Thread Prefix

[lazarote]

Hi guys, im working on a new design for my website and i was visiting de pixeledit site and i found this thread prefix , any idea of how replicate? it has an hover effect

 

[lazarote]

made it

.pixeledit {
    color: #518eda;
    background: #fff;
    font-size: 80%;
    border: 2px solid #718eda;
    border-radius: 4px;
    padding-top: 1px;
    padding-right: .35em;
    padding-bottom: 1px;
    padding-left: .35em;
    display: inline-block;
    line-height: 1.26;
    font-weight: 600 !important;
        &:hover {
    color: #fff;
    background: #518eda;
    }
}