Roughly half of hands continue. The button's range is weak enough that folding much more is burning the discount.
The reference tier. 3-bets are linear and value-heavy, live-style; calls are pairs, strong suited hands, and the best broadways.
The most common confrontation in live poker: button steal, big blind close. Defend wide — but depth decides which half of wide.
Assumes a ~4bb open; 3-bet to ~3x the open in position, ~4x from the blinds — larger as stacks deepen.