refined navbar styles in docs

docs/assets/css/docs.css

@@ -21,12 +21,18 @@ body {
 .bs-docs-nav {
   background-color: #b94a48;
 }
-.bs-docs-nav .navbar-brand,
+.bs-docs-nav .navbar-brand {
+  color: #fff;
+}
 .bs-docs-nav .navbar-nav > li > a {
+  color: #dfc9c8;
+}
+.bs-docs-nav .navbar-nav > li > a:hover {
   color: #fff;
 }
 .bs-docs-nav .navbar-nav > .active > a,
 .bs-docs-nav .navbar-nav > .active > a:hover {
+  color: #fff;
   background-color: #993c3a;
 }
 .bs-docs-nav .navbar-toggle {