fresh block

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
     div.tooltip {
        color: #222;
        background-color: #fff;
        padding: .5em;
        text-shadow: #f5f5f5 0 1px 0;
        border-radius: 2px;
        opacity: 0.9;
        position: absolute;
    }
  </style>
</head>

<body>
  <script>
		var width = 980,
  		  height = 780;
		var color = d3.scaleLinear()
    	.range(["pink","brown"]);
    var tooltip = d3.select('body').append('div')
            .attr('class', 'hidden tooltip');

var svg = d3.select( "body" )
  		.append( "svg" )
		  .attr( "width", width )
		  .attr( "height", height );

var projection = d3.geoConicConformal().center([2.454071, 	46.279229]).scale(2800);

var path = d3.geoPath() // d3.geo.path avec d3 version 3
                 .projection(projection);
    
    d3.csv("GrippeFrance2014.csv", function(data) {
    color.domain([0, 1500]);

d3.json("regions.json", function(json) {
      /* Fusionner les donnees avec le GeoJSON des regions: */
      for (var i = 0; i < data.length; i++) {
        for(var j=0; j<json.features.length; j++) {
          if(data[i].region == json.features[j].properties.nom) {
        		var dataValue = parseFloat(data[i].somme2014);
          	json.features[j].properties.value= dataValue;
      	}
        }
      }
      svg.selectAll("path")
           .data(json.features)
           .enter()
           .append("path")
           .attr("d", path);
      
      svg.selectAll("path")
        .style("fill", function(d) {
              var value = d.properties.value;
              return color(value)})
      
      .on('mousemove', function(d) {
                    var mouse = d3.mouse(svg.node()).map(function(d) {
                        return parseInt(d);
                    });
                    tooltip.classed('hidden', false)
                        .attr('style', 'left:' + (mouse[0] + 15) +
                                'px; top:' + (mouse[1] - 35) + 'px')
                        .html(d.properties.nom);
                })
    });
      
});
    //Encapsulation:
    
  </script>
</body>

https://d3js.org/d3.v4.min.js