Help styling Appointments+ buttons to match the theme

Hello, dear WPMUDEV-Team,

On this page the Appointement+ Plugin generate content:

Please help me style (CSS) these 4 buttons:

Button 1: “Previous Month”

Button 2 : “Next Month

Button 3: “Please click here to confirm this appointment”

Button 4: “Cancel Button”

so they look like these green button “Jetzt Termin vereinbaren” on these page:

Best Regards