<div class="title">
    <h1>HI</h1>
    <h3>and welcome</h3>
  </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
  &:hover
    background: #edf3f8
    color: #212121

body
  margin: 0
  padding: 0
  overflow: hidden
  width: 100%
  height: 100%
  background: #000000


.title
  z-index: 10
  position: absolute
  left: 50%
  top: 50%
  transform: translateX(-50%) translateY(-50%)
  font-family: "Montserrat"
  text-align: center
  width: 100%
  h1
    position: relative
    color: #EEEEEE
    font-weight: 600
    font-size: 100px
    padding: 0
    margin: 0
    line-height: 1
    text-shadow: 0 0 30px #000155

    span
      font-weight: 600
      padding: 0
      margin: 0
      color: #BBB

  h3
    font-weight: 200
    font-size: 50px
    padding: 0
    margin: 0
    line-height: 1
    color: #EEEEEE
    letter-spacing: 2px
    text-shadow: 0 0 30px #000155

let max_particles    = 300;
let particles        = [];
let frequency        = 100;
let init_num         = max_particles;
let max_time         = frequency*max_particles;
let time_to_recreate = false;

// Enable repopolate
setTimeout(function(){
  time_to_recreate = true;
}.bind(this), max_time)

// Popolate particles
popolate(max_particles);

var tela = document.createElement('canvas');
    tela.width = $(window).width();
    tela.height = $(window).height();
    $("body").append(tela);

var canvas = tela.getContext('2d');

class Particle{
  constructor(canvas, options){
    let colors = ["#feea00","#a9df85","#5dc0ad", "#ff9a00","#fa3f20"]
    let types  = ["full","fill","empty"]
    this.random = Math.random()
    this.canvas = canvas;
    this.progress = 0;

    this.x = ($(window).width()/2)  + (Math.random()*200 - Math.random()*200)
    this.y = ($(window).height()/2) + (Math.random()*200 - Math.random()*200)
    this.w = $(window).width()
    this.h = $(window).height()
    this.radius = 1 + (8*this.random)
    this.type  = types[this.randomIntFromInterval(0,types.length-1)];
    this.color = colors[this.randomIntFromInterval(0,colors.length-1)];
    this.a = 0
    this.s = (this.radius + (Math.random() * 1))/10;
    //this.s = 12 //Math.random() * 1;
  }

  getCoordinates(){
    return {
      x: this.x,
      y: this.y
    }
  }

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

  render(){
    // Create arc
    let lineWidth = 0.2 + (2.8*this.random);
    let color = this.color;
    switch(this.type){
      case "full":
        this.createArcFill(this.radius, color)
        this.createArcEmpty(this.radius+lineWidth, lineWidth/2, color)
      break;
      case "fill":
        this.createArcFill(this.radius, color)
      break;
      case "empty":
        this.createArcEmpty(this.radius, lineWidth, color)
      break;
    }
  }

  createArcFill(radius, color){
    this.canvas.beginPath();
    this.canvas.arc(this.x, this.y, radius, 0, 2 * Math.PI);
    this.canvas.fillStyle = color;
    this.canvas.fill();
    this.canvas.closePath();
  }

  createArcEmpty(radius, lineWidth, color){
    this.canvas.beginPath();
    this.canvas.arc(this.x, this.y, radius, 0, 2 * Math.PI);
    this.canvas.lineWidth = lineWidth;
    this.canvas.strokeStyle = color;
    this.canvas.stroke();
    this.canvas.closePath();
  }

  move(){

    this.x += Math.cos(this.a) * this.s;
    this.y += Math.sin(this.a) * this.s;
    this.a += Math.random() * 0.4 - 0.2;

    if(this.x < 0 || this.x > this.w - this.radius){
      return false
    }

    if(this.y < 0 || this.y > this.h - this.radius){
      return false
    }
    this.render()
    return true
  }

  calculateDistance(v1, v2){
    let x = Math.abs(v1.x - v2.x);
    let y = Math.abs(v1.y - v2.y);
    return Math.sqrt((x * x) + (y * y));
  }
}

/*
 * Function to clear layer canvas
 * @num:number number of particles
 */
function popolate(num){
  for (var i = 0; i < num; i++) {
   setTimeout(
     function(x){
       return function(){
         // Add particle
         particles.push(new Particle(canvas))
       };
     }(i)
     ,frequency*i);
  }
  return particles.length
 }

function clear(){
  // canvas.globalAlpha=0.04;
  canvas.fillStyle='#111111';
  canvas.fillRect(0, 0, tela.width, tela.height);
  // canvas.globalAlpha=1;
}

function connection(){
  let old_element = null
  $.each(particles, function(i, element){
    if(i>0){
      let box1 = old_element.getCoordinates()
      let box2 = element.getCoordinates()
      canvas.beginPath();
      canvas.moveTo(box1.x,box1.y);
      canvas.lineTo(box2.x,box2.y);
      canvas.lineWidth = 0.45;
      canvas.strokeStyle="#3f47ff";
      canvas.stroke();
      canvas.closePath();
    }

    old_element = element
  })
}

/*
 * Function to update particles in canvas
 */
function update(){
  clear();
  connection()
  particles = particles.filter(function(p) { return p.move() })
  // Recreate particles
  if(time_to_recreate){
    if(particles.length < init_num){ popolate(1);}
  }
  requestAnimationFrame(update.bind(this))
}

update()