.margin-t-10{
    margin-top :10px;
}

.margin-t-20{
    margin-top :20px;
}

.margin-t-30{
    margin-top :30px;
}

.margin-b-10{
    margin-bottom :10px;
}

.margin-b-20{
    margin-bottom :20px;
}

.margin-b-30{
    margin-bottom :30px;
}