.presentation {
    padding-bottom: 20px;
}
.button {
    font-size: 0.8em;
    background-color: #fff;
    border-color: #dbdbdb;
    border-width: 1px;
    color: #363636;
    cursor: pointer;
    justify-content: center;
    padding-bottom: calc(0.5em - 1px);
    padding-left: 1em;
    padding-right: 1em;
    padding-top: calc(0.5em - 1px);
    text-align: center;
    white-space: nowrap;
}
.button.twitter {
    background-color: #00aced;
    border-color: transparent;
    color: #fff;
}
.button.linkedin {
    background-color: #2867b2;;
    border-color: transparent;
    color: #fff;
}

.card {
	margin-bottom: 2em;	
}

.cards {
    display: flex;
    flex-wrap: wrap;
 }

 .card-date {
     float: right;
     color: #777;
 }

.card {
    flex: 1 0 500px;
    margin: 2rem;
}

@media screen and (min-width: 40em) {
    .card {
       max-width: calc(50% -  5em);
    }
}