Responsive theme header missing

Help,
I have done something stupid I am using responsive theme and I decided to edit it and lost my header image I tried to paste back the original code but the image still has not come back, please can somebody tell me how to rectify this mistake, this is the code that I pasted back but it still did not work
#logo {
float:left;
margin:0;
}

.site-name {
display:block;
font-size:2em;
padding-top:20px;
}

.site-name a {
font-weight:700;
}

.site-description {
display:block;
font-size:14px;
margin:10px 33px 10px 0;
}

/* =Content