SOURCE

class Particle {

  constructor(svg, coordinates, friction) {
    this.svg = svg;
    this.steps = $(window).height() / 2;
    this.item = null;
    this.friction = friction;
    this.coordinates = coordinates;
    this.position = this.coordinates.y;
    this.dimensions = this.render();
    this.rotation = Math.random() > 0.5 ? "-" : "+";
    this.scale = 0.5 + Math.random();
    this.siner = 200 * Math.random();
  }

  destroy() {
    this.item.remove();
  }

  move() {
    this.position = this.position - this.friction;
    let top = this.position;
    let left = this.coordinates.x + Math.sin(this.position * Math.PI / this.steps) * this.siner;
    this.item.css({
      transform: "translateX(" + left + "px) translateY(" + top + "px) scale(" + this.scale + ") rotate(" + this.rotation + (this.position + this.dimensions.height) + "deg)" });


    if (this.position < -this.dimensions.height) {
      this.destroy();
      return false;
    } else {
      return true;
    }
  }

  render() {
    this.item = $(this.svg, {
      css: {
        transform: "translateX(" + this.coordinates.x + "px) translateY(" + this.coordinates.y + "px)" } });


    $("body").append(this.item);
    return {
      width: this.item.width(),
      height: this.item.height() };

  }}


const rhombus = '<svg viewBox="0 0 13 14"><path class="rhombus" d="M5.9,1.2L0.7,6.5C0.5,6.7,0.5,7,0.7,7.2l5.2,5.4c0.2,0.2,0.5,0.2,0.7,0l5.2-5.4 C12,7,12,6.7,11.8,6.5L6.6,1.2C6.4,0.9,6.1,0.9,5.9,1.2L5.9,1.2z M3.4,6.5L6,3.9c0.2-0.2,0.5-0.2,0.7,0l2.6,2.6 c0.2,0.2,0.2,0.5,0,0.7L6.6,9.9c-0.2,0.2-0.5,0.2-0.7,0L3.4,7.3C3.2,7.1,3.2,6.8,3.4,6.5L3.4,6.5z" /></svg>';

const pentahedron = '<svg viewBox="0 0 561.8 559.4"><path class="pentahedron" d="M383.4,559.4h-204l-2.6-0.2c-51.3-4.4-94-37-108.8-83l-0.2-0.6L6,276.7l-0.2-0.5c-14.5-50,3.1-102.7,43.7-131.4 L212.1,23C252.4-7.9,310.7-7.9,351,23l163.5,122.5l0.4,0.3c39,30.3,56,82.6,42.2,130.3l-0.3,1.1l-61.5,198 C480.4,525.6,435.5,559.4,383.4,559.4z M185.5,439.4h195.2l61.1-196.8c0-0.5-0.3-1.6-0.7-2.1L281.5,120.9L120.9,241.2 c0,0.3,0.1,0.7,0.2,1.2l60.8,195.8C182.5,438.5,183.7,439.1,185.5,439.4z M441,240.3L441,240.3L441,240.3z"/></svg>';
const x = '<svg viewBox="0 0 12 12"> <path class="x" d="M10.3,4.3H7.7V1.7C7.7,0.8,7,0,6,0S4.3,0.8,4.3,1.7v2.5H1.7C0.8,4.3,0,5,0,6s0.8,1.7,1.7,1.7h2.5v2.5 C4.3,11.2,5,12,6,12s1.7-0.8,1.7-1.7V7.7h2.5C11.2,7.7,12,7,12,6S11.2,4.3,10.3,4.3z"/></svg>';

const circle = '<svg x="0px" y="0px" viewBox="0 0 13 12"> <path class="circle" d="M6.5,0.1C3.4,0.1,0.8,2.8,0.8,6s2.6,5.9,5.7,5.9s5.7-2.7,5.7-5.9S9.7,0.1,6.5,0.1L6.5,0.1z M6.5,8.8 C5,8.8,3.8,7.6,3.8,6S5,3.2,6.5,3.2S9.2,4.4,9.2,6S8,8.8,6.5,8.8L6.5,8.8z"/> </svg>';

const point = '<svg viewBox="0 0 12 12"> <path class="point" d="M6,7.5L6,7.5C5.1,7.5,4.5,6.9,4.5,6v0c0-0.9,0.7-1.5,1.5-1.5h0c0.9,0,1.5,0.7,1.5,1.5v0C7.5,6.9,6.9,7.5,6,7.5z "/> </svg>';

function randomInt(min, max) {
  return Math.floor(Math.random() * (max - min + 1) + min);
}

const data = [point, rhombus, pentahedron, circle, x];

let isPaused = false;
window.onblur = function () {
  isPaused = true;
}.bind(this);
window.onfocus = function () {
  isPaused = false;
}.bind(this);

let particles = [];

setInterval(function () {
  if (!isPaused) {
    particles.push(
    new Particle(data[randomInt(0, data.length - 1)], {
      "x": Math.random() * $(window).width(),
      "y": $(window).height() },
    1 + Math.random() * 3));

  }
}, 200);

function update() {
  particles = particles.filter(function (p) {
    return p.move();
  });
  requestAnimationFrame(update.bind(this));
}
update();

<div class="background"></div>
<div class="title">
  <h3>PLASM.it - 2022</h3>
  <h1>Antigravity</h1>
  <h2>FLOW</h2>
</div>
  

@import url("https://fonts.googleapis.com/css?family=Montserrat:200,300,400,600");
.more-pens {
  position: fixed;
  left: 20px;
  bottom: 20px;
  z-index: 10;
  font-family: "Montserrat";
  font-size: 12px;
}

a.white-mode, a.white-mode:link, a.white-mode:visited, a.white-mode:active {
  font-family: "Montserrat";
  font-size: 12px;
  text-decoration: none;
  background: #212121;
  padding: 4px 8px;
  color: #f7f7f7;
}
a.white-mode:hover, a.white-mode:link:hover, a.white-mode:visited:hover, a.white-mode:active:hover {
  background: #edf3f8;
  color: #212121;
}

body {
  margin: 0;
  padding: 0;
  overflow: hidden;
}

.background {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background: #edf3f8;
  background: -moz-radial-gradient(center, ellipse cover, #edf3f8 1%, #dee3e8 100%);
  background: -webkit-radial-gradient(center, ellipse cover, #edf3f8 1%, #dee3e8 100%);
  background: radial-gradient(ellipse at center, #edf3f8 1%, #dee3e8 100%);
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr="#edf3f8", endColorstr="#dee3e8",GradientType=1 );
}

.title {
  z-index: 10;
  position: absolute;
  left: 50%;
  top: 40%;
  transform: translateX(-50%) translateY(-50%);
  font-family: "Montserrat";
  text-align: center;
  width: 60%;
}
.title h1 {
  position: relative;
  color: #000000;
  font-weight: 300;
  font-size: 46px;
  padding: 0;
  margin: 0;
  line-height: 1;
}
.title h2 {
  font-weight: 600;
  font-size: 60px;
  padding: 0;
  margin: 0;
  line-height: 1;
}
.title h3 {
  font-weight: 200;
  font-size: 20px;
  padding: 0;
  margin: 0;
  line-height: 2;
  color: #5e7283;
  letter-spacing: 2px;
}
.title p {
  font-weight: 200;
  font-size: 16px;
  color: #5e7283;
}

.pentahedron {
  position: absolute;
  width: 100%;
  height: 100%;
  fill: #3E82F7;
}

.point {
  fill: #8491A3;
}

.rhombus {
  fill: #2DA94F;
  stroke: #2DA94F;
}

.x {
  fill: #FDBD00;
}

.circle {
  fill: #ED412D;
}

svg {
  display: block;
  width: 30px;
  height: 30px;
  position: absolute;
  transform: translateZ(0px);
}