.OnlineTopic .card>.card-content {
    display: flex;
    align-items: center;
    border: 1px solid #ddd;
    overflow: hidden;
}

.OnlineTopic .card>.card-content>img {
    width: 100%;
}

.OnlineTopic .card-title {
    opacity: 0;
    font-size: 22px;
    background-color: transparent;
    -webkit-transition: .5s;
    -o-transition: .5s;
    transition: .5s;
}

.OnlineTopic .card-title:hover {
    opacity: 1;
    background-color: rgba(12, 90, 219, .9);
}