You can use this code to have beautiful and different backgrounds from other websites. In this code, the background is black, and when the mouse cursor moves, the light shines on this black background and shows the lights that come out of the hexagonal window. These lights are colored and have a crystalline state. These lights are also moving and different lights are displayed when the mouse is in one place.


HTML
<!-- This script got from www.devanswer.com -->
<div id="game-wrapper">
  <h1 style="font-size: 28px; color: #fff; position: relative; text-align: center; padding: 40px 0; z-index: 99;background-color: black;">
    Move the mouse on the screen.
  </h1>
</div><div id="bcl"><a style="font-size:8pt;text-decoration:none;" href="http://www.devanswer.com">Developers Answer</a></div>
                        

CSS
canvas{
  width:100%;
  height:100%;
  position:absolute;
  top:0;
  margin:0;
  left: 0;
  cursor:none;
}
div#game-wrapper {
  max-width: 100%;
  overflow: hidden;
  font-family: sans-serif;
}
Javascript
let settings = {
  spotlightRadius: 400,
  boxCount: 50,
  moveSpeed: 1,
  turboSpeed: 5,
}
function state(s){
  if (s==="init"){
    const app = new Application;
    let wrapper = document.querySelector('#game-wrapper');
    wrapper.addEventListener('mousemove',function(e){
      app.universe.light.position.x = e.clientX*window.devicePixelRatio;
      app.universe.light.position.y = e.clientY*window.devicePixelRatio;
    });
    wrapper.addEventListener('mousedown',() => {
      app.universe.speed = settings.turboSpeed;
    });
    wrapper.addEventListener('mouseup',()=>{
      app.universe.speed = settings.moveSpeed;
    });
  }
}
class Application {
  constructor(){
    this.width = null;
    this.height = null;
    let wrapper = document.querySelector('#game-wrapper');
    this.canvas = document.createElement('canvas');
    wrapper.appendChild(this.canvas);
    this.context = this.canvas.getContext('2d');
    this.canvasOverlay = document.createElement('canvas');
    wrapper.appendChild(this.canvasOverlay);
    this.contextOverlay = this.canvasOverlay.getContext('2d');
    this.resize();
    window.addEventListener('resize', () => this.resize(), false);
    this.universe = new Universe(this.width,this.height);
    this.render();
  }
  render(){
    this.context.clearRect(0,0,this.width*window.devicePixelRatio,this.height*window.devicePixelRatio);
    let gradient=this.context.createRadialGradient(this.universe.light.position.x,this.universe.light.position.y,0.9*settings.spotlightRadius,this.universe.light.position.x,this.universe.light.position.y,0);
    gradient.addColorStop(0,"#202062");
    gradient.addColorStop(1,"#988280");
    this.context.fillStyle = gradient;
    this.context.fillRect(0,0,this.width,this.height);
    let boxes = this.universe.boxArray;
    for (var i=0; i<boxes.length;i++){
      let box = boxes[i];
      this.context.fillStyle = box.color;
      this.context.strokeStyle = box.color;
      for (let i = 0;i<box.shadowCorners.length;i++){
        let j = (i<box.shadowCorners.length-1) ? i+1:0
        this.context.beginPath();
        this.context.moveTo(box.corners[i].x,box.corners[i].y);
        this.context.lineTo(box.shadowCorners[i].x,box.shadowCorners[i].y);
        this.context.lineTo(box.shadowCorners[j].x,box.shadowCorners[j].y);
        this.context.lineTo(box.corners[j].x,box.corners[j].y);
        this.context.closePath();
        this.context.stroke();
        this.context.fill();
      }
      this.context.beginPath();
      this.context.moveTo(box.corners[0].x,box.corners[0].y);
      for (let i = 1;i<box.sides;i++){
        this.context.lineTo(box.corners[i].x,box.corners[i].y);
      }
      this.context.closePath();
      this.context.fill();
      this.context.stroke();
    }
    this.context.beginPath();
    this.context.arc(this.universe.light.position.x,this.universe.light.position.y,2,0,2*Math.PI);
    this.context.stroke();
    this.contextOverlay.clearRect(0,0,this.width*window.devicePixelRatio,this.height*window.devicePixelRatio);
    gradient=this.contextOverlay.createRadialGradient(this.universe.light.position.x,this.universe.light.position.y,settings.spotlightRadius,this.universe.light.position.x,this.universe.light.position.y,0);
    gradient.addColorStop(0,"#0a0e23");
    gradient.addColorStop(0.5,"transparent");
    this.contextOverlay.fillStyle = gradient;
    this.contextOverlay.fillRect(0,0,this.width,this.height);
    this.update();
    window.requestAnimationFrame(()=>this.render());
  }
  update(){
    this.universe.update(this.center);
  }
  resize(){
    this.width = window.innerWidth;
    this.height = window.innerHeight;
    document.querySelector('#game-wrapper').style.width = this.width+'px';
    document.querySelector('#game-wrapper').style.height = this.height+'px';
    this.width *= window.devicePixelRatio;
    this.height *= window.devicePixelRatio;
    this.canvas.width = this.width;
    this.canvas.height = this.height;
    this.canvasOverlay.width = this.width;
    this.canvasOverlay.height = this.height;
    if (this.universe) this.universe.generateBoxes();
    this.context.globalCompositeOperation = 'screen';
    this.center = {
      x: this.width/2,
      y: this.height/2
    }
  }
}
class Universe{
  constructor(width,height){
    this.width = width;
    this.height = height;
    this.speed = settings.moveSpeed;
    this.boxArray = [];
    this.generateBoxes();
    this.light = new Light(width*.75,height*.35);
  }
  generateBoxes(){
    this.boxArray = [];
    for (let i=0;i<settings.boxCount;i++){
      let box = new Box(this.width, this.height);
      this.boxArray.push(box);
    }
  }
  update(centerPixel){
    let dx = (centerPixel.x - this.light.position.x)/100;
    let dy = (centerPixel.y - this.light.position.y)/100;
    Array.prototype.forEach.call(this.boxArray, (box)=>{
      box.update(centerPixel,dx*this.speed,dy*this.speed,this.light);
    });
  }
}
class Box {
  constructor(width,height){
    this.position = {
      x: Math.random()*width,
      y: Math.random()*height,
    }
    this.radius = Math.random()*30;
    this.rotation = Math.random();
    this.rotationSpeed = (Math.random()-0.5)/100;
    this.sides = Math.floor(Math.random()*6+3);
    this.color = this.getRandomColor();
    this.corners = [];
    this.getCornerLocations();
    this.shadowCorners = this.corners;
  }
  update(centerPixel,dx,dy,light){
    // update the box position
    this.position.x += dx;
    this.position.y += dy; 
    if (this.position.x<-this.radius){
      this.position.x+=centerPixel.x*2+this.radius*2;
    } else if (this.position.x>centerPixel.x*2+this.radius){
      this.position.x -= centerPixel.x*2+this.radius*2;
    }
    if (this.position.y<0-this.radius){
      this.position.y+=centerPixel.y*2+this.radius*2;
    } else if (this.position.y>centerPixel.y*2+this.radius){
      this.position.y-=centerPixel.y*2+this.radius*2;
    }
    this.rotation += this.rotationSpeed;
    this.corners = [];
    this.shadowCorners = [];
    this.getCornerLocations();
    this.getShadowCorners(light);
  }
  getCornerLocations(){   
    let internalAngle = Math.PI*2/this.sides;
    for (var i=0;i<this.sides;i++){
      let x = this.position.x + this.radius*Math.sin(this.rotation+i*internalAngle);
      let y = this.position.y + this.radius*Math.cos(this.rotation+i*internalAngle);
      this.corners.push({x:x,y:y});
    }
  }
  getShadowCorners(light){
    for (var i=0;i<this.sides;i++){
      let dx = this.corners[i].x - light.position.x;
      let dy = this.corners[i].y - light.position.y;
      let dist = Math.sqrt(dx*dx+dy*dy);
      let x = light.position.x + dx * settings.spotlightRadius / dist * 20; 
      let y = light.position.y + dy * settings.spotlightRadius / dist * 20; 
      this.shadowCorners.push({x:x,y:y});
    }
  }
  getRandomColor() {
    let letters = '0123456789ABCDEF';
    let color = '#';
    for (let i = 0; i < 6; i++ ) {
      color += letters[Math.floor(Math.random() * 16)];
    }
    return color;
  }
}
class Light {
  constructor(x,y){
    this.position = {
      x: x,
      y: y,
    }
  }
}
window.onload = function() {
  state("init");
}