.viewer {
    position: relative;
    margin: 20px 0;
}

#pdtViewer {
    width: 67%;
    margin: 0 auto;
}

#pdtViewer img {
    padding: 40px 20px;
    border: .5px solid #eee;
    user-select: none;
    /*-moz-user-select: none;*/
}

#dummy {
    display: none;
}

.loader {
    width: 100%;
    height: 100%;
    position: absolute;
    /*background: rgba(0, 0, 0, .5);*/
    z-index: 1;
    top: 0;
}

.three-bounce {
    text-align: center;
    font-size: 26px;
    position: absolute;
    top: 50%;
    left: 50%;
}

.three-bounce div {
    display: inline-block;
    width: 18px;
    height: 18px;
    border-radius: 100%;
    background-color: #fff;
    animation: bouncedelay 1.4s infinite ease-in-out both;
}

/* Rest of the CSS rules remain the same */