Splitting into files
The answer to the exercise in Splitting into files.
/pill.js hands its class name out with export default, so the name never
gets a name of its own. A namespace import only carries the named exports,
which is why styles.pill was undefined, and React draws an element with no
class at all. A default import takes the default, so pill is the class name
again.
The pills are back on the artwork, and the page is the four-file app again.