diff --git a/app.py b/app.py
index 5739c8b..0384154 100644
--- a/app.py
+++ b/app.py
@@ -595,7 +595,7 @@ async def hair_grow_b(
     marked_image_file: Optional[UploadFile] = File(default=None, description="划线图片文件（JPG/PNG，≤ 1 MB）"),
     marked_image_url: Optional[str] = Form(default=None, description="划线图片 URL"),
     marked_image_base64: Optional[str] = Form(default=None, description="划线图片 base64"),
-    use_mask: bool = Form(default=True, description="是否启用自动检测遮罩（测试对比用）。false 时跳过检测、直接送划线图（空遮罩）"),
+    use_mask: bool = Form(default=True, description="是否画发际线（测试对比用）。false 时跳过划线检测、直接送划线图"),
 ):
     # 划线图三选一取图（只需这一张）
     marked_raw, e = await resolve_image_bytes(marked_image_file, marked_image_url, marked_image_base64)
diff --git a/docs/接口文档.md b/docs/接口文档.md
index 7769375..a0ebae7 100644
--- a/docs/接口文档.md
+++ b/docs/接口文档.md
@@ -244,7 +244,7 @@
 | 参数 | 类型 | 必填 | 说明 |
 |------|------|------|------|
 | marked_image_* | file / string | 是 | 已用马克笔标注发际线的图片，三选一 |
-| use_mask | bool | 否 | 是否启用自动检测遮罩，默认 `true`。`false` 时跳过划线检测、直接送划线图（空遮罩），模型仅凭手绘黑线生发，供测试对比 |
+| use_mask | bool | 否 | 是否画发际线，默认 `true`。`false` 时跳过划线检测、直接送划线图，模型仅凭手绘黑线生发，供测试对比 |
 
 ### 输出（data）
 
diff --git a/static/test_interface2.html b/static/test_interface2.html
index c5b8c32..5c5134d 100644
--- a/static/test_interface2.html
+++ b/static/test_interface2.html
@@ -73,6 +73,13 @@
           <label>性别</label>
           <select id="gender"><option value="female" selected>👩 Female</option><option value="male">👨 Male</option></select>
         </div>
+        <div class="form-group">
+          <label>inpaint 遮罩</label>
+          <select id="useMask">
+            <option value="true" selected>✅ 启用（默认）</option>
+            <option value="false">⬜ 关闭 — 空遮罩，不烧模板线</option>
+          </select>
+        </div>
         <button class="btn btn-primary" id="submitBtn" onclick="submitTest()">🚀 提交</button>
         <button class="btn btn-outline btn-sm" onclick="clearResults()">清除</button>
       </div>
@@ -118,6 +125,7 @@ async function submitTest() {
   setStatus('⏳ 请求中（生发图生成较慢，请耐心）...', 'info'); $('resultsArea').classList.add('hidden');
 
   const fd = new FormData(); fd.append('image_file', f); fd.append('gender', $('gender').value);
+  fd.append('use_mask', $('useMask').value);
   try {
     const r = await fetch(API_BASE + '/api/v1/hair/grow', { method:'POST', body:fd });
     const json = await r.json();
diff --git a/static/test_interface3.html b/static/test_interface3.html
index 0488721..443c124 100644
--- a/static/test_interface3.html
+++ b/static/test_interface3.html
@@ -52,6 +52,17 @@
   .result-field .name { font-size: 12px; font-weight: 600; color: #6b7280; margin-bottom: 4px; text-transform: uppercase; letter-spacing: .5px; }
   .badge { display: inline-block; padding: 2px 10px; border-radius: 10px; font-size: 12px; font-weight: 600; background: #dbeafe; color: #1e40af; }
 
+  /* blend */
+  .blend-container { position: relative; width: 100%; background: #222; border-radius: 8px; overflow: hidden; line-height: 0; }
+  .blend-container img { display: block; width: 100%; max-height: 500px; object-fit: contain; }
+  .blend-bottom { position: relative; z-index: 1; }
+  .blend-top { position: absolute; top: 0; left: 0; z-index: 2; transition: opacity 0.06s; }
+  .blend-placeholder { color: #9ca3af; font-size: 12px; padding: 80px 20px; background: #f9fafb; line-height: 1.5; }
+  .blend-controls { display: flex; align-items: center; gap: 10px; margin-top: 14px; justify-content: center; }
+  .blend-controls input[type=range] { width: 220px; accent-color: #2563eb; }
+  .blend-label { font-size: 12px; color: #6b7280; font-weight: 600; }
+  .blend-value { font-size: 13px; font-weight: 600; color: #374151; min-width: 42px; text-align: center; background: #f3f4f6; border-radius: 6px; padding: 2px 8px; }
+
   .json-panel { max-height: 550px; overflow: auto; }
   .json-content { padding: 14px 16px; font-family: "SF Mono", "Fira Code", monospace; font-size: 12px; line-height: 1.6; white-space: pre-wrap; word-break: break-all; }
 
@@ -72,6 +83,14 @@
         <div class="label">✏️ 划线图（marked_image）<span class="tag required">必填</span></div>
         <input type="file" id="markedFile" accept="image/jpeg,image/png,.jpg,.jpeg,.png">
       </div>
+      <div class="upload-group" style="margin-top:14px">
+        <div class="label">🪄 画发际线（use_mask）<span class="tag-new">NEW</span></div>
+        <select id="useMask" style="padding:8px 12px;border:2px solid #ddd;border-radius:8px;font-size:14px;background:#fff;min-width:280px">
+          <option value="true" selected>✅ 画发际线（默认）— 检测划线并生成遮罩</option>
+          <option value="false">⬜ 不画发际线 — 跳过划线检测，直接送划线图（测试对比用）</option>
+        </select>
+        <div class="hint">false 时跳过划线检测、直接送划线图，用于对比测试</div>
+      </div>
       <div style="margin-top:14px;display:flex;gap:12px;align-items:center">
         <button class="btn btn-primary" id="submitBtn" onclick="submitTest()">🚀 提交</button>
         <button class="btn btn-outline btn-sm" onclick="clearResults()">清除</button>
@@ -83,24 +102,19 @@
 
   <div class="results-layout hidden" id="resultsArea">
     <div class="col-main">
-      <!-- 输入预览 -->
       <div class="card">
-        <div class="card-header"><span>📸 划线图预览</span></div>
+        <div class="card-header"><span>🔄 原图 / 生发图 叠加对比 &nbsp;</span><span class="badge" id="hairlineType" style="display:none"></span></div>
         <div class="card-body" style="text-align:center">
-          <div class="thumb" id="markedThumb"><span style="color:#9ca3af;padding:40px">—</span></div>
-        </div>
-      </div>
-      <!-- 结果 -->
-      <div class="card">
-        <div class="card-header"><span>🎯 生发效果</span></div>
-        <div class="card-body">
-          <div class="result-field">
-            <div class="name">发际线类型</div>
-            <span class="badge" id="hairlineType">—</span>
+          <div class="blend-container" id="blendContainer">
+            <img id="blendBottom" class="blend-bottom" alt="原图（划线图）" style="display:none">
+            <img id="blendTop" class="blend-top" alt="生发效果图" style="display:none;opacity:0.5">
+            <div class="blend-placeholder" id="blendPlaceholder">—</div>
           </div>
-          <div class="result-field">
-            <div class="name">生发效果图（hair_growth_image）<span class="tag-new">ComfyUI</span></div>
-            <div class="thumb" id="growthImg"><span style="color:#9ca3af;padding:40px">—</span></div>
+          <div class="blend-controls hidden" id="blendControls">
+            <span class="blend-label">原图</span>
+            <input type="range" id="blendSlider" min="0" max="1" step="0.01" value="0.5">
+            <span class="blend-label">生发图</span>
+            <span class="blend-value" id="blendValue">0.50</span>
           </div>
         </div>
       </div>
@@ -125,14 +139,20 @@ async function submitTest() {
   if (!mf) { setStatus('请选择划线图', 'error'); return; }
   if (mf.size > 1_000_000) { setStatus('文件超过 1 MB', 'error'); return; }
 
-  // 预览划线图
-  $('markedThumb').innerHTML = '<img src="'+URL.createObjectURL(mf)+'" alt="划线图">';
+  const markedUrl = URL.createObjectURL(mf);
+  // 先显示原图
+  $('blendPlaceholder').style.display = 'none';
+  $('blendBottom').src = markedUrl;
+  $('blendBottom').style.display = 'block';
+  $('blendTop').style.display = 'none';
+  $('blendControls').classList.add('hidden');
 
   $('submitBtn').disabled = true; $('submitBtn').textContent = '⏳ ...';
-  setStatus('请求中（生发需要数十秒）...', 'info'); $('resultsArea').classList.add('hidden');
+  setStatus('请求中（生发需要数十秒）...', 'info'); $('resultsArea').classList.remove('hidden');
 
   const fd = new FormData();
   fd.append('marked_image_file', mf);
+  fd.append('use_mask', $('useMask').value);
 
   try {
     const r = await fetch(API_BASE + '/api/v1/hair/grow-b', { method:'POST', body:fd });
@@ -142,18 +162,29 @@ async function submitTest() {
 
     if (json.code === 0) {
       const d = json.data;
-      $('hairlineType').textContent = d.hairline_type || '—';
+      if (d.hairline_type) {
+        $('hairlineType').textContent = '发际线: ' + d.hairline_type;
+        $('hairlineType').style.display = 'inline-block';
+      }
 
-      if (d.hair_growth_image_url) {
-        $('growthImg').innerHTML = '<img src="'+d.hair_growth_image_url+'" alt="生发效果">';
+      const grownSrc = d.hair_growth_image_url || d.hair_growth_image_base64;
+      if (grownSrc) {
+        $('blendTop').src = grownSrc;
+        $('blendTop').style.display = 'block';
+        $('blendTop').style.opacity = $('blendSlider').value;
+        $('blendControls').classList.remove('hidden');
+        $('blendValue').textContent = parseFloat($('blendSlider').value).toFixed(2);
       } else {
-        $('growthImg').innerHTML = '<div class="na">⚠ 生发图未返回<br><span style="font-size:10px;color:#9ca3af">ComfyUI 未就绪或生成失败</span></div>';
+        $('blendTop').style.display = 'none';
+        $('blendControls').classList.add('hidden');
+        setStatus('⚠ 生发图未返回 — ComfyUI 未就绪或生成失败', 'info');
+        return;
       }
 
       setStatus('✅ 成功 &nbsp;|&nbsp; 发际线类型: ' + (d.hairline_type || '—'), 'success');
     } else {
       setStatus('❌ code=' + json.code + ' ' + json.message, 'error');
-      $('growthImg').innerHTML = '<div class="na">—</div>';
+      $('blendTop').style.display = 'none';
     }
   } catch(e) { setStatus('❌ ' + e.message, 'error'); $('resultsArea').classList.remove('hidden'); }
   finally { $('submitBtn').disabled = false; $('submitBtn').textContent = '🚀 提交'; }
@@ -162,11 +193,19 @@ async function submitTest() {
 function clearResults() {
   $('resultsArea').classList.add('hidden'); $('statusBar').className='status hidden';
   $('markedFile').value=''; $('jsonContent').textContent='';
-  $('markedThumb').innerHTML='<span style="color:#9ca3af;padding:40px">—</span>';
-  $('growthImg').innerHTML='<span style="color:#9ca3af;padding:40px">—</span>';
-  $('hairlineType').textContent='—';
+  $('blendBottom').src = ''; $('blendBottom').style.display = 'none';
+  $('blendTop').src = ''; $('blendTop').style.display = 'none';
+  $('blendPlaceholder').style.display = 'block';
+  $('blendControls').classList.add('hidden');
+  $('blendSlider').value = 0.5; $('blendValue').textContent = '0.50';
+  $('hairlineType').textContent = ''; $('hairlineType').style.display = 'none';
 }
 
+$('blendSlider').addEventListener('input', function() {
+  $('blendTop').style.opacity = this.value;
+  $('blendValue').textContent = parseFloat(this.value).toFixed(2);
+});
+
 function copyJson() {
   navigator.clipboard.writeText($('jsonContent').textContent).then(() => {
     const b = event.target, o = b.textContent; b.textContent = '✅ 已复制'; setTimeout(() => b.textContent = o, 1500);