feat: add ButtonGroup primitive and redesign TopBar time range selector

Replace the TimeRangeDropdown popover with inline FilterPills inside a
new ButtonGroup component. The ButtonGroup merges adjacent children into
a single visual strip with shared borders and rounded end-caps.

The time readout is now an integrated inset display cell at the right end
of the group. Preset ranges show "HH:MM – now"; custom ranges show both
timestamps. Default changed from 3h to 1h.

TopBar reordered to: Breadcrumb | Search | Status pills | Time pills | Right.
FilterPill upgraded to forwardRef with data-active attribute.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/design-system/layout/TopBar/TopBar.module.css

@@ -22,7 +22,7 @@
   flex-shrink: 0;
 }
 
-/* Center search trigger */
+/* Search trigger */
 .search {
   display: flex;
   align-items: center;
@@ -36,9 +36,9 @@
   font-family: var(--font-body);
   cursor: pointer;
   transition: border-color 0.15s;
-  min-width: 180px;
+  width: 200px;
-  flex: 1;
+  flex-shrink: 1;
-  max-width: 280px;
+  min-width: 120px;
   text-align: left;
 }
 

src/design-system/layout/TopBar/TopBar.tsx

@@ -39,23 +39,7 @@ export function TopBar({
       {/* Left: Breadcrumb */}
       <Breadcrumb items={breadcrumb} className={styles.breadcrumb} />
 
-      {/* Filters: time range + status pills */}
+      {/* Search trigger */}
-      <div className={styles.filters}>
-        <TimeRangeDropdown
-          value={globalFilters.timeRange}
-          onChange={globalFilters.setTimeRange}
-        />
-        {STATUS_PILLS.map(({ status, label }) => (
-          <FilterPill
-            key={status}
-            label={label}
-            active={globalFilters.statusFilters.has(status)}
-            onClick={() => globalFilters.toggleStatus(status)}
-          />
-        ))}
-      </div>
-
-      {/* Center: Search trigger */}
       <button
         className={styles.search}
         onClick={() => commandPalette.setOpen(true)}
@@ -72,6 +56,24 @@ export function TopBar({
         <span className={styles.kbd}>Ctrl+K</span>
       </button>
 
+      {/* Status pills */}
+      <div className={styles.filters}>
+        {STATUS_PILLS.map(({ status, label }) => (
+          <FilterPill
+            key={status}
+            label={label}
+            active={globalFilters.statusFilters.has(status)}
+            onClick={() => globalFilters.toggleStatus(status)}
+          />
+        ))}
+      </div>
+
+      {/* Time range pills */}
+      <TimeRangeDropdown
+        value={globalFilters.timeRange}
+        onChange={globalFilters.setTimeRange}
+      />
+
       {/* Right: env badge, user */}
       <div className={styles.right}>
         {environment && (

src/design-system/primitives/ButtonGroup/ButtonGroup.module.css

@@ -0,0 +1,60 @@
+.group {
+  display: inline-flex;
+  isolation: isolate;
+}
+
+/* Horizontal (default) */
+.horizontal {
+  flex-direction: row;
+}
+
+.horizontal > :global(*) {
+  border-radius: 0;
+  margin-left: -1px;
+  position: relative;
+}
+
+.horizontal > :global(*:first-child) {
+  border-radius: var(--radius-sm) 0 0 var(--radius-sm);
+  margin-left: 0;
+}
+
+.horizontal > :global(*:last-child) {
+  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
+}
+
+.horizontal > :global(*:only-child) {
+  border-radius: var(--radius-sm);
+}
+
+/* Vertical */
+.vertical {
+  flex-direction: column;
+}
+
+.vertical > :global(*) {
+  border-radius: 0;
+  margin-top: -1px;
+  position: relative;
+}
+
+.vertical > :global(*:first-child) {
+  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
+  margin-top: 0;
+}
+
+.vertical > :global(*:last-child) {
+  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
+}
+
+.vertical > :global(*:only-child) {
+  border-radius: var(--radius-sm);
+}
+
+/* Active/hovered items sit above siblings so their borders win */
+.group > :global(*:hover),
+.group > :global(*:focus-visible),
+.group > :global(*[data-active="true"]),
+.group > :global(*.active) {
+  z-index: 1;
+}

src/design-system/primitives/ButtonGroup/ButtonGroup.tsx

@@ -0,0 +1,23 @@
+import { type ReactNode } from 'react'
+import styles from './ButtonGroup.module.css'
+
+interface ButtonGroupProps {
+  children: ReactNode
+  orientation?: 'horizontal' | 'vertical'
+  className?: string
+}
+
+export function ButtonGroup({
+  children,
+  orientation = 'horizontal',
+  className,
+}: ButtonGroupProps) {
+  return (
+    <div
+      className={`${styles.group} ${styles[orientation]} ${className ?? ''}`}
+      role="group"
+    >
+      {children}
+    </div>
+  )
+}

src/design-system/primitives/FilterPill/FilterPill.tsx

@@ -1,3 +1,4 @@
+import { forwardRef } from 'react'
 import styles from './FilterPill.module.css'
 
 interface FilterPillProps {
@@ -10,7 +11,8 @@ interface FilterPillProps {
   className?: string
 }
 
-export function FilterPill({
+export const FilterPill = forwardRef<HTMLButtonElement, FilterPillProps>(
+  ({
     label,
     count,
     active = false,
@@ -18,7 +20,7 @@ export function FilterPill({
     dotColor,
     onClick,
     className,
-}: FilterPillProps) {
+  }, ref) => {
     const classes = [
       styles.pill,
       active ? styles.active : '',
@@ -26,7 +28,7 @@ export function FilterPill({
     ].filter(Boolean).join(' ')
 
     return (
-    <button className={classes} onClick={onClick} type="button">
+      <button ref={ref} className={classes} onClick={onClick} type="button" data-active={active || undefined}>
         {dot && (
           <span
             className={styles.dot}
@@ -39,4 +41,7 @@ export function FilterPill({
         )}
       </button>
     )
-}
+  },
+)
+
+FilterPill.displayName = 'FilterPill'

src/design-system/primitives/TimeRangeDropdown/TimeRangeDropdown.module.css

@@ -1,45 +1,78 @@
-.trigger {
+/* ── Integrated readout cell ──────────────────────────────
-  display: flex;
+   First child of the ButtonGroup — styled as a recessed
+   instrument-panel display, not a clickable control.       */
+
+.readout {
+  display: inline-flex;
   align-items: center;
-  gap: 4px;
+  padding: 4px 12px;
-  padding: 4px 10px;
   height: 28px;
   border: 1px solid var(--border);
-  border-radius: var(--radius-sm);
+  background: var(--bg-inset);
-  background: var(--bg-raised);
+  box-shadow: inset 0 1px 3px rgba(44, 37, 32, 0.06);
-  color: var(--amber, var(--warning));
   font-family: var(--font-mono);
+  font-size: 11px;
+  font-weight: 500;
+  letter-spacing: 0.02em;
+  color: var(--text-secondary);
+  white-space: nowrap;
+  cursor: default;
+  user-select: none;
+}
+
+[data-theme="dark"] .readout {
+  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.2);
+}
+
+/* ── Custom date picker panel ────────────────────────── */
+
+.panel {
+  position: absolute;
+  display: flex;
+  flex-direction: column;
+  gap: 10px;
+  padding: 12px;
+  min-width: 220px;
+  background: var(--bg-surface);
+  border: 1px solid var(--border-subtle);
+  border-radius: var(--radius-md);
+  box-shadow: var(--shadow-lg);
+  z-index: 500;
+  animation: panelIn 150ms ease-out;
+}
+
+@keyframes panelIn {
+  from {
+    opacity: 0;
+    transform: scale(0.97);
+  }
+  to {
+    opacity: 1;
+    transform: scale(1);
+  }
+}
+
+.applyBtn {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: 5px 14px;
+  border: none;
+  border-radius: var(--radius-sm);
+  background: var(--amber);
+  color: #fff;
+  font-family: var(--font-body);
   font-size: 12px;
   font-weight: 600;
   cursor: pointer;
-  transition: border-color 0.15s, background 0.15s;
+  transition: opacity 0.15s;
-  white-space: nowrap;
 }
 
-.trigger:hover {
+.applyBtn:hover {
-  border-color: var(--text-faint);
+  opacity: 0.85;
-  background: var(--bg-surface);
 }
 
-.icon {
+.applyBtn:disabled {
-  font-size: 13px;
+  opacity: 0.4;
-  line-height: 1;
+  cursor: not-allowed;
-}
-
-.label {
-  line-height: 1;
-}
-
-.caret {
-  font-size: 9px;
-  opacity: 0.7;
-  line-height: 1;
-}
-
-.presetList {
-  display: flex;
-  flex-direction: column;
-  gap: 4px;
-  padding: 8px;
-  min-width: 100px;
 }

src/design-system/primitives/TimeRangeDropdown/TimeRangeDropdown.tsx

@@ -1,15 +1,46 @@
+import { useState, useRef, useEffect, useCallback, useMemo } from 'react'
+import { createPortal } from 'react-dom'
 import styles from './TimeRangeDropdown.module.css'
-import { Popover } from '../../composites/Popover/Popover'
 import { FilterPill } from '../FilterPill/FilterPill'
-import { computePresetRange, PRESET_SHORT_LABELS } from '../../utils/timePresets'
+import { ButtonGroup } from '../ButtonGroup/ButtonGroup'
+import { DateTimePicker } from '../DateTimePicker/DateTimePicker'
+import { computePresetRange } from '../../utils/timePresets'
 import type { TimeRange } from '../../providers/GlobalFilterProvider'
 
-const DROPDOWN_PRESETS = [
+function formatRangeLabel(range: TimeRange): string {
+  const start = range.preset ? computePresetRange(range.preset).start : range.start
+
+  const time = (d: Date) =>
+    d.toLocaleTimeString(undefined, { hour: '2-digit', minute: '2-digit', hour12: false })
+  const dateTime = (d: Date) =>
+    d.toLocaleDateString(undefined, { month: 'short', day: 'numeric' }) + '\u2009' + time(d)
+
+  // Preset ranges are open-ended ("since X"), so only show the start
+  if (range.preset) {
+    const now = new Date()
+    const sameDay =
+      start.getFullYear() === now.getFullYear() &&
+      start.getMonth() === now.getMonth() &&
+      start.getDate() === now.getDate()
+    return sameDay ? `${time(start)}\u2009\u2013\u2009now` : `${dateTime(start)}\u2009\u2013\u2009now`
+  }
+
+  // Custom range: show both ends
+  const end = range.end
+  const sameDay =
+    start.getFullYear() === end.getFullYear() &&
+    start.getMonth() === end.getMonth() &&
+    start.getDate() === end.getDate()
+
+  if (sameDay) return `${time(start)}\u2009\u2013\u2009${time(end)}`
+  return `${dateTime(start)}\u2009\u2013\u2009${dateTime(end)}`
+}
+
+const PRESETS = [
   { value: 'last-1h', label: '1h' },
   { value: 'last-3h', label: '3h' },
   { value: 'last-6h', label: '6h' },
   { value: 'today', label: 'Today' },
-  { value: 'shift', label: 'Shift' },
   { value: 'last-24h', label: '24h' },
   { value: 'last-7d', label: '7d' },
 ]
@@ -21,35 +52,112 @@ interface TimeRangeDropdownProps {
 }
 
 export function TimeRangeDropdown({ value, onChange, className }: TimeRangeDropdownProps) {
-  const activeLabel = value.preset ? (PRESET_SHORT_LABELS[value.preset] ?? value.preset) : 'Custom'
+  const [open, setOpen] = useState(false)
+  const [customFrom, setCustomFrom] = useState<Date | null>(value.start)
+  const [customTo, setCustomTo] = useState<Date | null>(value.end)
+  const customRef = useRef<HTMLButtonElement>(null)
+  const panelRef = useRef<HTMLDivElement>(null)
+  const [panelPos, setPanelPos] = useState({ top: 0, left: 0 })
+  const isCustom = value.preset === null || value.preset === 'custom'
+
+  const reposition = useCallback(() => {
+    if (!customRef.current) return
+    const rect = customRef.current.getBoundingClientRect()
+    const panelWidth = panelRef.current?.offsetWidth ?? 240
+    setPanelPos({
+      top: rect.bottom + window.scrollY + 8,
+      left: rect.right + window.scrollX - panelWidth,
+    })
+  }, [])
+
+  useEffect(() => {
+    if (open) {
+      const id = requestAnimationFrame(reposition)
+      return () => cancelAnimationFrame(id)
+    }
+  }, [open, reposition])
+
+  useEffect(() => {
+    if (!open) return
+    function handleMouseDown(e: MouseEvent) {
+      if (
+        customRef.current?.contains(e.target as Node) ||
+        panelRef.current?.contains(e.target as Node)
+      ) return
+      setOpen(false)
+    }
+    function handleKey(e: KeyboardEvent) {
+      if (e.key === 'Escape') setOpen(false)
+    }
+    document.addEventListener('mousedown', handleMouseDown)
+    document.addEventListener('keydown', handleKey)
+    return () => {
+      document.removeEventListener('mousedown', handleMouseDown)
+      document.removeEventListener('keydown', handleKey)
+    }
+  }, [open])
+
+  const rangeLabel = useMemo(() => formatRangeLabel(value), [value])
 
   return (
-    <Popover
+    <>
-      className={className}
+      <ButtonGroup className={className}>
-      position="bottom"
+        {PRESETS.map((preset) => (
-      align="start"
-      trigger={
-        <button className={styles.trigger} type="button" aria-label="Select time range">
-          <span className={styles.icon} aria-hidden="true">&#9201;</span>
-          <span className={styles.label}>{activeLabel}</span>
-          <span className={styles.caret} aria-hidden="true">&#9662;</span>
-        </button>
-      }
-      content={
-        <div className={styles.presetList}>
-          {DROPDOWN_PRESETS.map((preset) => (
           <FilterPill
             key={preset.value}
             label={preset.label}
             active={value.preset === preset.value}
             onClick={() => {
+              setOpen(false)
               const range = computePresetRange(preset.value)
               onChange({ ...range, preset: preset.value })
             }}
           />
         ))}
-        </div>
+        <FilterPill
-      }
+          ref={customRef}
+          label="Custom"
+          active={isCustom}
+          onClick={() => setOpen((prev) => !prev)}
         />
+        <span className={styles.readout} aria-label="Active time range">
+          {rangeLabel}
+        </span>
+      </ButtonGroup>
+
+      {open && createPortal(
+        <div
+          ref={panelRef}
+          className={styles.panel}
+          style={{ top: panelPos.top, left: panelPos.left }}
+          role="dialog"
+        >
+          <DateTimePicker
+            label="From"
+            value={customFrom ?? undefined}
+            onChange={(d) => setCustomFrom(d)}
+          />
+          <DateTimePicker
+            label="To"
+            value={customTo ?? undefined}
+            onChange={(d) => setCustomTo(d)}
+          />
+          <button
+            type="button"
+            className={styles.applyBtn}
+            disabled={!customFrom || !customTo}
+            onClick={() => {
+              if (customFrom && customTo) {
+                onChange({ start: customFrom, end: customTo, preset: null })
+                setOpen(false)
+              }
+            }}
+          >
+            Apply
+          </button>
+        </div>,
+        document.body,
+      )}
+    </>
   )
 }

src/design-system/primitives/index.ts

@@ -2,6 +2,7 @@ export { Alert } from './Alert/Alert'
 export { Avatar } from './Avatar/Avatar'
 export { Badge } from './Badge/Badge'
 export { Button } from './Button/Button'
+export { ButtonGroup } from './ButtonGroup/ButtonGroup'
 export { Card } from './Card/Card'
 export { Checkbox } from './Checkbox/Checkbox'
 export { CodeBlock } from './CodeBlock/CodeBlock'

src/design-system/providers/GlobalFilterProvider.tsx

@@ -20,7 +20,7 @@ interface GlobalFilterContextValue {
 
 const GlobalFilterContext = createContext<GlobalFilterContextValue | null>(null)
 
-const DEFAULT_PRESET = 'last-3h'
+const DEFAULT_PRESET = 'last-1h'
 
 function getDefaultTimeRange(): TimeRange {
   const { start, end } = computePresetRange(DEFAULT_PRESET)