Unable to change css

I cannot override css for the weight of the h3 headings in an event list. Trying to make the weight lighter. Other css I’v added to hide some fields works, but targeting the heads does not. Like to change font-weight to 400, 500 or normal.

.wpem-event-listings .wpem-event-layout-wrapper .wpem-event-infomation .wpem-event-details .wpem-event-title .wpem-heading-text {
    font-size: 22px;
    line-height: 30px;
    font-weight: 700;
    color: var(--wpem-dark-color);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin: 0;
}

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