Update

app.js

@@ -22,7 +22,8 @@ import {
   saveSettings,
   applySettingsToDom,
 } from './client/settings.js'
-import { drawMultiChart, CHART_PALETTE, pushRing } from './ui/charts.js'
+import { drawChart, CHART_PALETTE, pushRing } from './ui/charts.js'
+import { defaultModeFromMeta } from './shared/chart-types.js'
 import { createMetricsDashboard } from './ui/dashboard.js'
 import {
   buildFleetRoster,
@@ -266,7 +267,7 @@ function pushPeerCpu(peerId, value) {
 }
 
 function paint(canvasId, lines, opts = {}) {
-  drawMultiChart($(canvasId), lines, { ...opts, maxPoints: seriesMax() })
+  drawChart($(canvasId), lines, { ...opts, maxPoints: seriesMax() })
 }
 
 function panelForChart(chart) {
@@ -388,9 +389,12 @@ function redrawCpu() {
       { values: series.cpuIowait, color: CHART_PALETTE.cpuIowait, label: 'iowait', fill: false },
     ].filter((l) => l.values.length >= 2)
     if (!lines.length) {
-      paint('chart-cpu', [{ values: series.cpu, color: CHART_PALETTE.cpuUser }], opts)
+      paint('chart-cpu', [{ values: series.cpu, color: CHART_PALETTE.cpuUser }], {
+        ...opts,
+        mode: 'area',
+      })
     } else {
-      paint('chart-cpu', lines, { ...opts, stacked: false })
+      paint('chart-cpu', lines, { ...opts, mode: 'stacked' })
     }
     if (els.chartCpuLabel) els.chartCpuLabel.textContent = 'system.cpu'
     if (els.legendCpu) {
@@ -405,38 +409,49 @@ function redrawAll() {
   applyAnomalyHighlights()
   redrawCpu()
   const ramChart = anomalyByChart.has('mem.available') ? 'mem.available' : 'system.ram'
-  paint('chart-ram', [{ values: series.ram, color: CHART_PALETTE.ram }], anomalyOptsFor(ramChart))
+  paint(
+    'chart-ram',
+    [{ values: series.ram, color: CHART_PALETTE.ram }],
+    { ...anomalyOptsFor(ramChart), mode: 'area' }
+  )
   paint(
     'chart-net',
     [
-      { values: series.net, color: CHART_PALETTE.net, label: 'rx', fill: false },
-      { values: series.netTx, color: CHART_PALETTE.disk, label: 'tx', fill: false },
+      { values: series.net, color: CHART_PALETTE.net, label: 'rx' },
+      { values: series.netTx, color: CHART_PALETTE.disk, label: 'tx' },
     ].filter((l) => l.values.length >= 2).length
       ? [
-          { values: series.net, color: CHART_PALETTE.net, fill: false },
-          { values: series.netTx, color: CHART_PALETTE.disk, fill: false },
+          { values: series.net, color: CHART_PALETTE.net },
+          { values: series.netTx, color: CHART_PALETTE.disk },
         ]
       : [{ values: series.net, color: CHART_PALETTE.net }],
-    anomalyOptsFor('system.net')
+    { ...anomalyOptsFor('system.net'), mode: 'area' }
   )
   paint(
     'chart-io',
     [
-      { values: series.io, color: CHART_PALETTE.disk, fill: false },
-      { values: series.ioWrite, color: CHART_PALETTE.cpuIowait, fill: false },
+      { values: series.io, color: CHART_PALETTE.disk },
+      { values: series.ioWrite, color: CHART_PALETTE.cpuIowait },
     ].filter((l) => l.values.length >= 2).length
       ? [
-          { values: series.io, color: CHART_PALETTE.disk, fill: false },
-          { values: series.ioWrite, color: CHART_PALETTE.cpuIowait, fill: false },
+          { values: series.io, color: CHART_PALETTE.disk },
+          { values: series.ioWrite, color: CHART_PALETTE.cpuIowait },
         ]
       : [{ values: series.io, color: CHART_PALETTE.disk }],
-    anomalyOptsFor('system.io')
+    { ...anomalyOptsFor('system.io'), mode: 'area' }
+  )
+  paint(
+    'chart-load',
+    [{ values: series.load, color: CHART_PALETTE.load }],
+    { ...anomalyOptsFor('system.load'), mode: 'line' }
   )
-  paint('chart-load', [{ values: series.load, color: CHART_PALETTE.load }], anomalyOptsFor('system.load'))
   paint(
     'chart-explore',
     [{ values: series.explore, color: CHART_PALETTE.explore }],
-    anomalyOptsFor(exploreChartId)
+    {
+      ...anomalyOptsFor(exploreChartId),
+      mode: defaultModeFromMeta(chartCatalog[exploreChartId] || { chartType: 'line' }),
+    }
   )
   if (selectedCatalogChart && series.detail.length) {
     paint('chart-detail', [{ values: series.detail, color: CHART_PALETTE.cpuUser }])
@@ -854,8 +869,8 @@ async function selectCatalogChart(id) {
         if (i === 0) series.detail = values.slice()
       }
       paint('chart-detail', lines, {
-        stacked: String(meta.chartType || '').toLowerCase() === 'stacked',
-        showYAxis: true,
+        mode: defaultModeFromMeta(meta),
+        showYAxis: defaultModeFromMeta(meta) !== 'pie',
       })
     } else {
       for (const row of q.data || []) pushPoint('detail', row[1] ?? 0)

docs/DASHBOARD.md

@@ -54,7 +54,7 @@ Do not name third-party products in code, commits, or user-facing copy.
 - [x] Pan / zoom / reset on a card (updates shared window)
 - [x] Synced crosshair / shared hover time across visible cards
 - [x] Dimension show/hide + sort by name / latest value
-- [x] Chart type switch (line / area / stacked) where units allow
+- [x] Chart type switch (line / area / stacked / bar / multibar / pie) — catalog default + sensible cycle
 - [x] Resize card height; persist prefs
 - [x] Section overview KPI strip (latest values) above detail charts
 

shared/chart-types.js

@@ -0,0 +1,134 @@
+/**
+ * Chart display modes — how a metrics card should paint its series.
+ *
+ * Catalog agents emit chartType: line | area | stacked.
+ * The desktop can also render bar / multibar / pie where they make sense.
+ */
+
+/** @typedef {'line'|'area'|'stacked'|'bar'|'multibar'|'pie'} ChartMode */
+
+/** @type {ChartMode[]} */
+export const CHART_MODES = ['line', 'area', 'stacked', 'bar', 'multibar', 'pie']
+
+/** Short labels for the type toggle button */
+export const CHART_MODE_LABEL = {
+  line: 'line',
+  area: 'area',
+  stacked: 'stack',
+  bar: 'bar',
+  multibar: 'bars',
+  pie: 'pie',
+}
+
+/**
+ * @param {unknown} raw
+ * @returns {ChartMode}
+ */
+export function normalizeChartMode(raw) {
+  const m = String(raw || 'line')
+    .trim()
+    .toLowerCase()
+    .replace(/[_-]/g, '')
+  if (m === 'multibar' || m === 'bargroup') return 'multibar'
+  if (m === 'stack') return 'stacked'
+  if (CHART_MODES.includes(/** @type {ChartMode} */ (m))) {
+    return /** @type {ChartMode} */ (m)
+  }
+  return 'line'
+}
+
+/**
+ * Default mode from catalog metadata.
+ * @param {object} [meta]
+ * @returns {ChartMode}
+ */
+export function defaultModeFromMeta(meta = {}) {
+  return normalizeChartMode(meta.chartType || meta.chart_type || 'line')
+}
+
+/**
+ * @param {object} [meta]
+ */
+function dimCount(meta = {}) {
+  const dims = meta.dimensions
+  if (Array.isArray(dims)) return dims.length
+  if (dims && typeof dims === 'object') return Object.keys(dims).length
+  return 0
+}
+
+/**
+ * Composition charts (parts of a whole) — pie / stacked are natural.
+ * @param {object} [meta]
+ */
+export function isCompositionChart(meta = {}) {
+  const mode = defaultModeFromMeta(meta)
+  if (mode === 'stacked') return true
+  const units = String(meta.units || '')
+  if (/%|percentage|percent/i.test(units)) return true
+  const id = String(meta.id || meta.name || '')
+  // Common composition contexts
+  if (/\.(cpu|ram|swap|slab|kernel|states|usage)$/i.test(id)) return true
+  if (/^(system\.cpu|system\.ram|mem\.(swap|kernel|slab))/i.test(id)) return true
+  return false
+}
+
+/**
+ * Modes that make sense for this chart (catalog default first).
+ * @param {object} [meta]
+ * @returns {ChartMode[]}
+ */
+export function allowedModesFor(meta = {}) {
+  const preferred = defaultModeFromMeta(meta)
+  const n = dimCount(meta)
+  const composition = isCompositionChart(meta)
+  /** @type {Set<ChartMode>} */
+  const set = new Set(['line', 'area'])
+
+  if (n !== 1) set.add('stacked')
+  set.add('bar')
+  if (n === 0 || (n >= 2 && n <= 16)) set.add('multibar')
+  if (composition || preferred === 'stacked') set.add('pie')
+
+  // Always allow the catalog default
+  set.add(preferred)
+
+  const order = /** @type {ChartMode[]} */ ([
+    preferred,
+    ...CHART_MODES.filter((m) => m !== preferred && set.has(m)),
+  ])
+  return order
+}
+
+/**
+ * Cycle to the next allowed mode.
+ * @param {ChartMode|string} current
+ * @param {object} [meta]
+ * @returns {ChartMode}
+ */
+export function nextChartMode(current, meta = {}) {
+  const allowed = allowedModesFor(meta)
+  const cur = normalizeChartMode(current)
+  const idx = allowed.indexOf(cur)
+  return allowed[(idx < 0 ? 0 : idx + 1) % allowed.length]
+}
+
+/**
+ * Human hint for tooltips / empty states.
+ * @param {ChartMode|string} mode
+ */
+export function chartModeHint(mode) {
+  switch (normalizeChartMode(mode)) {
+    case 'area':
+      return 'Filled time series — good for volume and rates'
+    case 'stacked':
+      return 'Stacked over time — parts of a whole'
+    case 'bar':
+      return 'Columns over time — compare magnitude per sample'
+    case 'multibar':
+      return 'Grouped bars — compare dimensions side by side'
+    case 'pie':
+      return 'Snapshot share — latest values as a whole'
+    default:
+      return 'Lines over time — independent series'
+  }
+}

test/chart-types.test.js

@@ -0,0 +1,47 @@
+import test from 'brittle'
+import {
+  allowedModesFor,
+  defaultModeFromMeta,
+  nextChartMode,
+  normalizeChartMode,
+  isCompositionChart,
+} from '../shared/chart-types.js'
+
+test('normalizeChartMode aliases', (t) => {
+  t.is(normalizeChartMode('STACK'), 'stacked')
+  t.is(normalizeChartMode('multi-bar'), 'multibar')
+  t.is(normalizeChartMode('nope'), 'line')
+})
+
+test('defaultModeFromMeta respects catalog', (t) => {
+  t.is(defaultModeFromMeta({ chartType: 'area' }), 'area')
+  t.is(defaultModeFromMeta({ chart_type: 'stacked' }), 'stacked')
+  t.is(defaultModeFromMeta({}), 'line')
+})
+
+test('composition charts get pie in allowed modes', (t) => {
+  const meta = {
+    id: 'system.cpu',
+    chartType: 'stacked',
+    units: 'percentage',
+    dimensions: ['user', 'system', 'idle'],
+  }
+  t.ok(isCompositionChart(meta))
+  const allowed = allowedModesFor(meta)
+  t.ok(allowed.includes('pie'))
+  t.ok(allowed.includes('stacked'))
+  t.is(allowed[0], 'stacked')
+})
+
+test('line charts cycle through sensible modes', (t) => {
+  const meta = { chartType: 'line', dimensions: ['a', 'b'] }
+  let mode = 'line'
+  const seen = new Set()
+  for (let i = 0; i < 8; i++) {
+    mode = nextChartMode(mode, meta)
+    seen.add(mode)
+  }
+  t.ok(seen.has('area'))
+  t.ok(seen.has('bar'))
+  t.absent(seen.has('pie'))
+})

ui/charts.js

@@ -1,11 +1,13 @@
 /**
- * Canvas chart helpers — multi-series lines / stacked areas for the desktop.
+ * Canvas chart helpers — line / area / stacked / bar / multibar / pie.
  */
+import { normalizeChartMode } from '../shared/chart-types.js'
 
 /**
  * @param {HTMLCanvasElement|null} canvas
  * @param {Array<{ values: number[], color: string, label?: string, fill?: boolean, hidden?: boolean }>} lines
  * @param {{
+ *   mode?: string,
  *   threshold?: number|null,
  *   severity?: string|null,
  *   stacked?: boolean,
@@ -19,6 +21,25 @@
  *   dimmed?: boolean,
  * }} [opts]
  */
+export function drawChart(canvas, lines, opts = {}) {
+  const mode = normalizeChartMode(
+    opts.mode || (opts.stacked ? 'stacked' : undefined) || 'line'
+  )
+  if (mode === 'pie') return drawPieChart(canvas, lines, opts)
+  if (mode === 'bar') return drawBarChart(canvas, lines, { ...opts, grouped: false })
+  if (mode === 'multibar') return drawBarChart(canvas, lines, { ...opts, grouped: true })
+  return drawMultiChart(canvas, lines, {
+    ...opts,
+    stacked: mode === 'stacked',
+    mode,
+  })
+}
+
+/**
+ * @param {HTMLCanvasElement|null} canvas
+ * @param {Array<{ values: number[], color: string, label?: string, fill?: boolean, hidden?: boolean }>} lines
+ * @param {object} [opts]
+ */
 export function drawMultiChart(canvas, lines, opts = {}) {
   if (!canvas) return
   const ctx = canvas.getContext('2d')
@@ -31,80 +52,315 @@ export function drawMultiChart(canvas, lines, opts = {}) {
   ctx.setTransform(dpr, 0, 0, dpr, 0, 0)
   ctx.clearRect(0, 0, w, h)
 
+  const mode = normalizeChartMode(opts.mode || (opts.stacked ? 'stacked' : 'line'))
   const maxPoints = opts.maxPoints || 90
-  const padL = opts.padLeft ?? (opts.showYAxis ? 44 : 0)
-  const padR = 8
-  const padT = 6
-  const padB = 6
+  const units = opts.units ? String(opts.units) : ''
+  const padL = opts.padLeft ?? (opts.showYAxis !== false ? (units.length > 6 ? 52 : 46) : 0)
+  const padR = 10
+  const padT = 12
+  const padB = 10
   const plotW = Math.max(1, w - padL - padR)
   const plotH = Math.max(1, h - padT - padB)
 
-  if (opts.grid !== false) {
-    ctx.strokeStyle = 'rgba(154, 168, 188, 0.12)'
-    ctx.lineWidth = 1
-    for (let i = 1; i < 4; i++) {
-      const y = padT + (plotH / 4) * i
-      ctx.beginPath()
-      ctx.moveTo(padL, y)
-      ctx.lineTo(padL + plotW, y)
-      ctx.stroke()
-    }
-  }
-
-  const prepared = lines
-    .filter((l) => !l.hidden)
-    .map((l) => ({ ...l, values: (l.values || []).slice(-maxPoints) }))
-    .filter((l) => l.values.length >= 2)
+  const prepared = prepareSeries(lines, maxPoints)
   if (!prepared.length) {
-    ctx.fillStyle = 'rgba(154, 168, 188, 0.55)'
-    ctx.font = '12px "Outfit", ui-sans-serif, system-ui, sans-serif'
-    const msg = opts.emptyMessage || 'No data'
-    const linesMsg = String(msg).split('\n')
-    linesMsg.forEach((line, i) => {
-      ctx.fillText(line, padL + 8, padT + 20 + i * 16)
-    })
+    drawEmpty(ctx, padL, padT, opts.emptyMessage)
     return
   }
 
   if (opts.dimmed) ctx.globalAlpha = 0.72
 
+  const stacked = mode === 'stacked' || opts.stacked === true
+  const { min, max, span } = computeScale(prepared, { stacked, threshold: opts.threshold })
+  const xAt = (i, len) => padL + (i / Math.max(1, Math.max(maxPoints, len) - 1)) * plotW
+  const yAt = (v) => padT + plotH - ((v - min) / span) * plotH
+
+  drawGrid(ctx, padL, padT, plotW, plotH, min, max, yAt)
+  if (opts.showYAxis !== false) drawYAxis(ctx, padL, padT, plotH, min, max, span, units)
+
+  if (opts.threshold != null && Number.isFinite(opts.threshold)) {
+    drawThreshold(ctx, padL, plotW, yAt(opts.threshold), opts.severity)
+  }
+
+  if (stacked) {
+    drawStacked(ctx, prepared, xAt, yAt, maxPoints)
+  } else {
+    prepared.forEach((line) => {
+      const wantFill = mode === 'area' ? line.fill !== false : line.fill === true
+      drawLineSeries(ctx, line, xAt, yAt, padT, plotH, wantFill)
+    })
+  }
+
+  if (opts.hoverIndex != null && Number.isFinite(opts.hoverIndex)) {
+    drawHoverCrosshair(ctx, prepared, opts.hoverIndex, xAt, yAt, padT, plotH, maxPoints)
+  }
+  ctx.globalAlpha = 1
+}
+
+/**
+ * Time-series columns (bar) or grouped columns (multibar).
+ * @param {HTMLCanvasElement|null} canvas
+ * @param {Array<{ values: number[], color: string, label?: string, hidden?: boolean }>} lines
+ * @param {object} [opts]
+ */
+export function drawBarChart(canvas, lines, opts = {}) {
+  if (!canvas) return
+  const ctx = canvas.getContext('2d')
+  if (!ctx) return
+  const dpr = window.devicePixelRatio || 1
+  const w = canvas.clientWidth || 320
+  const h = canvas.clientHeight || canvas.height || 140
+  canvas.width = w * dpr
+  canvas.height = h * dpr
+  ctx.setTransform(dpr, 0, 0, dpr, 0, 0)
+  ctx.clearRect(0, 0, w, h)
+
+  const maxPoints = opts.maxPoints || 90
+  const units = opts.units ? String(opts.units) : ''
+  const padL = opts.padLeft ?? (units.length > 6 ? 52 : 46)
+  const padR = 10
+  const padT = 12
+  const padB = 10
+  const plotW = Math.max(1, w - padL - padR)
+  const plotH = Math.max(1, h - padT - padB)
+  const grouped = Boolean(opts.grouped)
+
+  let prepared = prepareSeries(lines, maxPoints)
+  // Multibar with many dims becomes unreadable — keep top series by latest |value|
+  if (grouped && prepared.length > 6) {
+    prepared = [...prepared]
+      .sort((a, b) => Math.abs(last(b.values)) - Math.abs(last(a.values)))
+      .slice(0, 6)
+  }
+  if (!prepared.length) {
+    drawEmpty(ctx, padL, padT, opts.emptyMessage)
+    return
+  }
+
+  if (opts.dimmed) ctx.globalAlpha = 0.72
+
+  const stackedBars = !grouped && prepared.length > 1
+  const { min, max, span } = computeScale(prepared, {
+    stacked: stackedBars,
+    threshold: opts.threshold,
+  })
+  const len = Math.max(...prepared.map((l) => l.values.length))
+  const yAt = (v) => padT + plotH - ((v - min) / span) * plotH
+  const y0 = yAt(Math.max(min, Math.min(max, 0)))
+
+  drawGrid(ctx, padL, padT, plotW, plotH, min, max, yAt)
+  drawYAxis(ctx, padL, padT, plotH, min, max, span, units)
+
+  const slot = plotW / Math.max(1, len)
+  const groupCount = grouped ? prepared.length : 1
+  const barW = Math.max(1.5, Math.min(14, (slot * 0.72) / groupCount))
+
+  for (let i = 0; i < len; i++) {
+    const cx = padL + slot * i + slot / 2
+    if (grouped) {
+      prepared.forEach((line, gi) => {
+        const v = line.values[i] ?? 0
+        const x = cx - (groupCount * barW) / 2 + gi * barW
+        const y = yAt(v)
+        ctx.fillStyle = withAlpha(line.color, i === opts.hoverIndex ? 0.95 : 0.75)
+        roundRect(ctx, x, Math.min(y, y0), barW - 0.5, Math.abs(y0 - y), 2)
+        ctx.fill()
+      })
+    } else if (stackedBars) {
+      let acc = 0
+      for (const line of prepared) {
+        const v = line.values[i] ?? 0
+        const y1 = yAt(acc)
+        const y2 = yAt(acc + v)
+        ctx.fillStyle = withAlpha(line.color, i === opts.hoverIndex ? 0.95 : 0.8)
+        roundRect(ctx, cx - barW / 2, Math.min(y1, y2), barW, Math.abs(y2 - y1), 1)
+        ctx.fill()
+        acc += v
+      }
+    } else {
+      const line = prepared[0]
+      const v = line.values[i] ?? 0
+      const y = yAt(v)
+      ctx.fillStyle = withAlpha(line.color, i === opts.hoverIndex ? 0.95 : 0.8)
+      roundRect(ctx, cx - barW / 2, Math.min(y, y0), barW, Math.abs(y0 - y), 2)
+      ctx.fill()
+    }
+  }
+
+  if (opts.hoverIndex != null && Number.isFinite(opts.hoverIndex)) {
+    const idx = clampIdx(opts.hoverIndex, len)
+    const x = padL + slot * idx + slot / 2
+    ctx.strokeStyle = 'rgba(226, 232, 240, 0.4)'
+    ctx.beginPath()
+    ctx.moveTo(x, padT)
+    ctx.lineTo(x, padT + plotH)
+    ctx.stroke()
+  }
+  ctx.globalAlpha = 1
+}
+
+/**
+ * Donut / pie of the latest sample (composition snapshot).
+ * @param {HTMLCanvasElement|null} canvas
+ * @param {Array<{ values: number[], color: string, label?: string, hidden?: boolean }>} lines
+ * @param {object} [opts]
+ */
+export function drawPieChart(canvas, lines, opts = {}) {
+  if (!canvas) return
+  const ctx = canvas.getContext('2d')
+  if (!ctx) return
+  const dpr = window.devicePixelRatio || 1
+  const w = canvas.clientWidth || 320
+  const h = canvas.clientHeight || canvas.height || 140
+  canvas.width = w * dpr
+  canvas.height = h * dpr
+  ctx.setTransform(dpr, 0, 0, dpr, 0, 0)
+  ctx.clearRect(0, 0, w, h)
+
+  const prepared = prepareSeries(lines, opts.maxPoints || 90)
+  const slices = prepared
+    .map((l) => ({
+      label: l.label || '',
+      color: l.color,
+      value: Math.abs(last(l.values)),
+    }))
+    .filter((s) => s.value > 0)
+    .sort((a, b) => b.value - a.value)
+
+  if (!slices.length) {
+    drawEmpty(ctx, 12, 16, opts.emptyMessage || 'No data')
+    return
+  }
+
+  if (opts.dimmed) ctx.globalAlpha = 0.72
+
+  const total = slices.reduce((s, x) => s + x.value, 0) || 1
+  const cx = w * 0.38
+  const cy = h / 2
+  const r = Math.min(w * 0.32, h * 0.42)
+  const inner = r * 0.58
+  let angle = -Math.PI / 2
+
+  for (const slice of slices) {
+    const sweep = (slice.value / total) * Math.PI * 2
+    ctx.beginPath()
+    ctx.arc(cx, cy, r, angle, angle + sweep, false)
+    ctx.arc(cx, cy, inner, angle + sweep, angle, true)
+    ctx.closePath()
+    ctx.fillStyle = slice.color
+    ctx.fill()
+    angle += sweep
+  }
+
+  // Center total
+  ctx.fillStyle = 'rgba(244, 247, 251, 0.9)'
+  ctx.font = '600 12px "Outfit", ui-sans-serif, system-ui, sans-serif'
+  ctx.textAlign = 'center'
+  ctx.textBaseline = 'middle'
+  ctx.fillText(formatAxis(total), cx, cy - 6)
+  if (opts.units) {
+    ctx.fillStyle = 'rgba(154, 168, 188, 0.85)'
+    ctx.font = '9px "IBM Plex Mono", ui-monospace, Menlo, monospace'
+    ctx.fillText(String(opts.units).slice(0, 12), cx, cy + 10)
+  }
+
+  // Side legend (top contributors)
+  const lx = w * 0.62
+  let ly = Math.max(14, cy - slices.slice(0, 6).length * 11)
+  ctx.textAlign = 'left'
+  ctx.textBaseline = 'middle'
+  for (const slice of slices.slice(0, 6)) {
+    const pct = ((slice.value / total) * 100).toFixed(0)
+    ctx.fillStyle = slice.color
+    ctx.beginPath()
+    ctx.arc(lx, ly, 3.5, 0, Math.PI * 2)
+    ctx.fill()
+    ctx.fillStyle = 'rgba(200, 209, 223, 0.92)'
+    ctx.font = '11px "IBM Plex Mono", ui-monospace, Menlo, monospace'
+    const name = slice.label.length > 14 ? slice.label.slice(0, 13) + '…' : slice.label
+    ctx.fillText(`${name}  ${pct}%`, lx + 10, ly)
+    ly += 16
+  }
+  ctx.globalAlpha = 1
+}
+
+/* ─── shared draw helpers ─── */
+
+function prepareSeries(lines, maxPoints) {
+  return (lines || [])
+    .filter((l) => !l.hidden)
+    .map((l) => ({ ...l, values: (l.values || []).slice(-maxPoints) }))
+    .filter((l) => l.values.length >= 1)
+    .filter((l) => l.values.some((v) => Number.isFinite(v)))
+}
+
+function computeScale(prepared, { stacked, threshold }) {
   let max = 1
   let min = 0
-  if (opts.stacked) {
+  if (stacked) {
     const len = Math.max(...prepared.map((l) => l.values.length))
     for (let i = 0; i < len; i++) {
       let sum = 0
       for (const l of prepared) sum += l.values[i] ?? 0
       max = Math.max(max, sum)
     }
+    min = 0
   } else {
     const all = prepared.flatMap((l) => l.values)
     max = Math.max(...all, 1e-9)
     min = Math.min(...all, 0)
   }
-  if (opts.threshold != null && Number.isFinite(opts.threshold)) {
-    max = Math.max(max, opts.threshold)
-    min = Math.min(min, opts.threshold)
+  if (threshold != null && Number.isFinite(threshold)) {
+    max = Math.max(max, threshold)
+    min = Math.min(min, threshold)
   }
+  if (max > 0) max *= 1.05
   const span = max - min || 1
+  return { min, max, span }
+}
 
-  if (opts.showYAxis) {
-    ctx.fillStyle = 'rgba(154, 168, 188, 0.65)'
-    ctx.font = '10px ui-monospace, SFMono-Regular, Menlo, monospace'
+function drawGrid(ctx, padL, padT, plotW, plotH, min, max, yAt) {
+  for (let i = 0; i <= 4; i++) {
+    const y = padT + (plotH * i) / 4
+    ctx.strokeStyle = i === 4 ? 'rgba(154, 168, 188, 0.18)' : 'rgba(154, 168, 188, 0.1)'
+    ctx.lineWidth = 1
+    ctx.beginPath()
+    ctx.moveTo(padL, y)
+    ctx.lineTo(padL + plotW, y)
+    ctx.stroke()
+  }
+  if (min <= 0 && max > 0) {
+    const y0 = yAt(0)
+    ctx.strokeStyle = 'rgba(154, 168, 188, 0.32)'
+    ctx.beginPath()
+    ctx.moveTo(padL, y0)
+    ctx.lineTo(padL + plotW, y0)
+    ctx.stroke()
+  }
+}
+
+function drawYAxis(ctx, padL, padT, plotH, min, max, span, units) {
+  ctx.fillStyle = 'rgba(154, 168, 188, 0.7)'
+  ctx.font = '10px "IBM Plex Mono", ui-monospace, Menlo, monospace'
   ctx.textAlign = 'right'
   ctx.textBaseline = 'middle'
   for (let i = 0; i <= 4; i++) {
     const v = max - (span * i) / 4
     const y = padT + (plotH * i) / 4
-      ctx.fillText(formatAxis(v), padL - 4, y)
+    ctx.fillText(formatAxis(v), padL - 5, y)
   }
+  if (units) {
     ctx.textAlign = 'left'
+    ctx.textBaseline = 'bottom'
+    ctx.fillStyle = 'rgba(45, 212, 191, 0.75)'
+    ctx.font = '9px "IBM Plex Mono", ui-monospace, Menlo, monospace'
+    ctx.fillText(units.length > 14 ? units.slice(0, 13) + '…' : units, padL + 2, padT - 1)
+  }
 }
 
-  if (opts.threshold != null && Number.isFinite(opts.threshold)) {
-    const y = padT + plotH - ((opts.threshold - min) / span) * plotH
+function drawThreshold(ctx, padL, plotW, y, severity) {
   ctx.strokeStyle =
-      opts.severity === 'critical' ? 'rgba(248, 113, 113, 0.8)' : 'rgba(251, 191, 36, 0.8)'
+    severity === 'critical' ? 'rgba(248, 113, 113, 0.85)' : 'rgba(251, 191, 36, 0.85)'
   ctx.setLineDash([5, 4])
   ctx.lineWidth = 1.5
   ctx.beginPath()
@@ -114,10 +370,7 @@ export function drawMultiChart(canvas, lines, opts = {}) {
   ctx.setLineDash([])
 }
 
-  const xAt = (i, len) => padL + (i / Math.max(1, Math.max(maxPoints, len) - 1)) * plotW
-  const yAt = (v) => padT + plotH - ((v - min) / span) * plotH
-
-  if (opts.stacked) {
+function drawStacked(ctx, prepared, xAt, yAt, maxPoints) {
   const len = Math.max(...prepared.map((l) => l.values.length))
   /** @type {number[]} */
   const acc = new Array(len).fill(0)
@@ -125,28 +378,56 @@ export function drawMultiChart(canvas, lines, opts = {}) {
     ctx.beginPath()
     for (let i = 0; i < len; i++) {
       const v = (line.values[i] ?? 0) + acc[i]
-        const x = xAt(i, len)
+      const x = xAt(i, Math.max(maxPoints, len))
       const y = yAt(v)
       if (i === 0) ctx.moveTo(x, y)
       else ctx.lineTo(x, y)
     }
     for (let i = len - 1; i >= 0; i--) {
-        const v = acc[i]
-        const x = xAt(i, len)
-        const y = yAt(v)
-        ctx.lineTo(x, y)
+      ctx.lineTo(xAt(i, Math.max(maxPoints, len)), yAt(acc[i]))
     }
     ctx.closePath()
-      ctx.fillStyle = withAlpha(line.color, 0.55)
+    ctx.fillStyle = withAlpha(line.color, 0.5)
     ctx.fill()
+    ctx.beginPath()
+    for (let i = 0; i < len; i++) {
+      const v = (line.values[i] ?? 0) + acc[i]
+      const x = xAt(i, Math.max(maxPoints, len))
+      const y = yAt(v)
+      if (i === 0) ctx.moveTo(x, y)
+      else ctx.lineTo(x, y)
+    }
+    ctx.strokeStyle = withAlpha(line.color, 0.9)
+    ctx.lineWidth = 1.25
+    ctx.stroke()
     for (let i = 0; i < len; i++) acc[i] += line.values[i] ?? 0
   }
-  } else {
-    prepared.forEach((line, li) => {
+}
+
+function drawLineSeries(ctx, line, xAt, yAt, padT, plotH, wantFill) {
   const values = line.values
   const len = values.length
+  if (wantFill) {
+    const grad = ctx.createLinearGradient(0, padT, 0, padT + plotH)
+    grad.addColorStop(0, withAlpha(line.color, 0.28))
+    grad.addColorStop(1, withAlpha(line.color, 0.02))
+    ctx.beginPath()
+    values.forEach((v, i) => {
+      const x = xAt(i, len)
+      const y = yAt(v)
+      if (i === 0) ctx.moveTo(x, y)
+      else ctx.lineTo(x, y)
+    })
+    ctx.lineTo(xAt(len - 1, len), padT + plotH)
+    ctx.lineTo(xAt(0, len), padT + plotH)
+    ctx.closePath()
+    ctx.fillStyle = grad
+    ctx.fill()
+  }
   ctx.strokeStyle = line.color
   ctx.lineWidth = 2
+  ctx.lineJoin = 'round'
+  ctx.lineCap = 'round'
   ctx.beginPath()
   values.forEach((v, i) => {
     const x = xAt(i, len)
@@ -155,21 +436,13 @@ export function drawMultiChart(canvas, lines, opts = {}) {
     else ctx.lineTo(x, y)
   })
   ctx.stroke()
-      if ((line.fill || (li === 0 && prepared.length === 1)) && line.fill !== false) {
-        ctx.lineTo(xAt(len - 1, len), padT + plotH)
-        ctx.lineTo(xAt(0, len), padT + plotH)
-        ctx.closePath()
-        ctx.fillStyle = withAlpha(line.color, 0.16)
-        ctx.fill()
-      }
-    })
 }
 
-  if (opts.hoverIndex != null && Number.isFinite(opts.hoverIndex)) {
+function drawHoverCrosshair(ctx, prepared, hoverIndex, xAt, yAt, padT, plotH, maxPoints) {
   const len = Math.max(...prepared.map((l) => l.values.length))
-    const idx = Math.max(0, Math.min(len - 1, Math.round(opts.hoverIndex)))
-    const x = xAt(idx, len)
-    ctx.strokeStyle = 'rgba(226, 232, 240, 0.45)'
+  const idx = clampIdx(hoverIndex, len)
+  const x = xAt(idx, Math.max(maxPoints, len))
+  ctx.strokeStyle = 'rgba(226, 232, 240, 0.4)'
   ctx.lineWidth = 1
   ctx.beginPath()
   ctx.moveTo(x, padT)
@@ -179,13 +452,45 @@ export function drawMultiChart(canvas, lines, opts = {}) {
     const v = line.values[idx]
     if (v == null) continue
     const y = yAt(v)
+    ctx.beginPath()
+    ctx.fillStyle = 'rgba(10, 12, 16, 0.85)'
+    ctx.arc(x, y, 5, 0, Math.PI * 2)
+    ctx.fill()
     ctx.fillStyle = line.color
     ctx.beginPath()
-      ctx.arc(x, y, 3.5, 0, Math.PI * 2)
+    ctx.arc(x, y, 3.25, 0, Math.PI * 2)
     ctx.fill()
   }
 }
-  ctx.globalAlpha = 1
+
+function drawEmpty(ctx, padL, padT, message) {
+  ctx.fillStyle = 'rgba(154, 168, 188, 0.5)'
+  ctx.font = '12px "Outfit", ui-sans-serif, system-ui, sans-serif'
+  String(message || 'No data')
+    .split('\n')
+    .forEach((line, i) => {
+      ctx.fillText(line, padL + 8, padT + 18 + i * 16)
+    })
+}
+
+function roundRect(ctx, x, y, w, h, r) {
+  const rr = Math.min(r, w / 2, h / 2)
+  if (h < 0.5) return
+  ctx.beginPath()
+  ctx.moveTo(x + rr, y)
+  ctx.arcTo(x + w, y, x + w, y + h, rr)
+  ctx.arcTo(x + w, y + h, x, y + h, rr)
+  ctx.arcTo(x, y + h, x, y, rr)
+  ctx.arcTo(x, y, x + w, y, rr)
+  ctx.closePath()
+}
+
+function last(arr) {
+  return arr?.length ? arr[arr.length - 1] : 0
+}
+
+function clampIdx(idx, len) {
+  return Math.max(0, Math.min(len - 1, Math.round(idx)))
 }
 
 /**
@@ -197,8 +502,8 @@ export function drawMultiChart(canvas, lines, opts = {}) {
 export function hoverIndexFromEvent(canvas, clientX, opts = {}) {
   const rect = canvas.getBoundingClientRect()
   const w = rect.width || canvas.clientWidth || 320
-  const padL = opts.padLeft ?? (opts.showYAxis ? 44 : 0)
-  const padR = 8
+  const padL = opts.padLeft ?? (opts.showYAxis !== false ? 46 : 0)
+  const padR = 10
   const plotW = Math.max(1, w - padL - padR)
   const x = clientX - rect.left - padL
   if (x < 0 || x > plotW) return null
@@ -209,14 +514,16 @@ export function hoverIndexFromEvent(canvas, clientX, opts = {}) {
 }
 
 /** @param {number} v */
-function formatAxis(v) {
+export function formatAxis(v) {
   const a = Math.abs(v)
   if (a >= 1e9) return (v / 1e9).toFixed(1) + 'G'
   if (a >= 1e6) return (v / 1e6).toFixed(1) + 'M'
   if (a >= 1e3) return (v / 1e3).toFixed(1) + 'k'
-  if (a >= 10) return v.toFixed(0)
-  if (a >= 1) return v.toFixed(1)
-  return v.toFixed(2)
+  if (a >= 100) return v.toFixed(0)
+  if (a >= 10) return v.toFixed(1)
+  if (a >= 1) return v.toFixed(2)
+  if (a >= 0.01) return v.toFixed(3)
+  return v.toFixed(4)
 }
 
 /** @param {string} color @param {number} alpha */

ui/dashboard.js

@@ -3,7 +3,14 @@
  */
 import { groupCatalog, TIME_PRESETS } from '../shared/taxonomy.js'
 import { rankRelatedCharts } from '../shared/related-metrics.js'
-import { drawMultiChart, hoverIndexFromEvent, pushDim, seriesColor } from './charts.js'
+import {
+  CHART_MODE_LABEL,
+  chartModeHint,
+  defaultModeFromMeta,
+  nextChartMode,
+  normalizeChartMode,
+} from '../shared/chart-types.js'
+import { drawChart, hoverIndexFromEvent, pushDim, seriesColor } from './charts.js'
 
 const GROUPS = ['average', 'min', 'max', 'sum']
 
@@ -11,6 +18,23 @@ const MIN_WINDOW = 30
 const MAX_WINDOW = 21600
 const DEFAULT_HEIGHT = 148
 const HERO_HEIGHT = 200
+const LEGEND_CHIP_CAP = 10
+
+function scrollBehavior() {
+  try {
+    if (document.body?.dataset?.reduceMotion === '1') return 'auto'
+    if (typeof matchMedia === 'function' && matchMedia('(prefers-reduced-motion: reduce)').matches) {
+      return 'auto'
+    }
+  } catch {
+    // ignore
+  }
+  return 'smooth'
+}
+
+function smoothScrollIntoView(el, block = 'start') {
+  el?.scrollIntoView({ behavior: scrollBehavior(), block })
+}
 
 /**
  * @typedef {{
@@ -109,15 +133,14 @@ export function createMetricsDashboard(opts) {
 
   function ensureCard(id, meta = {}) {
     let card = state.cards.get(id)
-    const defaultMode =
-      String(meta.chartType || '').toLowerCase() === 'stacked' ? 'stacked' : 'line'
+    const defaultMode = defaultModeFromMeta(meta)
     if (!card) {
       card = {
         dims: new Map(),
         labels: [],
         status: 'idle',
         meta: meta || {},
-        mode: state.chartTypes.get(id) || defaultMode,
+        mode: normalizeChartMode(state.chartTypes.get(id) || defaultMode),
         source: '',
       }
       state.cards.set(id, card)
@@ -487,23 +510,25 @@ export function createMetricsDashboard(opts) {
     const height = cardHeightFor(id, card)
     canvas.style.height = `${height}px`
     const { dims, hidden } = sortedDims(card, id)
+    const mode = normalizeChartMode(card.mode || defaultModeFromMeta(card.meta))
+    card.mode = mode
     const lines = []
     let i = 0
     for (const dim of dims) {
       const values = card.dims.get(dim) || []
-      const mode = card.mode || 'line'
       lines.push({
         values,
         color: seriesColor(i),
         label: dim,
         hidden: hidden.has(dim),
-        fill: mode === 'area' || mode === 'stacked' ? true : mode === 'line' ? false : undefined,
+        fill: mode === 'area' ? true : mode === 'line' ? false : undefined,
       })
       i++
     }
     const anomaly = opts.getAnomaly?.(id) || null
     if (anomaly?.severity) article.dataset.severity = anomaly.severity
     else delete article.dataset.severity
+    article.dataset.chartMode = mode
     const emptyMsg =
       card.status === 'loading'
         ? card.emptyReason || 'Loading…'
@@ -512,28 +537,40 @@ export function createMetricsDashboard(opts) {
           : card.status === 'empty'
             ? card.emptyReason || 'No data'
             : 'No data'
-    drawMultiChart(canvas, lines, {
+    const units = card.meta?.units || ''
+    drawChart(canvas, lines, {
+      mode,
       maxPoints: maxPoints(),
-      stacked: card.mode === 'stacked',
-      showYAxis: true,
-      hoverIndex: state.hoverIndex,
-      threshold: anomaly?.threshold ?? null,
+      showYAxis: mode !== 'pie',
+      hoverIndex: mode === 'pie' ? null : state.hoverIndex,
+      threshold: mode === 'pie' ? null : anomaly?.threshold ?? null,
       severity: anomaly?.severity || null,
       emptyMessage: emptyMsg,
       dimmed: Boolean(card.updating),
+      units,
     })
+    updateCardTooltip(article, id, card, lines, units)
     const statsEl = article.querySelector('.metric-card-stats')
     if (statsEl && article.classList.contains('expanded')) {
-      statsEl.innerHTML = renderStatsHtml(card, dims, hidden)
+      statsEl.innerHTML = renderStatsHtml(card, dims, hidden, units)
     }
     if (legend && !card.updating) {
-      const nextHtml = lines
+      const visibleLines = lines.filter((l) => !l.hidden)
+      const show = lines.slice(0, LEGEND_CHIP_CAP)
+      const extra = Math.max(0, lines.length - LEGEND_CHIP_CAP)
+      const unitSuffix = units ? ` ${units}` : ''
+      const nextHtml =
+        show
           .map((line) => {
             const last = line.values[line.values.length - 1]
-          const text = `${line.label}${last != null ? ` ${formatVal(last)}` : ''}`
+            const text = `${line.label}${last != null ? ` ${formatVal(last)}${unitSuffix}` : ''}`
             return `<button type="button" class="dim-chip${line.hidden ? ' off' : ''}" style="--dim-color:${line.color}" data-dim="${escapeAttr(line.label)}" title="Toggle dimension">${escapeHtml(text)}</button>`
           })
-        .join('')
+          .join('') +
+        (extra
+          ? `<span class="dim-chip-more muted" title="${extra} more dimensions">+${extra}</span>`
+          : '')
+      void visibleLines
       if (legend.dataset.sig !== nextHtml) {
         legend.dataset.sig = nextHtml
         legend.innerHTML = nextHtml
@@ -547,6 +584,93 @@ export function createMetricsDashboard(opts) {
     }
   }
 
+  /**
+   * Per-card hover tooltip with values + units.
+   * @param {HTMLElement} article
+   * @param {string} id
+   * @param {object} card
+   * @param {Array<{ label: string, values: number[], color: string, hidden?: boolean }>} lines
+   * @param {string} units
+   */
+  function updateCardTooltip(article, id, card, lines, units) {
+    let tip = article.querySelector('.chart-hover-tip')
+    if (!tip) {
+      tip = document.createElement('div')
+      tip.className = 'chart-hover-tip hidden'
+      tip.setAttribute('aria-hidden', 'true')
+      article.style.position = 'relative'
+      article.appendChild(tip)
+    }
+    const mode = normalizeChartMode(card.mode)
+    const unitSuffix = units ? ` ${escapeHtml(units)}` : ''
+
+    // Pie = snapshot of latest values (always show while card hovered via canvas leave/enter)
+    if (mode === 'pie') {
+      if (!state.visible.has(id) || !article.matches(':hover')) {
+        tip.classList.add('hidden')
+        article.classList.remove('is-hovering')
+        return
+      }
+      const rows = lines
+        .filter((l) => !l.hidden)
+        .map((l) => ({
+          label: l.label,
+          value: l.values[l.values.length - 1],
+          color: l.color,
+        }))
+        .filter((r) => r.value != null && Number.isFinite(r.value) && Math.abs(r.value) > 0)
+        .sort((a, b) => Math.abs(b.value) - Math.abs(a.value))
+      const total = rows.reduce((s, r) => s + Math.abs(r.value), 0) || 1
+      tip.innerHTML =
+        `<header>Share · latest</header>` +
+        rows
+          .slice(0, 8)
+          .map((r) => {
+            const pct = ((Math.abs(r.value) / total) * 100).toFixed(0)
+            return `<div class="tip-row"><i style="background:${r.color}"></i><span>${escapeHtml(r.label)}</span><strong>${pct}% · ${escapeHtml(formatVal(r.value))}${unitSuffix}</strong></div>`
+          })
+          .join('')
+      tip.classList.remove('hidden')
+      article.classList.add('is-hovering')
+      return
+    }
+
+    if (state.hoverIndex == null || !state.visible.has(id)) {
+      tip.classList.add('hidden')
+      article.classList.remove('is-hovering')
+      return
+    }
+    const idx = Math.round(state.hoverIndex)
+    const rows = lines
+      .filter((l) => !l.hidden)
+      .map((l) => {
+        const vals = l.values || []
+        const i = Math.max(0, Math.min(vals.length - 1, idx))
+        return { label: l.label, value: vals[i], color: l.color }
+      })
+      .filter((r) => r.value != null && Number.isFinite(r.value))
+      .sort((a, b) => Math.abs(b.value) - Math.abs(a.value))
+      .slice(0, 8)
+
+    if (!rows.length) {
+      tip.classList.add('hidden')
+      return
+    }
+
+    const frac = maxPoints() > 1 ? idx / (maxPoints() - 1) : 1
+    const age = state.endOffset + state.afterSeconds * (1 - frac)
+    tip.innerHTML =
+      `<header>${escapeHtml(formatDuration(Math.max(0, age)))} ago</header>` +
+      rows
+        .map(
+          (r) =>
+            `<div class="tip-row"><i style="background:${r.color}"></i><span>${escapeHtml(r.label)}</span><strong>${escapeHtml(formatVal(r.value))}${unitSuffix}</strong></div>`
+        )
+        .join('')
+    tip.classList.remove('hidden')
+    article.classList.add('is-hovering')
+  }
+
   function cardHeightFor(id, card) {
     const base = state.cardHeight || DEFAULT_HEIGHT
     if (state.pinned.has(id)) return Math.max(base, HERO_HEIGHT)
@@ -575,13 +699,15 @@ export function createMetricsDashboard(opts) {
   function cycleChartType(id) {
     const card = state.cards.get(id)
     if (!card) return
-    const order = ['line', 'area', 'stacked']
-    const next = order[(order.indexOf(card.mode) + 1) % order.length]
+    const next = nextChartMode(card.mode, { ...card.meta, id, dimensions: card.labels })
     card.mode = next
     state.chartTypes.set(id, next)
     persistPrefs({ chartTypes: Object.fromEntries(state.chartTypes) })
     const typeBtn = state.cardEls.get(id)?.querySelector('.metric-type-btn')
-    if (typeBtn) typeBtn.textContent = next
+    if (typeBtn) {
+      typeBtn.textContent = CHART_MODE_LABEL[next] || next
+      typeBtn.title = chartModeHint(next)
+    }
     paintCard(id)
   }
 
@@ -662,7 +788,7 @@ export function createMetricsDashboard(opts) {
     }
     const frac = maxPoints() > 1 ? state.hoverIndex / (maxPoints() - 1) : 0
     const age = state.endOffset + state.afterSeconds * (1 - frac)
-    opts.els.hoverReadout.textContent = `cursor · ~${formatDuration(Math.max(0, age))} ago`
+    opts.els.hoverReadout.textContent = `~${formatDuration(Math.max(0, age))} ago`
   }
 
   function bindCanvasInteractions(canvas, chartId) {
@@ -686,6 +812,8 @@ export function createMetricsDashboard(opts) {
     canvas.addEventListener(
       'wheel',
       (ev) => {
+        const card = state.cards.get(chartId)
+        if (normalizeChartMode(card?.mode) === 'pie') return
         ev.preventDefault()
         const factor = ev.deltaY > 0 ? 1.25 : 0.8
         setWindow(Math.round(state.afterSeconds * factor), state.endOffset)
@@ -695,6 +823,8 @@ export function createMetricsDashboard(opts) {
     canvas.addEventListener('pointerdown', (ev) => {
       if (ev.button !== 0) return
       if (state.forcePlay) return
+      const card = state.cards.get(chartId)
+      if (normalizeChartMode(card?.mode) === 'pie') return
       // Drag to pan time (pause + shift window end)
       canvas.setPointerCapture(ev.pointerId)
       state.pan = { active: true, startX: ev.clientX, startOffset: state.endOffset }
@@ -761,10 +891,8 @@ export function createMetricsDashboard(opts) {
       pinBtn.className = 'toc-item'
       pinBtn.innerHTML = `<span>Pinned</span><span class="toc-count">${state.pinned.size}</span>`
       pinBtn.addEventListener('click', () => {
-        opts.els.wall?.querySelector('[data-section="pinned"]')?.scrollIntoView({
-          behavior: 'smooth',
-          block: 'start',
-        })
+        const el = opts.els.wall?.querySelector('[data-section="pinned"]')
+        if (el) smoothScrollIntoView(el, 'start')
       })
       toc.appendChild(pinBtn)
     }
@@ -782,7 +910,7 @@ export function createMetricsDashboard(opts) {
       btn.innerHTML = `<span>${escapeHtml(sec.title)}</span><span class="toc-count">${sec.count}</span>`
       btn.addEventListener('click', () => {
         const el = opts.els.wall?.querySelector(`[data-section="${sec.id}"]`)
-        el?.scrollIntoView({ behavior: 'smooth', block: 'start' })
+        if (el) smoothScrollIntoView(el, 'start')
       })
       toc.appendChild(btn)
       for (const g of sec.groups.slice(0, 12)) {
@@ -799,7 +927,7 @@ export function createMetricsDashboard(opts) {
                 (n) => n.getAttribute('data-family') === g.family
               )
             : null
-          el?.scrollIntoView({ behavior: 'smooth', block: 'start' })
+          if (el) smoothScrollIntoView(el, 'start')
         })
         toc.appendChild(sub)
       }
@@ -996,7 +1124,7 @@ export function createMetricsDashboard(opts) {
         <div class="metric-card-actions">
           <button type="button" class="btn btn-ghost metric-pin-btn" title="Pin">${state.pinned.has(id) ? '★' : '☆'}</button>
           <button type="button" class="btn btn-ghost metric-related-btn" title="Find related">⇢</button>
-          <button type="button" class="btn btn-ghost metric-type-btn" title="Chart type">${escapeHtml(card.mode)}</button>
+          <button type="button" class="btn btn-ghost metric-type-btn" title="${escapeAttr(chartModeHint(card.mode))}">${escapeHtml(CHART_MODE_LABEL[card.mode] || card.mode)}</button>
           <span class="metric-card-status muted"></span>
         </div>
       </header>
@@ -1010,6 +1138,14 @@ export function createMetricsDashboard(opts) {
       canvas.style.height = `${height}px`
       bindCanvasInteractions(canvas, id)
     }
+    article.addEventListener('mouseenter', () => {
+      if (normalizeChartMode(card.mode) === 'pie') paintCard(id)
+    })
+    article.addEventListener('mouseleave', () => {
+      const tip = article.querySelector('.chart-hover-tip')
+      tip?.classList.add('hidden')
+      article.classList.remove('is-hovering')
+    })
     article.querySelector('.metric-pin-btn')?.addEventListener('click', (ev) => {
       ev.stopPropagation()
       togglePin(id)
@@ -1031,7 +1167,7 @@ export function createMetricsDashboard(opts) {
       if (article.classList.contains('expanded')) {
         statsEl.classList.remove('hidden')
         const { dims, hidden } = sortedDims(card, id)
-        statsEl.innerHTML = renderStatsHtml(card, dims, hidden)
+        statsEl.innerHTML = renderStatsHtml(card, dims, hidden, card.meta?.units || '')
       } else {
         statsEl.classList.add('hidden')
       }
@@ -1231,7 +1367,7 @@ export function createMetricsDashboard(opts) {
   function scrollToChart(id) {
     const el = state.cardEls.get(id)
     if (el) {
-      el.scrollIntoView({ behavior: 'smooth', block: 'center' })
+      smoothScrollIntoView(el, 'center')
       el.classList.add('flash')
       setTimeout(() => el.classList.remove('flash'), 1200)
       return
@@ -1241,9 +1377,10 @@ export function createMetricsDashboard(opts) {
     render()
     requestAnimationFrame(() => {
       const again = state.cardEls.get(id)
-      again?.scrollIntoView({ behavior: 'smooth', block: 'center' })
-      again?.classList.add('flash')
-      setTimeout(() => again?.classList.remove('flash'), 1200)
+      if (!again) return
+      smoothScrollIntoView(again, 'center')
+      again.classList.add('flash')
+      setTimeout(() => again.classList.remove('flash'), 1200)
     })
   }
 
@@ -1336,7 +1473,8 @@ function formatDuration(sec) {
  * @param {string[]} dims
  * @param {Set<string>} hidden
  */
-function renderStatsHtml(card, dims, hidden) {
+function renderStatsHtml(card, dims, hidden, units = '') {
+  const u = units ? ` <small class="muted">${escapeHtml(units)}</small>` : ''
   const rows = dims
     .filter((d) => !hidden.has(d))
     .map((d) => {
@@ -1352,7 +1490,7 @@ function renderStatsHtml(card, dims, hidden) {
       }
       const avg = sum / arr.length
       const last = arr[arr.length - 1]
-      return `<tr><td>${escapeHtml(d)}</td><td>${formatVal(last)}</td><td>${formatVal(min)}</td><td>${formatVal(avg)}</td><td>${formatVal(max)}</td></tr>`
+      return `<tr><td>${escapeHtml(d)}</td><td>${formatVal(last)}${u}</td><td>${formatVal(min)}</td><td>${formatVal(avg)}</td><td>${formatVal(max)}</td></tr>`
     })
     .filter(Boolean)
   if (!rows.length) return '<p class="muted">No dimension stats</p>'

ui/styles.css

@@ -148,6 +148,111 @@ body[data-reduce-motion='1'] *::after {
   transition-duration: 0.01ms !important;
 }
 
+/* ─── Mini scrollbars ─── */
+:root {
+  --scrollbar-size: 6px;
+  --scrollbar-thumb: rgba(255, 255, 255, 0.16);
+  --scrollbar-thumb-hover: color-mix(in srgb, var(--accent-primary) 55%, rgba(255, 255, 255, 0.35));
+}
+html[data-theme='light'] {
+  --scrollbar-thumb: rgba(15, 23, 42, 0.2);
+  --scrollbar-thumb-hover: color-mix(in srgb, var(--accent-primary) 45%, rgba(15, 23, 42, 0.35));
+}
+
+/* Main app pane — slim, styled */
+#content {
+  scrollbar-width: thin;
+  scrollbar-color: var(--scrollbar-thumb) transparent;
+}
+#content::-webkit-scrollbar {
+  width: 6px;
+  height: 6px;
+}
+#content::-webkit-scrollbar-track {
+  background: transparent;
+  margin: 4px 0;
+}
+#content::-webkit-scrollbar-thumb {
+  background: var(--scrollbar-thumb);
+  border-radius: 999px;
+  border: 1px solid transparent;
+  background-clip: padding-box;
+  min-height: 40px;
+}
+#content::-webkit-scrollbar-thumb:hover {
+  background: var(--scrollbar-thumb-hover);
+  background-clip: padding-box;
+}
+#content::-webkit-scrollbar-corner {
+  background: transparent;
+}
+
+.metrics-wall,
+.metrics-toc-nav,
+.metrics-toc,
+.metric-card-stats,
+#sidebar,
+.fleet-cards,
+.event-list,
+.log,
+.invite-out {
+  scrollbar-width: thin;
+  scrollbar-color: var(--scrollbar-thumb) transparent;
+}
+
+.metrics-wall::-webkit-scrollbar,
+.metrics-toc-nav::-webkit-scrollbar,
+.metrics-toc::-webkit-scrollbar,
+.metric-card-stats::-webkit-scrollbar,
+#sidebar::-webkit-scrollbar,
+.fleet-cards::-webkit-scrollbar,
+.event-list::-webkit-scrollbar,
+.log::-webkit-scrollbar {
+  width: var(--scrollbar-size);
+  height: var(--scrollbar-size);
+}
+
+.metrics-wall::-webkit-scrollbar-track,
+.metrics-toc-nav::-webkit-scrollbar-track,
+.metrics-toc::-webkit-scrollbar-track,
+.metric-card-stats::-webkit-scrollbar-track,
+#sidebar::-webkit-scrollbar-track,
+.fleet-cards::-webkit-scrollbar-track,
+.event-list::-webkit-scrollbar-track,
+.log::-webkit-scrollbar-track {
+  background: transparent;
+}
+
+.metrics-wall::-webkit-scrollbar-thumb,
+.metrics-toc-nav::-webkit-scrollbar-thumb,
+.metrics-toc::-webkit-scrollbar-thumb,
+.metric-card-stats::-webkit-scrollbar-thumb,
+#sidebar::-webkit-scrollbar-thumb,
+.fleet-cards::-webkit-scrollbar-thumb,
+.event-list::-webkit-scrollbar-thumb,
+.log::-webkit-scrollbar-thumb {
+  background: var(--scrollbar-thumb);
+  border-radius: 999px;
+  border: 1px solid transparent;
+  background-clip: padding-box;
+}
+
+.metrics-wall::-webkit-scrollbar-thumb:hover,
+.metrics-toc-nav::-webkit-scrollbar-thumb:hover,
+#sidebar::-webkit-scrollbar-thumb:hover {
+  background: var(--scrollbar-thumb-hover);
+  background-clip: padding-box;
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .metrics-wall {
+    scroll-behavior: auto !important;
+  }
+}
+body[data-reduce-motion='1'] .metrics-wall {
+  scroll-behavior: auto !important;
+}
+
 /* ─── Titlebar ─── */
 #titlebar {
   grid-area: titlebar;
@@ -384,8 +489,17 @@ body.sidebar-collapsed #conn-meta {
 #content {
   grid-area: content;
   overflow: auto;
+  overflow-x: hidden;
   padding: var(--space-lg);
+  padding-right: calc(var(--space-lg) - 2px);
   min-width: 0;
+  overscroll-behavior: contain;
+  -webkit-overflow-scrolling: touch;
+  scroll-behavior: smooth;
+}
+
+body[data-reduce-motion='1'] #content {
+  scroll-behavior: auto;
 }
 
 .view.hidden,
@@ -397,6 +511,15 @@ body.sidebar-collapsed #conn-meta {
   animation: viewIn 0.28s ease;
 }
 
+@media (prefers-reduced-motion: reduce) {
+  #content {
+    scroll-behavior: auto;
+  }
+  .view {
+    animation: none;
+  }
+}
+
 @keyframes viewIn {
   from {
     opacity: 0;
@@ -569,7 +692,12 @@ body.is-offline .offline-banner:not(.hidden) {
 .chart-panel canvas {
   width: 100%;
   display: block;
-  border-radius: 8px;
+  border-radius: 10px;
+  background: rgba(0, 0, 0, 0.18);
+}
+
+html[data-theme='light'] .chart-panel canvas {
+  background: rgba(15, 23, 42, 0.03);
 }
 
 .chart-legend {
@@ -1055,8 +1183,10 @@ button.metrics-tf:disabled {
 .metrics-wall {
   min-height: 0;
   overflow: auto;
-  padding-right: 4px;
+  padding-right: 2px;
   scroll-behavior: smooth;
+  overscroll-behavior: contain;
+  -webkit-overflow-scrolling: touch;
 }
 
 .metrics-empty {
@@ -1066,6 +1196,7 @@ button.metrics-tf:disabled {
 
 .metrics-section {
   margin-bottom: 28px;
+  scroll-margin-top: 8px;
 }
 
 .metrics-section.collapsed .metrics-section-body {
@@ -1079,13 +1210,14 @@ button.metrics-tf:disabled {
   position: sticky;
   top: 0;
   z-index: 2;
-  padding: 8px 0;
+  padding: 10px 0 8px;
   background: linear-gradient(
     to bottom,
-    var(--bg-primary) 70%,
+    color-mix(in srgb, var(--bg-primary) 92%, transparent) 55%,
     transparent
   );
-  backdrop-filter: blur(6px);
+  backdrop-filter: blur(10px);
+  -webkit-backdrop-filter: blur(10px);
 }
 
 .metrics-section-head h2 {
@@ -1134,7 +1266,32 @@ button.metrics-tf:disabled {
     var(--bg-secondary);
   border: 1px solid var(--border-color);
   min-height: 0;
-  transition: border-color 0.15s ease, opacity 0.2s ease;
+  scroll-margin-top: 52px;
+  transition:
+    border-color 0.18s ease,
+    opacity 0.2s ease,
+    box-shadow 0.18s ease,
+    transform 0.18s ease;
+}
+
+.metric-card:hover {
+  border-color: color-mix(in srgb, var(--accent-primary) 28%, var(--border-color));
+  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.22);
+}
+
+.metric-card.is-hovering {
+  border-color: color-mix(in srgb, var(--accent-primary) 42%, var(--border-color));
+}
+
+.metric-card[data-chart-mode='pie'] canvas {
+  cursor: default;
+}
+
+.metric-type-btn {
+  text-transform: lowercase;
+  min-width: 3.4rem !important;
+  font-family: var(--font-mono) !important;
+  font-size: 11px !important;
 }
 
 .metric-card--hero {
@@ -1227,6 +1384,80 @@ html[data-theme='light'] .metric-card canvas {
   text-decoration: line-through;
 }
 
+.dim-chip-more {
+  font-size: 11px;
+  font-family: var(--font-mono);
+  padding: 3px 6px;
+  align-self: center;
+}
+
+.metric-card.is-hovering .dim-chip {
+  opacity: 0.45;
+}
+.metric-card.is-hovering .dim-chip:hover {
+  opacity: 1;
+}
+
+.chart-hover-tip {
+  position: absolute;
+  top: 44px;
+  right: 12px;
+  z-index: 6;
+  min-width: 140px;
+  max-width: min(280px, 70%);
+  padding: 8px 10px;
+  border-radius: 10px;
+  background: color-mix(in srgb, var(--bg-elevated) 94%, transparent);
+  border: 1px solid var(--border-strong);
+  box-shadow: var(--shadow-md);
+  backdrop-filter: blur(10px);
+  -webkit-backdrop-filter: blur(10px);
+  pointer-events: none;
+  font-size: 11px;
+  line-height: 1.35;
+}
+
+.chart-hover-tip.hidden {
+  display: none;
+}
+
+.chart-hover-tip header {
+  font-family: var(--font-mono);
+  color: var(--text-muted);
+  margin-bottom: 6px;
+  font-size: 10px;
+  letter-spacing: 0.02em;
+}
+
+.chart-hover-tip .tip-row {
+  display: grid;
+  grid-template-columns: 8px 1fr auto;
+  gap: 8px;
+  align-items: center;
+  margin-top: 3px;
+}
+
+.chart-hover-tip .tip-row i {
+  width: 8px;
+  height: 8px;
+  border-radius: 50%;
+  display: block;
+}
+
+.chart-hover-tip .tip-row span {
+  color: var(--text-secondary);
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.chart-hover-tip .tip-row strong {
+  font-family: var(--font-mono);
+  font-weight: 500;
+  color: var(--text-primary);
+  white-space: nowrap;
+}
+
 .metric-card.flash {
   box-shadow: 0 0 0 1px rgba(52, 211, 153, 0.55), 0 0 24px rgba(52, 211, 153, 0.18);
 }