.signature-lightbox {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.85);
    z-index: 9999;
    align-items: center;
    justify-content: center;
}

.signature-lightbox img {
    max-width: 90%;
    max-height: 90%;
    background: #fff;
    padding: 10px;
    border-radius: 4px;
}

.signature-lightbox .close {
    position: absolute;
    top: 20px;
    right: 30px;
    z-index: 10001;
    color: #fff;
    font-size: 40px;
    font-weight: bold;
    line-height: 1;
    cursor: pointer;
}