diff --git a/src/lib/documents/markdown.ts b/src/lib/documents/markdown.ts
index 2bbc7fd..982fcec 100644
--- a/src/lib/documents/markdown.ts
+++ b/src/lib/documents/markdown.ts
@@ -468,7 +468,7 @@ export function markdownToDoc(markdown: string): JSONContent {
     // Table: header row, | --- | separator, then body rows.
     if (/^\|.*\|\s*$/.test(line) && i + 1 < lines.length && /^\|[\s:|-]+\|\s*$/.test(lines[i + 1])) {
       flushParagraph();
-          const parseRow = (row: string, header: boolean): JSONContent => ({
+      const parseRow = (row: string, header: boolean): JSONContent => ({
         type: 'tableRow',
         content: row
           .replace(/^\|/, '')
diff --git a/src/lib/documents/sanitizeHtml.ts b/src/lib/documents/sanitizeHtml.ts
index ec1d37e..484f24c 100644
--- a/src/lib/documents/sanitizeHtml.ts
+++ b/src/lib/documents/sanitizeHtml.ts
@@ -42,6 +42,13 @@ const ALLOWED_ELEMENTS = new Set([
 /** class="task-list" / "task-item" and data-checked carry checklist state. */
 const ALLOWED_CLASSES = new Set(['task-list', 'task-item']);
 
+/**
+ * Elements whose entire subtree must be dropped rather than unwrapped: their
+ * text content is not safe to surface (e.g. `<script>alert(1)</script>` would
+ * otherwise become a literal "alert(1)" text node).
+ */
+const REMOVE_ENTIRELY = new Set(['script', 'style']);
+
 const SAFE_PROTOCOLS = new Set(['https:', 'http:', 'mailto:', 'nostr:']);
 
 function sanitizeHref(value: string | null): string | null {
@@ -94,12 +101,19 @@ function sanitizeAttributes(element: Element): void {
 }
 
 function sanitizeElement(element: Element): void {
+  const tag = element.tagName.toLowerCase();
+  if (REMOVE_ENTIRELY.has(tag)) {
+    // Drop the element and all of its content — unwrapping would surface
+    // script/style text as a literal text node.
+    element.remove();
+    return;
+  }
+
   // Children first: a disallowed child is unwrapped before we look up again.
   for (const child of [...element.children]) {
     sanitizeElement(child);
   }
 
-  const tag = element.tagName.toLowerCase();
   if (!ALLOWED_ELEMENTS.has(tag)) {
     // Unwrap: keep the (already sanitized) children, drop the wrapper. This
     // keeps the text of a <div> or <span> instead of deleting it.
diff --git a/src/lib/documents/ydoc.ts b/src/lib/documents/ydoc.ts
index 84ef0a1..eb9bb8d 100644
--- a/src/lib/documents/ydoc.ts
+++ b/src/lib/documents/ydoc.ts
@@ -28,6 +28,21 @@ function indexedDbAvailable(): boolean {
   }
 }
 
+/**
+ * Constructing `IndexeddbPersistence` can throw even when IndexedDB exists
+ * (e.g. blocked/denied storage in private browsing or locked-down
+ * environments). Treat persistence as best-effort and degrade to `null`
+ * (in-memory) rather than crashing the caller.
+ */
+function createPersistence(documentId: string, doc: Y.Doc): IndexeddbPersistence | null {
+  if (!indexedDbAvailable()) return null;
+  try {
+    return new IndexeddbPersistence(`${DB_PREFIX}${documentId}`, doc);
+  } catch {
+    return null;
+  }
+}
+
 /**
  * Opens the Yjs document for `documentId` with offline persistence behind it.
  *
@@ -49,9 +64,7 @@ export function openDocumentSession(
   events: DocumentSessionEvents,
 ): DocumentSession {
   const doc = new Y.Doc();
-  const persistence = indexedDbAvailable()
-    ? new IndexeddbPersistence(`${DB_PREFIX}${documentId}`, doc)
-    : null;
+  const persistence = createPersistence(documentId, doc);
 
   const onUpdate = () => events.onUpdate();
   doc.on('update', onUpdate);
@@ -91,13 +104,16 @@ export function openDocumentSession(
 
 /** Removes the persisted body of a document that was deleted from the index. */
 export async function deletePersistedDocument(documentId: string): Promise<void> {
-  if (!indexedDbAvailable()) return;
   const doc = new Y.Doc();
-  const persistence = new IndexeddbPersistence(`${DB_PREFIX}${documentId}`, doc);
   try {
-    await persistence.clearData();
+    const persistence = createPersistence(documentId, doc);
+    if (!persistence) return;
+    try {
+      await persistence.clearData();
+    } finally {
+      persistence.destroy();
+    }
   } finally {
-    persistence.destroy();
     doc.destroy();
   }
 }