How to HTML

<DOCTYPE! HTML>
    <html>
        <head>
            <h1 style="background-color:tomato;">This is a title</h1>
            <kbd style="background-color:tomato;">This is a note</kbd>
        </head>
        <body>
            <h2 style="background-color:tomato;">This is a heading</h2>
            <h3 style="background-color:tomato;">This is a sub-heading</h3>
            <p style="background-color:tomato;">This is a paragraph</p>
        </body>
    </html>