Gray area firefox when resizing contact-header

Hi I resized my contact header using.

.header-contact {
    padding: 3px;
}

Only when I use firefox there is a grayline between the sideheader and header-contact.
Safari and chrome works perfect.

How can I solve this ?

Kind regards,

Hello @yadihinz,

Can you please provide a link to your website?

Kind Regards, Roman.

Sorry it’s only on local host.

Hello @yadihinz,

Can you please let me know when your website is live?

Kind Regards, Roman.