GDPR Checkbox in Postery theme not displaying correctly

I am using the MailOptin plugin with Niteo Themes’ Postery theme. The GDPR Checkbox in the “Note” option is not displaying correctly and people can’t tell whether it is checked or not when they click it. I have asked MailOptin support and they suspect it has something to do with the CSS in the Postery Theme conflicting with it. Can you help me with this?

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