Constant GET_CLIP_RECT_JS 

pub const GET_CLIP_RECT_JS: &str = r#"
(function(selector) {
    const el = document.querySelector(selector);
    if (!el) return null;
    el.scrollIntoView({ block: 'center', inline: 'center' });
    const r = el.getBoundingClientRect();
    if (r.width === 0 || r.height === 0) return null;
    return {
        x: r.left + window.scrollX,
        y: r.top + window.scrollY,
        width: r.width,
        height: r.height,
    };
})
"#;

Resolves a selector to a clip rectangle in document coordinates, scrolling the element into view first. Returns null when the selector matches nothing or the element has zero area (hidden / detached).