diff --git a/bulk_action_bar.go b/bulk_action_bar.go
index ad4e0d7..0ca0e62 100644
--- a/bulk_action_bar.go
+++ b/bulk_action_bar.go
@@ -26,7 +26,7 @@ func BulkActionBar(c *ui.Context, selected int, opts BulkActionBarOptions, actio
 	k := Tokens(c)
 	u := Density(c).Unit()
 	count := fmt.Sprintf(msg(c, "bulk_action_bar.selected"), selected)
-	bar := ui.Row(c).AlignItems(ui.Center).Gap(u*3).Padding(u*2, u*2, u*2, u*4).MinHeight(Density(c).ControlHeight()+4*u).
+	bar := ui.Row(c).AlignItems(ui.Center).Gap(u*3).Padding(u*2, u*2, u*2, u*4).MinHeight(Density(c).ControlHeight() + 4*u).
 		Role(ui.RoleToolbar).Label(count).Disabled(opts.Disabled)
 	overlayStyle(c, bar, overlayEnter(c, bar))
 	said := ui.Local(bar, "bulk_action_bar.said", func() int { return 0 })
diff --git a/choice_chips.go b/choice_chips.go
index c979143..ac94e76 100644
--- a/choice_chips.go
+++ b/choice_chips.go
@@ -30,7 +30,7 @@ func ChoiceChips[T comparable](c *ui.Context, value *[]T, items []ToggleItem[T],
 	}
 	k := Tokens(c)
 	d := Density(c)
-	g := ui.Row(c).Wrap().Gap(d.Unit()*2).Disabled(opts.Disabled).Role(ui.RoleGroup).FocusGroup(ui.Horizontal)
+	g := ui.Row(c).Wrap().Gap(d.Unit() * 2).Disabled(opts.Disabled).Role(ui.RoleGroup).FocusGroup(ui.Horizontal)
 	if opts.Label != "" {
 		g.Label(opts.Label)
 	}
@@ -54,7 +54,7 @@ func ChoiceChips[T comparable](c *ui.Context, value *[]T, items []ToggleItem[T],
 }
 
 func choiceChipLook[T comparable](c *ui.Context, k theme.Tokens, d theme.Density, b *ui.Element, on bool, it ToggleItem[T]) {
-	b.MinHeight(max(theme.MinHitSize, d.ControlHeight()-4)).MinWidth(theme.MinHitSize).Padding(0, d.Unit()*3).Gap(d.Unit()*1.5).
+	b.MinHeight(max(theme.MinHitSize, d.ControlHeight()-4)).MinWidth(theme.MinHitSize).Padding(0, d.Unit()*3).Gap(d.Unit() * 1.5).
 		Radius(theme.PopupRadius)
 	internal.Ring(b, k.Focus, theme.PopupRadius)
 	bg, fg, line := k.Surface, k.Text, k.ControlBorder
diff --git a/currency_input.go b/currency_input.go
new file mode 100644
index 0000000..9b8f1cf
--- /dev/null
+++ b/currency_input.go
@@ -0,0 +1,146 @@
+package mujica
+
+import (
+	"fmt"
+	"log/slog"
+	"math"
+	"strconv"
+	"strings"
+
+	"github.com/egoist/mygo/ui"
+)
+
+// CurrencyInputOptions configure a CurrencyInput.
+type CurrencyInputOptions struct {
+	// Symbol goes before the amount, as "$" or "¥"; empty shows none.
+	Symbol string
+	// Decimals is the minor unit digits; zero is 2. NoFraction makes it 0, as for JPY.
+	Decimals   int
+	NoFraction bool
+	Label      string
+	Disabled   bool
+	// Error marks the value invalid and shows the message below.
+	Error string
+}
+
+// currencyInputDigits resolves the decimals of opts.
+func currencyInputDigits(opts CurrencyInputOptions) int {
+	switch {
+	case opts.Decimals < 0 || opts.Decimals > 6:
+		panic(fmt.Sprintf("mujica: CurrencyInput Decimals %d outside 0..6", opts.Decimals))
+	case opts.NoFraction && opts.Decimals != 0:
+		panic("mujica: CurrencyInput NoFraction with Decimals")
+	case opts.NoFraction:
+		return 0
+	case opts.Decimals == 0:
+		return 2
+	}
+	return opts.Decimals
+}
+
+// CurrencyFormat writes minor units as an amount with thousands separators.
+func CurrencyFormat(minor int64, decimals int, group bool) string {
+	neg := minor < 0
+	u := uint64(minor)
+	if neg {
+		u = -u
+	}
+	p := uint64(math.Pow10(decimals))
+	whole := strconv.FormatUint(u/p, 10)
+	if group {
+		var b strings.Builder
+		for i, r := range whole {
+			if i > 0 && (len(whole)-i)%3 == 0 {
+				b.WriteByte(',')
+			}
+			b.WriteRune(r)
+		}
+		whole = b.String()
+	}
+	s := whole
+	if decimals > 0 {
+		s += "." + fmt.Sprintf("%0*d", decimals, u%p)
+	}
+	if neg {
+		s = "-" + s
+	}
+	return s
+}
+
+// currencyInputParse reads an amount into minor units; reason is a message key when it fails.
+func currencyInputParse(text string, decimals int) (minor int64, reason string) {
+	t := strings.NewReplacer(",", "", " ", "", " ", "").Replace(strings.TrimSpace(text))
+	neg := strings.HasPrefix(t, "-")
+	t = strings.TrimPrefix(t, "-")
+	whole, frac, dot := strings.Cut(t, ".")
+	if whole == "" && frac == "" || strings.Trim(whole+frac, "0123456789") != "" || dot && strings.Contains(frac, ".") {
+		return 0, "currency_input.invalid"
+	}
+	if len(frac) > decimals {
+		return 0, "currency_input.precision"
+	}
+	frac += strings.Repeat("0", decimals-len(frac))
+	v, err := strconv.ParseInt(whole+frac, 10, 64)
+	if err != nil {
+		return 0, "currency_input.invalid"
+	}
+	if neg {
+		v = -v
+	}
+	return v, ""
+}
+
+// CurrencyInput edits *value, an amount in minor units (cents); it groups thousands while not focused.
+func CurrencyInput(c *ui.Context, value *int64, opts CurrencyInputOptions) InputResult {
+	if value == nil {
+		panic("mujica: CurrencyInput needs a value")
+	}
+	dec := currencyInputDigits(opts)
+	k := Tokens(c)
+	var r InputResult
+	look := &textInputLook{disabled: opts.Disabled, err: opts.Error}
+	r.Element, r.Input = textInputFrame(c, look, func(frame *ui.Element) *ui.Element {
+		if opts.Symbol != "" {
+			ui.Text(c, opts.Symbol).TextColor(k.TextMuted).SingleLine()
+		}
+		text := ui.Local(frame, "text", func() string { return CurrencyFormat(*value, dec, false) })
+		bad := ui.Local(frame, "bad", func() string { return "" })
+		seen := ui.Local(frame, "seen", func() int64 { return *value })
+		was := ui.Local(frame, "was", func() bool { return false })
+		if *seen != *value {
+			*bad = ""
+		}
+		// Grouped while resting; plain digits once focused, for editing.
+		focused := frame.FocusWithin()
+		switch {
+		case *bad != "":
+		case !focused:
+			*text = CurrencyFormat(*value, dec, true)
+		case !*was || *seen != *value:
+			*text = CurrencyFormat(*value, dec, false)
+		}
+		*was = focused
+		in := textInputEditor(c, frame, text, look.disabled, ui.TextInputBase).Grow(1).MinWidth(Density(c).Unit() * 16).Label(opts.Label)
+		if in.Changed() && !look.disabled {
+			v, why := currencyInputParse(*text, dec)
+			*bad = ""
+			switch {
+			case why == "currency_input.precision":
+				*bad = fmt.Sprintf(msg(c, why), dec)
+			case why != "":
+				*bad = msg(c, why)
+			case v != *value:
+				*value, r.changed = v, true
+			}
+		}
+		*seen = *value
+		if look.err == "" {
+			look.err = *bad
+		}
+		return in
+	}, nil)
+	if r.changed {
+		slog.Debug("mujica: currency_input change", "minor", *value)
+	}
+	return r
+}
diff --git a/currency_input_test.go b/currency_input_test.go
new file mode 100644
index 0000000..cef2209
--- /dev/null
+++ b/currency_input_test.go
@@ -0,0 +1,120 @@
+package mujica
+
+import (
+	"testing"
+
+	"github.com/egoist/mygo/ui"
+)
+
+func TestCurrencyFormatAndParse(t *testing.T) {
+	for _, tc := range []struct {
+		minor int64
+		dec   int
+		group bool
+		want  string
+	}{
+		{123450, 2, true, "1,234.50"}, {123450, 2, false, "1234.50"}, {-5, 2, true, "-0.05"},
+		{1234567, 0, true, "1,234,567"}, {0, 3, true, "0.000"}, {100000000, 2, true, "1,000,000.00"},
+	} {
+		if got := CurrencyFormat(tc.minor, tc.dec, tc.group); got != tc.want {
+			t.Errorf("CurrencyFormat(%d, %d) = %q, want %q", tc.minor, tc.dec, got, tc.want)
+		}
+	}
+	for text, want := range map[string]int64{"1,234.5": 123450, "0.07": 7, "-12": -1200, " 3 ": 300, "1.": 100} {
+		if v, why := currencyInputParse(text, 2); v != want || why != "" {
+			t.Errorf("parse %q = %d %q, want %d", text, v, why, want)
+		}
+	}
+	for text, want := range map[string]string{"1.234": "currency_input.precision", "abc": "currency_input.invalid", "": "currency_input.invalid", "1.2.3": "currency_input.invalid", "99999999999999999999": "currency_input.invalid"} {
+		if _, why := currencyInputParse(text, 2); why != want {
+			t.Errorf("parse %q: %q, want %q", text, why, want)
+		}
+	}
+}
+
+// fieldText copies the focused field's text through the clipboard.
+func fieldText(tt *ui.Tester) string {
+	tt.Command("selectAll")
+	tt.Command("copy")
+	return tt.Clipboard()
+}
+
+func TestCurrencyInputTypingGroupingAndErrors(t *testing.T) {
+	v := int64(123450)
+	dis := false
+	n := 0
+	tt := ui.NewTester(func(c *ui.Context) {
+		Use(c, Settings{})
+		if CurrencyInput(c, &v, CurrencyInputOptions{Symbol: "$", Label: "Price", Disabled: dis}).Changed() {
+			n++
+		}
+		Button(c, "Elsewhere", ButtonOptions{})
+	}, 500, 200)
+	if !tt.HasText("$") {
+		t.Fatalf("no symbol: %q", tt.Texts())
+	}
+	tt.Key(0, ui.KeyTab)
+	if got := fieldText(tt); got != "1234.50" {
+		t.Fatalf("focused text %q, want ungrouped", got)
+	}
+	tt.Command("selectAll")
+	tt.Type("2500.255")
+	if v != 123450 || !tt.HasText("Use at most 2 decimal places") {
+		t.Fatalf("too precise: %d %q", v, tt.Texts())
+	}
+	tt.Command("selectAll")
+	tt.Type("2500.25")
+	if v != 250025 || n != 1 || tt.HasText("decimal places") {
+		t.Fatalf("typed: %d (%d)", v, n)
+	}
+	tt.Key(0, ui.KeyTab)
+	tt.Key(ui.Shift, ui.KeyTab)
+	if got := fieldText(tt); got != "2500.25" {
+		t.Fatalf("refocused text %q", got)
+	}
+	dis = true
+	tt.Frame()
+	_ = tt.Click("Price")
+	tt.Type("9")
+	if v != 250025 {
+		t.Fatalf("disabled edit: %d", v)
+	}
+}
+
+func TestCurrencyInputNoFractionAndRejects(t *testing.T) {
+	v := int64(1500)
+	tt := ui.NewTester(func(c *ui.Context) {
+		Use(c, Settings{})
+		CurrencyInput(c, &v, CurrencyInputOptions{Symbol: "¥", NoFraction: true, Label: "Amount"})
+	}, 300, 100)
+	tt.Key(0, ui.KeyTab)
+	if got := fieldText(tt); got != "1500" {
+		t.Fatalf("yen %q", got)
+	}
+	tt.Command("selectAll")
+	tt.Type("12.5")
+	if v != 1500 || !tt.HasText("Use at most 0 decimal places") {
+		t.Fatalf("fraction accepted: %d", v)
+	}
+	for _, o := range []CurrencyInputOptions{{Decimals: -1}, {Decimals: 7}, {Decimals: 2, NoFraction: true}} {
+		func() {
+			defer func() {
+				if recover() == nil {
+					t.Errorf("%+v: no panic", o)
+				}
+			}()
+			ui.NewTester(func(c *ui.Context) { Use(c, Settings{}); CurrencyInput(c, &v, o) }, 200, 100)
+		}()
+	}
+}
+
+func TestCurrencyInputSnapshot(t *testing.T) {
+	a, b, d := int64(1234550), int64(98000), int64(0)
+	snapshot(t, "currency_input", 520, 80, func(c *ui.Context) {
+		ui.Row(c).Padding(16).Gap(12).Children(func() {
+			CurrencyInput(c, &a, CurrencyInputOptions{Symbol: "$"}).Element.Width(150)
+			CurrencyInput(c, &b, CurrencyInputOptions{Symbol: "¥", NoFraction: true}).Element.Width(150)
+			CurrencyInput(c, &d, CurrencyInputOptions{Symbol: "€", Disabled: true}).Element.Width(150)
+		})
+	})
+}
diff --git a/messages_essentials.go b/messages_essentials.go
index f4a4f68..fcb62b3 100644
--- a/messages_essentials.go
+++ b/messages_essentials.go
@@ -18,6 +18,9 @@ func init() {
 
 		"knob.label": {"Knob", "旋钮"},
 
+		"currency_input.invalid":   {"Enter an amount, such as 1,234.50", "请输入金额，例如 1,234.50"},
+		"currency_input.precision": {"Use at most %d decimal places", "最多保留 %d 位小数"},
+
 		"qr_code.label":    {"QR code", "二维码"},
 		"qr_code.too_long": {"Text too long for a QR code", "文字过长，无法生成二维码"},
 	})
diff --git a/scrub_input.go b/scrub_input.go
new file mode 100644
index 0000000..387bc67
--- /dev/null
+++ b/scrub_input.go
@@ -0,0 +1,75 @@
+package mujica
+
+import (
+	"log/slog"
+	"math"
+
+	"github.com/egoist/mygo/ui"
+
+	"mujicaui/theme"
+)
+
+// ScrubInputOptions configure a ScrubInput; the range and step rules are NumberInput's.
+type ScrubInputOptions struct {
+	Min, Max  float64
+	Step      float64
+	Precision int
+	Disabled  bool
+}
+
+// scrubInputPixels is how far a drag moves for one step.
+const scrubInputPixels float32 = 4
+
+// ScrubInput edits *value by dragging its label sideways, one Step per 4 DIPs, or by typing in its field.
+func ScrubInput(c *ui.Context, label string, value *float64, opts ScrubInputOptions) InputResult {
+	if label == "" || value == nil {
+		panic("mujica: ScrubInput needs a label and a value")
+	}
+	nopts := NumberInputOptions{Min: opts.Min, Max: opts.Max, Step: opts.Step, Precision: opts.Precision, Label: label, Disabled: opts.Disabled}
+	s := numberInputResolve(nopts)
+	k := Tokens(c)
+	var r InputResult
+	row := ui.Row(c).AlignItems(ui.Center).Gap(Density(c).Unit() * 2).Disabled(opts.Disabled)
+	row.Children(func() {
+		h := ui.Box(c).Shrink(0).MinHeight(theme.MinHitSize).MinWidth(theme.MinHitSize).Center().Cursor(ui.CursorResizeEW).Role(ui.RoleNone)
+		drag := ui.Local(h, "scrub_input.drag", func() float64 { return math.NaN() })
+		dx, _, held := h.Dragged()
+		scrubbed := false
+		switch {
+		case !held || h.IsDisabled():
+			*drag = math.NaN()
+		case math.IsNaN(*drag):
+			*drag = 0
+			fallthrough
+		default:
+			start := *value
+			*drag += float64(dx)
+			if n := int(*drag / float64(scrubInputPixels)); n != 0 {
+				*drag -= float64(n) * float64(scrubInputPixels)
+				// One grid step at a time, so a long drag stops at the bound.
+				v := start
+				for range max(n, -n) {
+					v = s.stepBy(v, max(-1, min(1, n)))
+				}
+				if v != *value {
+					*value, scrubbed = v, true
+				}
+			}
+		}
+		fg := k.TextMuted
+		if held || h.Hovered() {
+			fg = k.AccentText
+		}
+		h.Children(func() {
+			ui.Text(c, label).TextColor(fg).Underline().DecorationColor(k.Border).SingleLine()
+		})
+		r = NumberInput(c, value, nopts)
+		r.Element.Width(Density(c).Unit() * 36)
+		r.changed = r.changed || scrubbed
+		if scrubbed {
+			slog.Debug("mujica: scrub_input scrubbed", "label", label, "value", *value)
+		}
+	})
+	r.Element = row
+	return r
+}
diff --git a/scrub_input_test.go b/scrub_input_test.go
new file mode 100644
index 0000000..2e9502b
--- /dev/null
+++ b/scrub_input_test.go
@@ -0,0 +1,82 @@
+package mujica
+
+import (
+	"testing"
+
+	"github.com/egoist/mygo/ui"
+)
+
+func scrubTester(v *float64, opts *ScrubInputOptions, n *int) *ui.Tester {
+	return ui.NewTester(func(c *ui.Context) {
+		Use(c, Settings{})
+		ui.Row(c).Padding(20).Children(func() {
+			if ScrubInput(c, "Opacity", v, *opts).Changed() {
+				*n++
+			}
+		})
+	}, 500, 200)
+}
+
+func TestScrubInputDragAndRange(t *testing.T) {
+	v := 0.5
+	opts := ScrubInputOptions{Min: 0, Max: 1, Step: 0.1}
+	n := 0
+	tt := scrubTester(&v, &opts, &n)
+	r, _ := tt.Find("Opacity")
+	x, y := r.X+r.W/2, r.Y+r.H/2
+	tt.Press(x, y)
+	tt.Move(x+6, y) // one step, 2 DIPs carried
+	tt.Move(x+10, y)
+	tt.Release(x+10, y)
+	if v != 0.7 {
+		t.Fatalf("10 DIPs right: %v", v)
+	}
+	tt.Press(x, y)
+	tt.Move(x+400, y)
+	tt.Release(x+400, y)
+	if v != 1 {
+		t.Fatalf("past the max: %v", v)
+	}
+	tt.Press(x, y)
+	tt.Move(x-8, y)
+	tt.Release(x-8, y)
+	if v != 0.8 || n != 4 {
+		t.Fatalf("8 DIPs left: %v (%d)", v, n)
+	}
+}
+
+func TestScrubInputTypingAndDisabled(t *testing.T) {
+	v := 2.0
+	opts := ScrubInputOptions{Step: 1}
+	n := 0
+	tt := scrubTester(&v, &opts, &n)
+	tt.Key(0, ui.KeyTab)
+	tt.Key(0, ui.KeyUp)
+	if v != 3 {
+		t.Fatalf("Up in the field: %v", v)
+	}
+	tt.Command("selectAll")
+	tt.Type("12")
+	if v != 12 {
+		t.Fatalf("typed: %v", v)
+	}
+	opts.Disabled = true
+	tt.Frame()
+	r, _ := tt.Find("Opacity")
+	tt.Press(r.X+r.W/2, r.Y+r.H/2)
+	tt.Move(r.X+r.W/2+40, r.Y+r.H/2)
+	tt.Release(r.X+r.W/2+40, r.Y+r.H/2)
+	if v != 12 {
+		t.Fatalf("disabled scrub: %v", v)
+	}
+}
+
+func TestScrubInputSnapshot(t *testing.T) {
+	a, b := 0.6, 24.0
+	snapshot(t, "scrub_input", 520, 80, func(c *ui.Context) {
+		ui.Row(c).Padding(16).Gap(16).Children(func() {
+			ScrubInput(c, "Opacity", &a, ScrubInputOptions{Max: 1, Step: 0.1})
+			ScrubInput(c, "Size", &b, ScrubInputOptions{Disabled: true})
+		})
+	})
+}
diff --git a/testdata/snapshots/darwin/currency_input-dark.png b/testdata/snapshots/darwin/currency_input-dark.png
new file mode 100644
index 0000000..07aaac8
Binary files /dev/null and b/testdata/snapshots/darwin/currency_input-dark.png differ
diff --git a/testdata/snapshots/darwin/currency_input-light.png b/testdata/snapshots/darwin/currency_input-light.png
new file mode 100644
index 0000000..b4a5df3
Binary files /dev/null and b/testdata/snapshots/darwin/currency_input-light.png differ
diff --git a/testdata/snapshots/darwin/scrub_input-dark.png b/testdata/snapshots/darwin/scrub_input-dark.png
new file mode 100644
index 0000000..f5a4d87
Binary files /dev/null and b/testdata/snapshots/darwin/scrub_input-dark.png differ
diff --git a/testdata/snapshots/darwin/scrub_input-light.png b/testdata/snapshots/darwin/scrub_input-light.png
new file mode 100644
index 0000000..4d7f243
Binary files /dev/null and b/testdata/snapshots/darwin/scrub_input-light.png differ