bron: https://css-tricks.com/examples/ShapesOfCSS/

Please not some of these do not work because of the default stylesheet ‘box-sizing’:
html { -webkit-box-sizing: border-box; -moz-box-sizing: border-box; box-sizing: border-box; }
*, *:before, *:after { -webkit-box-sizing: inherit; -moz-box-sizing: inherit; box-sizing: inherit; }

TheShapes of CSS

All of the below use only a single HTML element. Any kind of CSS goes, as long as it’s supported in at least one browser.