Webleb - fragmentos de código - Galería de controles deslizantes de League of Legends

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Andev Web</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
        
    <header>
        <div class="logo">Andev.Web</div>
        <ul class="menu">
            <li>Home</li>
            <li>Blog</li>
            <li>Info</li>
        </ul>
        <div class="search">
            <svg aria-hidden="true" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 20 20">
                <path stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="m19 19-4-4m0-7A7 7 0 1 1 1 8a7 7 0 0 1 14 0Z"/>
            </svg>
        </div>
    </header>

<div class="slider">
        
        <div class="list">
            <div class="item active">
                <img src="https://ddragon.leagueoflegends.com/cdn/img/champion/splash/Ashe_0.jpg">
                <div class="content">
                    <p>The Frost Archer</p>
                    <h2>Ashe</h2>

</div>
            </div>
            <div class="item">
                <img src="https://ddragon.leagueoflegends.com/cdn/img/champion/splash/Ahri_0.jpg">
                <div class="content">
                    <p>The Nine-Tailed Fox</p>
                    <h2>Ahri</h2>

</div>
            </div>
            <div class="item">
                <img src="https://ddragon.leagueoflegends.com/cdn/img/champion/splash/Garen_0.jpg">
                <div class="content">
                    <p>The Might of Demacia</p>
                    <h2>Garen</h2>

</div>
            </div>
            <div class="item">
                <img src="https://ddragon.leagueoflegends.com/cdn/img/champion/splash/Janna_0.jpg">
                <div class="content">
                    <p>The Storm's Fury</p>
                    <h2>Janna</h2>

</div>
            </div>
            <div class="item">
                <img src="https://ddragon.leagueoflegends.com/cdn/img/champion/splash/Katarina_0.jpg">
                <div class="content">
                    <p>The Sinister Blade</p>
                    <h2>Katarina</h2>

</div>
            </div>
        </div>
        
        <div class="arrows">
            <button id="prev"><</button>
            <button id="next">></button>
        </div>
        
        <div class="thumbnail">
            <div class="item active">
                <img src="https://ddragon.leagueoflegends.com/cdn/img/champion/splash/Ashe_0.jpg">
                <div class="content">
                    Ashe
                </div>
            </div>
            <div class="item">
                <img src="https://ddragon.leagueoflegends.com/cdn/img/champion/splash/Ahri_0.jpg">
                <div class="content">
                    Ahri
                </div>
            </div>
            <div class="item">
                <img src="https://ddragon.leagueoflegends.com/cdn/img/champion/splash/Garen_0.jpg">
                <div class="content">
                    Garen
                </div>
            </div>
            <div class="item">
                <img src="https://ddragon.leagueoflegends.com/cdn/img/champion/splash/Janna_0.jpg">
                <div class="content">
                    Janna
                </div>
            </div>
            <div class="item">
                <img src="https://ddragon.leagueoflegends.com/cdn/img/champion/splash/Katarina_0.jpg">
                <div class="content">
                    Katarina
                </div>
            </div>
        </div>
    </div>

@import url('https://fonts.googleapis.com/css2?family=Poppins:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&display=swap');
body{
    font-family: Poppins;
    margin: 0;
    background-color: #010101;
    color: #eee;
}
svg{
    width: 25px;
}
header{
    width: 1200px;
    max-width: 90%;
    margin: auto;
    display: grid;
    grid-template-columns: 50px 1fr 50px;
    grid-template-rows: 50px;
    justify-content: center;
    align-items: center;
    position: relative;
    z-index: 100;
}
header .logo{
    font-weight: bold;
}
header .menu{
    padding: 0;
    margin: 0;
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 20px;
    font-weight: 500;
}
/* css slider */
.slider{
    height: 100vh;
    margin-top: -50px;
    position: relative;
}
.slider .list .item{
    position: absolute;
    inset: 0 0 0 0;
    overflow: hidden;
    opacity: 0;
    transition: .5s;
}
.slider .list .item img{
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.slider .list .item::after{
    content: '';
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    bottom: 0;
    background-image: linear-gradient(
        to top, #000 40%, transparent
    );
}
.slider .list .item .content{
    position: absolute;
    left: 10%;
    top: 20%;
    width: 500px;
    max-width: 80%;
    z-index: 1;
}
.slider .list .item .content p:nth-child(1){
    text-transform: uppercase;
    letter-spacing: 10px;
}
.slider .list .item .content h2{
    font-size: 100px;
    margin: 0;
}
.slider .list .item.active{
    opacity: 1;
    z-index: 10;
}
@keyframes showContent {
    to{
        transform: translateY(0);
        filter: blur(0);
        opacity: 1;
    }
}
.slider .list .item.active p:nth-child(1),
.slider .list .item.active h2,
.slider .list .item.active p:nth-child(3){
    transform: translateY(30px);
    filter: blur(20px);
    opacity: 0;
    animation: showContent .5s .7s ease-in-out 1 forwards;
}
.slider .list .item.active h2{
    animation-delay: 1s;
}
.slider .list .item.active p:nth-child(3){
    animation-duration: 1.3s;
}
.arrows{
    position: absolute;
    top: 30%;
    right: 50px;
    z-index: 100;
}
.arrows button{
    background-color: #eee5;
    border: none;
    font-family: monospace;
    width: 40px;
    height: 40px;
    border-radius: 5px;
    font-size: x-large;
    color: #eee;
    transition: .5s;
}
.arrows button:hover{
    background-color: #eee;
    color: black;
}
.thumbnail{
    position: absolute;
    bottom: 50px;
    z-index: 11;
    display: flex;
    gap: 10px;
    width: 100%;
    height: 250px;
    padding: 0 50px;
    box-sizing: border-box;
    overflow: auto;
    justify-content: center;
}
.thumbnail::-webkit-scrollbar{
    width: 0;
}
.thumbnail .item{
    width: 150px;
    height: 220px;
    filter: brightness(.5);
    transition: .5s;
    flex-shrink: 0;
}
.thumbnail .item img{
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 10px;
}
.thumbnail .item.active{
    filter: brightness(1.5);
}
.thumbnail .item .content{
    position: absolute;
    inset: auto 10px 10px 10px;
}
@media screen and (max-width: 678px) {
    .thumbnail{
        justify-content: start;
    }
    .slider .list .item .content h2{
        font-size: 60px;
    }
    .arrows{
        top: 10%;
    }
}

let items = document.querySelectorAll('.slider .list .item');
let next = document.getElementById('next');
let prev = document.getElementById('prev');
let thumbnails = document.querySelectorAll('.thumbnail .item');

// config param
let countItem = items.length;
let itemActive = 0;
// event next click
next.onclick = function(){
    itemActive = itemActive + 1;
    if(itemActive >= countItem){
        itemActive = 0;
    }
    showSlider();
}
//event prev click
prev.onclick = function(){
    itemActive = itemActive - 1;
    if(itemActive < 0){
        itemActive = countItem - 1;
    }
    showSlider();
}
// auto run slider
let refreshInterval = setInterval(() => {
    next.click();
}, 5000)
function showSlider(){
    // remove item active old
    let itemActiveOld = document.querySelector('.slider .list .item.active');
    let thumbnailActiveOld = document.querySelector('.thumbnail .item.active');
    itemActiveOld.classList.remove('active');
    thumbnailActiveOld.classList.remove('active');

// active new item
    items[itemActive].classList.add('active');
    thumbnails[itemActive].classList.add('active');

// clear auto time run slider
    clearInterval(refreshInterval);
    refreshInterval = setInterval(() => {
        next.click();
    }, 5000)
}

// click thumbnail
thumbnails.forEach((thumbnail, index) => {
    thumbnail.addEventListener('click', () => {
        itemActive = index;
        showSlider();
    })
})

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HTML

CSS

// active new item
    items[itemActive].classList.add('active');
    thumbnails[itemActive].classList.add('active');

// clear auto time run slider
    clearInterval(refreshInterval);
    refreshInterval = setInterval(() => {
        next.click();
    }, 5000)
}

// click thumbnail
thumbnails.forEach((thumbnail, index) => {
    thumbnail.addEventListener('click', () => {
        itemActive = index;
        showSlider();
    })
})