body, html {
    height: 100%;
    margin: 0;
    padding: 0;
    background-color: #121212 !important;
}

.image-container {
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: auto;
    background-color: #222;
    height: 100%;
}

.image-container img {
    max-width: none;
    max-height: none;
    width: auto;
    height: auto;
    transform-origin: 0 0;
}

.btn {
    min-width: 40px;
}