WebKit draws the same button 36x24 where Chromium draws 33x21, so the literal this pinned failed in CI on a build where nothing was wrong. A button's box comes from the UA stylesheet when the author sets nothing, and what each UA sets is its own business. What must not happen is that *we* set something. So: `min-width` and `min-height` compute to 0px, the font-size still equals that of a bare button probed in the same page, and all five boxes are identical -- which is what says the desktop is neither sized context. Checked by re-introducing the `font-size: inherit` regression, which it catches in Chromium; the literal form could only be checked by hand.