Adds an offset when jumping to a pages anchor/id to account for a fixed header that may overlap the content.

offset-anchor.css

/* When using a fixer header that takes up the top 100px
   or so, you can offset the anchor jump using the following */

.offset-anchor:before {
	display: block;
	content: " ";
	height: 100px;  /* Give height of your fixed element */
	margin-top: -100px; /* Give negative margin of your fixed element */
	visibility: hidden;
}