.content-section {
    background: #ffffff;
    padding: 10px 20px;
    border: 1px solid #dddddd;
    border-radius: 3px;
    margin-bottom: 20px;
}

/* Reference: https://stackoverflow.com/questions/39623405/vertically-stack-bootstrap-input-group-controls */
.vertical-input-group > * {
    background-color: #fff;
}

.vertical-input-group > *:first-child {
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;    
}
.vertical-input-group > *:last-child {
    border-top-left-radius: 0;
    border-top-right-radius: 0;
}
.vertical-input-group .input-group:not(:last-child):not(:first-child) {
    padding-top: 0;
    padding-bottom: 0;
}
.vertical-input-group .input-group:not(:last-child):not(:first-child) * {
    border-radius: 0;
}  
.vertical-input-group .input-group:not(:first-child) * {
    border-top: 0;
}