h1:before,h2:before,h3:before,h4:before,h5:before,h6:before{
background: #337ab7;
color: white;
padding: 0 2px;
margin-right: 2px;
border-radius: 5px;
border: 1px solid white;
box-sizing: border-box;
font-family: arial;
}
h1:before{
content: "H1";
}
h2:before{
content: "H2";
}
h3:before{
content: "H3";
}
h4:before{
content: "H4";
}
h5:before{
content: "H5";
}
h6:before{
content: "H6";
}