Make posts full width on twentysixteen and make the entry footer appear underneath the post. Use the following code:
@media screen and (min-width: 61.5625em) {
body:not(.search-results) article:not(.type-page) .entry-content,
body:not(.search-results) article:not(.type-page) .entry-footer {
width:100%;
float:none;
}
body:not(.search-results) article:not(.type-page) .entry-footer {
margin-top:20px;
padding-top:10px;
border-top:1px solid #efefef;
width:100%;
}
body.no-sidebar:not(.search-results) article:not(.type-page) .entry-content {
margin:0;
width: 50.00000001%;
float:none;
width:100%;
}
body.no-sidebar:not(.search-results) article:not(.type-page) .entry-footer {
margin:0;
float:none;
width:100%;
}
.no-sidebar .entry-header,
.no-sidebar .entry-content,
.no-sidebar .entry-summary,
.no-sidebar .entry-footer,
.no-sidebar .comments-area,
.no-sidebar .image-navigation,
.no-sidebar .post-navigation,
.no-sidebar .pagination,
.no-sidebar .page-header,
.no-sidebar .page-content,
.no-sidebar .content-bottom-widgets {
margin-right: 0;
margin-left: 0;
}
}