将nextImage和prevImage按钮添加到纯HTML和CSS幻灯片中

Question

我用纯HTML和CSS实现了包含五个图像的幻灯片显示。我尽量避免使用JavaScript。幻灯片效果很好，但是现在我想添加按钮以转到下一张幻灯片并返回到上一张。但是，它没有用。我该如何实现？

这是重要的代码段。我认为一种解决方案是使用单选按钮，但我无法使其正常工作。

  .slider {
    width: 100%;
    max-width: 100%;
    height: 300px;
    margin: auto;
    position: relative;
  }

  .sliderbox {
    width: 100%;
    overflow: hidden;
    position: absolute;
  }

  .slider ul {
    width: 500%;
    margin: 0;
    padding: 0;
    -webkit-animation: slide 40s infinite alternate;
    -moz-animation: slide 40s infinite alternate;
    animation: slide 40s infinite alternate;
  }

  .slider ul:hover {
    -webkit-animation-play-state: paused;
    -moz-animation-play-state: paused;
    animation-play-state: paused;
  }

  .slider li {
    float: left;
    width: 20%;
    height: 300px;
    list-style-type: none;
    position: relative;
  }

  .slider img {
    position: absolute;
    left: 50%;
    top: 50%;
    -webkit-transform: translateY(-50%) translateX(-50%);
    max-width: 100%;
  }

  .slider li .slider-caption {
    position: absolute;
    bottom: 0;
    text-align: center;
    left: 0;
    background-color: rgba(255, 255, 255, 0.8);
    padding: 2%;
    width: 96%;
  }

  .slider li .slider-text {
    padding: 5%;
    background-color: #f5f5f5;
  }

  .slider li .slider-text ul {
    width: 100%;
    animation: none;
    -webkit-animation: none;
    -moz-animation: none;
    padding: 0 20px;
  }

  .slider li .slider-text ul li {
    list-style-type: inherit;
    list-style-position: outside;
    padding-left: 25px;
    float: none;
    height: auto;
  }

  @keyframes slide {
    0% {
      margin-left: 0%;
    }
    21% {
      margin-left: 0%;
    }
    23% {
      margin-left: -100%;
    }
    43% {
      margin-left: -100%;
    }
    45% {
      margin-left: -200%;
    }
    65% {
      margin-left: -200%;
    }
    67% {
      margin-left: -300%;
    }
    87% {
      margin-left: -300%;
    }
    89% {
      margin-left: -400%;
    }
    100% {
      margin-left: -400%;
    }
  }

  @-webkit-keyframes slide {
    0% {
      margin-left: 0%;
    }
    21% {
      margin-left: 0%;
    }
    23% {
      margin-left: -100%;
    }
    43% {
      margin-left: -100%;
    }
    45% {
      margin-left: -200%;
    }
    65% {
      margin-left: -200%;
    }
    67% {
      margin-left: -300%;
    }
    87% {
      margin-left: -300%;
    }
    89% {
      margin-left: -400%;
    }
    100% {
      margin-left: -400%;
    }
  }

  @-moz-keyframes slide {
    0% {
      margin-left: 0%;
    }
    21% {
      margin-left: 0%;
    }
    23% {
      margin-left: -100%;
    }
    43% {
      margin-left: -100%;
    }
    45% {
      margin-left: -200%;
    }
    65% {
      margin-left: -200%;
    }
    67% {
      margin-left: -300%;
    }
    87% {
      margin-left: -300%;
    }
    89% {
      margin-left: -400%;
    }
    100% {
      margin-left: -400%;
    }
  }

  table a {
    display: block;
  }

<div class="slider">
<div class="sliderbox">
    <ul>
        <li>
            <img src="https://via.placeholder.com/250C/O%20https://placeholder.com/" alt="" />
        </li>
        <li>
            <img src="https://via.placeholder.com/250C/O%20https://placeholder.com/" alt="" />
        </li>
        <li>
            <img src="https://via.placeholder.com/250C/O%20https://placeholder.com/" alt="" />
        </li>
        <li>
            <img src="https://via.placeholder.com/250C/O%20https://placeholder.com/" alt="" />
        </li>
        <li>
            <img src="https://via.placeholder.com/250C/O%20https://placeholder.com/" alt="" />
        </li>
    </ul>
</div>
</div>