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                <button data-type="randomize">Go</button>

<div class="card | card--unselected" data-card-id="1">
    <h3>Selection 1</h3>

<div class="card | card--unselected" data-card-id="2">
    <h3>Selection 2</h3>

<div class="card | card--unselected" data-card-id="3000">
    <h3>Selection 3000</h3>

<div class="card | card--unselected" data-card-id="50">
    <h3>Selection 50</h3>


                .card {
  background-color: blue;

.card--unselected {
  background-color: red;


                // highlight different 'cards' randomly upon clicking the 'go' button
// never displays the same card twice in a row (well, unless when resetting)
// once all cards have been displayed once, then it resets to display them again in another random order

const random = () => {
    const button = document.querySelector('button[data-type="randomize"]')
    const cards = document.querySelectorAll('.card')

    // array that contains our card IDs
    const cardsCollection = Array.from(cards, (card) => card.getAttribute('data-card-id'));

    // array that keeps track of cards that have already been selected
    const cardsSelected = []

    button.addEventListener('click', () => {
        // generate a random number (randomNumber) that is less than the amount of items in the cardsCollection array
        // check if the random number exists as an index in the cardsSelected array
        // if it does, then run again
        // if it does not, then push that random number into the cardsSelected array
        let randomSelection;
        do {
            const randomNumber = Math.floor(Math.random() * cardsCollection.length)
            randomSelection = cardsCollection[randomNumber]
        } while (cardsSelected.includes(randomSelection))

        // if the cardsSelected array contains all of the possible random numbers
        // then reset it to 0 so that it can start over
        if (cardsSelected.length >= cardsCollection.length) {
            cardsSelected.length = 0

        cards.forEach((card) => {
            // hide all cards by adding the appropriate CSS class

            // display the randomly selected card by adding the appropriate CSS class
            if (card.dataset.cardId === randomSelection) {