Trouble raising header logo

[Derek765]

Well I created a logo for my header and got it successfully added, but the slogan I had is being cut off by the nav bar on my forum, and I can't seem to raise the logo to center it on the header, here are some coding i've tried adding to additional.css but still isn't doing anything, Ive also tried increasing the header.padding.

.logo-image {
clear:both;
display:block;
float:none;
text-align:center;
}
.logo-image {
clear:both;
display:block;
float:none;
text-align:center;
padding-top: 20px;
}