Measure Mixed with the active body font and include the input margins and caret allowance. Keep that minimum stable while typing so the full label is visible without shifting the row on each keystroke.
A themed panel regression fails against the old 40-pixel input, verifies the text fits inside the field margins and keeps the alignment control inside a 272-pixel pane. Linux scoped clippy, format tests, wasm, formatting, layering and assets pass.
Co-Authored-By: Codex GPT-6.1 <noreply@openai.com>