div.gallery-thumbs {
    padding-right: 17px;
    overflow: hidden;
    max-height: 250px;
}

div.gallery-thumbs img {
    max-width: 100%;
    border: 1px solid #ccc;
    margin: 5px;
    cursor: pointer;
}

div.gallery-thumbs:hover {
    padding-right: 10px;

    overflow-y: scroll;
    overflow-x: hidden;
    -webkit-overflow-scrolling: touch;
    -moz-overflow-scrolling: touch;
    -ms-overflow-scrolling: touch;
    -o-overflow-scrolling: touch;
    overflow-scrolling: touch;
    border-radius: 10px 0 0 10px;
    border-right: none;
}

.gallery-thumbs {
    scrollbar-width: thin;
    scrollbar-color: #aaaaaa #ffffff;
}

.gallery-thumbs::-webkit-scrollbar {
    left: -10px;
    -webkit-appearance: none;
    width: 7px;
}

.gallery-thumbs::-webkit-scrollbar-thumb {
    border-radius: 2px;
    background-color: rgba(0, 0, 0, 0.5);
    -webkit-box-shadow: 0 0 1px rgba(255, 255, 255, 0.5);
}