<!-- popup -->
    <div class="popup">
        <!-- top bar -->
        <div class="top-bar">
            <p class="image-name">img1.png</p>
            <span class="close-btn"></span>
        </div>
        <!-- arrows -->
        <button class="arrow-btn left-arrow"><img src="https://github.com/kunaal438/image-popup/blob/master/img/arrow.png?raw=true" alt=""></button>
        <button class="arrow-btn right-arrow"><img src="https://github.com/kunaal438/image-popup/blob/master/img/arrow.png?raw=true" alt=""></button>
        <!-- image -->
        <img src="img/img1.png" class="large-image" alt="">
        <!-- image-index -->
        <h1 class="index">01</h1>
    </div>

    <div class="gallery">
        <div class="gallery-image">
            <img src="https://github.com/kunaal438/image-popup/blob/master/img/img1.png?raw=true" alt="" class="image">
        </div>
        <div class="gallery-image">
            <img src="https://github.com/kunaal438/image-popup/blob/master/img/img2.png?raw=true" alt="" class="image">
        </div>
        <div class="gallery-image">
            <img src="https://github.com/kunaal438/image-popup/blob/master/img/img3.png?raw=true" alt="" class="image">
        </div>
        <div class="gallery-image">
            <img src="https://github.com/kunaal438/image-popup/blob/master/img/img4.png?raw=true" alt="" class="image">
        </div>
        <div class="gallery-image">
            <img src="https://github.com/kunaal438/image-popup/blob/master/img/img5.png?raw=true" alt="" class="image">
        </div>
        <div class="gallery-image">
            <img src="https://github.com/kunaal438/image-popup/blob/master/img/img6.png?raw=true" alt="" class="image">
        </div>
    </div>
*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

*:focus{
    outline: none;
}

body{
    width: 100%;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #ff7a2d;
    font-family: 'roboto', sans-serif;
}

.gallery{
    width: 80%;
    height: 90vh;
    max-width: 1600px;
    max-height: 800px;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
}

.gallery-image{
    width: 30%;
    height: calc(50% - 20px);
    min-width: 300px;
    min-height: 200px;
    margin: 10px;
    overflow: hidden;
}

.image{
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: 1s;
}

/* popup */

.popup{
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0);
    width: 80%;
    max-width: 1600px;
    height: 90vh;
    max-height: 800px;
    border-radius: 20px;
    background: rgba(0, 0, 0, 0.75);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 5;
    overflow: hidden;
    transition: 1s;
    opacity: 0;
}

.popup.active{
    transform: translate(-50%, -50%) scale(1);
    opacity: 1;
}

.popup.active .close-btn,
.popup.active .image-name,
.popup.active .index,
.popup.active .large-image,
.popup.active .arrow-btn{
    opacity: 1;
    transition: opacity .5s;
    transition-delay: 1s;
}

.top-bar{
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 50px;
    background: #000;
    color: #fff;
    text-align: center;
    line-height: 50px;
    font-weight: 300;
}

.image-name{
    opacity: 0;
}

.close-btn{
    opacity: 0;
    position: absolute;
    top: 15px;
    right: 20px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #f00;
    cursor: pointer;
}

.arrow-btn{
    opacity: 0;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    padding: 10px;
    border-radius: 50%;
    border: none;
    background: none;
    cursor: pointer;
}

.left-arrow{
    left: 10px;
}

.right-arrow{
    right: 10px;
    transform: translateY(-50%) rotate(180deg);
}

.arrow-btn:hover{
    background: rgba(0, 0, 0, 0.5);
}

.index{
    position: absolute;
    bottom: 10px;
    right: 10px;
    font-size: 80px;
    font-weight: 100;
    color: rgba(255, 255, 255, 0.4);
    opacity: 0;
}

.large-image{
    margin-top: 5%;
    width: 80%;
    height: 80%;
    object-fit: contain;
    opacity: 0;
}
const images = [...document.querySelectorAll('.image')];

// popup

const popup = document.querySelector('.popup');
const closeBtn = document.querySelector('.close-btn');
const imageName = document.querySelector('.image-name');
const largeImage = document.querySelector('.large-image');
const imageIndex = document.querySelector('.index');
const leftArrow = document.querySelector('.left-arrow');
const rightArrow = document.querySelector('.right-arrow');

let index = 0; // will track our current image;

images.forEach((item, i) => {
    item.addEventListener('click', () => {
        updateImage(i);
        popup.classList.toggle('active');
    })
})

const updateImage = (i) => {
    let path = `https://github.com/kunaal438/image-popup/blob/master/img/img${i+1}.png?raw=true`;
    largeImage.src = path;
    imageName.innerHTML = path;
    imageIndex.innerHTML = `0${i+1}`;
    index = i;
}

closeBtn.addEventListener('click', () => {
    popup.classList.toggle('active');
})

leftArrow.addEventListener('click', () => {
    if(index > 0){
        updateImage(index - 1);
    }
})

rightArrow.addEventListener('click', () => {
    if(index < images.length - 1){
        updateImage(index + 1);
    }
})

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.