.osiDrop {
    text-align: center;
    overflow: hidden;
}

 .arrowOdd {
    background-color: blue;
    text-align: inherit;
}

.arrowEven {
    background-color: black;
    text-align: inherit;
}

.osiDrop .oddBtn {
    cursor: pointer;
    font-size: 16px;
    border: none;
    outline: none;
    color: #f2f2f2;
    background-color: blue;
    font-family: inherit;
    margin: 0;
}

.osiDrop .evenBtn {
    cursor: pointer;
    font-size: 16px;
    border: none;
    outline: none;
    color: #f2f2f2;
    background-color: black;
    font-family: inherit;
    margin: 0;
}

.osiODrop-content {
    display: none;
    position: absolute;
    background-color: blue;
    color: #ddd;
    min-width: 160px;
    z-index: 1;
}

.osiEDrop-content {
    display: none;
    position: absolute;
    background-color: blue;
    color: #ddd;
    min-width: 160px;
    z-index: 1;
}

.osiOshow {
    display: block;
}