Sidebar: Add left border to TOC

Fix usages of color-foreground. It's oklch based,
but had usages directly on color without oklch
wrapper

Author: nginx-jack

assets/css/v2/style.css

@@ -602,7 +602,7 @@ ol li:last-child {
 .header__sidebar__panel,
 .sidebar__panel {
   cursor: pointer;
-  color: var(--color-foreground);
+  color: oklch(var(--color-foreground));
   label {
     cursor: pointer;
   }
@@ -1188,7 +1188,7 @@ nav.sidebar.sidebar__mobile-open {
 
 .sidebar {
   grid-area: sidebar;
-  --color-foreground: oklch(0 0 0 / 0.75);
+  color: oklch(var(--color-foreground) / 0.75);
 
   display: flex;
   flex-direction: column;
@@ -1238,7 +1238,7 @@ nav.sidebar.sidebar__mobile-open {
     padding: 0.25rem 0.5rem;
     border-radius: 5px 0 0 5px;
     font-weight: 500;
-    color: var(--color-foreground);
+    color: oklch(var(--color-foreground));
 
     &:hover {
       background-color: oklch(var(--color-brand) / 0.06);
@@ -1299,14 +1299,15 @@ nav.sidebar.sidebar__mobile-open {
     #TableOfContents {
       padding: 0 0.75rem 0 0;
       margin: 0.5rem 0.25rem 0.5rem 0.8rem;
-      border-left: 1px solid var(--color-divider);
-      color: oklch(0 0 0 / 0.75);
+      border-left: 1px solid oklch(var(--color-divider));
+      color: oklch(var(--color-foreground) / 0.75);
 
       &[hidden] {
         display: none;
       }
 
       a {
+        color: oklch(var(--color-foreground));
         text-decoration: none;
       }