Text from JSON appear on click from D3 node that already has mouseover events

Question

Beginner here. How can I create a text box (from text from a JSON file) with D3 that appears when you click a node that already has mouseover events? Here's the fiddle. I've done it using "alert," but obviously that's awful. From reading several related but different questions, I tried creating and styling a class related to the pop-up text, but it just caused all the text on the visualization to disappear. Any and all help is appreciated!

Here's my code right now (adapted from this block):

var diameter = 960;

var tree = d3.layout.tree()
    .size([360, diameter / 2 - 200])
    .separation(function(a, b) { return (a.parent == b.parent ? 1 : 2) / a.depth; });

var diagonal = d3.svg.diagonal.radial()
    .projection(function(d) { return [d.y, d.x / 180 * Math.PI]; });

var svg = d3.select("body").append("svg")
    .attr("width", diameter)
    .attr("height", diameter - 50)
  .append("g")
    .attr("transform", "translate(" + diameter / 2 + "," + diameter / 2 + ")");

d3.json("https://api.myjson.com/bins/3yuxo", function(error, root) { 
  var nodes = tree.nodes(root),
      links = tree.links(nodes);

  var link = svg.selectAll(".link")
      .data(links)
    .enter().append("path")
      .attr("class", "link")
      .attr("d", diagonal);

  var node = svg.selectAll(".node")
      .data(nodes)
    .enter().append("g")
      .attr("class", "node")
      .attr("transform", function(d) { return "rotate(" + (d.x - 90) + ")translate(" + d.y + ")"; })
      .on("mouseover", mouseover) 
      .on("mouseout", mouseout)
      .on("click", function(d) { 
         d3.select(this)
           console.log(d.context); 
         });    

  node.append("circle")
      .attr("r", 4.5);

  node.append("text")
      .attr("dy", ".31em")
      .attr("text-anchor", function(d) { return d.x < 180 ? "start" : "end"; })
      .attr("transform", function(d) { return d.x < 180 ? "translate(8)" : "rotate(180)translate(-8)"; })
      .text(function(d) { return d.name; });
});

d3.select(self.frameElement).style("height", diameter - 150 + "px");

function mouseover() { //makes the text size increase on mouseover
  d3.select(this).select("text").transition()
    .duration(750)
    .style("font-size", "40px");

 }

function mouseout() { //returns text to original size
 d3.select(this).select("text").transition()
    .duration(750)
    .style("font-size", "15px");

 }