Vanilla JS, CSS grids, Theme Switchers, calculator, class objects

Hi your job is great and there is some feedback 1-- Use semantic elements to avoid accessibility like "main" "header" and "footer" or you can use role attribute to describe the role of the screen readers check this https://dequeuniversity.com/rules/axe/4.3/region?application=axeAPI. 2-- Instead of putting the theme class to the HTML tag give it to the body tag it works too. 3-- If you want to use input for the toggle you should use label too, but I think the 'UL' tag with some of the CSS you will get the job done too 4-- If you could render the sum it will be very good so the user can see the whole sum he could mistake and want to delete rendering the whole sum will help him very will 5 -- The app didn't make the calculation when I click on the equal button if it's not correct so if you can handle this to show an error 'Syntax error' to the user when it happens it will be great.