_includes/examples/ex1.html

<html>
  <head>
    <style>

.red {
  fill: red; /* not background-color! */
}

.fancy {
  fill: none;
  stroke: black; /* similar to border-color */
  stroke-width: 3pt; /* similar to border-width */
  stroke-dasharray: 3,5,10;
}

    </style>
  </head>
  <body>


<svg width="300" height="180">
  <circle cx="30"  cy="50" r="25" />
  <circle cx="90"  cy="50" r="25" class="red" />
  <circle cx="150" cy="50" r="25" class="fancy" />

  <rect x="10"  y="80" width="40" height="40"
    fill="steelBlue" />
  <rect x="70"  y="80" width="40" height="40"
    style="fill: steelBlue" />
  <rect x="130" y="80" width="40" height="40"
    class="fancy" />
</svg>

    <script src="../javascripts/d3.v5.min.js"></script>
  </body>
</html>