change size of font

Hi there,

In the black sign up box, above my footer, I am trying to change the size of the font of the text that says ’10 ideas, every 10 days….’

I have tried the following code but something seems to be overriding it:

p.selectionShareable label {
font-size: 30px;
}

Can anyone help please?

The page I need help with: [log in to see the link]