Selects have 2 states - active and disabled. By default, a blue underline appears when select drop downs are active. However, you can force the active state appearance by adding the .is-active modifier or attribute to your select dropdown. Select dropdowns that are disabled have a greyed out appearance. The disabled appearance can be accessed by adding the .is-disabled modifier to your select dropdowns.
Denali offers 3 selects sizes - default, medium, and small. The default field size is automatically built into our selects. However, you may access smaller sizes using the .is-medium or .is-small modifiers.