Open the Console (Cmd/Ctrl + Shift + J). Every section prints what it hears.
Hover, leave, and click the box. Watch the Console and the color.
Move your mouse over this section.
Click into the field and type. Try the arrow keys and Enter.
Type to see live echo. Press the button to "submit" without a page reload.
One listener on the container handles every button — including ones added after load. Click a name to remove it; add more with the button.