States

<button>

default disabled-attr --is-busy

<a>

default disabled-attr --is-busy

Icons

<button>

… __icon--before __icon--after X

<a>

… __icon--before __icon--after X

Width

<button>

--width-short --width-medium --width-long

<a>

--width-short --width-medium --width-long

Size

(no small size allowed)