body {
      margin: 0;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
      color: black;
      height: 3000px;
    }

    .slider {
      position: relative;
      overflow: hidden;
    }

    .slider__wrapper {
      display: flex;
      transition: transform 0.6s ease;
    }

    .slider__item {
      flex: 0 0 30%;
      max-width: 50%;
    }
    
    @media (max-width: 768px) {.slider__item {
      flex: 0 0 100%;
      max-width: 100%;
    }
  }
     

    .slider__control {
      position: absolute;
      top: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      width: 40px;
      color: #fff;
      text-align: center;
      opacity: 0.5;
      height: 50px;
      transform: translateY(-50%);
      background: rgba(0, 0, 0, .5);
    }

    .slider__control:hover,
    .slider__control:focus {
      color: #fff;
      text-decoration: none;
      outline: 0;
      opacity: .9;
    }

    .slider__control_left {
      left: 0;
    }

    .slider__control_right {
      right: 0;
    }

    .slider__control::before {
      content: '';
      display: inline-block;
      width: 40px;
      height: 40px;
      background: transparent no-repeat center center;
      background-size:  100%;
    }

    .slider__control_left::before {
      background-image: url('http://oc4.ansid.by/image/catalog/demo/banners/left_arrow_circle_icon_124213.png');
      background-color:white; 
      width: 40px;
  height: 50px;
  
    }

    .slider__control_right::before {
      background-image: url('http://oc4.ansid.by/image/catalog/demo/banners/1904671-arrow-arrow-right-change-direction-next-page-right_122521.png');
      background-color:white; 
       width: 40px;
  height: 50px;
   
    }

    .slider__item>div {
      line-height: 250px;
      font-size: 100px;
      text-align: center;
    }