Moving the box size to CSS broke `Popup.setSize()`; the function
expects a width for the padding computation. Because this function is
called before the div is added to the DOM, the size can't be
computed.
This reverts commit 134f24480a.
Moving the box size to CSS broke `Popup.setSize()`; the function
expects a width for the padding computation. Because this function is
called before the div is added to the DOM, the size can't be
computed.
This reverts commit 134f24480a.