diff --git a/dev/overlay.json b/dev/overlay.json
index ebb1692..2477d70 100644
--- a/dev/overlay.json
+++ b/dev/overlay.json
@@ -1 +1 @@
-{"Replace": {"C:/OtherFiles/Github/TamaBox-v4-mainline/internal/storage/s3.go": "C:/Users/TAMAKY~1/AppData/Local/Temp/tamabox_s3_stub.go"}}
+{"Replace": {"C:/OtherFiles/Github/TamaBox-v4-mainline/internal/storage/s3.go": "C:/OtherFiles/Github/TamaBox-v4-mainline/dev/s3stub/s3_stub.go"}}
diff --git a/route/question/share.go b/route/question/share.go
index 8d37cb2..c8f57a9 100644
--- a/route/question/share.go
+++ b/route/question/share.go
@@ -76,7 +76,6 @@ const (
 // 二维码尺寸
 const (
 	QRCodeSize = 165
-	QRCodeX    = (QRCardW - QRCodeSize) / 2
 )
 
 // 社交信息
@@ -505,23 +504,25 @@ func ShareCard(ctx context.Context) {
 		return
 	}
 
+	qrSize := qr.Bounds().Dx()
+
 	const (
-		qrToHintGap    = 26
+		qrToHintGap    = 24
 		hintLineHeight = 17
-		hintToSepGap   = 21
+		hintToSepGap   = 20
 		sepHeight      = 1
-		sepToLinkGap   = 21
-		linkLineHeight = 15
+		sepToLinkGap   = 20
+		linkLineHeight = 16
 	)
 	linkLines, linkFontSize := layoutLink(displayURL(boxURL))
-	totalContentH := QRCodeSize + qrToHintGap + hintLineHeight + hintToSepGap + sepHeight + sepToLinkGap + linkLineHeight*len(linkLines)
+	totalContentH := qrSize + qrToHintGap + hintLineHeight + hintToSepGap + sepHeight + sepToLinkGap + linkLineHeight*len(linkLines)
 	startY := QRCardY + (QRCardH-totalContentH)/2
 
-	qrDrawX := QRCardX + QRCodeX
+	qrDrawX := QRCardX + (QRCardW-qrSize)/2
 	qrDrawY := startY
-	draw.Draw(canvas, image.Rect(qrDrawX, qrDrawY, qrDrawX+QRCodeSize, qrDrawY+QRCodeSize), qr, image.Point{}, draw.Over)
+	draw.Draw(canvas, image.Rect(qrDrawX, qrDrawY, qrDrawX+qrSize, qrDrawY+qrSize), qr, image.Point{}, draw.Over)
 
-	hintY := qrDrawY + QRCodeSize + qrToHintGap + hintLineHeight
+	hintY := qrDrawY + qrSize + qrToHintGap + hintLineHeight
 	drawTextCentered(canvas, "扫码向我匿名提问", cardCenterX, hintY, FontSizeQRHint, ColorHintGray, fontCtx)
 
 	sepY := hintY + hintToSepGap
@@ -857,24 +858,28 @@ func generateQR(content string, logoImg image.Image, size int) (image.Image, err
 	qr.BackgroundColor = color.RGBA{255, 255, 255, 255}
 	qr.ForegroundColor = color.RGBA{0, 0, 0, 255}
 
-	modules := len(qr.Bitmap()) // 含静默区
+	// 静默区由承载二维码的白色卡片提供（四周留白远超 4 模块），图像本身只输出符号：
+	// 若把静默区画进图里，再叠加居中留白，目标 165px 实际只剩 111px，模块被压到 3px，
+	// 微信/QQ 二次压缩后极易扫不动。
+	qr.DisableBorder = true
+
+	modules := len(qr.Bitmap())
 	perModule := size / modules
 	if perModule < 1 {
 		perModule = 1
 	}
 	symbol := qr.Image(-perModule)
 
-	dst := image.NewRGBA(image.Rect(0, 0, size, size))
-	draw.Draw(dst, dst.Bounds(), &image.Uniform{ColorWhite}, image.Point{}, draw.Src)
-	offset := image.Pt((size-symbol.Bounds().Dx())/2, (size-symbol.Bounds().Dy())/2)
-	draw.Draw(dst, symbol.Bounds().Add(offset), symbol, image.Point{}, draw.Src)
+	dst := image.NewRGBA(symbol.Bounds())
+	draw.Draw(dst, dst.Bounds(), symbol, image.Point{}, draw.Src)
 
 	if logoImg != nil {
-		logoSize := size * 48 / 256
+		w := dst.Bounds().Dx()
+		logoSize := w * 3 / 16
 		logo := imaging.Fill(logoImg, logoSize, logoSize, imaging.Center, imaging.Lanczos)
 		// 白边保证头像与模块之间有对比度，H 级容错（30%）足以覆盖这点面积
 		holder := image.Rect(0, 0, logoSize+4, logoSize+4)
-		holder = holder.Add(image.Pt((size-holder.Dx())/2, (size-holder.Dy())/2))
+		holder = holder.Add(image.Pt((w-logoSize-4)/2, (w-logoSize-4)/2))
 		draw.Draw(dst, holder, &image.Uniform{ColorWhite}, image.Point{}, draw.Src)
 		draw.Draw(dst, logo.Bounds().Add(holder.Min.Add(image.Pt(2, 2))), logo, image.Point{}, draw.Over)
 	}
@@ -911,8 +916,7 @@ const (
 	QQRCardH = 255
 	QQRCardX = QContentX + QContentW - QQRCardW
 	QQRCardY = QContentY + (QContentH-QQRCardH)/2
-	QQRSize  = 128
-	QQRCodeX = (QQRCardW - QQRSize) / 2
+	QQRSize  = 150
 
 	// 内容区最大宽度（左侧，避开二维码卡片）
 	QTextMaxW = QQRCardX - QContentX - 30
@@ -1072,12 +1076,15 @@ func QuestionShareCard(ctx context.Context) {
 		logrus.WithContext(ctx.Request().Context()).WithError(err).Error("Failed to generate QR code for question share card")
 		return
 	}
-	qrDrawX := QQRCardX + QQRCodeX
+	qrSize := qr.Bounds().Dx()
+	qrDrawX := QQRCardX + (QQRCardW-qrSize)/2
 	// 二维码与提示语整体垂直居中（已删除底部冗余的长链接，卡片更简洁）
-	qrDrawY := QQRCardY + 40
-	draw.Draw(canvas, image.Rect(qrDrawX, qrDrawY, qrDrawX+QQRSize, qrDrawY+QQRSize), qr, image.Point{}, draw.Over)
+	const qrToHintGap, hintLineHeight = 30, 17
+	contentH := qrSize + qrToHintGap + hintLineHeight
+	qrDrawY := QQRCardY + (QQRCardH-contentH)/2
+	draw.Draw(canvas, image.Rect(qrDrawX, qrDrawY, qrDrawX+qrSize, qrDrawY+qrSize), qr, image.Point{}, draw.Over)
 
-	hintY := qrDrawY + QQRSize + 30
+	hintY := qrDrawY + qrSize + qrToHintGap + hintLineHeight
 	drawTextCentered(canvas, "扫码查看回答", QQRCardX+QQRCardW/2, hintY, 17, ColorHintGray, fontCtx)
 
 	// 底部水印
diff --git a/route/question/share_layout_test.go b/route/question/share_layout_test.go
index 7b79fb6..5766c7d 100644
--- a/route/question/share_layout_test.go
+++ b/route/question/share_layout_test.go
@@ -141,7 +141,7 @@ func TestDrawTextCenteredIsCentered(t *testing.T) {
 	}
 }
 
-// 内嵌头像不能吃掉静默区（否则扫码器找不到边界），且必须真的画在中心。
+// 内嵌头像必须画在中心，且符号本身不被裁切（四角是定位图案，应当是黑的）。
 func TestGenerateQRWithLogo(t *testing.T) {
 	logo := image.NewRGBA(image.Rect(0, 0, 64, 40))
 	draw.Draw(logo, logo.Bounds(), &image.Uniform{color.RGBA{200, 40, 40, 255}}, image.Point{}, draw.Src)
@@ -150,14 +150,15 @@ func TestGenerateQRWithLogo(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	r, _, _, _ := img.At(QRCodeSize/2, QRCodeSize/2).RGBA()
+	cx, cy := img.Bounds().Dx()/2, img.Bounds().Dy()/2
+	r, _, _, _ := img.At(cx, cy).RGBA()
 	if r < 0x8000 || r > 0xf000 {
 		t.Errorf("center pixel should be the logo color, got %#x", r)
 	}
-	for _, p := range []image.Point{{0, 0}, {QRCodeSize - 1, 0}, {0, QRCodeSize - 1}, {QRCodeSize - 1, QRCodeSize - 1}} {
+	for _, p := range []image.Point{{0, 0}, {img.Bounds().Dx() - 1, 0}, {0, img.Bounds().Dy() - 1}} {
 		r, g, b, _ := img.At(p.X, p.Y).RGBA()
-		if r != 0xffff || g != 0xffff || b != 0xffff {
-			t.Errorf("quiet zone at %v is not white: %#x %#x %#x", p, r, g, b)
+		if r == 0xffff && g == 0xffff && b == 0xffff {
+			t.Errorf("corner %v is white: finder pattern missing, symbol likely cropped", p)
 		}
 	}
 }
@@ -170,7 +171,8 @@ func abs(v int) int {
 }
 
 // 二维码必须按模块整数倍绘制：任何宽度落差的游程都意味着模块被拉伸，
-// 小尺寸（微信/QQ 二次压缩后）最容易出现「扫不动」。
+// 小尺寸（微信/QQ 二次压缩后）最容易出现「扫不动」。同时必须把目标尺寸用满，
+// 否则模块像素偏小，实际可扫距离大幅缩水。
 func TestGenerateQRIsModuleAligned(t *testing.T) {
 	const url = "https://box.shiroko.one/_/tamakyi"
 	for _, size := range []int{QRCodeSize, QQRSize} {
@@ -178,44 +180,50 @@ func TestGenerateQRIsModuleAligned(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		if got := img.Bounds().Dx(); got != size {
-			t.Fatalf("size %d: got width %d", size, got)
-		}
 
 		probe, err := qrcode.New(url, qrcode.High)
 		if err != nil {
 			t.Fatal(err)
 		}
+		probe.DisableBorder = true
 		modules := len(probe.Bitmap())
 		perModule := size / modules
-		if perModule < 1 {
-			t.Fatalf("size %d cannot hold %d modules", size, modules)
+		want := modules * perModule
+		if got := img.Bounds().Dx(); got != want {
+			t.Fatalf("size %d: got width %d, want %d (%d modules x %dpx)", size, got, want, modules, perModule)
+		}
+		if got := img.Bounds().Dy(); got != want {
+			t.Fatalf("size %d: got height %d, want %d", size, got, want)
+		}
+		// 至少用掉目标尺寸的 80%，防止静默区/留白再次吃掉模块像素
+		if float64(want) < 0.8*float64(size) {
+			t.Fatalf("size %d: symbol only %dpx, wastes %.0f%% of the target", size, want, 100*(1-float64(want)/float64(size)))
 		}
-		start := (size - modules*perModule) / 2
 
-		// 中间一行：所有黑白游程（限定在符号区域内）都必须是模块宽度的整数倍
-		y := size / 2
-		runLen := 0
-		for x := start; x < start+modules*perModule; x++ {
-			r, _, _, _ := img.At(x, y).RGBA()
-			black := r < 0x8000
-			if x == start {
-				runLen = 1
-				continue
-			}
-			prevR, _, _, _ := img.At(x-1, y).RGBA()
-			if (prevR < 0x8000) != black {
-				if runLen%perModule != 0 {
-					t.Fatalf("size %d: run of %dpx at x=%d is not a multiple of module %d",
-						size, runLen, x-runLen, perModule)
+		// 逐行扫描：所有黑白游程都必须是模块宽度的整数倍
+		for _, y := range []int{want / 2, want / 3} {
+			runLen := 0
+			for x := 0; x < want; x++ {
+				r, _, _, _ := img.At(x, y).RGBA()
+				black := r < 0x8000
+				if x == 0 {
+					runLen = 1
+					continue
 				}
-				runLen = 1
-				continue
+				prevR, _, _, _ := img.At(x-1, y).RGBA()
+				if (prevR < 0x8000) != black {
+					if runLen%perModule != 0 {
+						t.Fatalf("size %d: run of %dpx at x=%d is not a multiple of module %d",
+							size, runLen, x-runLen, perModule)
+					}
+					runLen = 1
+					continue
+				}
+				runLen++
+			}
+			if runLen%perModule != 0 {
+				t.Fatalf("size %d: trailing run %dpx not a multiple of %d", size, runLen, perModule)
 			}
-			runLen++
-		}
-		if runLen%perModule != 0 {
-			t.Fatalf("size %d: trailing run %dpx not a multiple of %d", size, runLen, perModule)
 		}
 	}
 }
@@ -250,17 +258,19 @@ func TestShareCardLinkPreview(t *testing.T) {
 		fctx.SetDPI(72)
 
 		lines, size := layoutLink(display)
-		const qrToHintGap, hintLineHeight, hintToSepGap, sepHeight, sepToLinkGap, linkLineHeight = 26, 17, 21, 1, 21, 15
-		total := QRCodeSize + qrToHintGap + hintLineHeight + hintToSepGap + sepHeight + sepToLinkGap + linkLineHeight*len(lines)
-		startY := (QRCardH - total) / 2
+		const qrToHintGap, hintLineHeight, hintToSepGap, sepHeight, sepToLinkGap, linkLineHeight = 24, 17, 20, 1, 20, 16
 
 		qr, err := generateQR("https://"+display, nil, QRCodeSize)
 		if err != nil {
 			t.Fatal(err)
 		}
-		draw.Draw(canvas, image.Rect(QRCodeX, startY, QRCodeX+QRCodeSize, startY+QRCodeSize), qr, image.Point{}, draw.Over)
+		qrSize := qr.Bounds().Dx()
+		total := qrSize + qrToHintGap + hintLineHeight + hintToSepGap + sepHeight + sepToLinkGap + linkLineHeight*len(lines)
+		startY := (QRCardH - total) / 2
 
-		hintY := startY + QRCodeSize + qrToHintGap + hintLineHeight
+		draw.Draw(canvas, image.Rect((QRCardW-qrSize)/2, startY, (QRCardW+qrSize)/2, startY+qrSize), qr, image.Point{}, draw.Over)
+
+		hintY := startY + qrSize + qrToHintGap + hintLineHeight
 		drawTextCentered(canvas, "扫码向我匿名提问", QRCardW/2, hintY, FontSizeQRHint, ColorHintGray, fctx)
 		sepY := hintY + hintToSepGap
 		drawLine(canvas, QRCardW/2-90, sepY, QRCardW/2+90, sepY, color.NRGBA{200, 200, 200, 180})