<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>Self Building Square Spinner</title>
    <style>
      .self-building-square-spinner,
      .self-building-square-spinner * {
        box-sizing: border-box;
      }

      .self-building-square-spinner {
        height: 40px;
        width: 40px;
        top: calc(-10px * 2 / 3);
      }

      .self-building-square-spinner .square {
        height: 10px;
        width: 10px;
        top: calc(-10px * 2 / 3);
        margin-r