Active Page Footer Links

I think your quickest approach will be to assign a bold link per collection.  Try inserting this into CUSTOM CSS:

/*Homepage*/
#collection-649d74abb21c116f17a9fc23
#block-yui_3_17_2_1_1688402606420_25603
a:first-child{font-weight: 900 !important;}


/*About*/
#collection-64a2a952762de64617a90212
#block-yui_3_17_2_1_1688402606420_25603
a:nth-child(2){font-weight: 900 !important;}


/*Services*/
#collection-64a2a95e48f12318878a5706
#block-yui_3_17_2_1_1688402606420_25603
a:nth-child(3){font-weight: 900 !important;}


/*Contact*/
#collection-64a2a967b299003f9fbecef8
#block-yui_3_17_2_1_1688402606420_25603
a:last-child{font-weight: 900 !important;}