<div class="box">
  <div class="slider">
    <div class="slide"><span>slide 1</span></div>
    <div class="slide"><span>slide 2</span></div>
    <div class="slide"><span>slide 3</span></div>
    <div class="slide"><span>slide 4</span></div>
    <div class="slide"><span>slide 5</span></div>
    <div class="slide"><span>slide 6</span></div>
  </div
</div>

body {
  background-color: #ccc;
  margin: 0;
  padding: 0;
}

.box {
  position: relative;
  max-width: 80%;
  margin: 0 auto;
}

.slider {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  z-index: 10;
}


.slide {
  text-align: center;
  box-sizing: border-box;
  height: 40vh;
  background-color: yellow;
  border: 1px solid #000;
  cursor: pointer;
  display: flex !important;
  align-items: flex-end;
  justify-content: center;
  padding-bottom: 20px;
  font-size: 30px;
  min-height: 300px;
  transition: .5s all;
  transform: scale(.5);
}

.slick-now .slide {
  background-color: rgb(70, 174, 125);
  transform: scale(1);
}

$('.slider').slick({
  slidesToShow: 2,
  slidesToScroll: 1,
  dots: true,
  focusOnSelect: true
});

// On before slide change
$('.slider').on('beforeChange', function(event, { slideCount: count }, currentSlide, nextSlide){
  let selectors = [nextSlide, nextSlide - count, nextSlide + count].map(n => `[data-slick-index="${n}"]`).join(', ');
  $('.slick-now').removeClass('slick-now');
  $(selectors).addClass('slick-now');
});

$('[data-slick-index="0"]').addClass('slick-now');