In between margin trick

in-between-margin-trick.css

/* Old */
.classname {
    ...
    margin-top: 20px;
}

    .classname:first-child {
        margin-top: 0;
    }

/* New */
.classname {
    ...
}
    
.classname:not(:first-child):not(:root) {
    margin-top: 20px;
}
    
    /* @fix IE8 */
    .ie8 .classname * + * {
        margin-top: 20px;
    }