JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
  <head>
    <title>Mashups with google.maps.Data</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
    <script
      src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBIwzALxUPNbatRBj3Xi1Uhp0fFzwWNBkE&callback=initMap&libraries=&v=weekly"
      defer
    ></script>
    <style type="text/css">
      html,
      body,
      #map {
        height: 100%;
        margin: 0;
        padding: 0;
        overflow: hidden;
      }

      .nicebox {
        position: absolute;
        text-align: center;
        font-family: "Roboto", "Arial", sans-serif;
        font-size: 13px;
        z-index: 5;
        box-shadow: 0 4px 6px -4px #333;
        padding: 5px 10px;
        background: white;
        background: linear-gradient(to bottom, white 0%, whitesmoke 100%);
        border: #e5e5e5 1px solid;
      }

.bt{
  background-color: black;
  border: 5;
  color:cyan;
  padding: 5px 2px;
  text-align: center;
  text-decoration: none;
  display: inline-flex;
  font-size: 16px;
  margin: 4px 2px;
  cursor: pointer;
 border-color: #908C8C;
}

      #controls {
        top: 450px;
        left: 900px;
        width: 400px;
        height: 45px;
      }

      #data-box {
        top: 570px;
        left: 110px;
        height: 45px;
        line-height: 45px;
        display: none;
      }

      #census-variable {
        width: 400px;
        height: 20px;
      }

      #legend {
        display: flex;
        display: -webkit-box;
        padding-top: 7px;
      }

      .color-key {
        background: linear-gradient(
          to right,
          #db4639 0%,
          #db7f29 17%,
          #d1bf1f 33%,
          #92c51b 50%,
          #48ba17 67%,
          #12ab24 83%,
          #0f9f59 100%
        );
        flex: 1;
        -webkit-box-flex: 1;
        margin: 0 5px;
        text-align: left;
        font-size: 1em;
        line-height: 1em;
      }

      #data-value {
        font-size: 2em;
  ...