diff --git a/comments-view/src/CommentThread.tsx b/comments-view/src/CommentThread.tsx
index 5fbfbda4..087aaecb 100644
--- a/comments-view/src/CommentThread.tsx
+++ b/comments-view/src/CommentThread.tsx
@@ -392,12 +392,15 @@ function CuteDraftEditor(props: {
 
 // Reactively track a single attribute on `element`, seeded from its current
 // value and updated via a `MutationObserver`. Used to receive the host's
-// per-thread selection state as a `data-*` attribute.
+// per-thread selection state as a `data-*` attribute. The host sets it on the
+// `<patchwork-view>`, but the tool is handed the content element that view
+// renders into, so it's read from the view.
 function createElementAttribute(
-  element: HTMLElement,
+  toolElement: HTMLElement,
   name: string,
   fallback: string
 ): () => string {
+  const element = toolElement.closest("patchwork-view") ?? toolElement;
   const read = () => element.getAttribute(name) ?? fallback;
   const [value, setValue] = createSignal(read());
   onMount(() => {
diff --git a/comments-view/src/CommentsView.tsx b/comments-view/src/CommentsView.tsx
index 82b75ff0..d13eafde 100644
--- a/comments-view/src/CommentsView.tsx
+++ b/comments-view/src/CommentsView.tsx
@@ -93,22 +93,15 @@ export function CommentsView(props: { element: HTMLElement }) {
 
   const threadTargetHandleMap = useResolvedHandleMap(threadTargetUrlMap, repo);
 
-  // A thread is only worth showing if at least one of its targets still
-  // resolves to a real, non-empty span. Targets that resolve to an empty
-  // string (a collapsed range) or an undefined value (an anchor that no
-  // longer resolves) are excluded — see `targetIsVisible`.
+  // A thread is worth showing unless every one of its targets is a text range
+  // that has collapsed to an empty string — see `targetIsVisible`.
   const threadsWithVisibleTarget = useThreadsWithVisibleTarget(
     threadTargetUrlMap,
     repo
   );
 
-  const renderableThreadUrls = createMemo<AutomergeUrl[]>(() =>
-    threadUrls().filter((url) => threadsWithVisibleTarget().has(url))
-  );
-
   // Document-level threads target the whole document (a bare url, no `/` path
-  // or `#` heads), so they have no resolvable range and never pass the
-  // visible-target filter. They should always be listed regardless.
+  // or `#` heads).
   const docLevelThreadUrls = createMemo<Set<AutomergeUrl>>(() => {
     const map = threadTargetUrlMap();
     const set = new Set<AutomergeUrl>();
@@ -123,15 +116,19 @@ export function CommentsView(props: { element: HTMLElement }) {
     return set;
   });
 
-  // What the panel actually renders: ranged threads whose target is still
-  // visible, plus all document-level threads.
-  const displayedThreadUrls = createMemo<AutomergeUrl[]>(() =>
+  // Threads that can overlap the editor's selection. Document-level threads
+  // are left out: they cover the whole doc, so they'd match every selection.
+  const renderableThreadUrls = createMemo<AutomergeUrl[]>(() =>
     threadUrls().filter(
       (url) =>
-        threadsWithVisibleTarget().has(url) || docLevelThreadUrls().has(url)
+        threadsWithVisibleTarget().has(url) && !docLevelThreadUrls().has(url)
     )
   );
 
+  const displayedThreadUrls = createMemo<AutomergeUrl[]>(() =>
+    threadUrls().filter((url) => threadsWithVisibleTarget().has(url))
+  );
+
   const overlappingThreads = createMemo<AutomergeUrl[]>(() =>
     renderableThreadUrls().filter((url) =>
       threadOverlapsSelection(
@@ -165,10 +162,16 @@ export function CommentsView(props: { element: HTMLElement }) {
     return new Set(overlappingThreads().filter((u) => u !== p));
   });
 
+  // The thread card under the pointer, which highlights its targets in place
+  // of the primary thread's while hovered.
+  const [hoveredThread, setHoveredThread] = createSignal<
+    AutomergeUrl | undefined
+  >();
+
   createEffect(() => {
     const handle = focusHandle();
     if (!handle) return;
-    const p = primaryThreadUrl();
+    const p = hoveredThread() ?? primaryThreadUrl();
     const urls = p ? (threadTargetUrlMap().get(p) ?? []) : [];
     const desired: Record<AutomergeUrl, true> = {};
     for (const u of urls) desired[u] = true;
@@ -255,6 +258,10 @@ export function CommentsView(props: { element: HTMLElement }) {
             <div
               class="comments-thread"
               onClick={(e) => onClickThreadCard(e, threadUrl)}
+              onMouseEnter={() => setHoveredThread(threadUrl)}
+              onMouseLeave={() =>
+                setHoveredThread((u) => (u === threadUrl ? undefined : u))
+              }
             >
               <patchwork-view
                 doc-url={threadUrl}
@@ -403,22 +410,24 @@ function flatHandles(
   return out;
 }
 
-// A target "points to" a real value only when its anchored range still
-// resolves (`rangePositions` is defined) and spans at least one character
-// (`start !== end`). A missing range is an undefined value (the anchor no
-// longer resolves); an empty range is an empty string (the commented text was
-// deleted). Mirrors `buildCommentDecorations` in the codemirror tool.
+// A target is hidden only when it is a text range that has collapsed to an
+// empty string (the commented text was deleted). Every other target — a whole
+// document, a sub-doc path such as a notebook cell — stays listed.
 function targetIsVisible(handle: DocHandle<unknown>): boolean {
   const positions = handle.rangePositions();
-  if (!positions) return false;
+  if (!positions) return true;
   const [start, end] = positions;
   return start !== end;
 }
 
+// A selected text range overlaps a ranged target; a selected sub-doc (such as
+// a notebook cell) matches a target at or inside it.
 function threadOverlapsSelection(
   targets: DocHandle<unknown>[],
   selection: DocHandle<unknown>[]
 ): boolean {
-  return targets.some((t) => selection.some((s) => s.overlaps(t)));
+  return targets.some((t) =>
+    selection.some((s) => s.overlaps(t) || s.url === t.url || s.contains(t))
+  );
 }
 
diff --git a/comments-view/src/styles.css b/comments-view/src/styles.css
index 2c7fa312..275ae28d 100644
--- a/comments-view/src/styles.css
+++ b/comments-view/src/styles.css
@@ -88,7 +88,11 @@
   flex-direction: column;
   gap: 0.5rem;
   cursor: pointer;
-  transition: box-shadow 0.15s ease;
+  border-radius: 6px;
+  transition:
+    border-color 0.15s ease,
+    background 0.15s ease,
+    box-shadow 0.15s ease;
 }
 
 .comments-thread-card--primary {
@@ -107,6 +111,41 @@
   box-shadow: 0 1px 2px 0 rgb(0 0 0 / 0.05);
 }
 
+/* In the sidebar, where threads sit side by side, the selected one needs to
+   stand out from the rest: an accent border and ring, faintly tinted. A thread
+   embedded on its own defaults to primary, so this is scoped to the panel. */
+.comments-panel .comments-thread-card--primary {
+  border-color: var(--comments-accent);
+  background: color-mix(in srgb, var(--comments-accent) 6%, var(--comments-bg));
+  box-shadow:
+    0 0 0 1px var(--comments-accent),
+    0 6px 14px -4px rgb(0 0 0 / 0.15);
+}
+
+/* Threads that also overlap the selection: a softer accent border. */
+.comments-panel .comments-thread-card--secondary {
+  border-color: color-mix(
+    in srgb,
+    var(--comments-accent) 50%,
+    var(--comments-border)
+  );
+  box-shadow: 0 2px 4px -2px rgb(0 0 0 / 0.1);
+}
+
+.comments-panel .comments-thread-card--inactive {
+  box-shadow: none;
+}
+
+/* Hovering a thread highlights its target, so hint that it's live. */
+.comments-panel .comments-thread:hover .comments-thread-card--inactive {
+  border-color: color-mix(
+    in srgb,
+    var(--comments-accent) 40%,
+    var(--comments-border)
+  );
+  background: var(--comments-hover-bg);
+}
+
 /* Resolved threads are hidden in the sidebar but shown when embedded. Keep
    them clearly readable, just visibly "settled": muted fill, dashed border,
    and slightly dimmed so they read as archived rather than active. */