One column
Render one column
<body>
<main>
</body>
Two column
Render two columns
<body>
<main>
<aside>
</body>
Adjacent elements
Render two columns with adjacent elements
<body>
<any>
<main>
<aside>
<any>
</body>
Caveats
- Immediate descentants of body will be displayed as block level elements