The new Agora compact vertical form layout styles the selector ".mw-ui-vform > div input" as "display: block", turning all input fields within divs full-width.
This isn't be appropriate for some input fields, e.g. the simple captcha looks better with the input field inline and smaller
88+5 = [ ]
To fix this we could add a mw-ui-inline "reset" style, or we could make the selector only style input fields that are immediate children of the div full-width, i.e. ".mw-ui-vform > div > input". It's hard to know which approach is better until there are more clients of the form.