instructions

gistfile1.html

<style>
.slider {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
}
.slider__slides {
  position: relative;
  width: 400%;
  height: 100%;
  -webkit-transition: -webkit-transform 0.3s cubic-bezier(0.51, 0.92, 0.24, 1);
  transition: -webkit-transform 0.3s cubic-bezier(0.51, 0.92, 0.24, 1);
  transition: transform 0.3s cubic-bezier(0.51, 0.92, 0.24, 1);
  transition: transform 0.3s cubic-bezier(0.51, 0.92, 0.24, 1), -webkit-transform 0.3s cubic-bezier(0.51, 0.92, 0.24, 1);
  will-change: transform;
}
.slider[data-pos="0"] .slider__slides {
  -webkit-transform: translateX(0%);
          transform: translateX(0%);
}
.slider[data-pos="1"] .slider__slides {
  -webkit-transform: translateX(-25%);
          transform: translateX(-25%);
}
.slider[data-pos="2"] .slider__slides {
  -webkit-transform: translateX(-50%);
          transform: translateX(-50%);
}
.slider[data-pos="3"] .slider__slides {
  -webkit-transform: translateX(-75%);
          transform: translateX(-75%);
}
.slider__slide {
  float: left;
  width: 25%;
  height: 100%;
}
.slider__dots {
  display: -webkit-box;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  position: absolute;
  bottom: 1.5em;
  left: 50%;
  -webkit-transform: translateX(-50%);
          transform: translateX(-50%);
}
.slider__dot, .slider__indicator {
  display: block;
  margin: 0 0.5em;
  width: 1em;
  height: 1em;
  background: rgba(255, 255, 255, 0.5);
  border-radius: 100px;
}
.slider__indicator {
  position: absolute;
  background: white;
  width: auto;
}
.slider__indicator--left {
  -webkit-transition: left 0.3s cubic-bezier(0.51, 0.92, 0.24, 1.15), right 0.3s 0.1s cubic-bezier(0.51, 0.92, 0.24, 1.15);
  transition: left 0.3s cubic-bezier(0.51, 0.92, 0.24, 1.15), right 0.3s 0.1s cubic-bezier(0.51, 0.92, 0.24, 1.15);
}
.slider__indicator--right {
  -webkit-transition: left 0.3s 0.1s cubic-bezier(0.51, 0.92, 0.24, 1.15), right 0.3s cubic-bezier(0.51, 0.92, 0.24, 1.15);
  transition: left 0.3s 0.1s cubic-bezier(0.51, 0.92, 0.24, 1.15), right 0.3s cubic-bezier(0.51, 0.92, 0.24, 1.15);
}
.slider[data-pos="0"] .slider__indicator {
  left: 0em;
  right: 6em;
}
.slider[data-pos="1"] .slider__indicator {
  left: 2em;
  right: 4em;
}
.slider[data-pos="2"] .slider__indicator {
  left: 4em;
  right: 2em;
}
.slider[data-pos="3"] .slider__indicator {
  left: 6em;
  right: 0em;
}

.center {
  display: -webkit-box;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  height: 100vh;
  -webkit-box-pack: center;
  -webkit-justify-content: center;
      -ms-flex-pack: center;
          justify-content: center;
  -webkit-box-align: center;
  -webkit-align-items: center;
      -ms-flex-align: center;
          align-items: center;
  background: #333;
}

.slider {
  max-width: 600px;
  max-height: 400px;
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.8);
}
.slider__slide:nth-child(1) {
  background: #309954;
}
.slider__slide:nth-child(2) {
  background: #FFBD3C;
}
.slider__slide:nth-child(3) {
  background: #F8593E;
}
.slider__slide:nth-child(4) {
  background: #4086FA;
}
</style>
<div class="center">
	
	<div class="slider" data-pos="0">
		<div class="slider__slides">
			<div class="slider__slide"></div>
			<div class="slider__slide"></div>
			<div class="slider__slide"></div>
			<div class="slider__slide"></div>
		</div>
		<div class="slider__dots">
			<a href="#" class="slider__indicator"></a>
			<a href="#" class="slider__dot" data-pos="0"></a>
			<a href="#" class="slider__dot" data-pos="1"></a>
			<a href="#" class="slider__dot" data-pos="2"></a>
			<a href="#" class="slider__dot" data-pos="3"></a>
		</div>
	</div>
	
</div>
<script>
'use strict';
var dots = 4;
var sliderElem = document.querySelector('.slider');
var dotElems = sliderElem.querySelectorAll('.slider__dot');
var indicatorElem = sliderElem.querySelector('.slider__indicator');
Array.prototype.forEach.call(dotElems, function (dotElem) {
    dotElem.addEventListener('click', function (e) {
        var currentPos = parseInt(sliderElem.getAttribute('data-pos'));
        var newPos = parseInt(dotElem.getAttribute('data-pos'));
        var newDirection = newPos > currentPos ? 'right' : 'left';
        var currentDirection = newPos < currentPos ? 'right' : 'left';
        indicatorElem.classList.remove('slider__indicator--' + currentDirection);
        indicatorElem.classList.add('slider__indicator--' + newDirection);
        sliderElem.setAttribute('data-pos', newPos);
    });
});
</script>