Why is the slider height 1px?

Question

JavaScript

Wrote the gallery:
https://codepen.io/air_man6/full/aborjWV
When you click on the image, a modal window appears with a slider inside, but until you click on the arrow, the height of the slider is 1 pixel, what's wrong?

Answer 1

Add on click when showing modal $(".slider").slick("refresh");