<!DOCTYPE html>
<script src="https://code.iconify.design/iconify-icon/2.3.0/iconify-icon.min.js"></script>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Rectangle with Inner Square Grid</title>
  <style>
    .container {
      position: relative;
      width: 49mm;
      height: 82mm;
    }
    .background-rectangle {
      width: 49mm;
      height: 82mm;
      border: 2px dotted black;
      position: abs