diff --git a/.github/workflows/deploy-site.yml b/.github/workflows/deploy-site.yml
index ba66520e..2198e6c0 100644
--- a/.github/workflows/deploy-site.yml
+++ b/.github/workflows/deploy-site.yml
@@ -120,6 +120,11 @@ jobs:
       - name: Publish updated Nanpure reading controls after release integrity checks
         run: cp scripts/client-overrides/public/reading-tools.js _site/nanpure/assets/reading-tools.js
 
+      - name: Inject Nanpure notebook digit-size correction after release integrity checks
+        run: |
+          node --check scripts/client-overrides/public/notebook-digit-size.js
+          python3 scripts/inject-nanpure-digit-size.py _site
+
       - name: Check language and furigana controls
         if: needs.changes.outputs.reading == 'true'
         run: |
diff --git a/scripts/client-overrides/public/notebook-digit-size.js b/scripts/client-overrides/public/notebook-digit-size.js
new file mode 100644
index 00000000..94eb9075
--- /dev/null
+++ b/scripts/client-overrides/public/notebook-digit-size.js
@@ -0,0 +1,56 @@
+/* Correct notebook digit sizing and expose an independent Killer cage-sum size setting. */
+(()=>{'use strict';
+ const root=document.documentElement,px=n=>(Math.round(n*100)/100)+'px';
+ let queued=false,last='',cageLast='';
+ const readPrefs=()=>{try{const v=JSON.parse(localStorage.getItem('collection-workspace-v1')||'{}');return [100,125,150,175,200].includes(v.digitSize)?v.digitSize:100}catch{return 100}};
+ const readCageSize=()=>{try{const n=Number(localStorage.getItem('np-killer-sum-size-v1'));return [100,125,150,175,200].includes(n)?n:100}catch{return 100}};
+ function apply(){
+  queued=false;const board=document.querySelector('#board');if(!board)return;
+  const scale={small:.85,normal:1,large:1.15}[root.dataset.digitSize]||1,workspace=readPrefs();
+  const cells=Array.from(board.querySelectorAll('.cell')),cell=cells[0];if(!cell)return;
+  const digits=board.querySelectorAll('.cell>span.np-workspace-digit'),contentLength=Array.from(digits).reduce((n,span)=>n+span.textContent.length,0);
+  const signature=[scale,workspace,board.dataset.digitSize,board.className,board.clientWidth,board.clientHeight,cell.clientWidth,cell.clientHeight,cells.length,digits.length,contentLength].join('|');
+  if(signature!==last){last=signature;
+   const columns=getComputedStyle(board).gridTemplateColumns.trim().split(/\s+/).length||9,digitCount=String(board.classList.contains('hundred-board')?100:columns).length;
+   const limit=Math.max(1,Math.min(cell.clientHeight*(board.querySelector('.cage-label') ? .7 : .88),cell.clientWidth/(digitCount*.64)));
+   for(const span of digits){
+    if(span.classList.contains('notes')||span.classList.contains('hundred-notes')||span.classList.contains('cage-label')||span.classList.contains('cage-border'))continue;
+    const parentSize=parseFloat(getComputedStyle(span.parentElement).fontSize)||16;
+    let size=Math.max(1,Math.min(parentSize*scale*workspace/100,limit));
+    span.style.setProperty('font-size',px(size),'important');span.style.setProperty('line-height','1','important');span.style.setProperty('white-space','nowrap','important');
+    const width=span.getBoundingClientRect().width,available=Math.max(1,span.parentElement.clientWidth-Math.min(2,span.parentElement.clientWidth*.04));
+    if(width>available&&width>0)span.style.setProperty('font-size',px(Math.max(1,size*available/width)),'important');
+   }
+  }
+  applyCage(board);
+ }
+ function applyCage(board){
+  const labels=Array.from(board.querySelectorAll('.cell>.cage-label'));if(!labels.length){cageLast='';return}
+  const size=readCageSize(),cell=labels[0].parentElement;
+  const sig=[size,cell.clientWidth,cell.clientHeight,labels.length,labels.map(x=>x.textContent).join('|')].join(':');if(sig===cageLast)return;cageLast=sig;
+  for(const label of labels){
+   if(!label.dataset.npCageBase)label.dataset.npCageBase=String(parseFloat(getComputedStyle(label).fontSize)||8);
+   const base=Number(label.dataset.npCageBase)||8,box=label.parentElement,textLength=Math.max(1,label.textContent.trim().length);
+   const maxByWidth=Math.max(1,box.clientWidth*.72/(textLength*.62)),maxByHeight=Math.max(1,box.clientHeight*.34);
+   label.style.setProperty('font-size',px(Math.min(base*size/100,maxByWidth,maxByHeight)),'important');
+   label.style.setProperty('line-height','1','important');label.style.setProperty('white-space','nowrap','important');
+  }
+ }
+ function ensureCageControl(){
+  const board=document.querySelector('#board');if(!board?.querySelector('.cage-label'))return;
+  const dialog=document.querySelector('.np-workspace-dialog');if(!dialog||dialog.querySelector('[data-cage-sum-size]'))return;
+  const size=[100,125,150,175,200].includes(readCageSize())?readCageSize():100;
+  const label=document.createElement('label');label.dataset.cageSumSetting='true';label.append('キラー合計の数字サイズ');
+  const select=document.createElement('select');select.dataset.cageSumSize='true';select.setAttribute('aria-label','キラー合計の数字サイズ');
+  for(const n of [100,125,150,175,200]){const option=document.createElement('option');option.value=String(n);option.textContent=n+'%'+(n===100?'（標準）':'');select.append(option)}
+  select.value=String(size);select.addEventListener('change',()=>{try{localStorage.setItem('np-killer-sum-size-v1',select.value)}catch{}cageLast='';schedule()});
+  label.append(select);const digit=dialog.querySelector('[data-digit-size]')?.closest('label');if(digit?.parentNode)digit.parentNode.insertBefore(label,digit.nextSibling);else dialog.prepend(label);
+ }
+ function schedule(){if(!queued){queued=true;requestAnimationFrame(apply)}}
+ const watch=()=>{const board=document.querySelector('#board');if(board&&!board.dataset.npDigitFixObserved){board.dataset.npDigitFixObserved='true';new MutationObserver(schedule).observe(board,{attributes:true,attributeFilter:['data-digit-size','class','style'],childList:true,subtree:true})}ensureCageControl();schedule()};
+ new MutationObserver(records=>{if(records.some(r=>r.addedNodes.length||r.removedNodes.length)){watch();ensureCageControl()}}).observe(document.getElementById('app')||document.body,{childList:true,subtree:true});
+ new MutationObserver(schedule).observe(root,{attributes:true,attributeFilter:['data-digit-size']});
+ window.addEventListener('resize',()=>{last='';cageLast='';schedule()});window.addEventListener('orientationchange',()=>{last='';cageLast='';schedule()});
+ window.addEventListener('storage',e=>{if(e.key==='collection-workspace-v1'||e.key==='np-killer-sum-size-v1'){last='';cageLast='';schedule()}});
+ watch();
+})();
\ No newline at end of file
diff --git a/scripts/inject-nanpure-digit-size.py b/scripts/inject-nanpure-digit-size.py
new file mode 100644
index 00000000..cd8d4a46
--- /dev/null
+++ b/scripts/inject-nanpure-digit-size.py
@@ -0,0 +1,20 @@
+"""Inject the digit-size correction only after immutable Nanpure release checks."""
+from pathlib import Path
+import json, shutil, sys
+
+root = Path(sys.argv[1]) if len(sys.argv) > 1 else Path("_site")
+manifest = json.loads((root / "nanpure/release-manifest.json").read_text())
+version = manifest["version"]
+source = Path(__file__).resolve().parent / "client-overrides/public/notebook-digit-size.js"
+asset = root / "nanpure/assets/notebook-digit-size.js"
+asset.parent.mkdir(parents=True, exist_ok=True)
+shutil.copy2(source, asset)
+page = root / "nanpure/releases" / version / "notebook/index.html"
+html = page.read_text()
+tag = f'<script defer src="/nanpure/assets/notebook-digit-size.js?v=1"></script>'
+if tag not in html:
+    assert "</body>" in html, f"Missing body close in {page}"
+    html = html.replace("</body>", tag + "\n</body>", 1)
+    page.write_text(html)
+assert asset.is_file() and tag in page.read_text()
+print(f"Injected notebook digit-size correction for Nanpure {version}.")