diff --git a/sidepanel/sidepanel.css b/sidepanel/sidepanel.css
index e40671b..f40f857 100644
--- a/sidepanel/sidepanel.css
+++ b/sidepanel/sidepanel.css
@@ -243,33 +243,35 @@ header {
   color: var(--orange);
 }
 
-.contribution-entry {
-  display: flex;
-  flex-direction: column;
-  align-items: flex-start;
-  gap: 6px;
-  position: relative;
+.contribution-update-layer {
+  position: fixed;
+  inset: 0;
+  pointer-events: none;
+  z-index: 1400;
 }
 
 .contribution-update-hint {
-  position: relative;
+  --contribution-update-arrow-left: 20px;
+  position: absolute;
+  top: 0;
+  left: 0;
   display: flex;
   align-items: flex-start;
   gap: 8px;
-  max-width: 220px;
-  margin-left: 6px;
+  max-width: min(220px, calc(100vw - 24px));
   padding: 8px 10px;
   background: color-mix(in srgb, var(--amber) 10%, var(--bg-base));
   border: 1px solid color-mix(in srgb, var(--amber) 34%, var(--border));
   border-radius: 10px;
   box-shadow: var(--shadow-sm);
+  pointer-events: auto;
 }
 
 .contribution-update-hint::before {
   content: '';
   position: absolute;
   top: -7px;
-  left: 14px;
+  left: calc(var(--contribution-update-arrow-left) - 6px);
   width: 12px;
   height: 12px;
   background: inherit;
@@ -436,7 +438,7 @@ header {
 
 .run-group {
   display: flex;
-  align-items: flex-start;
+  align-items: center;
   gap: 4px;
   flex-wrap: wrap;
 }
diff --git a/sidepanel/sidepanel.html b/sidepanel/sidepanel.html
index 2f7f26c..ffd6bc0 100644
--- a/sidepanel/sidepanel.html
+++ b/sidepanel/sidepanel.html
@@ -34,17 +34,8 @@
     </div>
     <div class="header-btns">
       <div class="run-group">
-        <div class="contribution-entry">
-          <button id="btn-contribution-mode" class="btn btn-outline btn-sm btn-contribution-mode" type="button"
-            aria-pressed="false" title="进入贡献模式并打开上传页">贡献/使用</button>
-          <div id="contribution-update-hint" class="contribution-update-hint" aria-live="polite" hidden>
-            <p id="contribution-update-hint-text" class="contribution-update-hint-text">
-              公告 / 使用教程有更新了，可点上方“贡献/使用”查看。
-            </p>
-            <button id="btn-dismiss-contribution-update-hint" class="contribution-update-hint-close" type="button"
-              aria-label="关闭更新提示" title="关闭更新提示">×</button>
-          </div>
-        </div>
+        <button id="btn-contribution-mode" class="btn btn-outline btn-sm btn-contribution-mode" type="button"
+          aria-pressed="false" title="进入贡献模式并打开上传页">贡献/使用</button>
         <input type="number" id="input-run-count" class="run-count-input" value="1" min="1" max="50" title="运行次数" />
         <button id="btn-auto-run" class="btn btn-success" title="自动执行全部步骤">
           <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor">
@@ -90,6 +81,16 @@
     </div>
   </header>
 
+  <div id="contribution-update-layer" class="contribution-update-layer" hidden>
+    <div id="contribution-update-hint" class="contribution-update-hint" aria-live="polite" hidden>
+      <p id="contribution-update-hint-text" class="contribution-update-hint-text">
+        公告 / 使用教程有更新了，可点上方“贡献/使用”查看。
+      </p>
+      <button id="btn-dismiss-contribution-update-hint" class="contribution-update-hint-close" type="button"
+        aria-label="关闭更新提示" title="关闭更新提示">×</button>
+    </div>
+  </div>
+
   <section id="update-section" hidden>
     <div class="update-card">
       <div class="update-card-header">
diff --git a/sidepanel/sidepanel.js b/sidepanel/sidepanel.js
index a11c81d..e3f368b 100644
--- a/sidepanel/sidepanel.js
+++ b/sidepanel/sidepanel.js
@@ -57,6 +57,7 @@ const btnSaveSettings = document.getElementById('btn-save-settings');
 const btnStop = document.getElementById('btn-stop');
 const btnReset = document.getElementById('btn-reset');
 const btnContributionMode = document.getElementById('btn-contribution-mode');
+const contributionUpdateLayer = document.getElementById('contribution-update-layer');
 const contributionUpdateHint = document.getElementById('contribution-update-hint');
 const contributionUpdateHintText = document.getElementById('contribution-update-hint-text');
 const btnDismissContributionUpdateHint = document.getElementById('btn-dismiss-contribution-update-hint');
@@ -2226,9 +2227,40 @@ function getContributionUpdateHintMessage(snapshot = currentContributionContentS
   return '公告 / 使用教程有更新了，可点上方“贡献/使用”查看。';
 }
 
+function positionContributionUpdateHint() {
+  if (!contributionUpdateLayer || !contributionUpdateHint || !btnContributionMode) {
+    return;
+  }
+  if (contributionUpdateLayer.hidden || contributionUpdateHint.hidden) {
+    return;
+  }
+
+  const buttonRect = btnContributionMode.getBoundingClientRect();
+  const viewportWidth = Math.max(document.documentElement?.clientWidth || 0, window.innerWidth || 0);
+  const viewportHeight = Math.max(document.documentElement?.clientHeight || 0, window.innerHeight || 0);
+  const hintWidth = contributionUpdateHint.offsetWidth || 220;
+  const hintHeight = contributionUpdateHint.offsetHeight || 56;
+  const viewportPadding = 12;
+  const gap = 10;
+
+  const maxLeft = Math.max(viewportPadding, viewportWidth - hintWidth - viewportPadding);
+  const left = Math.min(Math.max(viewportPadding, Math.round(buttonRect.left)), maxLeft);
+  const shouldPlaceAbove = (buttonRect.bottom + gap + hintHeight) > (viewportHeight - viewportPadding)
+    && buttonRect.top > (hintHeight + gap + viewportPadding);
+  const top = shouldPlaceAbove
+    ? Math.max(viewportPadding, Math.round(buttonRect.top - hintHeight - gap))
+    : Math.max(viewportPadding, Math.round(buttonRect.bottom + gap));
+  const buttonCenter = Math.round(buttonRect.left + (buttonRect.width / 2));
+  const arrowOffset = Math.min(Math.max(16, buttonCenter - left), Math.max(16, hintWidth - 16));
+
+  contributionUpdateHint.style.left = `${left}px`;
+  contributionUpdateHint.style.top = `${top}px`;
+  contributionUpdateHint.style.setProperty('--contribution-update-arrow-left', `${arrowOffset}px`);
+}
+
 function shouldShowContributionUpdateHint(snapshot = currentContributionContentSnapshot) {
   const promptVersion = String(snapshot?.promptVersion || '').trim();
-  if (!contributionUpdateHint || !contributionUpdateHintText || !btnContributionMode) {
+  if (!contributionUpdateLayer || !contributionUpdateHint || !contributionUpdateHintText || !btnContributionMode) {
     return false;
   }
   if (!promptVersion) {
@@ -2244,17 +2276,23 @@ function shouldShowContributionUpdateHint(snapshot = currentContributionContentS
 }
 
 function renderContributionUpdateHint(snapshot = currentContributionContentSnapshot) {
-  if (!contributionUpdateHint) {
+  if (!contributionUpdateLayer || !contributionUpdateHint) {
     return;
   }
 
   const visible = shouldShowContributionUpdateHint(snapshot);
+  contributionUpdateLayer.hidden = !visible;
   contributionUpdateHint.hidden = !visible;
   if (!visible || !contributionUpdateHintText) {
     return;
   }
 
   contributionUpdateHintText.textContent = getContributionUpdateHintMessage(snapshot);
+  if (typeof window.requestAnimationFrame === 'function') {
+    window.requestAnimationFrame(() => positionContributionUpdateHint());
+    return;
+  }
+  positionContributionUpdateHint();
 }
 
 function dismissContributionUpdateHint() {
@@ -4720,6 +4758,14 @@ document.addEventListener('keydown', (event) => {
   }
 });
 
+window.addEventListener('resize', () => {
+  positionContributionUpdateHint();
+});
+
+document.addEventListener('scroll', () => {
+  positionContributionUpdateHint();
+}, true);
+
 // ============================================================
 // Init
 // ============================================================
diff --git a/tests/sidepanel-contribution-button.test.js b/tests/sidepanel-contribution-button.test.js
index 552c183..90b99f4 100644
--- a/tests/sidepanel-contribution-button.test.js
+++ b/tests/sidepanel-contribution-button.test.js
@@ -11,6 +11,8 @@ test('sidepanel html keeps a single contribution mode button in header', () => {
   assert.equal(matches.length, 1);
   assert.match(html, /id="btn-contribution-mode"[^>]*title="进入贡献模式并打开上传页"/);
   assert.match(html, />贡献\/使用<\/button>/);
+  assert.match(html, /<\/header>\s*<div id="contribution-update-layer"/);
+  assert.match(html, /id="contribution-update-layer"/);
   assert.match(html, /id="contribution-update-hint"/);
   assert.match(html, /id="contribution-update-hint-text"/);
   assert.match(html, /id="btn-dismiss-contribution-update-hint"/);