h1 { outline: 1px solid #f00 !important; }
h2 { outline: 1px solid #00f !important; }
h3 { outline: 1px solid #0f0 !important; }
h4 { outline: 1px solid #f00 !important; }
h5 { outline: 1px solid #00f !important; }
h6 { outline: 1px solid #0f0 !important; }

h1:before { content: "<h1>" !important; }
h2:before { content: "<h2>" !important; }
h3:before { content: "<h3>" !important; }
h4:before { content: "<h4>" !important; }
h5:before { content: "<h5>" !important; }
h6:before { content: "<h6>" !important; }
