Expand on nav_list styles

- Consolidate SCSS partials

assets/_scss/_navigation.scss

@@ -212,4 +212,93 @@
       }
     }
   }
+}
+
+
+/*
+   Navigation list
+   ========================================================================== */
+
+.nav__list {
+  a {
+    display: block;
+    padding: 2px 0;
+
+    &:hover {
+      text-decoration: underline;
+    }
+  }
+
+  .active {
+    color: $primary-color;
+    font-weight: bold;
+  }
+}
+
+.nav__title {
+  margin: 0;
+  padding: 10px 20px;
+  font-family: $sans-serif-narrow;
+  font-size: 16px;
+  font-weight: bold;
+  border-bottom: 1px solid $border-color;
+}
+
+.nav__sub-title {
+  display: block;
+  margin: 10px 0;
+  padding: 10px 0;
+  font-family: $sans-serif-narrow;
+  font-size: 14px;
+  font-weight: bold;
+  border-bottom: 1px solid $border-color;
+}
+
+
+/*
+   Table of contents navigation
+   ========================================================================== */
+
+.toc {
+  padding: 0 0 1em;
+  font-family: $sans-serif-narrow;
+  color: $gray;
+  text-transform: uppercase;
+  letter-spacing: 1px;
+  background-color: #fff;
+}
+
+.toc__menu {
+  margin: 0;
+  padding: 0;
+  width: 100%;
+  list-style: none;
+
+  a {
+    display: block;
+    padding: 10px 20px;
+    color: $gray;
+    font-size: 11px;
+    font-weight: bold;
+    line-height: 1.5;
+    border-bottom: 1px solid $border-color;
+
+    &:hover {
+      color: #000;
+      background: $lighter-gray;
+    }
+  }
+
+  li ul > li a {
+    font-weight: normal;
+  }
+
+  // hide sub sub links on small screens
+  li > ul li {
+    display: none;
+
+    @include breakpoint($medium) {
+      display: block;
+    }
+  }
 }