<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>CSS Grid Template Areas Example</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

html, body {
      height: 100%;
    }

.container {
      display: grid;
      height: 100vh;
      grid-template-columns: 200px 1fr;
      grid-template-rows: 100px auto 50px;
      grid-template-areas:
        "header header"
        "sidebar content"
        "footer footer";
      gap: 10px;
      padding: 10px;
      background-color: #f0f0f0;
    }

.header {
      grid-area: header;
      background-color: lightblue;
      display: flex;
      align-items: center;
      justify-content: center;
    }

.sidebar {
      grid-area: sidebar;
      background-color: lightgreen;
      display: flex;
      align-items: center;
      justify-content: center;
    }

.content {
      grid-area: content;
      background-color: lightcoral;
      display: flex;
      align-items: center;
      justify-content: center;
    }

.footer {
      grid-area: footer;
      background-color: lightyellow;
      display: flex;
      align-items: center;
      justify-content: center;
    }
  </style>
</head>
<body>

<div class="container">
    <div class="header">Header (100px)</div>
    <div class="sidebar">Sidebar (200px)</div>
    <div class="content">Main Content (Flexible)</div>
    <div class="footer">Footer (50px)</div>
  </div>

</body>
</html>