SOURCE

~ function() {

    'use strict';

    var spans = [],
        screen = document.getElementById("screen"),
        text = "";

    document.currentScript.text.split(/[\s,.=><\&\-!'/\]\+;()\\["]+/, 169).forEach(function(w) {
        if (w.length > 1) text += w + " ";
    });
    var CObj = function(elem) {
        this.elem = elem;
        this.x = elem.offsetLeft;
        this.y = elem.offsetTop;
        this.zooming = false;
        this.scale = 1;
    }

    CObj.prototype.init = function() {
        this.elem.obj = this;
        this.elem.className = 'word';
        this.elem.style.left = this.x + "px";
        this.elem.style.top = this.y + "px";
        this.glow = document.createElement("span");
        this.glow.innerHTML = this.elem.innerHTML;
        this.glow.className = "wordZoom";
        screen.appendChild(this.glow);
        this.glow.style.left = this.x + "px";
        this.glow.style.top = this.y + "px";
    }

    CObj.prototype.start = function() {
        if (!this.zooming) {
            this.elem.className = "word over";
            this.zooming = true;
            this.glow.style.visibility = "visible";
        }
    }

    CObj.prototype.zoom = function() {
        if (this.zooming) {
            this.scale *= 1.05;
            if (this.scale < 20) {
                var c = 512 - this.scale * 20;
                this.glow.style.transform = this.glow.style.webkitTransform = "scale(" + this.scale + ")";
                this.glow.style.color = "rgb(" + Math.round(c * .5) + "," + Math.round(c * .5) + "," + Math.round(c) + ")";
            } else {
                this.zooming = false;
                this.scale = 1;
                this.glow.style.transform = this.glow.style.webkitTransform = "scale(1)";
                this.glow.style.visibility = "hidden";
                this.elem.className = "word";
            }
        }
    }

    text += " ... ";
    var comp = "",
        word = "",
        tag = false;

    for (var i = 0; i < text.length; i++) {
        var c = text.charAt(i);
        if (c == "<") {
            var j = text.indexOf(">", i);
            word += text.substring(i, j + 1);
            i = j;
            tag = true;
        } else {
            if (c == " ") {
                if (tag) {
                    comp += word + "  ";
                    tag = false;
                } else {
                    comp += "<span>" + word + "</span>  ";
                }
                word = "";
            } else word += c;
        }
    }
    screen.innerHTML = comp;

    var n = screen.getElementsByTagName("*");
    for (var i = 0; i < n.length; i++) {
        var word = n[i];
        spans[i] = new CObj(word);
    }

    for (var i = 0; i < spans.length; i++) {
        spans[i].init();
    }

    screen.onmouseover = function(e) {
        e.preventDefault();
        if (e.target.obj) e.target.obj.start();
    };

    var run = function() {
        requestAnimationFrame(run);
        for (var i = 0; i < spans.length; i++) {
            spans[i].zoom();
        }
    };

    run();

}();

<div id="screen"></div>

html {
    overflow: hidden;
    touch-action: none;
    content-zooming: none;
}
body {
    position: absolute;
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    background: #252527;
}
#screen {
    position: absolute;
    text-align: justify;
    top: 50%;
    left: 50%;
    width: 300px;
    height: 240px;
    margin-left: -220px;
    margin-top: -180px;
    font-size: 12px;
    font-family: arial;
    font-weight: normal;
    color: #666;
    user-select: none;
    cursor: default;
    background: #000;
    font-family: arial;
    padding: 60px;
    overflow: hidden;
}
.word {
    cursor: pointer;
    color: #666;
    position: absolute;
    z-index: 1;
}
.over {
    color: #fff;
    font-weight: bold;
}
.wordZoom {
    position: absolute;
    font-weight: bold;
    z-index: 0;
    visibility: hidden;
    pointer-events: none;
}