t" content="A new block formatting context is established when overflow is set to 'hidden'." />
        <style type="text/css">* { margin: 0; padding: 0 }
            #div1
            {
                height: 200px;
                width: 200px;
            }
            div div
            {
                height: 50px;
                width: 50px;
            }
            #div2
            {
                background: blue;
                float: left;
            }
            #div3