text: export default class Theme {
  	constructor() {
  		var sections = document.querySelectorAll('section');
  		var main = document.querySelector('main');
  
  		sections.forEach(section => {
  			var tp = section.offsetTop; // top position
  			var bg = section.dataset.backgroundcolor; // background color obtained from html
  
  			document.addEventListener('scroll', () => {
  				if (window.pageYOffset > tp) {
  					main.style.backgroundColor = bg;
  				}
  			});
  
  		});
  	};
  };