"use strict"

function setup() {
  let highlighted
  document.addEventListener("click", (event) => {
    const card = event.target
    if (!card.classList.contains("card") || card.classList.contains("cat")) {
      return
    }
    if (card === highlighted) {
      highlighted = null
      card.classList.add("hidden")
      return
    }
    if (highlighted) {
      highlighted.classList.remove("highlight")
    }
    highlighted = card
    card.classList.add("highlight")
  })
}

setup()