Smaller Header

I’ve got Longevity theme, the support gave me this to make the box smaller
@media (min-width: 1200px) {
body .container {
width: 1000px;
}
}
#page.boxed1200 {
max-width: 1000px;
margin: 24px auto;
}

and this to make the header and footer smaller

@media (min-width: 992px) {
#no-banner {
height: 13px;
}
}
body #content {
padding: 3px 0 60px 0;
}

I don’t know if helps, but on the extra css you can easily try