Untitled

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <link rel="stylesheet" href="style.css">
  <title>Document</title>
</head>

<header>
    <h1>nagłówek</h1>
</header>

<body>

<div class="app-container">

    <div class="link-box">
        <ul>
            <li class="linkbtn"><a onclick="loadLink1()">link 1</a></li>
            <li class="linkbtn"><a href="#">link 2</a></li>
            <li class="linkbtn"><a href="#">link 3</a></li>
        </ul>
    </div>

    <div class="main-content">
        <embed id="content">
asd
        </embed>
    </div>

    <div class="news-container">
        <h2 class="news-title"> news </h2>
        <div class="news-content">
            <p>
                Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
            </p>
        </div>
    </div>

</div>

<footer>
     &copy; STOPKA | 2019
</footer>


<script>
        function loadLink1() {
            document.getElementById("content").src = "link1.html";


        }
        </script>

</body>


</html>