JSFiddle - React, Tailwind, and code Playground

by HDL52

HTML

<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Montserrat:400,700">

<section>
  <div id="parallax" class="parallax-item">
    <h2>
      Div 1
    </h2>
  </div>
  <div class="parallax-item">
    <h2>
      Div 2
    </h2>
  </div>
  <div class="parallax-item">
    <h2>
      Div 3
    </h2>
  </div>
  <div class="parallax-item">
    <h2>
      Div 4
    </h2>
  </div>
</section>

CSS

* {
  padding: 0;
  margin: 0;
}

html {
  scroll-behavior: smooth;
}

.parallax-item {
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-family: Montserrat, sans-serif;
  width: 100%;
  min-height: 100vh;
}

.parallax-item h2 {
  font-size: 3rem;
  text-transform: uppercase;
  background-color: whitesmoke;
  padding: 1rem 1.5rem 1rem 1.5rem;
  font-weight: bold;
}

.parallax-item:first-child {
  background: url("https://raw.githubusercontent.com/Hongda-OSU/PicGo-2.3.1/master/img%E5%85%8B%E9%B2%81%E8%B5%9B%E5%BE%B7%E6%88%98%E8%AE%B03.jpg");
  background-size: cover;
}

.parallax-item:nth-child(2) {
  background: #000000;
}

.parallax-item:nth-child(3) {
  background: url("https://raw.githubusercontent.com/Hongda-OSU/PicGo-2.3.1/master/img1l99wbel5ip2y1oivo40zrh051humxd.png");
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
}

.parallax-item:nth-child(4) {
  background: #00f8f8;
}

@media screen and (max-width: 768px) {
  .parallax-item h2 {
    font-size: 1.5rem;
  }
}

JavaScript

const parallax = document.getElementById("parallax");

window.addEventListener("scroll", () => {
  const offset = window.pageYOffset;
  parallax.style.backgroundPositionY = offset * 0.7 + "px";
});