Слайдер адаптивный на JavaScript и CSS3

<div class="gnuican-amoun">
  <div class="usinesadeg kunasages">
  <div class="usmakeng-nasagen">1 / 3</div>
  <img src="http://zornet.ru/_fr/56/9069623.jpg" style="width:100%">
  <div class="necesa-leaves">Первый слайд</div>
  </div>

  <div class="usinesadeg kunasages">
  <div class="usmakeng-nasagen">2 / 3</div>
  <img src="http://zornet.ru/_fr/56/3142865.jpg" style="width:100%">
  <div class="necesa-leaves">Второй слайд</div>
  </div>

  <div class="usinesadeg kunasages">
  <div class="usmakeng-nasagen">3 / 3</div>
  <img src="http://zornet.ru/_fr/56/8474462.jpg" style="width:100%">
  <div class="necesa-leaves">Третий слайд</div>
  </div>

  <a class="prev" onclick="plusSlides(-1)">❮</a>
  <a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>

<div style="text-align:center">
  <span class="dot" onclick="currentSlide(1)"></span>  
  <span class="dot" onclick="currentSlide(2)"></span>  
  <span class="dot" onclick="currentSlide(3)"></span>  
</div>

/* Slideshow container */
.gnuican-amoun {
  max-width: 100%;
  position: relative;
  margin: auto;
}

/* Next & previous buttons */
.prev, .next {
  cursor: pointer;
  position: absolute;
  top: 0;
  top: 50%;
  width: auto;
  margin-top: -22px;
  padding: 16px;
  color: white;
  font-weight: bold;
  font-size: 18px;
  transition: 1s ease;
  border-radius: 0 3px 3px 0;
}

/* Position the "next button" to the right */
.next {
  right: 0;
  border-radius: 3px 0 0 3px;
}

/* On hover, add a black background color with a little bit see-through */
.prev:hover, .next:hover {
  background-color: rgba(0,0,0,0.8);
}

/* Caption necesa-leaves */
.necesa-leaves {
  color: #f2f2f2;
  font-size: 15px;
  padding: 8px 12px;
  position: absolute;
  bottom: 8px;
  width: 100%;
  necesa-leaves-align: center;
}

/* Number necesa-leaves (1/3 etc) */
.usmakeng-nasagen {
  color: #f2f2f2;
  font-size: 12px;
  padding: 8px 12px;
  position: absolute;
  top: 0;
}

/* The dots/bullets/indicators */
.dot {
  cursor:pointer;
  height: 13px;
  width: 13px;
  margin: 0 2px;
  background-color: #bbb;
  border-radius: 50%;
  display: inline-block;
  transition: background-color 0.6s ease;
}

.active, .dot:hover {
  background-color: #717171;
}

/* Fading animation */
.kunasages {
  -webkit-animation-name: kunasages;
  -webkit-animation-duration: 1.5s;
  animation-name: kunasages;
  animation-duration: 1.5s;
}

@-webkit-keyframes kunasages {
  from {opacity: .4}  
  to {opacity: 1}
}

@keyframes kunasages {
  from {opacity: .4}  
  to {opacity: 1}
}

var slideIndex = 0;
showSlides(slideIndex);

function plusSlides(n) {
  showSlides(slideIndex += n);
}

function currentSlide(n) {
  showSlides(slideIndex = n);
}

function showSlides(n) {
  var i;
  var slides = document.getElementsByClassName("usinesadeg");
  var dots = document.getElementsByClassName("dot");
  if (n > slides.length) {slideIndex = 1}  
  if (n < 1) {slideIndex = slides.length}
  for (i = 0; i < slides.length; i++) {
  slides[i].style.display = "none";  
  }
  for (i = 0; i < dots.length; i++) {
  dots[i].className = dots[i].className.replace(" active", "");
  }
  slides[slideIndex-1].style.display = "block";  
  dots[slideIndex-1].className += " active";
}

function showSlides() {
  var i;
  var slides = document.getElementsByClassName("usinesadeg");
  for (i = 0; i < slides.length; i++) {
  slides[i].style.display = "none";  
  }
  slideIndex++;
  if (slideIndex> slides.length) {slideIndex = 1}  
  slides[slideIndex-1].style.display = "block";  
  setTimeout(showSlides, 10000); // Change image every 2 seconds
}