It's hard to say without seeing the code, but just as you refer to parts of a map, just as you apply styles.
If you have section1 then you css could be
#section1{ border://something background-color://something else }
Or, in your script, when you link to a click, you also add some styles, like
$('#section1').click(function(){ //whatever $(this).css({'background-color' : 'red', 'border' : '1px solid black'}); });
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