console 命令行工具 X clear

console

const body = document.body
const slides = document.querySelectorAll('.slide')
const leftBtn = document.getElementById('left')
const rightBtn = document.getElementById('right')


let activeSilde = 0;
rightBtn.addEventListener('click', () => {
  activeSilde++;
  if (activeSilde === slides.length) {
    activeSilde = 0;
  }
  setBgToBody();
  setActiveSlide();
})

leftBtn.addEventListener('click', () => {
  activeSilde--;
  if (activeSilde < 0) {
    activeSilde = slides.length - 1;
  }
  setBgToBody();
  setActiveSlide();
})


function setBgToBody() {
  body.style.backgroundImage = slides[activeSilde].style.backgroundImage;
}

function setActiveSlide() {
  slides.forEach(slide => slide.classList.remove('active'));
  slides[activeSilde].classList.add('active');
}

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link
      rel="stylesheet"
      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.14.0/css/all.min.css"
      integrity="sha512-1PKOgIY59xJ8Co8+NE6FZ+LOAZKjy+KY8iq0G4B3CyeY6wYHN3yt9PW0XpSriVlkMXe40PTKnXrLnZ9+fkDaog=="
      crossorigin="anonymous"
    />
    <link rel="stylesheet" href="style.css" />
    <title>Background Slider</title>
  </head>
  <body>
    <div class="slider-container">
      <div
        class="slide active"
        style="
          background-image: url('https://images.unsplash.com/photo-1549880338-65ddcdfd017b?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2100&q=80');
        "
      ></div>
      <div
        class="slide"
        style="
          background-image: url('https://images.unsplash.com/photo-1511593358241-7eea1f3c84e5?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=1934&q=80');
        "
      ></div>
      <div
        class="slide"
        style="
          background-image: url('https://images.unsplash.com/photo-1495467033336-2effd8753d51?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2100&q=80');
        "
      ></div>
      <div
        class="slide"
        style="
          background-image: url('https://images.unsplash.com/photo-1522735338363-cc7313be0ae0?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2689&q=80');
        "
      ></div>
      <div
        class="slide"
        style="
          background-image: url('https://images.unsplash.com/photo-1559087867-ce4c91325525?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2100&q=80');
        "
      ></div>
      <button class="arrow left-arrow" id="left">
        <i class="fas fa-arrow-left"></i>
      </button>

      <button class="arrow right-arrow" id="right">
        <i class="fas fa-arrow-right"></i>
      </button>
    </div>
    <script src="script.js"></script>
  </body>
</html>

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  display: grid;
  place-items: center;
  height: 100vh;
  background: center/cover;
  overflow: hidden;
  transition: 0.4s;
  position: relative;
  background-image: url("https://images.unsplash.com/photo-1549880338-65ddcdfd017b?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2100&q=80");
}

body::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(0, 0, 0, 0.7);
  z-index: -1;
}

.slider-container {
  width: 70vw;
  height: 70vh;
  box-shadow: 0 3px 6px rgba(0, 0, 0, 0.3);
  overflow: hidden;
  position: relative;
}

.slide {
  position: absolute;
  width: 100vw;
  height: 100vh;
  top: -15vh;
  left: -15vw;
  opacity: 0;
  background: center/cover;
    transition: 0.4s;

}

.slide.active {
  opacity: 1;
}

.arrow {
  position: fixed;
  background-color: transparent;
  border: 2px solid orange;
  padding: 20px;
  font-size: 30px;
  color: white;
  top: 50%;
  transform: translateY(-50%);
  cursor: pointer;
}

.left-arrow {
  left: calc(15vw - 70px);
}
.right-arrow {
  right: calc(15vw - 70px);
}