Table column highlighting?

Question

css

Tell me, you need highlighting not the rows in the table, but the columns.
If you hover over cell number 2, all cells with number 2 should be highlighted, even the header. There can be 30 such columns in the table. https://codepen.io/brezze/pen/ZxBYxN

Answer 1

main idea -
https://codepen.io/coderisimo/pen/RMoNeL