[Duster Theme] Do I need to pay somewhere to change the css?

I’m trying to hide the search bar and remove the white space above the header image by using these CSS codes suggested in another thread, but it doesn’t seem to be working:

#searchform, #site-title, #site-description {
display: none;
}

#branding #searchform {
display: none;
}

Website here:
http://andyl.mine.nu/g/socialclub/