Show an image on hover on xaringan slides

I have tested the following codes on a normal HTML webpage with no problem. However, I can't get it work on a xaringan slide. xaringan is an R presentation template.

I am not sure if there is any limitation on xaringan.

.hover-title {
    display: inline;
    pointer-events: auto;
    cursor: pointer;
}

.hover-image {
    visibility: hidden;
}

body:not(.mobile) .hover-title:hover + .hover-image {
    visibility: visible;
    pointer-events: none;
}

.hover-image {
    display: flex;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: -1;
    pointer-events: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;

/* Change width and height to scale images */
    width: 90vw;
    height: 90vh;
}

.hover-image img {
    max-width: 100% !important;
    max-height: 100% !important;
    width: auto !important;
    height: auto !important;
    margin-bottom: 0;
}

<div class = "hover-title">
      Default Setting
      </div> 
      <div class = "hover-image">
        <img src="https://images.unsplash.com/photo-1486312338219-ce68d2c6f44d?w=752&ixid=dW5zcGxhc2guY29tOzs7Ozs%3D" alt="">
</div>

Solution

You are not seeing the image on hover inside xaringan because the hover-image class has z-index set to -1 and xaringan slides are contained within a div with class remark-visible which has z-index set to 2.

So to show the image on hover you just need to increase the z-index of hover-image little more, say 5.

.hover-image {
    display: flex;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 5; /* increased z index */
    pointer-events: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;

/* Change width and height to scale images */
    width: 90vw;
    height: 90vh;
}