<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Side Panel Modal with Dialog Element</title>
  <style>
  * {
    box-sizing: border-box;
  }

  body {
    font-family: Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #f5f5f5;
  }

  h1, h2, h3 {
    font-weight: 500;
  }

  .controls {
    margin-bottom: 20px;
    background-color: white;
    padding: 15px;
    border-radiu