/* Lightbox Overlay */
#grundriss-lightbox {
    display: none;
    position: fixed;
    z-index: 9999;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(0, 0, 0, 0.85);
    justify-content: center;
    align-items: center;
    cursor: zoom-out;
}
#grundriss-lightbox.active {
    display: flex;
}
#grundriss-lightbox img {
    max-width: 90vw;
    max-height: 90vh;
    border-radius: 4px;
    box-shadow: 0 8px 40px rgba(0,0,0,0.6);
    cursor: default;
    animation: grundriss-zoomin 0.2s ease;
}
@keyframes grundriss-zoomin {
    from { transform: scale(0.92); opacity: 0; }
    to   { transform: scale(1);    opacity: 1; }
}
#grundriss-lightbox-close {
    position: fixed;
    top: 20px; right: 28px;
    font-size: 36px;
    color: #fff;
    cursor: pointer;
    line-height: 1;
    font-family: sans-serif;
    font-weight: 300;
    opacity: 0.85;
    transition: opacity 0.15s;
    user-select: none;
}
#grundriss-lightbox-close:hover {
    opacity: 1;
}
.grundriss-thumb {
    cursor: zoom-in;
    transition: opacity 0.15s;
}
.grundriss-thumb:hover {
    opacity: 0.85;
}