diff --git a/packages/ui/src/components/chat/composer/ui/ComposerContextChips.tsx b/packages/ui/src/components/chat/composer/ui/ComposerContextChips.tsx
index cdb19baa..832dc623 100644
--- a/packages/ui/src/components/chat/composer/ui/ComposerContextChips.tsx
+++ b/packages/ui/src/components/chat/composer/ui/ComposerContextChips.tsx
@@ -40,14 +40,14 @@ type ChipGroup = {
     drafts: InlineCommentDraft[];
 };
 
-const REVIEW_SOURCES: readonly InlineCommentSource[] = ['diff', 'file', 'plan'];
+const REVIEW_SOURCES: readonly InlineCommentSource[] = ['diff', 'file', 'plan', 'file-quote'];
 
 /** Sources whose drafts carry a user-written comment that can be edited. */
 const editableSource = (source: InlineCommentSource): boolean => source !== 'terminal';
 
 /** Captured code/output kinds read better monospaced; quoted prose does not. */
 const monoSource = (source: InlineCommentSource): boolean =>
-    source !== 'chat-quote' && source !== 'preview-annotation';
+    source !== 'chat-quote' && source !== 'preview-annotation' && source !== 'file-quote';
 
 const basename = (path: string): string => {
     const segments = path.split('/').filter(Boolean);
@@ -259,6 +259,12 @@ export function ComposerContextChips({ draftTarget, colors }: ComposerContextChi
                 return t('chat.message.context.prCheck', { label: draft.fileLabel });
             case 'chat-quote':
                 return t('chat.message.context.chatQuote');
+            case 'file-quote':
+                return draft.startLine > 0 && draft.endLine > 0
+                    ? (draft.startLine === draft.endLine
+                        ? t('chat.message.context.codeCommentLine', { file: basename(draft.fileLabel), line: draft.startLine })
+                        : t('chat.message.context.codeComment', { file: basename(draft.fileLabel), start: draft.startLine, end: draft.endLine }))
+                    : t('chat.message.context.fileQuote', { file: basename(draft.fileLabel) });
             default:
                 return draft.startLine === draft.endLine
                     ? t('chat.message.context.codeCommentLine', { file: basename(draft.fileLabel), line: draft.startLine })
diff --git a/packages/ui/src/components/chat/message/TextSelectionMenu.tsx b/packages/ui/src/components/chat/message/TextSelectionMenu.tsx
index 6acb3dd0..d52f8d26 100644
--- a/packages/ui/src/components/chat/message/TextSelectionMenu.tsx
+++ b/packages/ui/src/components/chat/message/TextSelectionMenu.tsx
@@ -18,6 +18,7 @@ import { isVSCodeRuntime } from '@/lib/desktop';
 import { useI18n } from '@/lib/i18n';
 import { rangeToMarkdown, trimSelectionValue, wrapMarkdownSelectionForChat } from './selectionMarkdown';
 import { focusChatInput } from '@/components/chat/composer/editor/dom';
+import { collectSelectionOverlayRects } from '@/lib/selectionOverlayRects';
 
 interface TextSelectionMenuProps {
   containerRef: React.RefObject<HTMLElement | null>;
@@ -67,56 +68,7 @@ export const TextSelectionMenu: React.FC<TextSelectionMenuProps> = ({ containerR
       return;
     }
 
-    const textRects: DOMRect[] = [];
-    const pushNodeRects = (node: Text) => {
-      const nodeRange = document.createRange();
-      nodeRange.selectNodeContents(node);
-      if (node === range.startContainer) nodeRange.setStart(node, range.startOffset);
-      if (node === range.endContainer) nodeRange.setEnd(node, range.endOffset);
-      // Text rects cover only the glyph box; the native selection paints the
-      // full line box, so each rect is stretched to its element's line-height.
-      const lineHeight = node.parentElement
-        ? Number.parseFloat(window.getComputedStyle(node.parentElement).lineHeight)
-        : Number.NaN;
-      for (const rect of nodeRange.getClientRects()) {
-        if (rect.width <= 0 || rect.height <= 0) continue;
-        if (Number.isFinite(lineHeight) && lineHeight > rect.height) {
-          const expand = (lineHeight - rect.height) / 2;
-          textRects.push(new DOMRect(rect.left, rect.top - expand, rect.width, lineHeight));
-        } else {
-          textRects.push(rect);
-        }
-      }
-    };
-    const root = range.commonAncestorContainer;
-    if (root instanceof Text) {
-      pushNodeRects(root);
-    } else {
-      // SAFETY: the walker is created with SHOW_TEXT, so every node it
-      // yields is a Text node.
-      const walker = document.createTreeWalker(root, NodeFilter.SHOW_TEXT);
-      for (let node = walker.nextNode(); node; node = walker.nextNode()) {
-        if (range.intersectsNode(node)) pushNodeRects(node as Text);
-      }
-    }
-
-    // Merge rects that sit on the same visual line into one strip, the way
-    // the native selection paints a line box.
-    const lines: Array<{ left: number; right: number; top: number; bottom: number }> = [];
-    for (const rect of textRects) {
-      const line = lines.find((candidate) => (
-        Math.abs(candidate.top - rect.top) < 6 && Math.abs(candidate.bottom - rect.bottom) < 6
-      ));
-      if (line) {
-        line.left = Math.min(line.left, rect.left);
-        line.right = Math.max(line.right, rect.right);
-        line.top = Math.min(line.top, rect.top);
-        line.bottom = Math.max(line.bottom, rect.bottom);
-      } else {
-        lines.push({ left: rect.left, right: rect.right, top: rect.top, bottom: rect.bottom });
-      }
-    }
-    setCommentRects(lines.map((line) => new DOMRect(line.left, line.top, line.right - line.left, line.bottom - line.top)));
+    setCommentRects(collectSelectionOverlayRects(range));
   }, []);
 
   React.useEffect(() => {
diff --git a/packages/ui/src/components/chat/message/parts/UserContextPart.tsx b/packages/ui/src/components/chat/message/parts/UserContextPart.tsx
index 6b95823a..3f1e2cac 100644
--- a/packages/ui/src/components/chat/message/parts/UserContextPart.tsx
+++ b/packages/ui/src/components/chat/message/parts/UserContextPart.tsx
@@ -113,6 +113,15 @@ const UserContextPart: React.FC<{ payload: ContextPartPayload }> = ({ payload })
                     text={payload.text}
                 />
             );
+        case 'file-quote': {
+            const file = basename(payload.fileLabel);
+            const summary = payload.startLine != null && payload.endLine != null
+                ? (payload.startLine === payload.endLine
+                    ? t('chat.message.context.codeCommentLine', { file, line: payload.startLine })
+                    : t('chat.message.context.codeComment', { file, start: payload.startLine, end: payload.endLine }))
+                : t('chat.message.context.fileQuote', { file });
+            return <ContextCard icon="chat-1" summary={summary} title={payload.fileLabel} body={payload.quote} text={payload.text} />;
+        }
         case 'chat-quote':
             return (
                 <ContextCard
diff --git a/packages/ui/src/components/comments/FilePreviewCommentMenu.tsx b/packages/ui/src/components/comments/FilePreviewCommentMenu.tsx
new file mode 100644
index 00000000..5f5ada68
--- /dev/null
+++ b/packages/ui/src/components/comments/FilePreviewCommentMenu.tsx
@@ -0,0 +1,258 @@
+import React from 'react';
+import { createPortal } from 'react-dom';
+
+import { cn } from '@/lib/utils';
+import { useI18n } from '@/lib/i18n';
+import { useEffectiveDirectory } from '@/hooks/useEffectiveDirectory';
+import { useSessionUIStore } from '@/sync/session-ui-store';
+import { useInlineCommentDraftStore } from '@/stores/useInlineCommentDraftStore';
+import { focusChatInput } from '@/components/chat/composer/editor/dom';
+import { collectSelectionOverlayRects } from '@/lib/selectionOverlayRects';
+import { InlineCommentInput } from './InlineCommentInput';
+
+interface FilePreviewCommentMenuProps {
+  containerRef: React.RefObject<HTMLElement | null>;
+  filePath: string;
+  /** Raw file source, used to locate the selected fragment's line range. */
+  fileContent: string;
+}
+
+/**
+ * Comment-on-selection for read-only file previews (rendered markdown and the
+ * like). Selecting text shows a small Comment pill above the selection;
+ * choosing it opens the shared comment input, and attaching stores a
+ * file-quote context draft carrying the selected fragment (with a best-effort
+ * source line range) plus the user's comment.
+ */
+export function FilePreviewCommentMenu({ containerRef, filePath, fileContent }: FilePreviewCommentMenuProps) {
+  const { t } = useI18n();
+  const currentSessionId = useSessionUIStore((state) => state.currentSessionId);
+  const newSessionDraftOpen = useSessionUIStore((state) => state.newSessionDraft?.open);
+  const effectiveDirectory = useEffectiveDirectory();
+  const addDraft = useInlineCommentDraftStore((state) => state.addDraft);
+
+  const [anchor, setAnchor] = React.useState<{ x: number; y: number } | null>(null);
+  const [selectedText, setSelectedText] = React.useState('');
+  const [commentMode, setCommentMode] = React.useState(false);
+  const commentModeRef = React.useRef(false);
+  const menuRef = React.useRef<HTMLDivElement>(null);
+  const selectionRangeRef = React.useRef<Range | null>(null);
+  // The selected fragment stays visibly highlighted while the comment input
+  // owns focus, same as chat quote comments.
+  const [highlightRects, setHighlightRects] = React.useState<DOMRect[] | null>(null);
+
+  const hide = React.useCallback(() => {
+    setAnchor(null);
+    setSelectedText('');
+    setCommentMode(false);
+    commentModeRef.current = false;
+    selectionRangeRef.current = null;
+    setHighlightRects(null);
+  }, []);
+
+  React.useEffect(() => {
+    const container = containerRef.current;
+    if (!container) return;
+
+    const handleSelectionChange = () => {
+      if (commentModeRef.current) return;
+      const selection = window.getSelection();
+      const text = selection?.toString().trim() ?? '';
+      if (!selection || !text || selection.rangeCount === 0) {
+        hide();
+        return;
+      }
+      const range = selection.getRangeAt(0);
+      if (!container.contains(range.commonAncestorContainer)) {
+        hide();
+        return;
+      }
+      const rect = range.getBoundingClientRect();
+      selectionRangeRef.current = range.cloneRange();
+      setSelectedText(text);
+      setAnchor({ x: rect.left + rect.width / 2, y: rect.top - 10 });
+    };
+
+    const handlePointerDown = (event: PointerEvent) => {
+      // SAFETY: a pointer event target inside the document is always a Node;
+      // `contains` only needs that.
+      if (menuRef.current?.contains(event.target as Node)) return;
+      if (commentModeRef.current) {
+        hide();
+      }
+    };
+
+    document.addEventListener('selectionchange', handleSelectionChange);
+    document.addEventListener('pointerdown', handlePointerDown);
+    return () => {
+      document.removeEventListener('selectionchange', handleSelectionChange);
+      document.removeEventListener('pointerdown', handlePointerDown);
+    };
+  }, [containerRef, hide]);
+
+  /**
+   * Best-effort mapping of the rendered-text selection back to source lines:
+   * an exact match of the fragment (or its first line) in the raw content
+   * yields a range; markdown syntax usually breaks the match, in which case
+   * the draft simply carries no line numbers.
+   */
+  const resolveLineRange = React.useCallback((fragment: string): { start: number; end: number } | null => {
+    const lineAt = (index: number): number => fileContent.slice(0, index).split('\n').length;
+    // Inline markdown syntax (emphasis markers and such) breaks long matches,
+    // so each anchor line is tried at decreasing lengths.
+    const candidatesFor = (line: string): string[] => {
+      const trimmed = line.trim();
+      return [trimmed, trimmed.slice(0, 32), trimmed.split(' ').slice(0, 4).join(' ')]
+        .filter((candidate) => candidate.length >= 8);
+    };
+    const locate = (line: string, from: number): number => {
+      for (const candidate of candidatesFor(line)) {
+        const index = fileContent.indexOf(candidate, from);
+        if (index >= 0) return index;
+      }
+      return -1;
+    };
+
+    const exact = fragment.length >= 8 ? fileContent.indexOf(fragment) : -1;
+    if (exact >= 0) {
+      const start = lineAt(exact);
+      return { start, end: start + fragment.split('\n').length - 1 };
+    }
+
+    const fragmentLines = fragment.split('\n').map((line) => line.trim()).filter(Boolean);
+    if (fragmentLines.length === 0) return null;
+    const startIndex = locate(fragmentLines[0], 0);
+    if (startIndex < 0) return null;
+    const start = lineAt(startIndex);
+    if (fragmentLines.length === 1) return { start, end: start };
+    const endIndex = locate(fragmentLines[fragmentLines.length - 1], startIndex);
+    // A partially located multi-line fragment gets no range rather than a
+    // misleading single-line one.
+    if (endIndex < 0) return null;
+    return { start, end: Math.max(start, lineAt(endIndex)) };
+  }, [fileContent]);
+
+  const updateHighlightRects = React.useCallback(() => {
+    const range = selectionRangeRef.current;
+    if (!range) {
+      setHighlightRects(null);
+      return;
+    }
+    setHighlightRects(collectSelectionOverlayRects(range));
+  }, []);
+
+  React.useEffect(() => {
+    if (!commentMode) return;
+    let frame: number | null = null;
+    const scheduleUpdate = () => {
+      if (frame !== null) return;
+      frame = window.requestAnimationFrame(() => {
+        frame = null;
+        updateHighlightRects();
+      });
+    };
+    document.addEventListener('scroll', scheduleUpdate, { capture: true, passive: true });
+    window.addEventListener('resize', scheduleUpdate);
+    return () => {
+      if (frame !== null) window.cancelAnimationFrame(frame);
+      document.removeEventListener('scroll', scheduleUpdate, { capture: true });
+      window.removeEventListener('resize', scheduleUpdate);
+    };
+  }, [commentMode, updateHighlightRects]);
+
+  const openComment = React.useCallback(() => {
+    if (!selectedText) return;
+    setCommentMode(true);
+    commentModeRef.current = true;
+    updateHighlightRects();
+    window.getSelection()?.removeAllRanges();
+  }, [selectedText, updateHighlightRects]);
+
+  const saveComment = React.useCallback((text: string) => {
+    const sessionKey = currentSessionId ?? (newSessionDraftOpen ? 'draft' : null);
+    if (!selectedText || !sessionKey || !effectiveDirectory) {
+      hide();
+      return;
+    }
+    const lineRange = resolveLineRange(selectedText);
+    addDraft({ directory: effectiveDirectory, sessionKey }, {
+      source: 'file-quote',
+      fileLabel: filePath,
+      startLine: lineRange?.start ?? 0,
+      endLine: lineRange?.end ?? 0,
+      code: selectedText,
+      language: '',
+      text: text.trim(),
+    });
+    hide();
+    queueMicrotask(() => {
+      focusChatInput();
+    });
+  }, [addDraft, currentSessionId, effectiveDirectory, filePath, hide, newSessionDraftOpen, resolveLineRange, selectedText]);
+
+  if (!anchor) return null;
+
+  const lineRange = commentMode ? resolveLineRange(selectedText) : null;
+
+  return createPortal(
+    <div
+      ref={menuRef}
+      className="fixed z-50"
+      style={{
+        left: anchor.x,
+        top: anchor.y,
+        transform: 'translate(-50%, -100%)',
+      }}
+    >
+      {commentMode && highlightRects && highlightRects.length > 0
+        ? createPortal(
+          <div className="pointer-events-none fixed inset-0 z-40">
+            {highlightRects.map((rect, index) => (
+              <div
+                key={index}
+                className="oc-chat-comment-rect absolute"
+                style={{ left: rect.left, top: rect.top, width: rect.width, height: rect.height }}
+              />
+            ))}
+          </div>,
+          document.body,
+        )
+        : null}
+      {commentMode ? (
+        <div className="w-[min(420px,80vw)]">
+          <InlineCommentInput
+            fileLabel={filePath}
+            lineRange={lineRange ? { start: lineRange.start, end: lineRange.end } : undefined}
+            onSave={saveComment}
+            onCancel={hide}
+          />
+        </div>
+      ) : (
+        <div
+          className={cn(
+            'flex items-center whitespace-nowrap',
+            'rounded-full border border-[var(--interactive-border)]',
+            'bg-[var(--surface-elevated)] shadow-[0_4px_16px_-4px_rgb(0_0_0_/_0.12)]',
+            'p-1',
+          )}
+        >
+          <button
+            type="button"
+            onClick={openComment}
+            className={cn(
+              'px-3.5 py-1.5 rounded-full',
+              'text-sm font-medium',
+              'text-[var(--surface-foreground)]',
+              'hover:bg-[var(--interactive-hover)]',
+              'transition-colors duration-150'
+            )}
+            title={t('chat.textSelection.title.commentOnSelection')}
+          >
+            {t('chat.textSelection.actions.comment')}
+          </button>
+        </div>
+      )}
+    </div>,
+    document.body,
+  );
+}
diff --git a/packages/ui/src/components/comments/index.ts b/packages/ui/src/components/comments/index.ts
index 264f8db3..3f2dabec 100644
--- a/packages/ui/src/components/comments/index.ts
+++ b/packages/ui/src/components/comments/index.ts
@@ -4,3 +4,4 @@ export * from './useInlineCommentController';
 export * from './CodeMirrorCommentWidgets';
 export * from './PierreDiffCommentUtils';
 export * from './PierreDiffCommentOverlays';
+export * from './FilePreviewCommentMenu';
diff --git a/packages/ui/src/components/views/FilesView.tsx b/packages/ui/src/components/views/FilesView.tsx
index 212d02ec..05ca0323 100644
--- a/packages/ui/src/components/views/FilesView.tsx
+++ b/packages/ui/src/components/views/FilesView.tsx
@@ -60,7 +60,7 @@ import { useUIStore } from '@/stores/useUIStore';
 import { useFilesViewTabsStore } from '@/stores/useFilesViewTabsStore';
 import { useGitStatus } from '@/stores/useGitStore';
 import { useConfigStore } from '@/stores/useConfigStore';
-import { buildCodeMirrorCommentWidgets, normalizeLineRange, useInlineCommentController } from '@/components/comments';
+import { buildCodeMirrorCommentWidgets, FilePreviewCommentMenu, normalizeLineRange, useInlineCommentController } from '@/components/comments';
 import { opencodeClient } from '@/lib/opencode/client';
 import { useDirectoryShowHidden } from '@/lib/directoryShowHidden';
 import { useFilesViewShowGitignored } from '@/lib/filesViewShowGitignored';
@@ -1071,6 +1071,8 @@ export const FilesView: React.FC<FilesViewProps> = ({ mode = 'full' }) => {
     return lines.slice(startLine - 1, endLine).join('\n');
   }, []);
 
+  const markdownPreviewRef = React.useRef<HTMLDivElement | null>(null);
+
   const fileCommentController = useInlineCommentController<SelectedLineRange>({
     source: 'file',
     fileLabel: selectedFile?.path ?? null,
@@ -3943,7 +3945,12 @@ export const FilesView: React.FC<FilesViewProps> = ({ mode = 'full' }) => {
               </div>
             </ErrorBoundary>
           ) : selectedFile && isMarkdown && getMdViewMode() === 'preview' ? (
-            <div className="h-full overflow-auto p-3">
+            <div className="oc-file-preview h-full overflow-auto p-3" ref={markdownPreviewRef}>
+              <FilePreviewCommentMenu
+                containerRef={markdownPreviewRef}
+                filePath={selectedFile.path}
+                fileContent={fileContent}
+              />
               {fileContent.length > 500 * 1024 && (
                 <div className="mb-3 rounded-md border border-status-warning/20 bg-status-warning/10 px-3 py-2 text-sm text-status-warning">
                   {t('filesView.warning.largeFilePreviewLimited', { sizeKb: Math.round(fileContent.length / 1024) })}
@@ -4309,7 +4316,14 @@ export const FilesView: React.FC<FilesViewProps> = ({ mode = 'full' }) => {
               ) : null}
             </div>
           ) : isMarkdown && getMdViewMode() === 'preview' ? (
-            <div className="h-full overflow-auto p-4">
+            <div className="oc-file-preview h-full overflow-auto p-4" ref={markdownPreviewRef}>
+              {selectedFile ? (
+                <FilePreviewCommentMenu
+                  containerRef={markdownPreviewRef}
+                  filePath={selectedFile.path}
+                  fileContent={fileContent}
+                />
+              ) : null}
               {fileContent.length > 500 * 1024 && (
                   <div className="mb-3 rounded-md border border-status-warning/20 bg-status-warning/10 px-3 py-2 text-sm text-status-warning">
                     {t('filesView.warning.largeFilePreviewLimited', { sizeKb: Math.round(fileContent.length / 1024) })}
diff --git a/packages/ui/src/index.css b/packages/ui/src/index.css
index 0a87622c..c487cd09 100644
--- a/packages/ui/src/index.css
+++ b/packages/ui/src/index.css
@@ -76,7 +76,9 @@ button,
 }
 
 :root.light .message-content-text::selection,
-:root.light .message-content-text ::selection {
+:root.light .message-content-text ::selection,
+:root.light .oc-file-preview::selection,
+:root.light .oc-file-preview ::selection {
   background: color-mix(in srgb, var(--interactive-border-focus) 18%, transparent);
   color: var(--surface-foreground);
 }
diff --git a/packages/ui/src/lib/i18n/messages/de.ts b/packages/ui/src/lib/i18n/messages/de.ts
index 2afe1428..4f0f3bc2 100644
--- a/packages/ui/src/lib/i18n/messages/de.ts
+++ b/packages/ui/src/lib/i18n/messages/de.ts
@@ -2907,6 +2907,7 @@ export const dict = {
   'chat.message.context.codeComment': 'Kommentar zu {file}, Zeilen {start}-{end}',
   'chat.message.context.codeCommentLine': 'Kommentar zu {file}, Zeile {line}',
   'chat.message.context.chatQuote': 'Zitat aus einer früheren Nachricht',
+  'chat.message.context.fileQuote': 'Auswahl aus {file}',
   'chat.chatInput.chatQuoteContext': 'Chat-Zitate',
   'chat.chatInput.chatQuoteContextRemove': 'Chat-Zitate entfernen',
   'chat.chatInput.contextPreview.selectedLabel': 'Ausgewählter Text',
diff --git a/packages/ui/src/lib/i18n/messages/en.ts b/packages/ui/src/lib/i18n/messages/en.ts
index 3926eab2..fc9a2717 100644
--- a/packages/ui/src/lib/i18n/messages/en.ts
+++ b/packages/ui/src/lib/i18n/messages/en.ts
@@ -8,6 +8,7 @@ export const dict = {
   'chat.message.context.codeComment': 'Comment on {file}, lines {start}-{end}',
   'chat.message.context.codeCommentLine': 'Comment on {file}, line {line}',
   'chat.message.context.chatQuote': 'Quoted from an earlier message',
+  'chat.message.context.fileQuote': 'Selection from {file}',
   'chat.chatInput.chatQuoteContext': 'Chat quotes',
   'chat.chatInput.chatQuoteContextRemove': 'Remove chat quotes',
   'chat.chatInput.contextPreview.selectedLabel': 'Selected text',
diff --git a/packages/ui/src/lib/i18n/messages/es.ts b/packages/ui/src/lib/i18n/messages/es.ts
index d722b79c..17fec35e 100644
--- a/packages/ui/src/lib/i18n/messages/es.ts
+++ b/packages/ui/src/lib/i18n/messages/es.ts
@@ -9,6 +9,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.message.context.codeComment': 'Comentario en {file}, líneas {start}-{end}',
   'chat.message.context.codeCommentLine': 'Comentario en {file}, línea {line}',
   'chat.message.context.chatQuote': 'Cita de un mensaje anterior',
+  'chat.message.context.fileQuote': 'Selección de {file}',
   'chat.chatInput.chatQuoteContext': 'Citas del chat',
   'chat.chatInput.chatQuoteContextRemove': 'Quitar citas del chat',
   'chat.chatInput.contextPreview.selectedLabel': 'Texto seleccionado',
diff --git a/packages/ui/src/lib/i18n/messages/fr.ts b/packages/ui/src/lib/i18n/messages/fr.ts
index d65c0585..0cf10e61 100644
--- a/packages/ui/src/lib/i18n/messages/fr.ts
+++ b/packages/ui/src/lib/i18n/messages/fr.ts
@@ -8,6 +8,7 @@ export const dict = {
   'chat.message.context.codeComment': 'Commentaire sur {file}, lignes {start}-{end}',
   'chat.message.context.codeCommentLine': 'Commentaire sur {file}, ligne {line}',
   'chat.message.context.chatQuote': 'Citation d’un message précédent',
+  'chat.message.context.fileQuote': 'Sélection de {file}',
   'chat.chatInput.chatQuoteContext': 'Citations du chat',
   'chat.chatInput.chatQuoteContextRemove': 'Supprimer les citations du chat',
   'chat.chatInput.contextPreview.selectedLabel': 'Texte sélectionné',
diff --git a/packages/ui/src/lib/i18n/messages/ja.ts b/packages/ui/src/lib/i18n/messages/ja.ts
index fbaae9d8..5796a5b0 100644
--- a/packages/ui/src/lib/i18n/messages/ja.ts
+++ b/packages/ui/src/lib/i18n/messages/ja.ts
@@ -9,6 +9,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.message.context.codeComment': '{file} の {start}〜{end} 行へのコメント',
   'chat.message.context.codeCommentLine': '{file} の {line} 行へのコメント',
   'chat.message.context.chatQuote': '以前のメッセージからの引用',
+  'chat.message.context.fileQuote': '{file} からの選択',
   'chat.chatInput.chatQuoteContext': 'チャット引用',
   'chat.chatInput.chatQuoteContextRemove': 'チャット引用を削除',
   'chat.chatInput.contextPreview.selectedLabel': '選択したテキスト',
diff --git a/packages/ui/src/lib/i18n/messages/ko.ts b/packages/ui/src/lib/i18n/messages/ko.ts
index 8bc95a7e..80d4f60e 100644
--- a/packages/ui/src/lib/i18n/messages/ko.ts
+++ b/packages/ui/src/lib/i18n/messages/ko.ts
@@ -9,6 +9,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.message.context.codeComment': '{file} {start}-{end}행에 대한 댓글',
   'chat.message.context.codeCommentLine': '{file} {line}행에 대한 댓글',
   'chat.message.context.chatQuote': '이전 메시지에서 인용',
+  'chat.message.context.fileQuote': '{file}에서 선택한 부분',
   'chat.chatInput.chatQuoteContext': '채팅 인용',
   'chat.chatInput.chatQuoteContextRemove': '채팅 인용 제거',
   'chat.chatInput.contextPreview.selectedLabel': '선택한 텍스트',
diff --git a/packages/ui/src/lib/i18n/messages/pl.ts b/packages/ui/src/lib/i18n/messages/pl.ts
index b8bf6843..c29a1dfa 100644
--- a/packages/ui/src/lib/i18n/messages/pl.ts
+++ b/packages/ui/src/lib/i18n/messages/pl.ts
@@ -9,6 +9,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.message.context.codeComment': 'Komentarz do {file}, wiersze {start}-{end}',
   'chat.message.context.codeCommentLine': 'Komentarz do {file}, wiersz {line}',
   'chat.message.context.chatQuote': 'Cytat z wcześniejszej wiadomości',
+  'chat.message.context.fileQuote': 'Zaznaczenie z {file}',
   'chat.chatInput.chatQuoteContext': 'Cytaty z czatu',
   'chat.chatInput.chatQuoteContextRemove': 'Usuń cytaty z czatu',
   'chat.chatInput.contextPreview.selectedLabel': 'Zaznaczony tekst',
diff --git a/packages/ui/src/lib/i18n/messages/pt-BR.ts b/packages/ui/src/lib/i18n/messages/pt-BR.ts
index 7e2643ca..5e988ce3 100644
--- a/packages/ui/src/lib/i18n/messages/pt-BR.ts
+++ b/packages/ui/src/lib/i18n/messages/pt-BR.ts
@@ -9,6 +9,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.message.context.codeComment': 'Comentário em {file}, linhas {start}-{end}',
   'chat.message.context.codeCommentLine': 'Comentário em {file}, linha {line}',
   'chat.message.context.chatQuote': 'Citação de uma mensagem anterior',
+  'chat.message.context.fileQuote': 'Seleção de {file}',
   'chat.chatInput.chatQuoteContext': 'Citações do chat',
   'chat.chatInput.chatQuoteContextRemove': 'Remover citações do chat',
   'chat.chatInput.contextPreview.selectedLabel': 'Texto selecionado',
diff --git a/packages/ui/src/lib/i18n/messages/uk.ts b/packages/ui/src/lib/i18n/messages/uk.ts
index 1e660cd9..1f10374f 100644
--- a/packages/ui/src/lib/i18n/messages/uk.ts
+++ b/packages/ui/src/lib/i18n/messages/uk.ts
@@ -9,6 +9,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.message.context.codeComment': 'Коментар до {file}, рядки {start}-{end}',
   'chat.message.context.codeCommentLine': 'Коментар до {file}, рядок {line}',
   'chat.message.context.chatQuote': 'Цитата з попереднього повідомлення',
+  'chat.message.context.fileQuote': 'Виділене з {file}',
   'chat.chatInput.chatQuoteContext': 'Цитати з чату',
   'chat.chatInput.chatQuoteContextRemove': 'Прибрати цитати з чату',
   'chat.chatInput.contextPreview.selectedLabel': 'Виділений текст',
diff --git a/packages/ui/src/lib/i18n/messages/zh-CN.ts b/packages/ui/src/lib/i18n/messages/zh-CN.ts
index f54c4640..2b0c7263 100644
--- a/packages/ui/src/lib/i18n/messages/zh-CN.ts
+++ b/packages/ui/src/lib/i18n/messages/zh-CN.ts
@@ -9,6 +9,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.message.context.codeComment': '对 {file} 第 {start}-{end} 行的评论',
   'chat.message.context.codeCommentLine': '对 {file} 第 {line} 行的评论',
   'chat.message.context.chatQuote': '引用自先前的消息',
+  'chat.message.context.fileQuote': '来自 {file} 的选择',
   'chat.chatInput.chatQuoteContext': '聊天引用',
   'chat.chatInput.chatQuoteContextRemove': '移除聊天引用',
   'chat.chatInput.contextPreview.selectedLabel': '所选文本',
diff --git a/packages/ui/src/lib/i18n/messages/zh-TW.ts b/packages/ui/src/lib/i18n/messages/zh-TW.ts
index e2338503..842450c1 100644
--- a/packages/ui/src/lib/i18n/messages/zh-TW.ts
+++ b/packages/ui/src/lib/i18n/messages/zh-TW.ts
@@ -9,6 +9,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.message.context.codeComment': '對 {file} 第 {start}-{end} 行的評論',
   'chat.message.context.codeCommentLine': '對 {file} 第 {line} 行的評論',
   'chat.message.context.chatQuote': '引用自先前的訊息',
+  'chat.message.context.fileQuote': '來自 {file} 的選取內容',
   'chat.chatInput.chatQuoteContext': '聊天引用',
   'chat.chatInput.chatQuoteContextRemove': '移除聊天引用',
   'chat.chatInput.contextPreview.selectedLabel': '所選文字',
diff --git a/packages/ui/src/lib/messages/contextParts.test.ts b/packages/ui/src/lib/messages/contextParts.test.ts
index 81cfd8cc..eb980435 100644
--- a/packages/ui/src/lib/messages/contextParts.test.ts
+++ b/packages/ui/src/lib/messages/contextParts.test.ts
@@ -68,6 +68,13 @@ describe('model-facing text', () => {
             .toBe('Comment on this fragment of an earlier message in this conversation:\n> first line\n> second line\n\nwhy so?');
     });
 
+    test('file quotes carry the fragment with an optional line range', () => {
+        expect(formatContextText(contextPayloadFromDraft(draft({ source: 'file-quote', fileLabel: 'docs/CHANGELOG.md', startLine: 12, endLine: 13, code: 'a\nb', text: 'why?' }))))
+            .toBe('Comment on this fragment of `docs/CHANGELOG.md` lines 12-13:\n> a\n> b\n\nwhy?');
+        expect(formatContextText(contextPayloadFromDraft(draft({ source: 'file-quote', fileLabel: 'docs/CHANGELOG.md', startLine: 0, endLine: 0, code: 'a', text: '' }))))
+            .toBe('Comment on this fragment of `docs/CHANGELOG.md`:\n> a');
+    });
+
     test('PR comments and checks keep their attachment wording', () => {
         expect(formatContextText(contextPayloadFromDraft(draft({ source: 'pr-comment', fileLabel: 'octo/repo#7', code: 'the comment', text: '' }))))
             .toBe('Attached GitHub PR comment (octo/repo#7):\n\nthe comment');
@@ -91,6 +98,8 @@ describe('round-trip through part metadata', () => {
             contextPayloadFromDraft(draft({ source: 'pr-comment' })),
             contextPayloadFromDraft(draft({ source: 'pr-check' })),
             contextPayloadFromDraft(draft({ source: 'chat-quote', fileLabel: 'msg_1' })),
+            contextPayloadFromDraft(draft({ source: 'file-quote', startLine: 3, endLine: 5 })),
+            contextPayloadFromDraft(draft({ source: 'file-quote', startLine: 0, endLine: 0 })),
         ];
         for (const payload of payloads) {
             expect(readContextPart(asPart(payload))).toEqual(payload);
diff --git a/packages/ui/src/lib/messages/contextParts.ts b/packages/ui/src/lib/messages/contextParts.ts
index 41a95e2a..d31e0ee0 100644
--- a/packages/ui/src/lib/messages/contextParts.ts
+++ b/packages/ui/src/lib/messages/contextParts.ts
@@ -71,6 +71,16 @@ type GitHubIssueContext = {
     url: string;
 };
 
+type FileQuoteContext = {
+    kind: 'file-quote';
+    fileLabel: string;
+    /** Present when the fragment could be located in the file source. */
+    startLine?: number;
+    endLine?: number;
+    quote: string;
+    text: string;
+};
+
 type ChatQuoteContext = {
     kind: 'chat-quote';
     /** The message the quote came from, when known. */
@@ -92,6 +102,7 @@ export type ContextPartPayload =
     | BrowserAnnotationContext
     | PrCommentContext
     | PrCheckContext
+    | FileQuoteContext
     | ChatQuoteContext
     | GitHubIssueContext
     | GitHubPrContext;
@@ -128,6 +139,13 @@ export function formatContextText(payload: ContextPartPayload): string {
             return payload.text ? `${payload.prompt}\n\n${payload.text}` : payload.prompt;
         case 'pr-comment':
             return `Attached GitHub PR comment (${payload.label}):\n\n${payload.body}${payload.text ? `\n\n${payload.text}` : ''}`;
+        case 'file-quote': {
+            const location = payload.startLine != null && payload.endLine != null
+                ? ` lines ${payload.startLine}-${payload.endLine}`
+                : '';
+            const quoted = payload.quote.split('\n').map((line) => `> ${line}`).join('\n');
+            return `Comment on this fragment of \`${payload.fileLabel}\`${location}:\n${quoted}${payload.text ? `\n\n${payload.text}` : ''}`;
+        }
         case 'chat-quote': {
             const quoted = payload.quote.split('\n').map((line) => `> ${line}`).join('\n');
             return `Comment on this fragment of an earlier message in this conversation:\n${quoted}${payload.text ? `\n\n${payload.text}` : ''}`;
@@ -179,6 +197,14 @@ export function contextPayloadFromDraft(draft: InlineCommentDraft): ContextPartP
             return { kind: 'pr-comment', label: draft.fileLabel, body: draft.code, text: draft.text };
         case 'pr-check':
             return { kind: 'pr-check', label: draft.fileLabel, output: draft.code, text: draft.text };
+        case 'file-quote': {
+            const payload: FileQuoteContext = { kind: 'file-quote', fileLabel: draft.fileLabel, quote: draft.code, text: draft.text };
+            if (draft.startLine > 0 && draft.endLine > 0) {
+                payload.startLine = draft.startLine;
+                payload.endLine = draft.endLine;
+            }
+            return payload;
+        }
         case 'chat-quote': {
             const payload: ChatQuoteContext = { kind: 'chat-quote', quote: draft.code, text: draft.text };
             if (draft.fileLabel) payload.messageId = draft.fileLabel;
@@ -245,6 +271,14 @@ const contextPayloadSchema = z.discriminatedUnion('kind', [
         output: z.string(),
         text: z.string(),
     }),
+    z.object({
+        kind: z.literal('file-quote'),
+        fileLabel: z.string(),
+        startLine: z.number().optional(),
+        endLine: z.number().optional(),
+        quote: z.string(),
+        text: z.string(),
+    }),
     z.object({
         kind: z.literal('chat-quote'),
         messageId: z.string().optional(),
diff --git a/packages/ui/src/lib/selectionOverlayRects.ts b/packages/ui/src/lib/selectionOverlayRects.ts
new file mode 100644
index 00000000..322b2b38
--- /dev/null
+++ b/packages/ui/src/lib/selectionOverlayRects.ts
@@ -0,0 +1,57 @@
+/**
+ * Overlay rectangles for a captured text selection.
+ *
+ * While a comment input owns focus the native selection is gone, so the
+ * quoted fragment is repainted with these rects (styled by
+ * `.oc-chat-comment-rect`). Raw Range.getClientRects() mixes block-container
+ * boxes with text boxes and the translucent overlaps paint double-dark bands,
+ * so rects are taken from the text nodes only and merged into one strip per
+ * visual line, each stretched to its element's line-height the way the native
+ * selection paints a line box.
+ */
+export const collectSelectionOverlayRects = (range: Range): DOMRect[] => {
+    const textRects: DOMRect[] = [];
+    const pushNodeRects = (node: Text) => {
+        const nodeRange = document.createRange();
+        nodeRange.selectNodeContents(node);
+        if (node === range.startContainer) nodeRange.setStart(node, range.startOffset);
+        if (node === range.endContainer) nodeRange.setEnd(node, range.endOffset);
+        const lineHeight = node.parentElement
+            ? Number.parseFloat(window.getComputedStyle(node.parentElement).lineHeight)
+            : Number.NaN;
+        for (const rect of nodeRange.getClientRects()) {
+            if (rect.width <= 0 || rect.height <= 0) continue;
+            if (Number.isFinite(lineHeight) && lineHeight > rect.height) {
+                const expand = (lineHeight - rect.height) / 2;
+                textRects.push(new DOMRect(rect.left, rect.top - expand, rect.width, lineHeight));
+            } else {
+                textRects.push(rect);
+            }
+        }
+    };
+    const root = range.commonAncestorContainer;
+    if (root instanceof Text) {
+        pushNodeRects(root);
+    } else {
+        const walker = document.createTreeWalker(root, NodeFilter.SHOW_TEXT);
+        for (let node = walker.nextNode(); node; node = walker.nextNode()) {
+            if (node instanceof Text && range.intersectsNode(node)) pushNodeRects(node);
+        }
+    }
+
+    const lines: Array<{ left: number; right: number; top: number; bottom: number }> = [];
+    for (const rect of textRects) {
+        const line = lines.find((candidate) => (
+            Math.abs(candidate.top - rect.top) < 6 && Math.abs(candidate.bottom - rect.bottom) < 6
+        ));
+        if (line) {
+            line.left = Math.min(line.left, rect.left);
+            line.right = Math.max(line.right, rect.right);
+            line.top = Math.min(line.top, rect.top);
+            line.bottom = Math.max(line.bottom, rect.bottom);
+        } else {
+            lines.push({ left: rect.left, right: rect.right, top: rect.top, bottom: rect.bottom });
+        }
+    }
+    return lines.map((line) => new DOMRect(line.left, line.top, line.right - line.left, line.bottom - line.top));
+};
diff --git a/packages/ui/src/stores/useInlineCommentDraftStore.ts b/packages/ui/src/stores/useInlineCommentDraftStore.ts
index 5b144b78..c90bc07a 100644
--- a/packages/ui/src/stores/useInlineCommentDraftStore.ts
+++ b/packages/ui/src/stores/useInlineCommentDraftStore.ts
@@ -5,7 +5,7 @@ import { getRuntimeKey } from '@/lib/runtime-switch';
 import { normalizePath } from '@/lib/pathNormalization';
 import { createDeferredSafeJSONStorage } from './utils/safeStorage';
 
-export type InlineCommentSource = 'diff' | 'plan' | 'file' | 'preview-annotation' | 'terminal' | 'pr-comment' | 'pr-check' | 'chat-quote';
+export type InlineCommentSource = 'diff' | 'plan' | 'file' | 'preview-annotation' | 'terminal' | 'pr-comment' | 'pr-check' | 'chat-quote' | 'file-quote';
 
 export type InlineCommentDraftTarget = {
   directory: string;
@@ -170,7 +170,7 @@ const EMPTY_PERSISTED_STATE: InlineCommentDraftState = { drafts: {}, touchedAt:
 const persistedDraftSchema = z.object({
   id: z.string(),
   sessionKey: z.string(),
-  source: z.enum(['diff', 'plan', 'file', 'preview-annotation', 'terminal', 'pr-comment', 'pr-check', 'chat-quote']),
+  source: z.enum(['diff', 'plan', 'file', 'preview-annotation', 'terminal', 'pr-comment', 'pr-check', 'chat-quote', 'file-quote']),
   fileLabel: z.string(),
   startLine: z.number(),
   endLine: z.number(),