hi, I have a problem with the theme.
I would like to have a button that has the modal effect.
So I limited myself to creating the html and css but I don't understand why it doesn't work, yet the same code I have used for other sites and it works perfectly.
as an attachment you can notice that if I click on the button the box does not appear while if I force it with the console and active the target pseudo-element works

sorry for the insistence but why should I use a plugin and not the simple html and css code that doesn't work? why it doesn't work is a very simple structure, it should be simple.
logically I use a plugin if the function to use is complex, but something so simple I don't understand why it doesn't work

the js is not present because it is not necessary.
it simply works with a target that turns the item on and off.
as reported in the code
https://codepen.io/viki0003/pen/dymaENj

and there is no way to understand what creates the conflict?