JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<body>

<svg width="960" height="500"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>

CSS

body {
  background-color: #F1F3F3    
}
.axis {
	font: 10px sans-serif;
}

.axis path,
.axis line {
  fill: none;
  stroke: #D4D8DA;
  stroke-width: 2px;
  shape-rendering: crispEdges;
}

.line {
  fill: none;
  stroke: #6F257F;
  stroke-width: 5px;
}

.overlay {
  fill: none;
  pointer-events: all;
}

.focus circle {
  fill: #F1F3F3;
  stroke: #6F257F;
  stroke-width: 5px;
}
  
.hover-line {
  stroke: #6F257F;
  stroke-width: 2px;
  stroke-dasharray: 3,3;
}

JavaScript

var svg = d3.select("svg"),
    margin = {top: 20, right: 20, bottom: 30, left: 40},
    width = +svg.attr("width") - margin.left - margin.right,
    height = +svg.attr("height") - margin.top - margin.bottom;

var parseTime = d3.timeParse("%Y")
    bisectDate = d3.bisector(function(d) { return d.year; }).left;

var x = d3.scaleTime().range([0, width]);
var y = d3.scaleLinear().range([height, 0]);

var line = d3.line()
    .x(function(d) { return x(d.year); })
    .y(function(d) { return y(d.value); });

var g = svg.append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

d3.json("data.json", function(error, data) {
    if (error) throw error;

    data.forEach(function(d) {
      d.year = parseTime(d.year);
      d.value = +d.value;
    });

    x.domain(d3.extent(data, function(d) { return d.year; }));
    y.domain([d3.min(data, function(d) { return d.value; }) / 1.005, d3.max(data, function(d) { return d.value; }) * 1.005]);

    g.append("g")
        .attr("class", "axis axis--x")
        .attr("transform", "translate(0," + height + ")")
        .call(d3.axisBottom(x));

    g.append("g")
        .attr("class", "axis axis--y")
        .call(d3.axisLeft(y).ticks(6).tickFormat(function(d) { return parseInt(d / 1000) + "k"; }))
      .append("text")
        .attr("class", "axis-title")
        .attr("transform", "rotate(-90)")
        .attr("y", 6)
        .attr("dy", ".71em")
        .style("text-anchor", "end")
        .attr("fill", "#5D6971")
        .text("Population)");

    g.append("path")
        .datum(data)
        .attr("class", "line")
        .attr("d", line);

    var focus = g.append("g")
        .attr("class", "focus")
        .style("display", "none");

    focus.append("line")
        .attr("class", "x-hover-line hover-line")
        .attr("y1", 0)
        .attr("y2", height);

    focus.append("line")
        .attr("class", "y-hover-line hover-line")
        .attr("x1", width)
        .attr("x2", width);

   ...