.flashcard-container {
    float: left;
    padding: 0;
    margin: 0;
}

.flashcard-container li {
    float: left;
    margin: 6px;
    position: relative;
    display:inline;
}

.flashcard-container li>div {
    overflow: hidden;
    position: absolute;
    border: none;
    border-radius:10px;
    -webkit-border-radius:10px;
    padding: 0;
    background: lightGray;
    text-align: center;
}

.flashcard-container li>div.back {
    left: -999em;
    background: black;
    color: white;
}

.flashcard-container li>div>div{
    display: block;
    padding: 10px;
    line-height: 125%;
}