reduce footer nav-bar padding

Hello.
i’m trying to reduce the padding between the footer menu to the copyright text. I tried adding this code to the additional css:, but it didn’t work.

footer .menu {
padding-bottom: -50px;
}

but the weird thing is that if I try to increase the footer padding like this :, it work’s perfectly, as if I can’t deduce the padding but on;y increase it.

footer .menu {
padding-bottom: 50px;
}

Can you help me ?
Thank you in advance.

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