.content-container img, video {
    max-width: 500px;
    max-height: 500px;
    width: auto;
    height: auto;
    margin: 10px;
    display: block;
    border-radius: 5px;
}

@media screen and (max-width: 450px) {
    .content-container img, video {
        max-width: 300px;
        max-height: 300px;
        width: auto;
        height: auto;
        margin: 10px auto;
        text-align: center;
    }
}