Erik_Hansen

Besides setting entry-content width to 100% as you already have:

@media screen and (min-width: 61.5625em) {
body:not(.search-results) article:not(.type-page) .entry-content {
	width: 100% !important;
}

You need to set entry-footer width to 100% also:

body:not(.search-results) article:not(.type-page) .entry-footer {
    float: left;
    margin-top: 0.1538461538em;
    width: 100%;
}

then set this one to “inline” to show the “/” as divider between the footer content:

body:not(.search-results) article:not(.type-page) .entry-footer > span:not(:first-child):before {
	display: inline;
}

And finally set this one to “inline-block”

.single .byline,
.full-size-link,
body:not(.search-results).group-blog .byline,
body:not(.search-results) .entry-format,
body:not(.search-results) .cat-links,
body:not(.search-results) .tags-links,
body:not(.search-results) article:not(.sticky) .posted-on,
body:not(.search-results) article:not(.type-page) .comments-link,
body:not(.search-results) article:not(.type-page) .entry-footer .edit-link {
	display: inline-block;
	margin-bottom: 0.5384615385em;
}

That seems to do the trick! 😉