*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    outline: none;
    box-sizing: border-box;
}




/* Useful Classes */
.xy-center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.transition {
    transition: all 350ms ease-in-out;
}

.r-3-2 {
// width: 100%;
    padding-bottom: 66.667%;
    background-color: #ddd;
    padding-top: 15px;
}

.image-holder {
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;
}

/* Main Styles */
.gallery-wrapper {
    position: relative;
    overflow: hidden;
}

.gallery {
    position: relative;
    white-space: nowrap;
    font-size: 0;
}

.item-wrapper {
    cursor: pointer;
    width: 23%; /* arbitrary value */
    display: inline-block;
    background-color: white;
    padding-top: 15px;
}

.gallery-item { opacity: 0.5; }
.gallery-item.active { opacity: 1; }

.controls {
    font-size: 20px;
    border-top: none;
}
.move-btn {
    display: inline-block;
//width: 50%;
    border: none;
    color: #000000;
    background-color: transparent;
    padding: 0.2em 1.5em;
}
.move-btn:first-child {border-right: none;}
.move-btn.left  { cursor: w-resize; }
.move-btn.right { cursor: e-resize; }