diff --git a/README.md b/README.md
index c7936e7..2c8e418 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,8 @@ node dist/cli/index.js verify --path fixtures/product/trust-loop/review --target
 
 运行 `node dist/cli/index.js gui` 打开本机界面。修复前可查看计划，确认后再应用。默认未启用真实执行。
 
+网页检查会标出 YAML 语法错误所在的行和列。点击「定位错误」可回到原文修正，继续编辑会清除上一次的位置。
+
 ## 常见问题
 
 **网页能检查本机目录吗？** 网页只解析粘贴的文档。完整的目录、权限和交付物检查由本机 CLI 读取文件。
diff --git a/browser/index.html b/browser/index.html
index 055d801..59601e4 100644
--- a/browser/index.html
+++ b/browser/index.html
@@ -7,5 +7,5 @@
 <main><h1>检查 Skill 文档</h1><p>粘贴 SKILL.md，读取 YAML 文档头和正文。内容只在当前标签页处理。</p>
 <div class="columns"><section><label for="source">SKILL.md</label><textarea id="source" maxlength="24576" spellcheck="false" aria-describedby="limit"></textarea><small id="limit">最多 24 KiB。网页检查文档格式，本机 CLI 可继续检查来源、权限和交付物。</small>
 <div class="actions"><button id="check">检查文档</button><button id="example" class="secondary">载入示例</button></div></section>
-<section aria-live="polite"><h2>解析结果</h2><strong id="status">等待检查</strong><p id="message">运行检查后，这里会列出文档头字段和正文长度。</p><dl id="fields"></dl></section></div></main>
+<section aria-live="polite"><h2>解析结果</h2><strong id="status">等待检查</strong><p id="message">运行检查后，这里会列出文档头字段和正文长度。</p><button id="locate" type="button" class="secondary" hidden>定位错误</button><dl id="fields"></dl></section></div></main>
 <script type="module" src="./main.ts"></script></body></html>
diff --git a/browser/main.ts b/browser/main.ts
index e914ba8..d5ab2ff 100644
--- a/browser/main.ts
+++ b/browser/main.ts
@@ -2,6 +2,17 @@ import { parseSkillDocument } from "../src/domain/frontmatter";
 const input = document.querySelector<HTMLTextAreaElement>("#source")!;
 const status = document.querySelector<HTMLElement>("#status")!;
 const message = document.querySelector<HTMLElement>("#message")!;
+const locate = document.querySelector<HTMLButtonElement>("#locate")!;
+let errorLocation: {start: number; end: number} | undefined;
+function resetLocation() {
+  errorLocation = undefined;
+  locate.hidden = true;
+}
+locate.addEventListener("click", () => {
+  if (!errorLocation) return;
+  input.focus();
+  input.setSelectionRange(errorLocation.start, errorLocation.end);
+});
 const fields = document.querySelector<HTMLElement>("#fields")!;
 const example = "---\nname: inventory-check\ndescription: 对照清单核对库存。\n---\n\n先读取清单，再逐项核对应有与实收数量。";
 const byteLimit = 24 * 1024;
@@ -10,6 +21,7 @@ function tooLarge(value: string) {
   return value.length > byteLimit || encoder.encode(value).length > byteLimit;
 }
 function oversized() {
+  resetLocation();
   fields.replaceChildren();
   status.textContent = "文档过大";
   message.textContent = "最多可检查 24 KiB。请缩短文档后重试。";
@@ -27,18 +39,30 @@ input.addEventListener("beforeinput", event => {
   if (event.cancelable && event.inputType.startsWith("insert")) checkInsertion(event, event.data);
 });
 function clear() {
+  resetLocation();
   status.textContent = "等待检查";
   message.textContent = "文档已更新，请重新检查。";
   fields.replaceChildren();
 }
 function check() {
+  resetLocation();
   fields.replaceChildren();
   if (tooLarge(input.value)) {
     oversized(); return;
   }
   const parsed = parseSkillDocument(input.value);
   if (!parsed.ok) {
-    status.textContent = "无法解析文档"; message.textContent = parsed.error; return;
+    status.textContent = "无法解析文档";
+    errorLocation = parsed.location;
+    if (errorLocation) {
+      const lines = input.value.slice(0, errorLocation.start).split("\n");
+      const column = Array.from(lines[lines.length-1] ?? "").length + 1;
+      message.textContent = "第 " + lines.length + " 行，第 " + column + " 列。" + parsed.error;
+      locate.hidden = false;
+    } else {
+      message.textContent = parsed.error;
+    }
+    return;
   }
   status.textContent = "文档可解析";
   const {frontmatter, body} = parsed.value;
diff --git a/src/domain/frontmatter.ts b/src/domain/frontmatter.ts
index 8ec3d4a..ded11f3 100644
--- a/src/domain/frontmatter.ts
+++ b/src/domain/frontmatter.ts
@@ -1,4 +1,4 @@
-import { parse } from "yaml";
+import { parse, YAMLParseError } from "yaml";
 
 export type ParsedSkillDocument = {
   frontmatter: Record<string, unknown>;
@@ -8,7 +8,7 @@ export type ParsedSkillDocument = {
 
 export type ParseSkillDocumentResult =
   | { ok: true; value: ParsedSkillDocument }
-  | { ok: false; error: string };
+  | { ok: false; error: string; location?: { start: number; end: number } };
 
 function parserError(error: unknown): string {
   const message = error instanceof Error ? error.message : String(error);
@@ -20,6 +20,7 @@ export function parseSkillDocument(content: string): ParseSkillDocumentResult {
   if (!opening) {
     return {
       ok: false,
+      location: { start: 0, end: 0 },
       error: "Skill document must start with a YAML frontmatter delimiter.",
     };
   }
@@ -29,6 +30,7 @@ export function parseSkillDocument(content: string): ParseSkillDocumentResult {
   if (!closing) {
     return {
       ok: false,
+      location: { start: content.length, end: content.length },
       error: "Skill frontmatter closing delimiter is missing.",
     };
   }
@@ -39,9 +41,13 @@ export function parseSkillDocument(content: string): ParseSkillDocumentResult {
 
   let parsed: unknown;
   try {
-    parsed = parse(frontmatterText, { uniqueKeys: true });
+    parsed = parse(frontmatterText, { uniqueKeys: true, prettyErrors: false });
   } catch (error: unknown) {
+    const location = error instanceof YAMLParseError
+      ? { start: Math.min(yamlEnd, openingEnd + error.pos[0]), end: Math.min(yamlEnd, openingEnd + error.pos[1]) }
+      : undefined;
     return {
+      ...(location && { location }),
       ok: false,
       error: `Invalid YAML frontmatter: ${parserError(error)}`,
     };
@@ -55,6 +61,7 @@ export function parseSkillDocument(content: string): ParseSkillDocumentResult {
     return {
       ok: false,
       error: "Skill frontmatter must be a YAML mapping.",
+      location: { start: openingEnd, end: yamlEnd },
     };
   }
 
diff --git a/tests/domain/frontmatter.test.ts b/tests/domain/frontmatter.test.ts
index 70e47b9..7fdfac8 100644
--- a/tests/domain/frontmatter.test.ts
+++ b/tests/domain/frontmatter.test.ts
@@ -23,6 +23,13 @@ describe("parseSkillDocument", () => {
     });
   });
 
+  it("locates a duplicate key in the original document including CRLF and Unicode", () => {
+    const text = "---\r\nname: 鱼🐟\r\nname: b\r\n---\r\nbody";
+    const result = parseSkillDocument(text);
+    expect(result.ok).toBe(false);
+    if (!result.ok) expect(result.location?.start).toBe(text.lastIndexOf("name:"));
+  });
+
   it("rejects a document without an opening or closing delimiter", () => {
     const missingOpening = parseSkillDocument("name: review\n---\nbody");
     const missingClosing = parseSkillDocument("---\nname: review\nbody");