A few new button-related options were added to Themes:

• Button height: To make your buttons taller (or shorter) than default.
• Button min. width: Especially in modals, making your buttons wider and more prominent can look great.
• Button border radius: Userflow ships with a default border radius of 6 px. You can make the borders completely round or straight by adjusting this.
• Button horizontal alignment: By default, buttons are right-aligned (except for modals, where they're centered). You can change this to always be left, centered or right aligned.

Find all the new options under the "Buttons" section on the edit theme page (Settings -> Theme).

Some pretty examples of customized buttons from the Userflow customer PurelyHR: