What are the errors in the lines

Question

const mode = document.querySelector('.mode');
let dark = false;
mode.addEventListener('click',() => {
if(dark){
dark =false;
document.documentElement.
setAttribute('data-theme','dark');
mode.textcontent ='dark';
}
else{
dark = true;
document.documentElement.
setAttribute('data-theme','light');
mode.textcontent = 'light';
}
})

Answer 1

let not Let