from your site took
html
<div class="portfolio-slider"> <div class="slide-button slide-prev"></div> <div class="slide-content"> <div class="-slide slide-active"></div> <div class="-slide"></div> <div class="-slide"></div> </div> <div class="slide-button slide-next"></div> </div>
css
.portfolio-slider {display: grid; grid-template-columns: 50px 1fr 50px; grid-gap: 5px;} .portfolio-slider .slide-button, .portfolio-slider .slide-content {display: block; width: 100%; min-height: 500px;} .portfolio-slider .slide-button {background-repeat: no-repeat; background-size: calc(100% - 10px) auto; background-position: center center; border-radius: 5px; cursor: pointer;} .portfolio-slider .slide-button:hover {background-color: rgba(255,255,255,.15);} .portfolio-slider .slide-button.slide-prev {background-image: url('/core/img/slider/slide-button-prev.png');} .portfolio-slider .slide-button.slide-next {background-image: url('/core/img/slider/slide-button-next.png');} .portfolio-slider .slide-content {position: relative; overflow: hidden;} .portfolio-slider .-slide {display: none; width: 100%; height: 100%; background: #fff;} .portfolio-slider .-slide.slide-active {display: block;}
jq
$('.portfolio-slider .slide-button').on('click',function(){ var buttonPrev = $(this).hasClass('slide-prev'), buttonNext = $(this).hasClass('slide-next'); var slideBlock = $('.portfolio-slider .-slide'), slideActive = $('.portfolio-slider .-slide.slide-active'); var slideLen = slideBlock.length, slideActiveIndex = slideActive.index(); slideBlock.removeClass('slide-active'); if(buttonPrev) { var slidePrev = (slideActiveIndex-1); slideBlock.eq(slidePrev).addClass('slide-active'); console.info('slide: '+slidePrev+'/'+slideLen); } if(buttonNext) { var slideNext = (slideActiveIndex+1); if(slideNext==slideLen) var slideNext = 0; slideBlock.eq(slideNext).addClass('slide-active'); console.info('slide: '+slideNext+'/'+slideLen); } });