The more unequal a society, the harder it is to climb it — the rungs move apart. That relationship has a name: the Great Gatsby curve. Drag the country along the inequality axis to see mobility fall, then click a rung to stand on it and read your child's odds of ever reaching the top.
The Great Gatsby curve: intergenerational mobility falls as inequality rises — drag the country along the Gini axis and the mobility (chance of changing income rank) drops along the drawn curve, a real cross-country empirical relationship (Corak). Stand on a rung and the instrument reads your child's odds of reaching the top: higher inequality makes the bottom stickier, so the same child's climb is steeper in an unequal society. The inverse inequality–mobility relationship is the documented core.
The mobility function and the child's-odds numbers are stylised to the SHAPE of the real relationship, not a fitted model of a specific country; real mobility depends on schooling, place, race and policy, not the Gini alone. The direction — more unequal societies are less mobile, and the effect bites hardest at the bottom — is the real, measured content.