.gallery {
    display: flex;
    flex-wrap: wrap;
}

.thumbnail {
    width: 100px;
    height: 100px;
    object-fit: cover;
    margin: 5px;
    cursor: pointer;
}

#overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.9);
    z-index: 9999;
}

#closeBtn {
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 30px;
    color: #fff;
    cursor: pointer;
}

#prevBtn,
#nextBtn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    font-size: 30px;
    color: #fff;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.3s;
}

#prevBtn {
    left: 20px;
}

#nextBtn {
    right: 20px;
}

#expandedImg {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    max-width: 80%;
    max-height: 80%;
    opacity: 0;
    transition: opacity 0.3s;
}

.show {
    opacity: 1;
}

.show-buttons {
    opacity: 1;
}

.thumbnail-expanded {
    width: 200px;
    height: 200px;
}