E309 - Container dimension is "auto"

Cause

A container element declares width: "auto" or height: "auto". Container children are absolutely positioned (out of flow), so an auto-sized container box collapses to zero — and every %-sized child collapses with it.

Example

{ container: [{ markdown: "# Hi" }], position: [0, 5], width: 100, height: "auto" }

How to fix

Give the container numeric (or animated numeric) width and height. The defaults are 100 × 100 — the full enclosing space — so omitting both fields is always valid.