Help styling Appointments+ buttons to match the theme

Hello, dear WPMUDEV-Team,

On this page the Appointement+ Plugin generate content:
http://833.c4f.myftpupload.com/kontakt/

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:
http://833.c4f.myftpupload.com/hypnose-konstanz/

Best Regards
zmonk