and kingdoms. "Win" by being the first miner/town to discover it.

Or even a generic Tax system:

King demands X amount of resources at the end of each season.

I believe something like this would work nicely with what you have so far, which is really nice by the way, I don't mean to water down your work. Wishing you the best 👍