Adjusted Makefile and CSS to properly highlight current page

Makefile

@@ -31,7 +31,9 @@ $(outdir)/images/%.png: images/%.png | $(outdir)
 	cp -r $< $@
 
 $(outdir)/%.html: %.html $(header) $(footer) | $(outdir)
-	cat $(header) $< $(footer) > $@
+	cat $(header) \
+		| sed 's/\(<body\)/\1 class="$*"/' \
+		| cat - $< $(footer) > $@
 
 clean:
 	${RM} -r webroot

_includes/header.html

@@ -16,9 +16,11 @@
 
     <div id="menu">
       <ul>
-        <li class="selected"><a href="/">About</a></li>
-        <li><a href="manual-select.html">Manual</a></li>
-        <li><a href="https://github.com/mikegerwitz/easejs">Source Code</a></li>
+        <li id="about"><a href="/">About</a></li>
+        <li id="manual"><a href="manual-select.html">Manual</a></li>
+        <li id="source">
+          <a href="https://github.com/mikegerwitz/easejs">Source Code</a>
+        </li>
       </ul>
     </div>
 

style.css

@@ -117,11 +117,13 @@ html, body {
 }
 
 #menu a:hover,
-#menu ul li.selected a {
+body.index #about a,
+body.manual-select #manual a {
   background-color: #204a87;
 }
 
-#menu ul li.selected a {
+body.index #about a,
+body.manual-select #manual a {
   color: #f57900;
 }