30行js

js:

var canvas = document.body.appendChild(document.createElement('canvas')),
    context = canvas.getContext('2d'),
    t = 0,
    w, h;
context.globalCompositeOperation = 'lighter';
window.addEventListener('resize', resize, false);
resize();
animate();

function resize() {
    w = canvas.width = window.innerWidth;
    h = canvas.height = window.innerHeight;
}

function animate() {
    context.clearRect(0, 0, w, h);
    t += 0.1;
    for (var i = 0; i < 10000; i++) {

        var f = 0.05 + ((Math.sin(t * 0.00002) / Math.PI) * 0.2);

        var r = (Math.min(w, h)) * (Math.cos((t + i) * f) / Math.PI * 1.5);
        var x = Math.sin(i) * r + (canvas.width / 2);
        var y = Math.cos(i) * r + (canvas.height / 2);

        context.fillStyle = 'rgba(0,255,255,0.5)';
        context.fillRect(x, y, 1.5, 1.5);
    }
    setTimeout(animate, 16);
}

css :

body {
    background: #222;
    overflow: hidden;
    margin: 0;
}