The shape is being used to style an HTML element; naturally you use CSS for that. But if you're asking why the shape is being defined with text, inline in the

The shape is being used to style an HTML element; naturally you use CSS for that. But if you're asking why the shape is being defined with text, inline in the CSS, that's because defining shapes with SVG was postponed to level 2 of the CSS Shapes spec. http://dev.w3.org/csswg/css-shapes-2/#referencing-svg-shapes http://dev.w3.org/csswg/css-shapes-2/#referencing-svg-shapes