<header>
    <h1>DevCode</h1>
    <nav>
      <a href="">Home</a>
      <a href="">Nosotros</a>
      <a href="">Galeria</a>
      <a href="">Contacto</a>
    </nav>
    <canvas id='snow'></canvas>  
  </header>
  <div class="wrapper">
    <section id='steezy'>
      <h2> Header Navideño</h2>
      <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Harum enim sunt delectus, reiciendis omnis laudantium animi, et nulla quidem, aliquam aliquid. A consectetur deleniti voluptates eius neque, voluptate voluptatibus nostrum! Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ex libero cupiditate deserunt earum, fuga, ab labore esse animi, nihil est tenetur non delectus perferendis. Maxime accusamus ea rem sint at!</p>

      <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Harum enim sunt delectus, reiciendis omnis laudantium animi, et nulla quidem, aliquam aliquid. A consectetur deleniti voluptates eius neque, voluptate voluptatibus nostrum! Lorem ipsum dolor sit amet, consectetur adipisicing elit. A ut aspernatur omnis neque iusto. Veritatis rem ad atque optio perferendis. Dolorum qui consequatur, repellat soluta impedit porro totam molestiae sit.</p>

      <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Harum enim sunt delectus, reiciendis omnis laudantium animi, et nulla quidem, aliquam aliquid. A consectetur deleniti voluptates eius neque, voluptate voluptatibus nostrum! Lorem ipsum dolor sit amet, consectetur adipisicing elit. Possimus iusto, omnis quas, rem minus cupiditate, sunt voluptates minima sint nemo ipsa itaque consequatur dolor, quam necessitatibus vitae. Quod, eaque, quam.</p>

      <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Harum enim sunt delectus, reiciendis omnis laudantium animi, et nulla quidem, aliquam aliquid. A consectetur deleniti voluptates eius neque, voluptate voluptatibus nostrum!</p>

      <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Harum enim sunt delectus, reiciendis omnis laudantium animi, et nulla quidem, aliquam aliquid. A consectetur deleniti voluptates eius neque, voluptate voluptatibus nostrum!</p>
    </section>
  </div>
</body>
* {
  box-sizing: border-box;
}

html, body, header {
  margin: 0;
  padding: 0;
  border: 0;
}

body {
  background-color: #34495e;
  font-family: helvetica, arial, sans-serif;
  padding-top: 210px;
}

canvas {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 1;
}

header {
  width: 100%;
  height: 150px;
  background-color: #2980b9;
  text-align: center;
  position: fixed;
  top: 0;
  }

header h1 {
  font-size: 42px;
  color: #fff;
  line-height: 50px;
  font-weight: 100;
}

header nav {
  position: absolute;
  bottom: 0;
  height: 60px;
  line-height: 60px;
  width: 100%;
  background-color: rgba(0, 0, 0, 0.1);
}

header nav a {
  color: #fff;
  display: inline-block;
  padding: 10px 15px;
  line-height: 1;
  text-decoration: none;
}


h2 {
  font-size: 34px;
  font-weight: 100;
  line-height: 2;
  color: #2c3e50;
}

p {
  margin-bottom: 2rem;
  line-height: 2;
  color: #7f8c8d;
}

.wrapper {
  width: 70%;
  margin: 0 auto;
}

section {
  padding: 20px;
  margin-bottom: 40px;
  background-color: #fff;
}
var canvas = document.getElementById('snow');
var ctx = canvas.getContext('2d');

var w = canvas.width = window.innerWidth;
var h = canvas.height = 150;

var num = 30;
var tamaño = 40;
var elementos = [];

inicio();
nevada();

window.addEventListener("resize", function() {
  w = canvas.width = window.innerWidth;
  h = canvas.height = 150;
});

function inicio() {
  for (var i = 0; i < num; i++) {
    elementos[i] = {
      x: Math.ceil(Math.random() * w),
      y: Math.ceil(Math.random() * h),
      toX: Math.random() * 10 - 5,
      toY: Math.random() * 5 + 1,
      tamaño: Math.random() * tamaño
    }
  }
}

function nevada() {
  ctx.clearRect(0, 0, w, h);
  for (var i = 0; i < num; i++) {
    var e = elementos[i];
    ctx.beginPath();
    cristal(e.x, e.y, e.tamaño);
    ctx.fill();
    ctx.stroke();
    e.x = e.x + e.toX;
    e.y = e.y + e.toY;
    if (e.x > w) { e.x = 0;}
    if (e.x < 0) { e.x = w;}
    if (e.y > h) { e.y = 0;}
  }
  timer = setTimeout(nevada,10);
}

function cristal(cx, cy, long) {
  ctx.fillStyle = "white";
  ctx.lineWidth = long / 20;
  ctx.arc(cx, cy, long / 15, 0, 2 * Math.PI);
  for (i = 0; i < 6; i++) {
    ctx.strokeStyle = "white";
    ctx.moveTo(cx, cy);
    ctx.lineTo(cx + long / 2 * Math.sin(i * 60 / 180 * Math.PI),
               cy + long / 2 * Math.cos(i * 60 / 180 * Math.PI));
  }
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js