ss:before { content: 'CSS'; }
  pre.src-D:before { content: 'D'; }
  pre.src-ditaa:before { content: 'ditaa'; }
  pre.src-dot:before { content: 'Graphviz'; }
  pre.src-calc:before { content: 'Emacs Calc'; }
  pre.src-emacs-lisp:before { content: 'Emacs Lisp'; }
  pre.src-fortran:before { content: 'Fortran'; }
  pre.src-gnuplot:before { content: 'gnuplot'; }
  pre.src-haskell:before { content: 'Haskell'; }
  pre.src-hledger:before { content: 'hledger'; }
  pre.src-java:before { content: 'Java'; }
  pre.src-j