.css code how do i put it in

hi how do i put my .css code what im trying to do is make the image bits biger and layout diferently here my code im trying to do it show up correct in firebug when i input the code
}
.feature-box i.ic-holder-1 {
border-radius: 60px;
border-style: solid;
border-width: 2px;
display: inline-block !important;
font-style: normal;
height: 250px;
line-height: 200px;
margin: -50px !important;
vertical-align: 150px !important;
width: 200px;
}