/* Popup overlay */
    .popup-overlay {
        display: none; /* Hidden by default */
        position: fixed;
        top: 0; left: 0;
        width: 100%; height: 100%;
        background: rgba(0, 0, 0, 0.8);
        z-index: 1000;
        justify-content: center;
        align-items: center;
    }

    /* Popup content */
    .popup-content {
        position: relative;
        max-width: 90%;
        max-height: 90%;
    }

    /* Popup image */
    .popup-content img {
        width: 100%;
        height: auto;
        border-radius: 5px;
    }

    /* Close button */
    .close-btn {
        position: absolute;
        top: 10px;
        right: 10px;
        background: #fff;
        border: none;
        font-size: 20px;
        font-weight: bold;
        cursor: pointer;
        border-radius: 50%;
        width: 35px;
        height: 35px;
        text-align: center;
        line-height: 35px;
    }
    .close-btn:hover {
        background: #ddd;
    }