diff --git a/src/frontend/e2e/dashboard-list-view.spec.js b/src/frontend/e2e/dashboard-list-view.spec.js
index 7ebcc24ef..6cb5eea0d 100644
--- a/src/frontend/e2e/dashboard-list-view.spec.js
+++ b/src/frontend/e2e/dashboard-list-view.spec.js
@@ -332,3 +332,103 @@ test.describe('dashboard list column alignment + identity (#2358)', () => {
     }
   })
 })
+
+/**
+ * #3465 — the row layout follows the LIST's width. At a 768 window the systems
+ * rail (224px open, 48px collapsed) decides whether the list is ~496px or
+ * ~672px wide. The tablet row needs about 610px, so behind the open rail its
+ * success cell collapsed to 0 (the percentage painted over the capacity meter)
+ * and the task counts ran 50-67px past the row. Below 40rem of list
+ * (`list-mid:`) the compact row renders instead.
+ *
+ * The cascade itself is unit-tested (tests/unit/agentListLayoutSwitch.spec.js);
+ * this is the half only a layout engine can see: that whichever row renders,
+ * every cell stays inside it and no two cells of a line overlap. It is written
+ * against whatever agents the stack has, so it holds on a system-agent-only CI
+ * stack and bites hardest on a fleet with execution stats.
+ */
+test.describe('dashboard list rows fit a narrow list (#3465)', () => {
+  /** Geometry violations across every rendered row; [] when the layout holds. */
+  async function rowViolations(page) {
+    return page.evaluate(() => {
+      const out = []
+      const shown = (el) => getComputedStyle(el).display !== 'none'
+      for (const row of document.querySelectorAll('[data-agent]')) {
+        const slug = row.getAttribute('data-agent')
+        const rowBox = row.getBoundingClientRect()
+        if (rowBox.right > window.innerWidth + 1) out.push(`${slug}: row leaves the window`)
+        // The half-out avatar is `absolute` and overhangs the LEFT edge by
+        // design; the layout blocks are the in-flow children.
+        const blocks = [...row.children].filter(
+          (el) => getComputedStyle(el).position !== 'absolute' && shown(el)
+        )
+        for (const block of blocks) {
+          for (const line of block.children) {
+            if (!shown(line)) continue
+            const lineBox = line.getBoundingClientRect()
+            if (lineBox.right > rowBox.right + 1) {
+              out.push(`${slug}: a line ends ${Math.round(lineBox.right - rowBox.right)}px past the row`)
+            }
+            // The secondary / meta lines clip their own overflow by contract
+            // (a long slug plus tags never opens another row), so their cells
+            // may legitimately extend past the box; the line itself may not.
+            if (getComputedStyle(line).overflowX !== 'visible') continue
+            const cells = [...line.children].filter(shown)
+            let prevRight = -Infinity
+            for (const cell of cells) {
+              const box = cell.getBoundingClientRect()
+              const what = `${slug}: <${cell.tagName.toLowerCase()} class="${cell.className}">`
+              if (box.right > rowBox.right + 1) {
+                out.push(`${what} ends ${Math.round(box.right - rowBox.right)}px past the row`)
+              }
+              if (box.left < prevRight - 1) {
+                out.push(`${what} overlaps the cell before it by ${Math.round(prevRight - box.left)}px`)
+              }
+              prevRight = box.right
+              // A cell squeezed below its content paints that content over its
+              // neighbours without moving its own box — the success cell at 0px.
+              const cs = getComputedStyle(cell)
+              if (
+                !cs.display.startsWith('inline') &&
+                cs.overflowX === 'visible' &&
+                cell.scrollWidth > cell.clientWidth + 1
+              ) {
+                out.push(`${what} content is ${cell.scrollWidth - cell.clientWidth}px wider than its box`)
+              }
+            }
+          }
+        }
+      }
+      return out
+    })
+  }
+
+  for (const [rail, collapsed, tabletRow] of [
+    ['open', 'false', false],
+    ['collapsed', 'true', true],
+  ]) {
+    test(`768 window, rail ${rail}: no cell overlaps or leaves its row`, async ({ page }) => {
+      await page.addInitScript(
+        (value) => localStorage.setItem('trinity-sidebar-collapsed', value),
+        collapsed
+      )
+      await page.setViewportSize({ width: 768, height: 1024 })
+      await gotoList(page)
+      const row = page.locator('[data-agent]').first()
+      await expect(row).toBeVisible({ timeout: 15000 })
+
+      // Which row renders is the fix: the tablet row only where it fits.
+      const secondaryMd = row.locator('[data-testid="row-secondary-md"]')
+      if (tabletRow) await expect(secondaryMd).toBeVisible()
+      else await expect(secondaryMd).toBeHidden()
+
+      expect(await rowViolations(page)).toEqual([])
+      // Wide content never scrolls the page (contract, principle 7).
+      expect(
+        await page.evaluate(
+          () => document.documentElement.scrollWidth <= document.documentElement.clientWidth
+        )
+      ).toBe(true)
+    })
+  }
+})
diff --git a/src/frontend/src/components/AgentListPanel.vue b/src/frontend/src/components/AgentListPanel.vue
index 376de2d06..a9d6d9dd6 100644
--- a/src/frontend/src/components/AgentListPanel.vue
+++ b/src/frontend/src/components/AgentListPanel.vue
@@ -552,8 +552,14 @@
              desktop grid needs). `md:list-wide:hidden`, not `list-wide:hidden`:
              Tailwind 3 emits screen variants after custom ones, so a bare
              `list-wide:hidden` loses to `md:flex`, and this block then sits in
-             the row subgrid as an extra item that widens track 1. -->
-        <div class="hidden md:flex md:flex-col md:list-wide:hidden pl-8 pr-4 py-3 gap-2">
+             the row subgrid as an extra item that widens track 1.
+             It also needs the LIST to be at least 40rem wide (`list-mid:`,
+             #3465): its second line holds three reserved toggles, the success
+             bar, the meter and the task counts, about 610px. Behind the open
+             systems rail a 768 window leaves the list 496px — the success cell
+             collapsed to 0 and the task counts ran past the row — so there the
+             compact layout below renders instead. -->
+        <div class="hidden md:list-mid:flex md:list-mid:flex-col md:list-wide:hidden pl-8 pr-4 py-3 gap-2">
           <div class="flex items-center gap-3">
             <input
               type="checkbox"
@@ -737,8 +743,10 @@
           </div>
         </div>
 
-        <!-- Mobile layout (< md) -->
-        <div class="flex flex-col md:hidden pl-8 pr-4 py-3 gap-2">
+        <!-- Compact layout: a window below md, or a list narrower than the
+             tablet row needs (`md:list-mid:hidden` is the exact complement of
+             the tablet block's `md:list-mid:flex`, #3465). -->
+        <div class="flex flex-col md:list-mid:hidden pl-8 pr-4 py-3 gap-2">
           <div class="flex items-center gap-3">
             <input
               type="checkbox"
diff --git a/src/frontend/tailwind.config.js b/src/frontend/tailwind.config.js
index 9d45411b6..a32a2f2a1 100644
--- a/src/frontend/tailwind.config.js
+++ b/src/frontend/tailwind.config.js
@@ -54,7 +54,18 @@ export default {
     // not 72: a 1440 window with the rail open leaves 1152px, less a classic
     // scrollbar on Linux, and must still get the grid. The container is the
     // wrapper around the grid.
+    //
+    // `list-mid:` — the same container, one step down (#3465). The tablet row
+    // keeps three reserved toggles, the success bar, the meter and the task
+    // counts on one line and needs about 610px; a viewport `md:` alone gave it
+    // 496px at a 768 window with the rail open, where the success cell
+    // collapsed to 0 and the task counts ran past the row. Below 40rem the
+    // compact (phone) row renders instead. 40, not more: a 768 window with the
+    // rail collapsed leaves 664px, less a classic scrollbar, and keeps the
+    // tablet row. Registered BEFORE `list-wide` so `md:list-wide:hidden` is
+    // emitted after `md:list-mid:flex` and wins where both hold.
     function ({ addVariant }) {
+      addVariant('list-mid', '@container agent-list (min-width: 40rem)')
       addVariant('list-wide', '@container agent-list (min-width: 68rem)')
     },
   ],
diff --git a/src/frontend/tests/unit/agentListLayoutSwitch.spec.js b/src/frontend/tests/unit/agentListLayoutSwitch.spec.js
new file mode 100644
index 000000000..1038d65b0
--- /dev/null
+++ b/src/frontend/tests/unit/agentListLayoutSwitch.spec.js
@@ -0,0 +1,174 @@
+// @vitest-environment jsdom
+/**
+ * #3465 — which of the Dashboard list's three row layouts renders is decided
+ * by the LIST's width, not only the window's.
+ *
+ * The defect: the tablet layout switched on a viewport `md:` alone. At a 768
+ * window with the systems rail open the list is about 496px wide, and the
+ * tablet row's second line needs about 610px (three reserved toggles, the
+ * success bar, the meter, the task counts). The `flex-1 min-w-0` success cell
+ * collapsed to 0 with its text painting over the meter, and the no-wrap task
+ * counts ran 50-67px past the row's right edge.
+ *
+ * jsdom has no layout engine and evaluates no media or container query, so a
+ * mount alone cannot see which layout is displayed. This spec therefore does
+ * the two halves it CAN do for real, and nothing by regex:
+ *
+ *   1. mounts `AgentListPanel` and takes the class lists off the three
+ *      rendered layout blocks of a row, and
+ *   2. compiles exactly those classes through the real `tailwind.config.js`
+ *      and resolves the `display` cascade for a simulated (window, list)
+ *      width pair — source order, enclosing `@media` / `@container` and all.
+ *
+ * That catches what a class-string read cannot: a variant that is misspelled
+ * or unregistered (it emits nothing), and two rules whose winner depends on
+ * the order Tailwind emits them in (design-system-contract.md, #2662).
+ *
+ * What it cannot prove is that the tablet row FITS at the threshold — that is
+ * a browser measurement (e2e/dashboard-list-view.spec.js, #3465 case).
+ */
+import { describe, it, expect, vi, beforeAll, beforeEach } from 'vitest'
+import { mount } from '@vue/test-utils'
+import { createPinia, setActivePinia } from 'pinia'
+import { dirname, resolve } from 'node:path'
+import { fileURLToPath } from 'node:url'
+import postcss from 'postcss'
+import tailwindcss from 'tailwindcss'
+import loadConfig from 'tailwindcss/loadConfig.js'
+
+vi.mock('vue-router', () => ({ useRouter: () => ({ push: vi.fn() }) }))
+vi.mock('axios', () => {
+  const inst = {
+    get: vi.fn(() => Promise.resolve({ data: {} })), post: vi.fn(), put: vi.fn(), delete: vi.fn(),
+    interceptors: { request: { use: vi.fn() }, response: { use: vi.fn() } },
+    defaults: { headers: { common: {} } },
+  }
+  return { default: Object.assign(inst, { create: () => inst }) }
+})
+
+import AgentListPanel from '../../src/components/AgentListPanel.vue'
+
+const HERE = dirname(fileURLToPath(import.meta.url))
+const REM = 16
+
+const STUBS = {
+  AgentAvatar: true, RuntimeBadge: true, RunningStateToggle: true, AutonomyToggle: true,
+  ReadOnlyToggle: true, CapacityMeter: true, RouterLink: true,
+}
+
+/** The three layout blocks of the first rendered row, as class lists. */
+function mountedLayouts() {
+  const wrapper = mount(AgentListPanel, {
+    props: {
+      agents: [{ name: 'alpha', status: 'running', runtime: 'claude-code', tags: [], is_owner: true }],
+    },
+    global: { stubs: STUBS },
+  })
+  const row = wrapper.find('[data-agent="alpha"]').element
+  const lg = wrapper.find('[data-testid="row-secondary-lg"]').element.parentElement
+  const md = wrapper.find('[data-testid="row-secondary-md"]').element.parentElement
+  // The avatar and the lg / md blocks precede it; the base block is last.
+  const base = row.lastElementChild
+  expect(new Set([lg, md, base]).size, 'three distinct layout blocks').toBe(3)
+  for (const el of [lg, md, base]) expect(el.parentElement).toBe(row)
+  return {
+    html: wrapper.html(),
+    lg: [...lg.classList],
+    md: [...md.classList],
+    base: [...base.classList],
+  }
+}
+
+async function compile(html) {
+  const config = loadConfig(resolve(HERE, '../../tailwind.config.js'))
+  const result = await postcss([
+    tailwindcss({ ...config, content: [{ raw: html }], corePlugins: { preflight: false } }),
+  ]).process('@tailwind utilities;', { from: undefined })
+  return result.root
+}
+
+/** Does this at-rule hold for the simulated widths? Unknown shapes throw. */
+function atRuleHolds(node, { viewport, list }) {
+  if (node.name === 'media') {
+    const m = node.params.match(/^\(min-width:\s*([\d.]+)px\)$/)
+    if (!m) throw new Error(`unmodelled @media ${node.params}`)
+    return viewport >= Number(m[1])
+  }
+  if (node.name === 'container') {
+    const m = node.params.match(/^agent-list\s+\(min-width:\s*([\d.]+)rem\)$/)
+    if (!m) throw new Error(`unmodelled @container ${node.params}`)
+    return list >= Number(m[1]) * REM
+  }
+  throw new Error(`unmodelled at-rule @${node.name}`)
+}
+
+/**
+ * The `display` an element with these classes computes to. Every rule here is
+ * a single class selector (equal specificity), so the last one in source order
+ * whose enclosing conditions hold is the winner — the same answer the browser
+ * gives.
+ */
+function displayOf(root, classes, widths) {
+  let winner = 'block' // a <div> with no display utility
+  root.walkRules((rule) => {
+    const cls = rule.selector.replace(/^\./, '').replace(/\\/g, '')
+    if (!classes.includes(cls)) return
+    let display = null
+    rule.walkDecls('display', (d) => { display = d.value })
+    if (display === null) return
+    for (let p = rule.parent; p && p.type === 'atrule'; p = p.parent) {
+      if (!atRuleHolds(p, widths)) return
+    }
+    winner = display
+  })
+  return winner
+}
+
+describe('the list row layout follows the list width (#3465)', () => {
+  let layouts
+  let css
+
+  beforeEach(() => setActivePinia(createPinia()))
+  beforeAll(async () => {
+    setActivePinia(createPinia())
+    layouts = mountedLayouts()
+    css = await compile(layouts.html)
+  })
+
+  const shown = (widths) =>
+    ['lg', 'md', 'base'].filter((k) => displayOf(css, layouts[k], widths) !== 'none')
+
+  it('the reported case: a 768 window with the rail open gets the compact row', () => {
+    // 768 - 224 (rail) - 48 (panel padding) = 496. The tablet row's fixed
+    // parts alone are wider than that.
+    expect(shown({ viewport: 768, list: 496 })).toEqual(['base'])
+  })
+
+  it('a 768 window with the rail collapsed keeps the tablet row', () => {
+    expect(shown({ viewport: 768, list: 664 })).toEqual(['md'])
+  })
+
+  it('renders exactly one layout at every width, switching at 40rem and 68rem', () => {
+    const cases = [
+      // [window, list, layout]
+      [390, 342, 'base'],
+      // Below `md` the window still decides: unchanged by #3465.
+      [700, 652, 'base'],
+      [768, 639, 'base'],
+      [768, 640, 'md'],
+      [1024, 752, 'md'],
+      [1280, 992, 'md'],
+      [1440, 1087, 'md'],
+      [1440, 1088, 'lg'],
+      [1440, 1152, 'lg'],
+      [1920, 1632, 'lg'],
+    ]
+    for (const [viewport, list, layout] of cases) {
+      expect(shown({ viewport, list }), `window ${viewport}px, list ${list}px`).toEqual([layout])
+    }
+  })
+
+  it('the desktop row is a set of grid items, never a box', () => {
+    expect(displayOf(css, layouts.lg, { viewport: 1440, list: 1152 })).toBe('contents')
+  })
+})
diff --git a/src/frontend/tests/unit/agentName.spec.js b/src/frontend/tests/unit/agentName.spec.js
index 4bcb9b2d4..a05419369 100644
--- a/src/frontend/tests/unit/agentName.spec.js
+++ b/src/frontend/tests/unit/agentName.spec.js
@@ -530,10 +530,10 @@ describe('structural: the desktop grid switches on the list width, not the windo
 
   it('hides the tablet layout with the stacked `md:list-wide:hidden`', () => {
     // Tailwind 3 emits screen variants after custom ones, so a bare
-    // `list-wide:hidden` loses to `md:flex`. The tablet block then renders
+    // `list-wide:hidden` loses to the `md:` show rule. The tablet block then renders
     // inside the desktop row as an extra subgrid item and widens track 1 by
     // hundreds of pixels, which is what the first cut of this change did.
-    const tablet = classAttrsContaining(PANEL, 'md:flex md:flex-col')
+    const tablet = classAttrsContaining(PANEL, 'md:list-mid:flex md:list-mid:flex-col')
     expect(tablet).toHaveLength(1)
     expect(tablet[0]).toContain('md:list-wide:hidden')
     expect(tablet[0]).not.toMatch(/(?<!md:)list-wide:hidden/)