Grid-site HTML

 <link rel="stylesheet"

a href="style.css"></link>

<main>

    

    <div class="header">Header</div>

    <div class="box1">box1</div>

    <div class="box2">box2</div>

    <div class="box3">box3</div>

    <div id="section">Section</div>

    <div id="aside">Aside</div>

    <div id="footer">Footer</div>

</main>