This slightly modified version of the above css makes the header / footer a little more versatile. The text can now be aligned left / centre / right and the border above the footer now extends the full page width.
.exported-note::before {
font-family: 'Roboto Mono';
font-size: 10px;
color: darkgrey;
display: block;
text-align: right;
content: 'This is the header text';
}
.exported-note::after {
font-family: 'Roboto Mono';
font-size: 10px;
color: darkgrey;
display: block;
text-align: right;
border-top: 1px solid darkgrey;
content: 'This is the footer text';
}
Edit:
Added to Share Your CSS.