css - depth input

gistfile1

.depth {
    display: block;
    border: 1px solid rgba(255,255,255,0.6);
    background: linear-gradient(#eee, #fff);
    transition: all 0.3s ease-out;
    box-shadow: 
        inset 0 1px 4px rgba(0,0,0,0.4);
    padding: 5px;
    color: #555;
}
 
.depth:focus {
    outline: none;
    background-position: 0 -1.7em;
}