Warm at home — one light layer is likely plenty. Bare legs are fine.
For a baby of 6–12 months, awake, in a 26°C (79°F) room: short-sleeve bodysuit.
Above 26°C the answer stays the same: one light layer is as little as the app goes indoors.
Short sleeves from 21°C, covered arms below.
0–3 months: short-sleeve bodysuit. 3–6 months: short-sleeve bodysuit. 6–12 months: short-sleeve bodysuit. 1–3 years: T-shirt.
At 25°C the answer stays the same.
At 27°C the answer stays the same.
In a 26°C room the answer stays the same either way.
For sleep in the same room, the app suggests short-sleeve bodysuit.
No hat indoors — a baby cools through the head.
Check the neck — warm but not sweaty means just right.