CSS Fonts
    
    The following should appear as circular symbols rather than text. 
    
    add_circle remove_circle cancel check_circle
    
    The following lines should all show different fonts.
    Rye remote download woff2
    
    ABCDEFGabcdefg
    Default sans-serif
    
    ABCDEFGabcdefg
    Default serif
    
    ABCDEFGabcdefg
    Default typewriter (monospaced)
    
    ABCDEFGabcdefg
    Default fantasy
    
    ABCDEFGabcdefg
    CSS Shapes
    Example taken from the 
    MDN docs.
    This should show a right-angle isosceles triangle in maroon with text flowing 
    diagonally along the edge of the shape. The shape feature was introduced in ESR60. 
    The text flow feature was introduced in ESR62.
    
    
    We are not quite sure of any one thing in biology; our knowledge of geology
    is relatively very slight, and the economic laws of society are
    uncertain to every one except some individual who attempts to set them
    forth; but before the world was fashioned the square on the hypotenuse
    was equal to the sum of the squares on the other two sides of a right
    triangle, and it will be so after this world is dead; and the inhabitant
    of Mars, if he exists, probably knows its truth as we know it.
    
    Don't return null from getComputedStyle when there's no presentation test
    is adapted from the mozilla bug.