Q: Uncaught TypeError: Cannot read property 'classList' of undefined at HTMLDocument.document.onclick document.onclick = function(event){    
    const target = event.target;
    if (target.tagName.toLowerCase() === 'img') {
        console.log('working');
        const section = event.target.parentElement;
        const content = section.nextElementSibiling;
        content.classList.add('content-display');
    }
}


A: Easily done, but unfortunately you've misspelled 'sibling'.
