const title = document.querySelector('.error_title')
document.onmousemove = function(e) {
let x = e.pageX - window.innerWidth/2;
let y = e.pageY - window.innerHeight/2;
title.style.setProperty('--x', x + 'px')
title.style.setProperty('--y', y + 'px')
}
title.onmousemove = function(e) {
let x = e.pageX - window.innerWidth/2;
let y = e.pageY - window.innerHeight/2;
let rad = Math.atan2(y, x).toFixed(2);
let length = Math.round(Math.sqrt((Math.pow(x,2))+(Math.pow(y,2)))/10);
let x_shadow = Math.round(length * Math.cos(rad));
let y_shadow = Math.round(length * Math.sin(rad));
title.style.setProperty('--x-shadow', - x_shadow + 'px')
title.style.setProperty('--y-shadow', - y_shadow + 'px')
}