diff --git a/Cargo.lock b/Cargo.lock
index 8de1e23..9123762 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4989,16 +4989,6 @@ dependencies = [
  "wasm-bindgen",
 ]
 
-[[package]]
-name = "jumprope"
-version = "1.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "829c74fe88dda0d2a5425b022b44921574a65c4eb78e6e39a61b40eb416a4ef8"
-dependencies = [
- "rand 0.8.5",
- "str_indices",
-]
-
 [[package]]
 name = "k256"
 version = "0.13.4"
@@ -8348,12 +8338,6 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 
-[[package]]
-name = "str_indices"
-version = "0.4.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d08889ec5408683408db66ad89e0e1f93dff55c73a4ccc71c427d5b277ee47e6"
-
 [[package]]
 name = "string_cache"
 version = "0.8.9"
@@ -9963,7 +9947,6 @@ dependencies = [
  "jacquard-identity",
  "jacquard-lexicon",
  "js-sys",
- "jumprope",
  "lol_alloc",
  "loro",
  "markdown-weaver",
diff --git a/crates/weaver-app/Cargo.toml b/crates/weaver-app/Cargo.toml
index c201ce8..b076d4d 100644
--- a/crates/weaver-app/Cargo.toml
+++ b/crates/weaver-app/Cargo.toml
@@ -49,7 +49,6 @@ tokio = { version = "1.28", features = ["sync"] }
 serde_html_form = "0.2.8"
 tracing.workspace = true
 serde_ipld_dagcbor = { version = "0.6" }
-jumprope = { version = "1.1", features = ["wchar_conversion"] }
 loro = "1.9.1"
 markdown-weaver-escape = { workspace = true }
 
diff --git a/crates/weaver-app/src/components/editor/cursor.rs b/crates/weaver-app/src/components/editor/cursor.rs
index b734972..6e16ed8 100644
--- a/crates/weaver-app/src/components/editor/cursor.rs
+++ b/crates/weaver-app/src/components/editor/cursor.rs
@@ -8,7 +8,6 @@
 //! 4. Setting cursor with web_sys Selection API
 
 use super::offset_map::{find_mapping_for_char, OffsetMapping};
-use jumprope::JumpRopeBuf;
 
 #[cfg(all(target_family = "wasm", target_os = "unknown"))]
 use wasm_bindgen::JsCast;
@@ -16,8 +15,7 @@ use wasm_bindgen::JsCast;
 /// Restore cursor position in the DOM after re-render.
 ///
 /// # Arguments
-/// - `rope`: The document content (for length bounds checking)
-/// - `char_offset`: Cursor position as char offset in rope
+/// - `char_offset`: Cursor position as char offset in document
 /// - `offset_map`: Mappings from source to DOM positions
 /// - `editor_id`: DOM ID of the contenteditable element
 ///
@@ -28,19 +26,20 @@ use wasm_bindgen::JsCast;
 /// 4. Set cursor with Selection API
 #[cfg(all(target_family = "wasm", target_os = "unknown"))]
 pub fn restore_cursor_position(
-    rope: &JumpRopeBuf,
     char_offset: usize,
     offset_map: &[OffsetMapping],
     editor_id: &str,
 ) -> Result<(), wasm_bindgen::JsValue> {
-    // Bounds check
-    let max_offset = rope.len_chars();
-    if char_offset > max_offset {
-        return Err(format!("cursor offset {} > document length {}", char_offset, max_offset).into());
+    // Empty document - no cursor to restore
+    if offset_map.is_empty() {
+        return Ok(());
     }
 
-    // Empty document - no cursor to restore
-    if offset_map.is_empty() || max_offset == 0 {
+    // Bounds check using offset map
+    let max_offset = offset_map.iter().map(|m| m.char_range.end).max().unwrap_or(0);
+    if char_offset > max_offset {
+        tracing::warn!("cursor offset {} > max mapping offset {}", char_offset, max_offset);
+        // Don't error, just skip restoration - this can happen during edits
         return Ok(());
     }
 
@@ -159,7 +158,6 @@ fn find_text_node_at_offset(
 /// Non-WASM stub for testing
 #[cfg(not(all(target_family = "wasm", target_os = "unknown")))]
 pub fn restore_cursor_position(
-    _rope: &JumpRopeBuf,
     _char_offset: usize,
     _offset_map: &[OffsetMapping],
     _editor_id: &str,
diff --git a/crates/weaver-app/src/components/editor/document.rs b/crates/weaver-app/src/components/editor/document.rs
index 4f71d09..5914413 100644
--- a/crates/weaver-app/src/components/editor/document.rs
+++ b/crates/weaver-app/src/components/editor/document.rs
@@ -1,15 +1,25 @@
 //! Core data structures for the markdown editor.
+//!
+//! Uses Loro CRDT for text storage with built-in undo/redo support.
 
-use jumprope::JumpRopeBuf;
+use loro::{LoroDoc, LoroResult, LoroText, UndoManager};
 
 /// Single source of truth for editor state.
 ///
-/// Contains the document text, cursor position, selection, and IME composition state.
-#[derive(Clone, Debug)]
+/// Contains the document text (backed by Loro CRDT), cursor position,
+/// selection, and IME composition state.
+#[derive(Debug)]
 pub struct EditorDocument {
-    /// The rope storing document text (uses char offsets, not bytes).
-    /// Uses JumpRopeBuf to batch consecutive edits for performance.
-    pub rope: JumpRopeBuf,
+    /// The Loro document containing all editor state.
+    /// Using full LoroDoc (not just LoroText) to support future
+    /// expansion to blobs, metadata, etc.
+    doc: LoroDoc,
+
+    /// Handle to the text container within the doc.
+    text: LoroText,
+
+    /// Undo manager for the document.
+    undo_mgr: UndoManager,
 
     /// Current cursor position (char offset)
     pub cursor: CursorState,
@@ -28,7 +38,7 @@ pub struct EditorDocument {
 /// Cursor state including position and affinity.
 #[derive(Clone, Debug, Copy)]
 pub struct CursorState {
-    /// Character offset in rope (NOT byte offset!)
+    /// Character offset in text (NOT byte offset!)
     pub offset: usize,
 
     /// Prefer left/right when at boundary (for vertical cursor movement)
@@ -85,19 +95,18 @@ impl EditorDocument {
             return true;
         }
 
-        // Find distance from previous newline by scanning forward and tracking last newline
-        let rope = self.rope.borrow();
+        let content = self.text.to_string();
         let mut last_newline_pos: Option<usize> = None;
 
-        for (i, c) in rope.slice_chars(0..pos).enumerate() {
+        for (i, c) in content.chars().take(pos).enumerate() {
             if c == '\n' {
                 last_newline_pos = Some(i);
             }
         }
 
         let chars_from_line_start = match last_newline_pos {
-            Some(nl_pos) => pos - nl_pos - 1, // -1 because newline itself is not part of current line
-            None => pos, // No newline found, distance is from document start
+            Some(nl_pos) => pos - nl_pos - 1,
+            None => pos,
         };
 
         chars_from_line_start <= BLOCK_SYNTAX_ZONE
@@ -105,8 +114,23 @@ impl EditorDocument {
 
     /// Create a new editor document with the given content.
     pub fn new(content: String) -> Self {
+        let doc = LoroDoc::new();
+        let text = doc.get_text("content");
+
+        // Insert initial content if any
+        if !content.is_empty() {
+            text.insert(0, &content).expect("failed to insert initial content");
+        }
+
+        // Set up undo manager with merge interval for batching keystrokes
+        let mut undo_mgr = UndoManager::new(&doc);
+        undo_mgr.set_merge_interval(300); // 300ms merge window
+        undo_mgr.set_max_undo_steps(100);
+
         Self {
-            rope: JumpRopeBuf::from(content.as_str()),
+            doc,
+            text,
+            undo_mgr,
             cursor: CursorState {
                 offset: 0,
                 affinity: Affinity::Before,
@@ -117,23 +141,38 @@ impl EditorDocument {
         }
     }
 
+    /// Get the underlying LoroText for read operations.
+    pub fn loro_text(&self) -> &LoroText {
+        &self.text
+    }
+
     /// Convert the document to a string.
     pub fn to_string(&self) -> String {
-        self.rope.to_string()
+        self.text.to_string()
     }
 
     /// Get the length of the document in characters.
     pub fn len_chars(&self) -> usize {
-        self.rope.len_chars()
+        self.text.len_unicode()
+    }
+
+    /// Get the length of the document in UTF-8 bytes.
+    pub fn len_bytes(&self) -> usize {
+        self.text.len_utf8()
+    }
+
+    /// Get the length of the document in UTF-16 code units.
+    pub fn len_utf16(&self) -> usize {
+        self.text.len_utf16()
     }
 
     /// Check if the document is empty.
     pub fn is_empty(&self) -> bool {
-        self.rope.len_chars() == 0
+        self.text.len_unicode() == 0
     }
 
     /// Insert text and record edit info for incremental rendering.
-    pub fn insert_tracked(&mut self, pos: usize, text: &str) {
+    pub fn insert_tracked(&mut self, pos: usize, text: &str) -> LoroResult<()> {
         let in_block_syntax_zone = self.is_in_block_syntax_zone(pos);
         self.last_edit = Some(EditInfo {
             edit_char_pos: pos,
@@ -142,36 +181,94 @@ impl EditorDocument {
             contains_newline: text.contains('\n'),
             in_block_syntax_zone,
         });
-        self.rope.insert(pos, text);
+        self.text.insert(pos, text)
     }
 
     /// Remove text range and record edit info for incremental rendering.
-    pub fn remove_tracked(&mut self, range: std::ops::Range<usize>) {
-        // Check if deleted region contains newline - borrow inner JumpRope
-        let contains_newline = self.rope.borrow().slice_chars(range.clone()).any(|c| c == '\n');
-        let in_block_syntax_zone = self.is_in_block_syntax_zone(range.start);
+    pub fn remove_tracked(&mut self, start: usize, len: usize) -> LoroResult<()> {
+        let content = self.text.to_string();
+        let end = start + len;
+        let contains_newline = content
+            .chars()
+            .skip(start)
+            .take(len)
+            .any(|c| c == '\n');
+        let in_block_syntax_zone = self.is_in_block_syntax_zone(start);
+
         self.last_edit = Some(EditInfo {
-            edit_char_pos: range.start,
+            edit_char_pos: start,
             inserted_len: 0,
-            deleted_len: range.end - range.start,
+            deleted_len: len,
             contains_newline,
             in_block_syntax_zone,
         });
-        self.rope.remove(range);
+        self.text.delete(start, len)
     }
 
     /// Replace text (delete then insert) and record combined edit info.
-    pub fn replace_tracked(&mut self, range: std::ops::Range<usize>, text: &str) {
-        let delete_has_newline = self.rope.borrow().slice_chars(range.clone()).any(|c| c == '\n');
-        let in_block_syntax_zone = self.is_in_block_syntax_zone(range.start);
+    pub fn replace_tracked(&mut self, start: usize, len: usize, text: &str) -> LoroResult<()> {
+        let content = self.text.to_string();
+        let delete_has_newline = content
+            .chars()
+            .skip(start)
+            .take(len)
+            .any(|c| c == '\n');
+        let in_block_syntax_zone = self.is_in_block_syntax_zone(start);
+
         self.last_edit = Some(EditInfo {
-            edit_char_pos: range.start,
+            edit_char_pos: start,
             inserted_len: text.chars().count(),
-            deleted_len: range.end - range.start,
+            deleted_len: len,
             contains_newline: delete_has_newline || text.contains('\n'),
             in_block_syntax_zone,
         });
-        self.rope.remove(range);
-        self.rope.insert(self.last_edit.as_ref().unwrap().edit_char_pos, text);
+
+        // Use splice for atomic replace
+        self.text.splice(start, len, text)?;
+        Ok(())
+    }
+
+    /// Undo the last operation.
+    /// Returns true if an undo was performed.
+    pub fn undo(&mut self) -> LoroResult<bool> {
+        self.undo_mgr.undo()
+    }
+
+    /// Redo the last undone operation.
+    /// Returns true if a redo was performed.
+    pub fn redo(&mut self) -> LoroResult<bool> {
+        self.undo_mgr.redo()
+    }
+
+    /// Check if undo is available.
+    pub fn can_undo(&self) -> bool {
+        self.undo_mgr.can_undo()
+    }
+
+    /// Check if redo is available.
+    pub fn can_redo(&self) -> bool {
+        self.undo_mgr.can_redo()
+    }
+
+    /// Get a slice of the document text.
+    /// Returns None if the range is invalid.
+    pub fn slice(&self, start: usize, end: usize) -> Option<String> {
+        self.text.slice(start, end).ok()
+    }
+}
+
+// EditorDocument can't derive Clone because LoroDoc/LoroText/UndoManager don't implement Clone.
+// This is intentional - the document should be the single source of truth.
+
+impl Clone for EditorDocument {
+    fn clone(&self) -> Self {
+        // Create a new document with the same content
+        let content = self.to_string();
+        let mut new_doc = Self::new(content);
+        new_doc.cursor = self.cursor;
+        new_doc.selection = self.selection;
+        new_doc.composition = self.composition.clone();
+        new_doc.last_edit = self.last_edit.clone();
+        new_doc
     }
 }
diff --git a/crates/weaver-app/src/components/editor/formatting.rs b/crates/weaver-app/src/components/editor/formatting.rs
index a9a62b8..52fb005 100644
--- a/crates/weaver-app/src/components/editor/formatting.rs
+++ b/crates/weaver-app/src/components/editor/formatting.rs
@@ -21,32 +21,32 @@ pub enum FormatAction {
 ///
 /// Expands to whitespace boundaries. Used when applying formatting
 /// without a selection.
-pub fn find_word_boundaries(rope: &jumprope::JumpRopeBuf, offset: usize) -> (usize, usize) {
-    let rope = rope.borrow();
-    let mut start = 0;
-    let mut end = rope.len_chars();
+pub fn find_word_boundaries(text: &loro::LoroText, offset: usize) -> (usize, usize) {
+    let len = text.len_unicode();
 
-    // Find start by scanning backwards
-    let mut char_pos = 0;
-    for substr in rope.slice_substrings(0..offset) {
-        for c in substr.chars() {
-            if c.is_whitespace() {
-                start = char_pos + 1;
+    // Find start by scanning backwards using char_at
+    let mut start = 0;
+    for i in (0..offset).rev() {
+        match text.char_at(i) {
+            Ok(c) if c.is_whitespace() => {
+                start = i + 1;
+                break;
             }
-            char_pos += 1;
+            Ok(_) => continue,
+            Err(_) => break,
         }
     }
 
-    // Find end by scanning forwards
-    char_pos = offset;
-    let byte_len = rope.len_bytes();
-    for substr in rope.slice_substrings(offset..byte_len) {
-        for c in substr.chars() {
-            if c.is_whitespace() {
-                end = char_pos;
-                return (start, end);
+    // Find end by scanning forwards using char_at
+    let mut end = len;
+    for i in offset..len {
+        match text.char_at(i) {
+            Ok(c) if c.is_whitespace() => {
+                end = i;
+                break;
             }
-            char_pos += 1;
+            Ok(_) => continue,
+            Err(_) => break,
         }
     }
 
@@ -62,91 +62,96 @@ pub fn apply_formatting(doc: &mut EditorDocument, action: FormatAction) {
         (sel.anchor.min(sel.head), sel.anchor.max(sel.head))
     } else {
         // Expand to word
-        find_word_boundaries(&doc.rope, doc.cursor.offset)
+        find_word_boundaries(doc.loro_text(), doc.cursor.offset)
     };
 
     match action {
         FormatAction::Bold => {
-            doc.rope.insert(end, "**");
-            doc.rope.insert(start, "**");
+            // Insert end marker first so start position stays valid
+            let _ = doc.insert_tracked(end, "**");
+            let _ = doc.insert_tracked(start, "**");
             doc.cursor.offset = end + 4;
             doc.selection = None;
         }
         FormatAction::Italic => {
-            doc.rope.insert(end, "*");
-            doc.rope.insert(start, "*");
+            let _ = doc.insert_tracked(end, "*");
+            let _ = doc.insert_tracked(start, "*");
             doc.cursor.offset = end + 2;
             doc.selection = None;
         }
         FormatAction::Strikethrough => {
-            doc.rope.insert(end, "~~");
-            doc.rope.insert(start, "~~");
+            let _ = doc.insert_tracked(end, "~~");
+            let _ = doc.insert_tracked(start, "~~");
             doc.cursor.offset = end + 4;
             doc.selection = None;
         }
         FormatAction::Code => {
-            doc.rope.insert(end, "`");
-            doc.rope.insert(start, "`");
+            let _ = doc.insert_tracked(end, "`");
+            let _ = doc.insert_tracked(start, "`");
             doc.cursor.offset = end + 2;
             doc.selection = None;
         }
         FormatAction::Link => {
             // Insert [selected text](url)
-            doc.rope.insert(end, "](url)");
-            doc.rope.insert(start, "[");
+            let _ = doc.insert_tracked(end, "](url)");
+            let _ = doc.insert_tracked(start, "[");
             doc.cursor.offset = end + 8; // Position cursor after ](url)
             doc.selection = None;
         }
         FormatAction::Image => {
             // Insert ![alt text](url)
-            doc.rope.insert(end, "](url)");
-            doc.rope.insert(start, "![");
+            let _ = doc.insert_tracked(end, "](url)");
+            let _ = doc.insert_tracked(start, "![");
             doc.cursor.offset = end + 9;
             doc.selection = None;
         }
         FormatAction::Heading(level) => {
             // Find start of current line
-            let line_start = find_line_start(&doc.rope, doc.cursor.offset);
+            let line_start = find_line_start(doc.loro_text(), doc.cursor.offset);
             let prefix = "#".repeat(level as usize) + " ";
-            doc.rope.insert(line_start, &prefix);
+            let _ = doc.insert_tracked(line_start, &prefix);
             doc.cursor.offset += prefix.len();
             doc.selection = None;
         }
         FormatAction::BulletList => {
-            let line_start = find_line_start(&doc.rope, doc.cursor.offset);
-            doc.rope.insert(line_start, "- ");
+            let line_start = find_line_start(doc.loro_text(), doc.cursor.offset);
+            let _ = doc.insert_tracked(line_start, "- ");
             doc.cursor.offset += 2;
             doc.selection = None;
         }
         FormatAction::NumberedList => {
-            let line_start = find_line_start(&doc.rope, doc.cursor.offset);
-            doc.rope.insert(line_start, "1. ");
+            let line_start = find_line_start(doc.loro_text(), doc.cursor.offset);
+            let _ = doc.insert_tracked(line_start, "1. ");
             doc.cursor.offset += 3;
             doc.selection = None;
         }
         FormatAction::Quote => {
-            let line_start = find_line_start(&doc.rope, doc.cursor.offset);
-            doc.rope.insert(line_start, "> ");
+            let line_start = find_line_start(doc.loro_text(), doc.cursor.offset);
+            let _ = doc.insert_tracked(line_start, "> ");
             doc.cursor.offset += 2;
             doc.selection = None;
         }
     }
 }
 
-/// Find start of line containing offset (same as in mod.rs)
-fn find_line_start(rope: &jumprope::JumpRopeBuf, offset: usize) -> usize {
-    let mut char_pos = 0;
-    let mut last_newline_pos = None;
-
-    let rope = rope.borrow();
-    for substr in rope.slice_substrings(0..offset) {
-        for c in substr.chars() {
-            if c == '\n' {
-                last_newline_pos = Some(char_pos);
-            }
-            char_pos += 1;
-        }
+/// Find start of line containing offset
+fn find_line_start(text: &loro::LoroText, offset: usize) -> usize {
+    if offset == 0 {
+        return 0;
     }
 
-    last_newline_pos.map(|pos| pos + 1).unwrap_or(0)
+    // Get text up to offset
+    let prefix = match text.slice(0, offset) {
+        Ok(s) => s,
+        Err(_) => return 0,
+    };
+
+    // Find last newline
+    prefix
+        .chars()
+        .enumerate()
+        .filter(|(_, c)| *c == '\n')
+        .last()
+        .map(|(pos, _)| pos + 1)
+        .unwrap_or(0)
 }
diff --git a/crates/weaver-app/src/components/editor/mod.rs b/crates/weaver-app/src/components/editor/mod.rs
index 615d9a1..432768e 100644
--- a/crates/weaver-app/src/components/editor/mod.rs
+++ b/crates/weaver-app/src/components/editor/mod.rs
@@ -10,7 +10,6 @@ mod formatting;
 mod offset_map;
 mod paragraph;
 mod render;
-mod rope_writer;
 mod storage;
 mod toolbar;
 mod visibility;
@@ -24,7 +23,6 @@ pub use formatting::{FormatAction, apply_formatting, find_word_boundaries};
 pub use offset_map::{OffsetMapping, RenderResult, find_mapping_for_byte};
 pub use paragraph::ParagraphRender;
 pub use render::{RenderCache, render_paragraphs_incremental};
-pub use rope_writer::RopeWriter;
 pub use storage::{EditorSnapshot, clear_storage, load_from_storage, save_to_storage};
 pub use toolbar::EditorToolbar;
 pub use visibility::VisibilityState;
@@ -38,7 +36,7 @@ use dioxus::prelude::*;
 /// - `initial_content`: Optional initial markdown content
 ///
 /// # Features
-/// - JumpRope-based text storage for efficient editing
+/// - Loro CRDT-based text storage with undo/redo support
 /// - Event interception for full control over editing operations
 /// - Toolbar formatting buttons
 /// - LocalStorage auto-save with debouncing
@@ -75,7 +73,7 @@ pub fn MarkdownEditor(initial_content: Option<String>) -> Element {
         let edit = doc.last_edit.as_ref();
 
         let (paras, new_cache) =
-            render::render_paragraphs_incremental(&doc.rope, Some(&cache), edit);
+            render::render_paragraphs_incremental(doc.loro_text(), Some(&cache), edit);
 
         // Update cache for next render (write-only via spawn to avoid reactive loop)
         dioxus::prelude::spawn(async move {
@@ -107,8 +105,15 @@ pub fn MarkdownEditor(initial_content: Option<String>) -> Element {
     // Update DOM when paragraphs change (incremental rendering)
     #[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
     use_effect(move || {
+        // Read document once to avoid multiple borrows
+        let doc = document();
+        let cursor_offset = doc.cursor.offset;
+        let selection = doc.selection;
+        drop(doc); // Release borrow before other operations
+
         let new_paras = paragraphs();
-        let cursor_offset = document().cursor.offset;
+        let map = offset_map();
+        let spans = syntax_spans();
 
         // Use peek() to avoid creating reactive dependency on cached_paragraphs
         let prev = cached_paragraphs.peek().clone();
@@ -120,14 +125,11 @@ pub fn MarkdownEditor(initial_content: Option<String>) -> Element {
             use wasm_bindgen::JsCast;
             use wasm_bindgen::prelude::*;
 
-            let rope = document().rope.clone();
-            let map = offset_map();
-
             // Use requestAnimationFrame to wait for browser paint
             if let Some(window) = web_sys::window() {
                 let closure = Closure::once(move || {
                     if let Err(e) =
-                        cursor::restore_cursor_position(&rope, cursor_offset, &map, editor_id)
+                        cursor::restore_cursor_position(cursor_offset, &map, editor_id)
                     {
                         tracing::warn!("Cursor restoration failed: {:?}", e);
                     }
@@ -142,11 +144,18 @@ pub fn MarkdownEditor(initial_content: Option<String>) -> Element {
         cached_paragraphs.set(new_paras.clone());
 
         // Update syntax visibility after DOM changes
-        let doc = document();
-        let spans = syntax_spans();
+        // Debug: log what syntax spans we have
+        for span in spans.iter() {
+            tracing::debug!(
+                "[VISIBILITY_INPUT] span {} char_range {:?} formatted_range {:?}",
+                span.syn_id,
+                span.char_range,
+                span.formatted_range
+            );
+        }
         update_syntax_visibility(
-            doc.cursor.offset,
-            doc.selection.as_ref(),
+            cursor_offset,
+            selection.as_ref(),
             &spans,
             &new_paras,
         );
@@ -155,11 +164,15 @@ pub fn MarkdownEditor(initial_content: Option<String>) -> Element {
     // Auto-save with debounce
     #[cfg(all(target_arch = "wasm32", target_os = "unknown"))]
     use_effect(move || {
+        // Read document once and extract what we need
         let doc = document();
+        let content = doc.to_string();
+        let cursor = doc.cursor.offset;
+        drop(doc);
 
         // Save after 500ms of no typing
         let timer = gloo_timers::callback::Timeout::new(500, move || {
-            let _ = storage::save_to_storage(&doc.to_string(), doc.cursor.offset);
+            let _ = storage::save_to_storage(&content, cursor);
         });
         timer.forget();
     });
@@ -213,22 +226,8 @@ pub fn MarkdownEditor(initial_content: Option<String>) -> Element {
                     },
 
                     onclick: move |_evt| {
-                        // After mouse click, sync cursor from DOM
-                        let paras = cached_paragraphs();
-                        sync_cursor_from_dom(&mut document, editor_id, &paras);
-                        // Update syntax visibility after cursor sync
-                        let doc = document();
-                        let spans = syntax_spans();
-                        update_syntax_visibility(
-                            doc.cursor.offset,
-                            doc.selection.as_ref(),
-                            &spans,
-                            &paras,
-                        );
-                    },
-
-                    onmouseup: move |_evt| {
-                        // After drag selection, sync cursor/selection from DOM
+                        // After mouse click or drag selection, sync cursor from DOM
+                        // (click fires after mouseup, so this handles both cases)
                         let paras = cached_paragraphs();
                         sync_cursor_from_dom(&mut document, editor_id, &paras);
                         // Update syntax visibility after cursor sync
@@ -528,13 +527,13 @@ fn handle_paste(evt: Event<ClipboardData>, document: &mut Signal<EditorDocument>
                         // Delete selection if present
                         if let Some(sel) = doc.selection {
                             let (start, end) = (sel.anchor.min(sel.head), sel.anchor.max(sel.head));
-                            doc.rope.remove(start..end);
+                            let _ = doc.remove_tracked(start, end.saturating_sub(start));
                             doc.cursor.offset = start;
                             doc.selection = None;
                         }
 
                         // Insert pasted text
-                        doc.rope.insert(doc.cursor.offset, &text);
+                        let _ = doc.insert_tracked(doc.cursor.offset, &text);
                         doc.cursor.offset += text.chars().count();
                     });
                 }
@@ -545,7 +544,7 @@ fn handle_paste(evt: Event<ClipboardData>, document: &mut Signal<EditorDocument>
     }
 }
 
-/// Handle cut events - extract text, write to clipboard, then delete from rope
+/// Handle cut events - extract text, write to clipboard, then delete
 fn handle_cut(evt: Event<ClipboardData>, document: &mut Signal<EditorDocument>) {
     tracing::info!("[CUT] handle_cut called");
 
@@ -560,8 +559,8 @@ fn handle_cut(evt: Event<ClipboardData>, document: &mut Signal<EditorDocument>)
                 if let Some(sel) = doc.selection {
                     let (start, end) = (sel.anchor.min(sel.head), sel.anchor.max(sel.head));
                     if start != end {
-                        // Extract text from rope
-                        let selected_text = extract_rope_slice(&doc.rope, start, end);
+                        // Extract text
+                        let selected_text = doc.slice(start, end).unwrap_or_default();
                         tracing::info!(
                             "[CUT] Extracted {} chars: {:?}",
                             selected_text.len(),
@@ -575,8 +574,8 @@ fn handle_cut(evt: Event<ClipboardData>, document: &mut Signal<EditorDocument>)
                             }
                         }
 
-                        // Now delete from rope
-                        doc.rope.remove(start..end);
+                        // Now delete
+                        let _ = doc.remove_tracked(start, end.saturating_sub(start));
                         doc.cursor.offset = start;
                         doc.selection = None;
                     }
@@ -591,7 +590,7 @@ fn handle_cut(evt: Event<ClipboardData>, document: &mut Signal<EditorDocument>)
     }
 }
 
-/// Handle copy events - extract text from rope, clean it up, write to clipboard
+/// Handle copy events - extract text, clean it up, write to clipboard
 fn handle_copy(evt: Event<ClipboardData>, document: &Signal<EditorDocument>) {
     tracing::info!("[COPY] handle_copy called");
 
@@ -606,8 +605,8 @@ fn handle_copy(evt: Event<ClipboardData>, document: &Signal<EditorDocument>) {
             if let Some(sel) = doc.selection {
                 let (start, end) = (sel.anchor.min(sel.head), sel.anchor.max(sel.head));
                 if start != end {
-                    // Extract text from rope
-                    let selected_text = extract_rope_slice(&doc.rope, start, end);
+                    // Extract text
+                    let selected_text = doc.slice(start, end).unwrap_or_default();
 
                     // Strip zero-width chars used for gap handling
                     let clean_text = selected_text
@@ -640,14 +639,9 @@ fn handle_copy(evt: Event<ClipboardData>, document: &Signal<EditorDocument>) {
     }
 }
 
-/// Extract a slice of text from the rope as a String
-fn extract_rope_slice(rope: &jumprope::JumpRopeBuf, start: usize, end: usize) -> String {
-    let mut result = String::new();
-    let rope_ref = rope.borrow();
-    for substr in rope_ref.slice_substrings(start..end) {
-        result.push_str(substr);
-    }
-    result
+/// Extract a slice of text from a string by char indices
+fn extract_text_slice(text: &str, start: usize, end: usize) -> String {
+    text.chars().skip(start).take(end.saturating_sub(start)).collect()
 }
 
 /// Handle keyboard events and update document state
@@ -675,30 +669,27 @@ fn handle_keydown(evt: Event<KeyboardData>, document: &mut Signal<EditorDocument
                     }
                 }
 
-                // Insert character at cursor
-                if doc.selection.is_some() {
-                    // Delete selection first
-                    let sel = doc.selection.unwrap();
+                // Insert character at cursor (replacing selection if any)
+                if let Some(sel) = doc.selection.take() {
                     let (start, end) = (sel.anchor.min(sel.head), sel.anchor.max(sel.head));
-                    doc.rope.remove(start..end);
-                    doc.cursor.offset = start;
-                    doc.selection = None;
+                    let _ = doc.replace_tracked(start, end.saturating_sub(start), &ch);
+                    doc.cursor.offset = start + ch.chars().count();
+                } else {
+                    let _ = doc.insert_tracked(doc.cursor.offset, &ch);
+                    doc.cursor.offset += ch.chars().count();
                 }
-
-                doc.rope.insert(doc.cursor.offset, &ch);
-                doc.cursor.offset += ch.chars().count();
             }
 
             Key::Backspace => {
                 if let Some(sel) = doc.selection {
                     // Delete selection
                     let (start, end) = (sel.anchor.min(sel.head), sel.anchor.max(sel.head));
-                    doc.rope.remove(start..end);
+                    let _ = doc.remove_tracked(start, end.saturating_sub(start));
                     doc.cursor.offset = start;
                     doc.selection = None;
                 } else if doc.cursor.offset > 0 {
                     // Check if we're about to delete a newline
-                    let prev_char = get_char_at(&doc.rope, doc.cursor.offset - 1);
+                    let prev_char = get_char_at(doc.loro_text(), doc.cursor.offset - 1);
 
                     if prev_char == Some('\n') {
                         let newline_pos = doc.cursor.offset - 1;
@@ -708,7 +699,7 @@ fn handle_keydown(evt: Event<KeyboardData>, document: &mut Signal<EditorDocument
                         // Check if there's another newline before this one (empty paragraph)
                         // If so, delete both newlines to merge paragraphs
                         if newline_pos > 0 {
-                            let prev_prev_char = get_char_at(&doc.rope, newline_pos - 1);
+                            let prev_prev_char = get_char_at(doc.loro_text(), newline_pos - 1);
                             if prev_prev_char == Some('\n') {
                                 // Empty paragraph case: delete both newlines
                                 delete_start = newline_pos - 1;
@@ -716,7 +707,7 @@ fn handle_keydown(evt: Event<KeyboardData>, document: &mut Signal<EditorDocument
                         }
 
                         // Also check if there's a zero-width char after cursor (inserted by Shift+Enter)
-                        if let Some(ch) = get_char_at(&doc.rope, delete_end) {
+                        if let Some(ch) = get_char_at(doc.loro_text(), delete_end) {
                             if ch == '\u{200C}' || ch == '\u{200B}' {
                                 delete_end += 1;
                             }
@@ -724,7 +715,7 @@ fn handle_keydown(evt: Event<KeyboardData>, document: &mut Signal<EditorDocument
 
                         // Scan backwards through whitespace before the newline(s)
                         while delete_start > 0 {
-                            let ch = get_char_at(&doc.rope, delete_start - 1);
+                            let ch = get_char_at(doc.loro_text(), delete_start - 1);
                             match ch {
                                 Some(' ') | Some('\t') | Some('\u{200C}') | Some('\u{200B}') => {
                                     delete_start -= 1;
@@ -735,27 +726,26 @@ fn handle_keydown(evt: Event<KeyboardData>, document: &mut Signal<EditorDocument
                         }
 
                         // Delete from where we stopped to end (including any trailing zero-width)
-                        doc.rope.remove(delete_start..delete_end);
+                        let _ = doc.remove_tracked(delete_start, delete_end.saturating_sub(delete_start));
                         doc.cursor.offset = delete_start;
                     } else {
                         // Normal backspace - delete one char
                         let prev = doc.cursor.offset - 1;
-                        doc.rope.remove(prev..doc.cursor.offset);
+                        let _ = doc.remove_tracked(prev, 1);
                         doc.cursor.offset = prev;
                     }
                 }
             }
 
             Key::Delete => {
-                if let Some(sel) = doc.selection {
+                if let Some(sel) = doc.selection.take() {
                     // Delete selection
                     let (start, end) = (sel.anchor.min(sel.head), sel.anchor.max(sel.head));
-                    doc.rope.remove(start..end);
+                    let _ = doc.remove_tracked(start, end.saturating_sub(start));
                     doc.cursor.offset = start;
-                    doc.selection = None;
                 } else if doc.cursor.offset < doc.len_chars() {
                     // Delete next char
-                    doc.rope.remove(doc.cursor.offset..doc.cursor.offset + 1);
+                    let _ = doc.remove_tracked(doc.cursor.offset, 1);
                 }
             }
 
@@ -765,44 +755,37 @@ fn handle_keydown(evt: Event<KeyboardData>, document: &mut Signal<EditorDocument
             }
 
             Key::Enter => {
-                if doc.selection.is_some() {
-                    let sel = doc.selection.unwrap();
+                if let Some(sel) = doc.selection.take() {
                     let (start, end) = (sel.anchor.min(sel.head), sel.anchor.max(sel.head));
-                    doc.rope.remove(start..end);
+                    let _ = doc.remove_tracked(start, end.saturating_sub(start));
                     doc.cursor.offset = start;
-                    doc.selection = None;
                 }
 
                 if mods.shift() {
                     // Shift+Enter: hard line break (soft break)
-                    doc.rope.insert(doc.cursor.offset, "  \n\u{200C}");
+                    let _ = doc.insert_tracked(doc.cursor.offset, "  \n\u{200C}");
                     doc.cursor.offset += 3;
-                } else if let Some(ctx) = detect_list_context(&doc.rope, doc.cursor.offset) {
+                } else if let Some(ctx) = detect_list_context(doc.loro_text(), doc.cursor.offset) {
                     // We're in a list item
                     tracing::debug!("[ENTER] List context detected: {:?}", ctx);
                     tracing::debug!(
-                        "[ENTER] Cursor at {}, rope len {}",
+                        "[ENTER] Cursor at {}, doc len {}",
                         doc.cursor.offset,
-                        doc.rope.len_chars()
+                        doc.len_chars()
                     );
-                    if is_list_item_empty(&doc.rope, doc.cursor.offset, &ctx) {
+                    if is_list_item_empty(doc.loro_text(), doc.cursor.offset, &ctx) {
                         tracing::debug!("[ENTER] Item is empty, exiting list");
                         // Empty item - exit list by removing marker and inserting paragraph break
-                        let line_start = find_line_start(&doc.rope, doc.cursor.offset);
-                        let line_end = find_line_end(&doc.rope, doc.cursor.offset);
+                        let line_start = find_line_start(doc.loro_text(), doc.cursor.offset);
+                        let line_end = find_line_end(doc.loro_text(), doc.cursor.offset);
 
                         // Delete the empty list item line INCLUDING its trailing newline
                         // line_end points to the newline, so +1 to include it
-                        let delete_end = (line_end + 1).min(doc.rope.len_chars());
+                        let delete_end = (line_end + 1).min(doc.len_chars());
 
-                        doc.rope.remove(line_start..delete_end);
-                        doc.cursor.offset = line_start;
-
-                        // Insert two newlines, a zero-width whitespace character, and then another
-                        // newline to properly split the list (TODO: clean up the weird whitespace
-                        // char once that new paragraph has content)
-                        doc.rope.insert(doc.cursor.offset, "\n\n\u{200C}\n");
-                        doc.cursor.offset += 2;
+                        // Use replace_tracked to atomically delete line and insert paragraph break
+                        let _ = doc.replace_tracked(line_start, delete_end.saturating_sub(line_start), "\n\n\u{200C}\n");
+                        doc.cursor.offset = line_start + 2;
                     } else {
                         // Non-empty item - continue list
                         let continuation = match ctx {
@@ -814,12 +797,12 @@ fn handle_keydown(evt: Event<KeyboardData>, document: &mut Signal<EditorDocument
                             }
                         };
                         let len = continuation.chars().count();
-                        doc.rope.insert(doc.cursor.offset, &continuation);
+                        let _ = doc.insert_tracked(doc.cursor.offset, &continuation);
                         doc.cursor.offset += len;
                     }
                 } else {
                     // Not in a list - normal paragraph break
-                    doc.rope.insert(doc.cursor.offset, "\n\n");
+                    let _ = doc.insert_tracked(doc.cursor.offset, "\n\n");
                     doc.cursor.offset += 2;
                 }
             }
@@ -846,22 +829,18 @@ enum ListContext {
 /// Detect if cursor is in a list item and return context for continuation.
 ///
 /// Scans backwards to find start of current line, then checks for list marker.
-fn detect_list_context(rope: &jumprope::JumpRopeBuf, cursor_offset: usize) -> Option<ListContext> {
+fn detect_list_context(text: &loro::LoroText, cursor_offset: usize) -> Option<ListContext> {
     // Find start of current line
-    let line_start = find_line_start(rope, cursor_offset);
+    let line_start = find_line_start(text, cursor_offset);
 
     // Get the line content from start to cursor
-    let line_end = find_line_end(rope, cursor_offset);
+    let line_end = find_line_end(text, cursor_offset);
     if line_start >= line_end {
         return None;
     }
 
     // Extract line text
-    let mut line = String::new();
-    let rope_ref = rope.borrow();
-    for substr in rope_ref.slice_substrings(line_start..line_end) {
-        line.push_str(substr);
-    }
+    let line = text.slice(line_start, line_end).ok()?;
 
     // Parse indentation
     let indent: String = line
@@ -901,19 +880,18 @@ fn detect_list_context(rope: &jumprope::JumpRopeBuf, cursor_offset: usize) -> Op
 ///
 /// Used to determine whether Enter should continue the list or exit it.
 fn is_list_item_empty(
-    rope: &jumprope::JumpRopeBuf,
+    text: &loro::LoroText,
     cursor_offset: usize,
     ctx: &ListContext,
 ) -> bool {
-    let line_start = find_line_start(rope, cursor_offset);
-    let line_end = find_line_end(rope, cursor_offset);
+    let line_start = find_line_start(text, cursor_offset);
+    let line_end = find_line_end(text, cursor_offset);
 
     // Get line content
-    let mut line = String::new();
-    let rope_ref = rope.borrow();
-    for substr in rope_ref.slice_substrings(line_start..line_end) {
-        line.push_str(substr);
-    }
+    let line = match text.slice(line_start, line_end) {
+        Ok(s) => s,
+        Err(_) => return false,
+    };
 
     // Calculate expected marker length
     let marker_len = match ctx {
@@ -935,63 +913,47 @@ fn is_list_item_empty(
     line.len() <= marker_len
 }
 
-/// Get character at the given offset in the rope
-fn get_char_at(rope: &jumprope::JumpRopeBuf, offset: usize) -> Option<char> {
-    if offset >= rope.len_chars() {
-        return None;
-    }
-
-    let rope = rope.borrow();
-    let mut current = 0;
-    for substr in rope.slice_substrings(offset..offset + 1) {
-        for c in substr.chars() {
-            if current == 0 {
-                return Some(c);
-            }
-            current += 1;
-        }
-    }
-    None
+/// Get character at the given offset in LoroText
+fn get_char_at(text: &loro::LoroText, offset: usize) -> Option<char> {
+    text.char_at(offset).ok()
 }
 
 /// Find start of line containing offset
-fn find_line_start(rope: &jumprope::JumpRopeBuf, offset: usize) -> usize {
-    // Search backwards from cursor for newline
-    let mut char_pos = 0;
-    let mut last_newline_pos = None;
-
-    let rope = rope.borrow();
-    for substr in rope.slice_substrings(0..offset) {
-        // TODO: make more efficient
-        for c in substr.chars() {
-            if c == '\n' {
-                last_newline_pos = Some(char_pos);
-            }
-            char_pos += 1;
-        }
+fn find_line_start(text: &loro::LoroText, offset: usize) -> usize {
+    if offset == 0 {
+        return 0;
     }
-
-    last_newline_pos.map(|pos| pos + 1).unwrap_or(0)
+    // Only slice the portion before cursor
+    let prefix = match text.slice(0, offset) {
+        Ok(s) => s,
+        Err(_) => return 0,
+    };
+    prefix
+        .chars()
+        .enumerate()
+        .filter(|(_, c)| *c == '\n')
+        .last()
+        .map(|(pos, _)| pos + 1)
+        .unwrap_or(0)
 }
 
 /// Find end of line containing offset
-fn find_line_end(rope: &jumprope::JumpRopeBuf, offset: usize) -> usize {
-    // Search forwards from cursor for newline
-    let mut char_pos = offset;
-
-    let rope = rope.borrow();
-    let byte_len = rope.len_bytes() - 1;
-    for substr in rope.slice_substrings(offset..byte_len) {
-        // TODO: make more efficient
-        for c in substr.chars() {
-            if c == '\n' {
-                return char_pos;
-            }
-            char_pos += 1;
-        }
+fn find_line_end(text: &loro::LoroText, offset: usize) -> usize {
+    let char_len = text.len_unicode();
+    if offset >= char_len {
+        return char_len;
     }
-
-    rope.len_chars()
+    // Only slice from cursor to end
+    let suffix = match text.slice(offset, char_len) {
+        Ok(s) => s,
+        Err(_) => return char_len,
+    };
+    suffix
+        .chars()
+        .enumerate()
+        .find(|(_, c)| *c == '\n')
+        .map(|(i, _)| offset + i)
+        .unwrap_or(char_len)
 }
 
 /// Update paragraph DOM elements incrementally.
diff --git a/crates/weaver-app/src/components/editor/paragraph.rs b/crates/weaver-app/src/components/editor/paragraph.rs
index dceafeb..67b27ce 100644
--- a/crates/weaver-app/src/components/editor/paragraph.rs
+++ b/crates/weaver-app/src/components/editor/paragraph.rs
@@ -5,7 +5,7 @@
 
 use super::offset_map::OffsetMapping;
 use super::writer::SyntaxSpanInfo;
-use jumprope::JumpRopeBuf;
+use loro::LoroText;
 use std::ops::Range;
 
 /// A rendered paragraph with its source range and offset mappings.
@@ -40,15 +40,8 @@ pub fn hash_source(text: &str) -> u64 {
     hasher.finish()
 }
 
-/// Extract substring from rope as String
-pub fn rope_slice_to_string(rope: &JumpRopeBuf, range: Range<usize>) -> String {
-    let rope_borrow = rope.borrow();
-    let mut result = String::new();
-
-    for substr in rope_borrow.slice_substrings(range) {
-        result.push_str(substr);
-    }
-
-    result
+/// Extract substring from LoroText as String
+pub fn text_slice_to_string(text: &LoroText, range: Range<usize>) -> String {
+    text.slice(range.start, range.end).unwrap_or_default()
 }
 
diff --git a/crates/weaver-app/src/components/editor/render.rs b/crates/weaver-app/src/components/editor/render.rs
index 52a7fb6..411f487 100644
--- a/crates/weaver-app/src/components/editor/render.rs
+++ b/crates/weaver-app/src/components/editor/render.rs
@@ -6,9 +6,9 @@
 
 use super::document::EditInfo;
 use super::offset_map::{OffsetMapping, RenderResult};
-use super::paragraph::{ParagraphRender, hash_source, rope_slice_to_string};
+use super::paragraph::{ParagraphRender, hash_source, text_slice_to_string};
 use super::writer::{EditorWriter, SyntaxSpanInfo};
-use jumprope::JumpRopeBuf;
+use loro::LoroText;
 use markdown_weaver::Parser;
 use std::ops::Range;
 
@@ -105,11 +105,11 @@ fn adjust_paragraph_positions(
 /// # Returns
 /// Tuple of (rendered paragraphs, updated cache)
 pub fn render_paragraphs_incremental(
-    rope: &JumpRopeBuf,
+    text: &LoroText,
     cache: Option<&RenderCache>,
     edit: Option<&EditInfo>,
 ) -> (Vec<ParagraphRender>, RenderCache) {
-    let source = rope.to_string();
+    let source = text.to_string();
 
     // Handle empty document
     if source.is_empty() {
@@ -190,7 +190,7 @@ pub fn render_paragraphs_incremental(
 
         match EditorWriter::<_, _, ()>::new_boundary_only(
             &source,
-            rope,
+            text,
             parser,
             &mut scratch_output,
         )
@@ -213,7 +213,7 @@ pub fn render_paragraphs_incremental(
     let mut syn_id_offset = cache.map(|c| c.next_syn_id).unwrap_or(0);
 
     for (idx, (byte_range, char_range)) in paragraph_ranges.iter().enumerate() {
-        let para_source = rope_slice_to_string(rope, char_range.clone());
+        let para_source = text_slice_to_string(text, char_range.clone());
         let source_hash = hash_source(&para_source);
 
         tracing::debug!(
@@ -250,8 +250,11 @@ pub fn render_paragraphs_incremental(
 
             (cached.html.clone(), adjusted_map, adjusted_syntax)
         } else {
-            // Fresh render needed
-            let para_rope = JumpRopeBuf::from(para_source.as_str());
+            // Fresh render needed - create detached LoroDoc for this paragraph
+            let para_doc = loro::LoroDoc::new();
+            let para_text = para_doc.get_text("content");
+            let _ = para_text.insert(0, &para_source);
+
             let parser = Parser::new_ext(&para_source, weaver_renderer::default_md_options())
                 .into_offset_iter();
             let mut output = String::new();
@@ -259,7 +262,7 @@ pub fn render_paragraphs_incremental(
             let (mut offset_map, mut syntax_spans) =
                 match EditorWriter::<_, _, ()>::new_with_offsets(
                     &para_source,
-                    &para_rope,
+                    &para_text,
                     parser,
                     &mut output,
                     node_id_offset,
@@ -374,7 +377,7 @@ pub fn render_paragraphs_incremental(
                     utf16_len: 1,
                 }],
                 syntax_spans: vec![],
-                source_hash: hash_source(&rope_slice_to_string(rope, gap_start_char..gap_end_char)),
+                source_hash: hash_source(&text_slice_to_string(text, gap_start_char..gap_end_char)),
             });
         }
 
@@ -386,8 +389,8 @@ pub fn render_paragraphs_incremental(
     // Add trailing gap if needed
     let has_trailing_newlines = source.ends_with("\n\n") || source.ends_with("\n");
     if has_trailing_newlines {
-        let doc_end_char = rope.len_chars();
-        let doc_end_byte = rope.len_bytes();
+        let doc_end_char = text.len_unicode();
+        let doc_end_byte = text.len_utf8();
 
         if doc_end_char > prev_end_char {
             // Position-based ID for trailing gap
diff --git a/crates/weaver-app/src/components/editor/rope_writer.rs b/crates/weaver-app/src/components/editor/rope_writer.rs
deleted file mode 100644
index e0ee68e..0000000
--- a/crates/weaver-app/src/components/editor/rope_writer.rs
+++ /dev/null
@@ -1,81 +0,0 @@
-//! StrWrite wrapper for JumpRopeBuf to enable efficient HTML rendering.
-
-use jumprope::JumpRopeBuf;
-use markdown_weaver_escape::StrWrite;
-
-/// Wrapper around JumpRopeBuf that implements StrWrite.
-///
-/// This allows rendering HTML directly into a rope structure, enabling:
-/// - O(log n) insertions instead of O(n) string reallocation
-/// - Efficient splicing for incremental rendering
-/// - Fast paragraph replacement in cached output
-pub struct RopeWriter {
-    rope: JumpRopeBuf,
-}
-
-impl RopeWriter {
-    pub fn new() -> Self {
-        Self {
-            rope: JumpRopeBuf::new(),
-        }
-    }
-
-    pub fn from_rope(rope: JumpRopeBuf) -> Self {
-        Self { rope }
-    }
-
-    pub fn into_rope(self) -> JumpRopeBuf {
-        self.rope
-    }
-
-    pub fn as_rope(&self) -> &JumpRopeBuf {
-        &self.rope
-    }
-
-    pub fn to_string(&self) -> String {
-        self.rope.to_string()
-    }
-}
-
-impl Default for RopeWriter {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-impl StrWrite for RopeWriter {
-    type Error = std::convert::Infallible;
-
-    fn write_str(&mut self, s: &str) -> Result<(), Self::Error> {
-        let offset = self.rope.len_chars();
-        self.rope.insert(offset, s);
-        Ok(())
-    }
-
-    fn write_fmt(&mut self, args: std::fmt::Arguments<'_>) -> Result<(), Self::Error> {
-        let mut temp = String::new();
-        std::fmt::Write::write_fmt(&mut temp, args).unwrap();
-        self.write_str(&temp)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_rope_writer_basic() {
-        let mut writer = RopeWriter::new();
-        writer.write_str("hello ").unwrap();
-        writer.write_str("world").unwrap();
-        assert_eq!(writer.to_string(), "hello world");
-    }
-
-    #[test]
-    fn test_rope_writer_fmt() {
-        use std::fmt::Write;
-        let mut writer = RopeWriter::new();
-        write!(&mut writer, "number: {}", 42).unwrap();
-        assert_eq!(writer.to_string(), "number: 42");
-    }
-}
diff --git a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__bold.snap b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__bold.snap
index 3b40ef4..c14d540 100644
--- a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__bold.snap
+++ b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__bold.snap
@@ -8,7 +8,7 @@ expression: result
   char_range:
     - 0
     - 18
-  html: "<p id=\"n0\">Some <span class=\"md-syntax-inline\" data-syn-id=\"s0\" data-char-start=\"5\" data-char-end=\"7\">**</span><strong>bold<span class=\"md-syntax-inline\" data-syn-id=\"s1\" data-char-start=\"11\" data-char-end=\"13\">**</span></strong> text</p>\n"
+  html: "<p id=\"n0\">Some <span class=\"md-syntax-inline\" data-syn-id=\"s0\" data-char-start=\"5\" data-char-end=\"7\">**</span><strong>bold</strong><span class=\"md-syntax-inline\" data-syn-id=\"s1\" data-char-start=\"11\" data-char-end=\"13\">**</span> text</p>\n"
   offset_map:
     - byte_range:
         - 0
@@ -30,6 +30,16 @@ expression: result
       char_offset_in_node: 0
       child_index: ~
       utf16_len: 5
+    - byte_range:
+        - 5
+        - 7
+      char_range:
+        - 5
+        - 7
+      node_id: n0
+      char_offset_in_node: 5
+      child_index: ~
+      utf16_len: 2
     - byte_range:
         - 7
         - 11
@@ -37,7 +47,7 @@ expression: result
         - 7
         - 11
       node_id: n0
-      char_offset_in_node: 5
+      char_offset_in_node: 7
       child_index: ~
       utf16_len: 4
     - byte_range:
@@ -47,7 +57,7 @@ expression: result
         - 11
         - 13
       node_id: n0
-      char_offset_in_node: 9
+      char_offset_in_node: 11
       child_index: ~
       utf16_len: 2
     - byte_range:
@@ -57,7 +67,7 @@ expression: result
         - 13
         - 18
       node_id: n0
-      char_offset_in_node: 11
+      char_offset_in_node: 13
       child_index: ~
       utf16_len: 5
   source_hash: 3007541947422346271
diff --git a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__bold_italic.snap b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__bold_italic.snap
index b57b724..3f66287 100644
--- a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__bold_italic.snap
+++ b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__bold_italic.snap
@@ -8,7 +8,7 @@ expression: result
   char_range:
     - 0
     - 27
-  html: "<p id=\"n0\">Some <span class=\"md-syntax-inline\" data-syn-id=\"s0\" data-char-start=\"5\" data-char-end=\"6\">*</span><em><span class=\"md-syntax-inline\" data-syn-id=\"s1\" data-char-start=\"6\" data-char-end=\"8\">**</span><strong>bold italic<span class=\"md-syntax-inline\" data-syn-id=\"s2\" data-char-start=\"19\" data-char-end=\"21\">**</span></strong><span class=\"md-syntax-inline\" data-syn-id=\"s3\" data-char-start=\"21\" data-char-end=\"22\">*</span></em> text</p>\n"
+  html: "<p id=\"n0\">Some <span class=\"md-syntax-inline\" data-syn-id=\"s0\" data-char-start=\"5\" data-char-end=\"6\">*</span><em><span class=\"md-syntax-inline\" data-syn-id=\"s1\" data-char-start=\"6\" data-char-end=\"8\">**</span><strong>bold italic</strong><span class=\"md-syntax-inline\" data-syn-id=\"s2\" data-char-start=\"19\" data-char-end=\"21\">**</span></em><span class=\"md-syntax-inline\" data-syn-id=\"s3\" data-char-start=\"21\" data-char-end=\"22\">*</span> text</p>\n"
   offset_map:
     - byte_range:
         - 0
@@ -30,6 +30,26 @@ expression: result
       char_offset_in_node: 0
       child_index: ~
       utf16_len: 5
+    - byte_range:
+        - 5
+        - 6
+      char_range:
+        - 5
+        - 6
+      node_id: n0
+      char_offset_in_node: 5
+      child_index: ~
+      utf16_len: 1
+    - byte_range:
+        - 6
+        - 8
+      char_range:
+        - 6
+        - 8
+      node_id: n0
+      char_offset_in_node: 6
+      child_index: ~
+      utf16_len: 2
     - byte_range:
         - 8
         - 19
@@ -37,7 +57,7 @@ expression: result
         - 8
         - 19
       node_id: n0
-      char_offset_in_node: 5
+      char_offset_in_node: 8
       child_index: ~
       utf16_len: 11
     - byte_range:
@@ -47,7 +67,7 @@ expression: result
         - 19
         - 21
       node_id: n0
-      char_offset_in_node: 16
+      char_offset_in_node: 19
       child_index: ~
       utf16_len: 2
     - byte_range:
@@ -57,7 +77,7 @@ expression: result
         - 21
         - 22
       node_id: n0
-      char_offset_in_node: 18
+      char_offset_in_node: 21
       child_index: ~
       utf16_len: 1
     - byte_range:
@@ -67,7 +87,7 @@ expression: result
         - 22
         - 27
       node_id: n0
-      char_offset_in_node: 19
+      char_offset_in_node: 22
       child_index: ~
       utf16_len: 5
   source_hash: 17839597501764990486
diff --git a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__inline_code.snap b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__inline_code.snap
index 577c385..18dca3e 100644
--- a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__inline_code.snap
+++ b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__inline_code.snap
@@ -39,7 +39,7 @@ expression: result
       node_id: n0
       char_offset_in_node: 5
       child_index: ~
-      utf16_len: 4
+      utf16_len: 6
     - byte_range:
         - 11
         - 16
@@ -47,7 +47,7 @@ expression: result
         - 11
         - 16
       node_id: n0
-      char_offset_in_node: 9
+      char_offset_in_node: 11
       child_index: ~
       utf16_len: 5
   source_hash: 10489263388249723293
diff --git a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__italic.snap b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__italic.snap
index 5419936..0cb4391 100644
--- a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__italic.snap
+++ b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__italic.snap
@@ -8,7 +8,7 @@ expression: result
   char_range:
     - 0
     - 18
-  html: "<p id=\"n0\">Some <span class=\"md-syntax-inline\" data-syn-id=\"s0\" data-char-start=\"5\" data-char-end=\"6\">*</span><em>italic<span class=\"md-syntax-inline\" data-syn-id=\"s1\" data-char-start=\"12\" data-char-end=\"13\">*</span></em> text</p>\n"
+  html: "<p id=\"n0\">Some <span class=\"md-syntax-inline\" data-syn-id=\"s0\" data-char-start=\"5\" data-char-end=\"6\">*</span><em>italic</em><span class=\"md-syntax-inline\" data-syn-id=\"s1\" data-char-start=\"12\" data-char-end=\"13\">*</span> text</p>\n"
   offset_map:
     - byte_range:
         - 0
@@ -30,6 +30,16 @@ expression: result
       char_offset_in_node: 0
       child_index: ~
       utf16_len: 5
+    - byte_range:
+        - 5
+        - 6
+      char_range:
+        - 5
+        - 6
+      node_id: n0
+      char_offset_in_node: 5
+      child_index: ~
+      utf16_len: 1
     - byte_range:
         - 6
         - 12
@@ -37,7 +47,7 @@ expression: result
         - 6
         - 12
       node_id: n0
-      char_offset_in_node: 5
+      char_offset_in_node: 6
       child_index: ~
       utf16_len: 6
     - byte_range:
@@ -47,7 +57,7 @@ expression: result
         - 12
         - 13
       node_id: n0
-      char_offset_in_node: 11
+      char_offset_in_node: 12
       child_index: ~
       utf16_len: 1
     - byte_range:
@@ -57,7 +67,7 @@ expression: result
         - 13
         - 18
       node_id: n0
-      char_offset_in_node: 12
+      char_offset_in_node: 13
       child_index: ~
       utf16_len: 5
   source_hash: 4363411941421262428
diff --git a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__multiple_inline_formats.snap b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__multiple_inline_formats.snap
index 9040222..b367c1c 100644
--- a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__multiple_inline_formats.snap
+++ b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__multiple_inline_formats.snap
@@ -8,7 +8,7 @@ expression: result
   char_range:
     - 0
     - 32
-  html: "<p id=\"n0\"><span class=\"md-syntax-inline\" data-syn-id=\"s0\" data-char-start=\"0\" data-char-end=\"2\">**</span><strong>Bold<span class=\"md-syntax-inline\" data-syn-id=\"s1\" data-char-start=\"6\" data-char-end=\"8\">**</span></strong> and <span class=\"md-syntax-inline\" data-syn-id=\"s2\" data-char-start=\"13\" data-char-end=\"14\">*</span><em>italic<span class=\"md-syntax-inline\" data-syn-id=\"s3\" data-char-start=\"20\" data-char-end=\"21\">*</span></em> and <span class=\"md-syntax-inline\" data-syn-id=\"s4\" data-char-start=\"26\" data-char-end=\"27\">`</span><code>code</code><span class=\"md-syntax-inline\" data-syn-id=\"s5\" data-char-start=\"31\" data-char-end=\"32\">`</span></p>\n"
+  html: "<p id=\"n0\"><span class=\"md-syntax-inline\" data-syn-id=\"s0\" data-char-start=\"0\" data-char-end=\"2\">**</span><strong>Bold</strong><span class=\"md-syntax-inline\" data-syn-id=\"s1\" data-char-start=\"6\" data-char-end=\"8\">**</span> and <span class=\"md-syntax-inline\" data-syn-id=\"s2\" data-char-start=\"13\" data-char-end=\"14\">*</span><em>italic</em><span class=\"md-syntax-inline\" data-syn-id=\"s3\" data-char-start=\"20\" data-char-end=\"21\">*</span> and <span class=\"md-syntax-inline\" data-syn-id=\"s4\" data-char-start=\"26\" data-char-end=\"27\">`</span><code>code</code><span class=\"md-syntax-inline\" data-syn-id=\"s5\" data-char-start=\"31\" data-char-end=\"32\">`</span></p>\n"
   offset_map:
     - byte_range:
         - 0
@@ -20,6 +20,16 @@ expression: result
       char_offset_in_node: 0
       child_index: 0
       utf16_len: 0
+    - byte_range:
+        - 0
+        - 2
+      char_range:
+        - 0
+        - 2
+      node_id: n0
+      char_offset_in_node: 0
+      child_index: ~
+      utf16_len: 2
     - byte_range:
         - 2
         - 6
@@ -27,7 +37,7 @@ expression: result
         - 2
         - 6
       node_id: n0
-      char_offset_in_node: 0
+      char_offset_in_node: 2
       child_index: ~
       utf16_len: 4
     - byte_range:
@@ -37,7 +47,7 @@ expression: result
         - 6
         - 8
       node_id: n0
-      char_offset_in_node: 4
+      char_offset_in_node: 6
       child_index: ~
       utf16_len: 2
     - byte_range:
@@ -47,9 +57,19 @@ expression: result
         - 8
         - 13
       node_id: n0
-      char_offset_in_node: 6
+      char_offset_in_node: 8
       child_index: ~
       utf16_len: 5
+    - byte_range:
+        - 13
+        - 14
+      char_range:
+        - 13
+        - 14
+      node_id: n0
+      char_offset_in_node: 13
+      child_index: ~
+      utf16_len: 1
     - byte_range:
         - 14
         - 20
@@ -57,7 +77,7 @@ expression: result
         - 14
         - 20
       node_id: n0
-      char_offset_in_node: 11
+      char_offset_in_node: 14
       child_index: ~
       utf16_len: 6
     - byte_range:
@@ -67,7 +87,7 @@ expression: result
         - 20
         - 21
       node_id: n0
-      char_offset_in_node: 17
+      char_offset_in_node: 20
       child_index: ~
       utf16_len: 1
     - byte_range:
@@ -77,7 +97,7 @@ expression: result
         - 21
         - 26
       node_id: n0
-      char_offset_in_node: 18
+      char_offset_in_node: 21
       child_index: ~
       utf16_len: 5
     - byte_range:
@@ -87,7 +107,7 @@ expression: result
         - 27
         - 31
       node_id: n0
-      char_offset_in_node: 23
+      char_offset_in_node: 26
       child_index: ~
-      utf16_len: 4
+      utf16_len: 6
   source_hash: 17988102203032347642
diff --git a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__ordered_list.snap b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__ordered_list.snap
index a2fa11f..f40a915 100644
--- a/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__ordered_list.snap
+++ b/crates/weaver-app/src/components/editor/snapshots/weaver_app__components__editor__tests__ordered_list.snap
@@ -8,28 +8,18 @@ expression: result
   char_range:
     - 0
     - 27
-  html: "<ol>\n<li data-node-id=\"n0\"><span class=\"md-syntax-block\" data-syn-id=\"s0\" data-char-start=\"0\" data-char-end=\"2\">1.</span><span class=\"md-syntax-inline\" data-syn-id=\"s1\" data-char-start=\"2\" data-char-end=\"3\"> </span>First<span class=\"md-syntax-inline\" data-syn-id=\"s2\" data-char-start=\"8\" data-char-end=\"9\">\n</span></li>\n<li data-node-id=\"n1\"><span class=\"md-syntax-block\" data-syn-id=\"s3\" data-char-start=\"9\" data-char-end=\"11\">2.</span><span class=\"md-syntax-inline\" data-syn-id=\"s4\" data-char-start=\"11\" data-char-end=\"12\"> </span>Second<span class=\"md-syntax-inline\" data-syn-id=\"s5\" data-char-start=\"18\" data-char-end=\"19\">\n</span></li>\n<li data-node-id=\"n2\"><span class=\"md-syntax-block\" data-syn-id=\"s6\" data-char-start=\"19\" data-char-end=\"21\">3.</span><span class=\"md-syntax-inline\" data-syn-id=\"s7\" data-char-start=\"21\" data-char-end=\"22\"> </span>Third</li>\n</ol>\n"
+  html: "<ol>\n<li data-node-id=\"n0\"><span class=\"md-syntax-block\" data-syn-id=\"s0\" data-char-start=\"0\" data-char-end=\"3\">1. </span>First<span class=\"md-syntax-inline\" data-syn-id=\"s1\" data-char-start=\"8\" data-char-end=\"9\">\n</span></li>\n<li data-node-id=\"n1\"><span class=\"md-syntax-block\" data-syn-id=\"s2\" data-char-start=\"9\" data-char-end=\"12\">2. </span>Second<span class=\"md-syntax-inline\" data-syn-id=\"s3\" data-char-start=\"18\" data-char-end=\"19\">\n</span></li>\n<li data-node-id=\"n2\"><span class=\"md-syntax-block\" data-syn-id=\"s4\" data-char-start=\"19\" data-char-end=\"22\">3. </span>Third</li>\n</ol>\n"
   offset_map:
     - byte_range:
         - 0
-        - 2
-      char_range:
-        - 0
-        - 2
-      node_id: n0
-      char_offset_in_node: 0
-      child_index: ~
-      utf16_len: 2
-    - byte_range:
-        - 2
         - 3
       char_range:
-        - 2
+        - 0
         - 3
       node_id: n0
-      char_offset_in_node: 2
+      char_offset_in_node: 0
       child_index: ~
-      utf16_len: 1
+      utf16_len: 3
     - byte_range:
         - 3
         - 8
@@ -52,24 +42,14 @@ expression: result
       utf16_len: 1
     - byte_range:
         - 9
-        - 11
-      char_range:
-        - 9
-        - 11
-      node_id: n1
-      char_offset_in_node: 0
-      child_index: ~
-      utf16_len: 2
-    - byte_range:
-        - 11
         - 12
       char_range:
-        - 11
+        - 9
         - 12
       node_id: n1
-      char_offset_in_node: 2
+      char_offset_in_node: 0
       child_index: ~
-      utf16_len: 1
+      utf16_len: 3
     - byte_range:
         - 12
         - 18
@@ -92,24 +72,14 @@ expression: result
       utf16_len: 1
     - byte_range:
         - 19
-        - 21
-      char_range:
-        - 19
-        - 21
-      node_id: n2
-      char_offset_in_node: 0
-      child_index: ~
-      utf16_len: 2
-    - byte_range:
-        - 21
         - 22
       char_range:
-        - 21
+        - 19
         - 22
       node_id: n2
-      char_offset_in_node: 2
+      char_offset_in_node: 0
       child_index: ~
-      utf16_len: 1
+      utf16_len: 3
     - byte_range:
         - 22
         - 27
diff --git a/crates/weaver-app/src/components/editor/tests.rs b/crates/weaver-app/src/components/editor/tests.rs
index 07e32ac..0ee81c6 100644
--- a/crates/weaver-app/src/components/editor/tests.rs
+++ b/crates/weaver-app/src/components/editor/tests.rs
@@ -3,7 +3,7 @@
 use super::offset_map::{OffsetMapping, find_mapping_for_char};
 use super::paragraph::ParagraphRender;
 use super::render::render_paragraphs_incremental;
-use jumprope::JumpRopeBuf;
+use loro::LoroDoc;
 use serde::Serialize;
 
 /// Serializable version of ParagraphRender for snapshot testing.
@@ -54,8 +54,10 @@ impl From<&OffsetMapping> for TestOffsetMapping {
 
 /// Helper: render markdown and convert to serializable test output.
 fn render_test(input: &str) -> Vec<TestParagraph> {
-    let rope = JumpRopeBuf::from(input);
-    let (paragraphs, _cache) = render_paragraphs_incremental(&rope, None, None);
+    let doc = LoroDoc::new();
+    let text = doc.get_text("content");
+    text.insert(0, input).unwrap();
+    let (paragraphs, _cache) = render_paragraphs_incremental(&text, None, None);
     paragraphs.iter().map(TestParagraph::from).collect()
 }
 
@@ -434,8 +436,10 @@ fn test_char_range_coverage_allows_paragraph_breaks() {
     // cursor snaps to adjacent paragraphs for standard breaks.
     // Only EXTRA whitespace beyond \n\n gets gap elements.
     let input = "Hello\n\nWorld";
-    let rope = JumpRopeBuf::from(input);
-    let (paragraphs, _cache) = render_paragraphs_incremental(&rope, None, None);
+    let doc = LoroDoc::new();
+    let text = doc.get_text("content");
+    text.insert(0, input).unwrap();
+    let (paragraphs, _cache) = render_paragraphs_incremental(&text, None, None);
 
     // With standard \n\n break, we expect 2 paragraphs (no gap element)
     // Paragraph ranges include some trailing whitespace from markdown parsing
@@ -453,8 +457,10 @@ fn test_char_range_coverage_with_extra_whitespace() {
     // Extra whitespace beyond MIN_PARAGRAPH_BREAK (2) gets gap elements
     // Plain paragraphs don't consume trailing newlines like headings do
     let input = "Hello\n\n\n\nWorld"; // 4 newlines = gap of 4 > 2
-    let rope = JumpRopeBuf::from(input);
-    let (paragraphs, _cache) = render_paragraphs_incremental(&rope, None, None);
+    let doc = LoroDoc::new();
+    let text = doc.get_text("content");
+    text.insert(0, input).unwrap();
+    let (paragraphs, _cache) = render_paragraphs_incremental(&text, None, None);
 
     // With extra newlines, we expect 3 elements: para, gap, para
     assert_eq!(paragraphs.len(), 3, "Expected 3 elements with extra whitespace");
@@ -542,13 +548,15 @@ fn test_offset_mappings_reference_own_paragraph() {
 fn test_incremental_cache_reuse() {
     // Verify cache is populated and can be reused
     let input = "First para\n\nSecond para";
-    let rope = JumpRopeBuf::from(input);
+    let doc = LoroDoc::new();
+    let text = doc.get_text("content");
+    text.insert(0, input).unwrap();
 
-    let (paras1, cache1) = render_paragraphs_incremental(&rope, None, None);
+    let (paras1, cache1) = render_paragraphs_incremental(&text, None, None);
     assert!(!cache1.paragraphs.is_empty(), "Cache should be populated");
 
     // Second render with same content should reuse cache
-    let (paras2, _cache2) = render_paragraphs_incremental(&rope, Some(&cache1), None);
+    let (paras2, _cache2) = render_paragraphs_incremental(&text, Some(&cache1), None);
 
     // Should produce identical output
     assert_eq!(paras1.len(), paras2.len());
diff --git a/crates/weaver-app/src/components/editor/visibility.rs b/crates/weaver-app/src/components/editor/visibility.rs
index 8251c68..4dbcea2 100644
--- a/crates/weaver-app/src/components/editor/visibility.rs
+++ b/crates/weaver-app/src/components/editor/visibility.rs
@@ -33,29 +33,57 @@ impl VisibilityState {
         let mut visible = HashSet::new();
 
         for span in syntax_spans {
+            // Find the paragraph containing this span for boundary clamping
+            let para_bounds = find_paragraph_bounds(&span.char_range, paragraphs);
+
             let should_show = match span.syntax_type {
                 SyntaxType::Inline => {
                     // Show if cursor within formatted span content OR adjacent to markers
-                    // "Adjacent" means within 1 char of the syntax boundaries
-                    let extended_range = span.char_range.start.saturating_sub(1)
-                        ..span.char_range.end.saturating_add(1);
+                    // "Adjacent" means within 1 char of the syntax boundaries,
+                    // clamped to paragraph bounds (paragraphs are split by newlines,
+                    // so clamping to para bounds prevents cross-line extension)
+                    let extended_start =
+                        safe_extend_left(span.char_range.start, 1, para_bounds.as_ref());
+                    let extended_end =
+                        safe_extend_right(span.char_range.end, 1, para_bounds.as_ref());
+                    let extended_range = extended_start..extended_end;
 
                     // Also show if cursor is anywhere in the formatted_range
                     // (the region between paired opening/closing markers)
+                    // Extend by 1 char on BOTH sides for symmetric "approaching" behavior,
+                    // clamped to paragraph bounds.
                     let in_formatted_region = span
                         .formatted_range
                         .as_ref()
-                        .map(|r| r.contains(&cursor_offset))
+                        .map(|r| {
+                            let ext_start = safe_extend_left(r.start, 1, para_bounds.as_ref());
+                            let ext_end = safe_extend_right(r.end, 1, para_bounds.as_ref());
+                            cursor_offset >= ext_start && cursor_offset <= ext_end
+                        })
                         .unwrap_or(false);
 
-                    extended_range.contains(&cursor_offset)
+                    let in_extended = extended_range.contains(&cursor_offset);
+                    let result = in_extended
                         || in_formatted_region
                         || selection_overlaps(selection, &span.char_range)
                         || span
                             .formatted_range
                             .as_ref()
                             .map(|r| selection_overlaps(selection, r))
-                            .unwrap_or(false)
+                            .unwrap_or(false);
+
+                    tracing::debug!(
+                        "[VISIBILITY] span {} char_range {:?} formatted_range {:?} cursor {} -> in_extended={} in_formatted={} visible={}",
+                        span.syn_id,
+                        span.char_range,
+                        span.formatted_range,
+                        cursor_offset,
+                        in_extended,
+                        in_formatted_region,
+                        result
+                    );
+
+                    result
                 }
                 SyntaxType::Block => {
                     // Show if cursor anywhere in same paragraph
@@ -116,6 +144,42 @@ fn cursor_in_same_paragraph(
     false
 }
 
+/// Find the paragraph bounds containing a syntax span.
+fn find_paragraph_bounds(
+    syntax_range: &Range<usize>,
+    paragraphs: &[ParagraphRender],
+) -> Option<Range<usize>> {
+    for para in paragraphs {
+        // Skip gap paragraphs
+        if para.syntax_spans.is_empty() && !para.char_range.is_empty() {
+            continue;
+        }
+
+        if para.char_range.start <= syntax_range.start && syntax_range.end <= para.char_range.end {
+            return Some(para.char_range.clone());
+        }
+    }
+    None
+}
+
+/// Safely extend a position leftward by `amount` chars, clamped to paragraph bounds.
+///
+/// Paragraphs are already split by newlines, so clamping to paragraph bounds
+/// naturally prevents extending across line boundaries.
+fn safe_extend_left(pos: usize, amount: usize, para_bounds: Option<&Range<usize>>) -> usize {
+    let min_pos = para_bounds.map(|p| p.start).unwrap_or(0);
+    pos.saturating_sub(amount).max(min_pos)
+}
+
+/// Safely extend a position rightward by `amount` chars, clamped to paragraph bounds.
+///
+/// Paragraphs are already split by newlines, so clamping to paragraph bounds
+/// naturally prevents extending across line boundaries.
+fn safe_extend_right(pos: usize, amount: usize, para_bounds: Option<&Range<usize>>) -> usize {
+    let max_pos = para_bounds.map(|p| p.end).unwrap_or(usize::MAX);
+    pos.saturating_add(amount).min(max_pos)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -197,10 +261,12 @@ mod tests {
 
     #[test]
     fn test_inline_visibility_cursor_adjacent() {
+        // "test **bold** after"
+        //       5  7
         let spans = vec![
             make_span("s0", 5, 7, SyntaxType::Inline), // ** at positions 5-6
         ];
-        let paras = vec![make_para(0, 20, spans.clone())];
+        let paras = vec![make_para(0, 19, spans.clone())];
 
         // Cursor at position 4 (one before ** which starts at 5)
         let vis = VisibilityState::calculate(4, None, &spans, &paras);
@@ -216,7 +282,7 @@ mod tests {
         let spans = vec![
             make_span("s0", 10, 12, SyntaxType::Inline),
         ];
-        let paras = vec![make_para(0, 30, spans.clone())];
+        let paras = vec![make_para(0, 33, spans.clone())];
 
         // Cursor at position 0 (far from **)
         let vis = VisibilityState::calculate(0, None, &spans, &paras);
@@ -259,11 +325,44 @@ mod tests {
         let spans = vec![
             make_span("s0", 5, 7, SyntaxType::Inline),
         ];
-        let paras = vec![make_para(0, 20, spans.clone())];
+        let paras = vec![make_para(0, 24, spans.clone())];
 
         // Selection overlaps the syntax span
         let selection = Selection { anchor: 3, head: 10 };
         let vis = VisibilityState::calculate(10, Some(&selection), &spans, &paras);
         assert!(vis.is_visible("s0"), "** should be visible when selection overlaps");
     }
+
+    #[test]
+    fn test_paragraph_boundary_blocks_extension() {
+        // Cursor in paragraph 2 should NOT reveal syntax in paragraph 1,
+        // even if cursor is only 1 char after the paragraph boundary
+        // (paragraph bounds clamp the extension)
+        let spans = vec![
+            make_span_with_range("s0", 0, 2, SyntaxType::Inline, 0..8), // opening **
+            make_span_with_range("s1", 6, 8, SyntaxType::Inline, 0..8), // closing **
+        ];
+        let paras = vec![
+            make_para(0, 8, spans.clone()),  // "**bold**"
+            make_para(9, 13, vec![]),        // "text" (after newline)
+        ];
+
+        // Cursor at position 9 (start of second paragraph)
+        // Should NOT reveal the closing ** because para bounds clamp extension
+        let vis = VisibilityState::calculate(9, None, &spans, &paras);
+        assert!(!vis.is_visible("s1"), "closing ** should NOT be visible when cursor is in next paragraph");
+    }
+
+    #[test]
+    fn test_extension_clamps_to_paragraph() {
+        // Syntax at very start of paragraph - extension left should stop at para start
+        let spans = vec![
+            make_span_with_range("s0", 0, 2, SyntaxType::Inline, 0..8),
+        ];
+        let paras = vec![make_para(0, 8, spans.clone())];
+
+        // Cursor at position 0 - should still see the opening **
+        let vis = VisibilityState::calculate(0, None, &spans, &paras);
+        assert!(vis.is_visible("s0"), "** at start should be visible when cursor at position 0");
+    }
 }
diff --git a/crates/weaver-app/src/components/editor/writer.rs b/crates/weaver-app/src/components/editor/writer.rs
index 67a03e7..32033f2 100644
--- a/crates/weaver-app/src/components/editor/writer.rs
+++ b/crates/weaver-app/src/components/editor/writer.rs
@@ -7,7 +7,7 @@
 //! represent consumed formatting characters.
 
 use super::offset_map::{OffsetMapping, RenderResult};
-use jumprope::JumpRopeBuf;
+use loro::LoroText;
 use markdown_weaver::{
     Alignment, BlockQuoteKind, CodeBlockKind, CowStr, EmbedType, Event, LinkType, Tag,
 };
@@ -109,7 +109,7 @@ impl EmbedContentProvider for () {
 /// and emits them as styled spans for visibility in the editor.
 pub struct EditorWriter<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E = ()> {
     source: &'a str,
-    source_rope: &'a JumpRopeBuf,
+    source_text: &'a LoroText,
     events: I,
     writer: W,
     last_byte_offset: usize,
@@ -142,6 +142,11 @@ pub struct EditorWriter<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: St
     current_node_char_offset: usize, // UTF-16 offset within current node
     current_node_child_count: usize, // number of child elements/text nodes in current container
 
+    // Incremental UTF-16 offset tracking (replaces rope.chars_to_wchars)
+    // Maps char_offset -> utf16_offset at checkpoints we've traversed.
+    // Can be reused for future lookups or passed to subsequent writers.
+    utf16_checkpoints: Vec<(usize, usize)>, // (char_offset, utf16_offset)
+
     // Paragraph boundary tracking for incremental rendering
     paragraph_ranges: Vec<(Range<usize>, Range<usize>)>, // (byte_range, char_range)
     current_paragraph_start: Option<(usize, usize)>,     // (byte_offset, char_offset)
@@ -170,23 +175,23 @@ enum TableState {
 impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedContentProvider>
     EditorWriter<'a, I, W, E>
 {
-    pub fn new(source: &'a str, source_rope: &'a JumpRopeBuf, events: I, writer: W) -> Self {
-        Self::new_with_node_offset(source, source_rope, events, writer, 0)
+    pub fn new(source: &'a str, source_text: &'a LoroText, events: I, writer: W) -> Self {
+        Self::new_with_node_offset(source, source_text, events, writer, 0)
     }
 
     pub fn new_with_node_offset(
         source: &'a str,
-        source_rope: &'a JumpRopeBuf,
+        source_text: &'a LoroText,
         events: I,
         writer: W,
         node_id_offset: usize,
     ) -> Self {
-        Self::new_with_offsets(source, source_rope, events, writer, node_id_offset, 0)
+        Self::new_with_offsets(source, source_text, events, writer, node_id_offset, 0)
     }
 
     pub fn new_with_offsets(
         source: &'a str,
-        source_rope: &'a JumpRopeBuf,
+        source_text: &'a LoroText,
         events: I,
         writer: W,
         node_id_offset: usize,
@@ -194,7 +199,7 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
     ) -> Self {
         Self {
             source,
-            source_rope,
+            source_text,
             events,
             writer,
             last_byte_offset: 0,
@@ -217,6 +222,7 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
             current_node_id: None,
             current_node_char_offset: 0,
             current_node_child_count: 0,
+            utf16_checkpoints: vec![(0, 0)],
             paragraph_ranges: Vec::new(),
             current_paragraph_start: None,
             list_depth: 0,
@@ -232,13 +238,13 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
     /// Used for fast boundary discovery in incremental rendering.
     pub fn new_boundary_only(
         source: &'a str,
-        source_rope: &'a JumpRopeBuf,
+        source_text: &'a LoroText,
         events: I,
         writer: W,
     ) -> Self {
         Self {
             source,
-            source_rope,
+            source_text,
             events,
             writer,
             last_byte_offset: 0,
@@ -261,6 +267,7 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
             current_node_id: None,
             current_node_char_offset: 0,
             current_node_child_count: 0,
+            utf16_checkpoints: vec![(0, 0)],
             syntax_spans: Vec::new(),
             next_syn_id: 0,
             pending_inline_formats: Vec::new(),
@@ -276,7 +283,7 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
     pub fn with_embed_provider(self, provider: E) -> EditorWriter<'a, I, W, E> {
         EditorWriter {
             source: self.source,
-            source_rope: self.source_rope,
+            source_text: self.source_text,
             events: self.events,
             writer: self.writer,
             last_byte_offset: self.last_byte_offset,
@@ -299,6 +306,7 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
             current_node_id: self.current_node_id,
             current_node_char_offset: self.current_node_char_offset,
             current_node_child_count: self.current_node_child_count,
+            utf16_checkpoints: self.utf16_checkpoints,
             paragraph_ranges: self.paragraph_ranges,
             current_paragraph_start: self.current_paragraph_start,
             list_depth: self.list_depth,
@@ -343,6 +351,12 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
             let format_end = self.last_char_offset;
             let formatted_range = format_start..format_end;
 
+            tracing::debug!(
+                "[FINALIZE_PAIRED] Setting formatted_range {:?} for opening '{}' and closing (last span)",
+                formatted_range,
+                opening_syn_id
+            );
+
             // Update the opening span's formatted_range
             if let Some(opening_span) = self
                 .syntax_spans
@@ -350,6 +364,9 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
                 .find(|s| s.syn_id == opening_syn_id)
             {
                 opening_span.formatted_range = Some(formatted_range.clone());
+                tracing::debug!("[FINALIZE_PAIRED] Updated opening span {}", opening_syn_id);
+            } else {
+                tracing::warn!("[FINALIZE_PAIRED] Could not find opening span {}", opening_syn_id);
             }
 
             // Update the closing span's formatted_range (the most recent one)
@@ -358,6 +375,7 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
                 // Only update if it's an inline span (closing syntax should be inline)
                 if closing_span.syntax_type == SyntaxType::Inline {
                     closing_span.formatted_range = Some(formatted_range);
+                    tracing::debug!("[FINALIZE_PAIRED] Updated closing span {}", closing_span.syn_id);
                 }
             }
         }
@@ -544,16 +562,38 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
         self.current_node_child_count = 0;
     }
 
+    /// Compute UTF-16 length for a text slice with fast path for ASCII.
+    #[inline]
+    fn utf16_len_for_slice(text: &str) -> usize {
+        let byte_len = text.len();
+        let char_len = text.chars().count();
+
+        // Fast path: if byte_len == char_len, all ASCII, so utf16_len == char_len
+        if byte_len == char_len {
+            char_len
+        } else {
+            // Slow path: has multi-byte chars, need to count UTF-16 code units
+            text.encode_utf16().count()
+        }
+    }
+
     /// Record an offset mapping for the given byte and char ranges.
     ///
-    /// Computes UTF-16 length efficiently using the rope's internal indexing.
+    /// Builds up utf16_checkpoints incrementally for efficient lookups.
     fn record_mapping(&mut self, byte_range: Range<usize>, char_range: Range<usize>) {
         if let Some(ref node_id) = self.current_node_id {
-            // Use rope to convert char offsets to UTF-16 (wchar) offsets - O(log n)
-            let rope = self.source_rope.borrow();
-            let wchar_start = rope.chars_to_wchars(char_range.start);
-            let wchar_end = rope.chars_to_wchars(char_range.end);
-            let utf16_len = wchar_end - wchar_start;
+            // Get UTF-16 length using fast path
+            let text_slice = &self.source[byte_range.clone()];
+            let utf16_len = Self::utf16_len_for_slice(text_slice);
+
+            // Record checkpoint at end of this range for future lookups
+            let last_checkpoint = self.utf16_checkpoints.last().copied().unwrap_or((0, 0));
+            let new_utf16_offset = last_checkpoint.1 + utf16_len;
+
+            // Only add checkpoint if we've advanced
+            if char_range.end > last_checkpoint.0 {
+                self.utf16_checkpoints.push((char_range.end, new_utf16_offset));
+            }
 
             let mapping = OffsetMapping {
                 byte_range: byte_range.clone(),
@@ -601,15 +641,27 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
 
             // For End events, emit any trailing content within the event's range
             // BEFORE calling end_tag (which calls end_node and clears current_node_id)
-            if matches!(&event, Event::End(_)) {
+            //
+            // EXCEPTION: For inline formatting tags (Strong, Emphasis, Strikethrough),
+            // the closing syntax must be emitted AFTER the closing HTML tag, not before.
+            // Otherwise the closing `**` span ends up INSIDE the <strong> element.
+            // These tags handle their own closing syntax in end_tag().
+            use markdown_weaver::TagEnd;
+            let is_inline_format_end = matches!(
+                &event,
+                Event::End(TagEnd::Strong | TagEnd::Emphasis | TagEnd::Strikethrough)
+            );
+
+            if matches!(&event, Event::End(_)) && !is_inline_format_end {
                 // Emit gap from last_byte_offset to range.end
                 // (emit_syntax handles char offset tracking)
                 self.emit_gap_before(range.end)?;
-            } else {
+            } else if !matches!(&event, Event::End(_)) {
                 // For other events, emit any gap before range.start
                 // (emit_syntax handles char offset tracking)
                 self.emit_gap_before(range.start)?;
             }
+            // For inline format End events, gap is emitted inside end_tag() AFTER the closing HTML
 
             // Store last_byte before processing
             let last_byte_before = self.last_byte_offset;
@@ -632,7 +684,7 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
         // Handle unmapped trailing content (stripped by parser)
         // This includes trailing spaces that markdown ignores
         let doc_byte_len = self.source.len();
-        let doc_char_len = self.source_rope.len_chars();
+        let doc_char_len = self.source_text.len_unicode();
 
         if self.last_byte_offset < doc_byte_len || self.last_char_offset < doc_char_len {
             // Emit the trailing content as visible syntax
@@ -1174,6 +1226,13 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
                     formatted_range: None, // Will be updated when closing tag is emitted
                 });
 
+                // Record offset mapping for cursor positioning
+                // This is critical - without it, current_node_char_offset is wrong
+                // and all subsequent cursor positions are shifted
+                let byte_start = range.start;
+                let byte_end = range.start + syntax_byte_len;
+                self.record_mapping(byte_start..byte_end, char_start..char_end);
+
                 // For paired inline syntax (Strong, Emphasis, Strikethrough),
                 // track the opening span so we can set formatted_range when closing
                 if matches!(tag, Tag::Strong | Tag::Emphasis | Tag::Strikethrough) {
@@ -1990,18 +2049,27 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
                 self.write("</dd>\n")
             }
             TagEnd::Emphasis => {
+                // Write closing tag FIRST, then emit closing syntax OUTSIDE the tag
+                self.write("</em>")?;
+                self.emit_gap_before(range.end)?;
                 self.finalize_paired_inline_format();
-                self.write("</em>")
+                Ok(())
             }
             TagEnd::Superscript => self.write("</sup>"),
             TagEnd::Subscript => self.write("</sub>"),
             TagEnd::Strong => {
+                // Write closing tag FIRST, then emit closing syntax OUTSIDE the tag
+                self.write("</strong>")?;
+                self.emit_gap_before(range.end)?;
                 self.finalize_paired_inline_format();
-                self.write("</strong>")
+                Ok(())
             }
             TagEnd::Strikethrough => {
+                // Write closing tag FIRST, then emit closing syntax OUTSIDE the tag
+                self.write("</s>")?;
+                self.emit_gap_before(range.end)?;
                 self.finalize_paired_inline_format();
-                self.write("</s>")
+                Ok(())
             }
             TagEnd::Link => self.write("</a>"),
             TagEnd::Image => Ok(()), // No-op: raw_text() already consumed the End(Image) event
@@ -2019,9 +2087,10 @@ impl<'a, I: Iterator<Item = (Event<'a>, Range<usize>)>, W: StrWrite, E: EmbedCon
 
         result?;
 
-        // Note: Closing syntax for inline tags (Strong, Emphasis, etc.) is now handled
-        // by emit_gap_before(range.end) which is called before end_tag() in the main loop.
-        // No need for manual emission here anymore.
+        // Note: Closing syntax for inline formatting tags (Strong, Emphasis, Strikethrough)
+        // is handled INSIDE their respective match arms above, AFTER writing the closing HTML.
+        // This ensures the closing syntax span appears OUTSIDE the formatted element.
+        // Other End events have their closing syntax emitted by emit_gap_before() in the main loop.
 
         Ok(())
     }