d solid; border-color: red yellow black yellow; border-width: 1em; content: ''; height: 0; }
   .nose div    :after { display: block; border-style: solid solid none; border-color: black yellow red yellow; border-width: 1em; content: ''; height: 0; }

   /* between lines nine and ten: margin collapsing with 'float' and 'clear' */
   .empty { margin: 6.25em; height: 10%; /* computes to auto which makes it empty per 8.3.1:7 (own margins) */ }
   .empty div { margin: 0 2em -6em 4em; }
   .smile { margin: 5em 3e