sidebar width

hi there,

working on a site for a buddy and love your theme
the sidebar feels a bit ‘thin’ to me
i read somewhere else on here that it was set to a third but feels again thin
i would like to widen it up a bit

anyway

found a bit of css online that i have been using but doesn’t seem to work

.content {
width: 610px;
}
.sidebar {
width: 260px;
}

any help would be greatly appreciated