diff --git a/src/lib/components/FocusTimer.svelte b/src/lib/components/FocusTimer.svelte
new file mode 100644
index 0000000..4fcdc0f
--- /dev/null
+++ b/src/lib/components/FocusTimer.svelte
@@ -0,0 +1,270 @@
+<script lang="ts">
+  // Floating focus-timer overlay. Renders nothing when no timer is
+  // active. When a timer is running, pins a compact SVG progress ring
+  // to the top-right of the viewport with the remaining mm:ss in the
+  // centre. Completion plays a gentle chime, flashes a success ring
+  // for 3 s, then disappears. Cancel button appears on hover.
+  //
+  // Mounted once in +layout.svelte. Listens for `kon:start-timer`
+  // events from anywhere in the app (e.g. MicroSteps) and delegates
+  // to the focus-timer store.
+  //
+  // Design tokens used: --color-accent (mid-progress),
+  // --color-warning (final 15%), --color-success (flourish),
+  // --color-border (unfilled ring track). No literals, so the ring
+  // follows the sensory-zone theme switcher in Settings.
+
+  import { onMount, onDestroy } from "svelte";
+  import { X, Plus } from "lucide-svelte";
+  import { focusTimer } from "$lib/stores/focusTimer.svelte.js";
+
+  const RING_SIZE = 64;
+  const RING_STROKE = 5;
+  const RING_RADIUS = (RING_SIZE - RING_STROKE) / 2;
+  const RING_CIRCUMFERENCE = 2 * Math.PI * RING_RADIUS;
+
+  // Progress ring fills as time elapses. Stroke-dashoffset goes from
+  // circumference (empty) to 0 (full) — we want it the other way,
+  // because the UX is a shrinking-time disc: more elapsed = less
+  // ring visible. Render the remaining arc: dashoffset = circumference * progress.
+  let dashOffset = $derived(RING_CIRCUMFERENCE * focusTimer.progress);
+
+  function formatRemaining(ms: number): string {
+    const total = Math.ceil(ms / 1000);
+    const mins = Math.floor(total / 60);
+    const secs = total % 60;
+    return `${mins}:${secs.toString().padStart(2, "0")}`;
+  }
+
+  // Colour shifts over the last 15% of the timer to cue "nearly done"
+  // without resorting to red (which the brief flags as anxiogenic for
+  // the target audience).
+  let ringColor = $derived.by(() => {
+    if (focusTimer.showingCompletionFlash) return "var(--color-success)";
+    if (focusTimer.progress >= 0.85) return "var(--color-warning)";
+    return "var(--color-accent)";
+  });
+
+  // Event handler: start a timer when any component fires `kon:start-timer`.
+  // Payload shape from MicroSteps.svelte and task row buttons:
+  //   { taskId?: string, seconds: number, label?: string }
+  function handleStartEvent(evt: Event) {
+    const detail = (evt as CustomEvent).detail ?? {};
+    const seconds = Number(detail.seconds);
+    if (!Number.isFinite(seconds) || seconds <= 0) return;
+    focusTimer.start(seconds, {
+      taskId: detail.taskId ?? null,
+      label: detail.label ?? null,
+    });
+  }
+
+  onMount(() => {
+    window.addEventListener("kon:start-timer", handleStartEvent);
+    // Rehydrate any in-flight timer that survived a window close.
+    focusTimer.rehydrate();
+  });
+
+  onDestroy(() => {
+    window.removeEventListener("kon:start-timer", handleStartEvent);
+  });
+
+  function handleCancel() {
+    focusTimer.cancel();
+  }
+
+  function handleExtend() {
+    focusTimer.extend(60);
+  }
+
+  function handleDismissFlash() {
+    focusTimer.dismissCompletionFlash();
+  }
+</script>
+
+{#if focusTimer.active || focusTimer.showingCompletionFlash}
+  <div
+    class="focus-timer"
+    class:completed={focusTimer.showingCompletionFlash}
+    role="status"
+    aria-live="polite"
+    aria-label={focusTimer.label ?? "Focus timer"}
+  >
+    <div class="ring-wrap">
+      <svg
+        width={RING_SIZE}
+        height={RING_SIZE}
+        viewBox={`0 0 ${RING_SIZE} ${RING_SIZE}`}
+        aria-hidden="true"
+      >
+        <!-- Track -->
+        <circle
+          cx={RING_SIZE / 2}
+          cy={RING_SIZE / 2}
+          r={RING_RADIUS}
+          fill="none"
+          stroke="var(--color-border)"
+          stroke-width={RING_STROKE}
+        />
+        <!-- Progress (shrinking slice — full ring at start, none at end) -->
+        <circle
+          cx={RING_SIZE / 2}
+          cy={RING_SIZE / 2}
+          r={RING_RADIUS}
+          fill="none"
+          stroke={ringColor}
+          stroke-width={RING_STROKE}
+          stroke-linecap="round"
+          stroke-dasharray={RING_CIRCUMFERENCE}
+          stroke-dashoffset={dashOffset}
+          transform={`rotate(-90 ${RING_SIZE / 2} ${RING_SIZE / 2})`}
+          style="transition: stroke-dashoffset 250ms linear, stroke 400ms ease"
+        />
+      </svg>
+      <div class="time" aria-hidden={focusTimer.showingCompletionFlash}>
+        {#if focusTimer.showingCompletionFlash}
+          <span class="done">done</span>
+        {:else}
+          {formatRemaining(focusTimer.remainingMs)}
+        {/if}
+      </div>
+    </div>
+
+    <div class="controls">
+      {#if focusTimer.showingCompletionFlash}
+        <button
+          class="icon-btn"
+          onclick={handleDismissFlash}
+          aria-label="Dismiss completion"
+          title="Dismiss"
+        >
+          <X size={14} aria-hidden="true" />
+        </button>
+      {:else}
+        <button
+          class="icon-btn"
+          onclick={handleExtend}
+          aria-label="Add one minute"
+          title="+1 min"
+        >
+          <Plus size={14} aria-hidden="true" />
+        </button>
+        <button
+          class="icon-btn"
+          onclick={handleCancel}
+          aria-label="Cancel timer"
+          title="Cancel"
+        >
+          <X size={14} aria-hidden="true" />
+        </button>
+      {/if}
+    </div>
+
+    {#if focusTimer.label}
+      <div class="label" aria-hidden="true">{focusTimer.label}</div>
+    {/if}
+  </div>
+{/if}
+
+<style>
+  .focus-timer {
+    position: fixed;
+    top: 52px;
+    right: 16px;
+    z-index: 40;
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    padding: 6px 10px 6px 6px;
+    background: var(--color-bg-elevated);
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-lg);
+    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
+    font-family: var(--font-family-body);
+    font-variant-numeric: tabular-nums;
+    transition: opacity 200ms ease, transform 200ms ease;
+  }
+
+  .focus-timer.completed {
+    border-color: var(--color-success);
+  }
+
+  .ring-wrap {
+    position: relative;
+    width: 64px;
+    height: 64px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    flex-shrink: 0;
+  }
+
+  .time {
+    position: absolute;
+    inset: 0;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    font-size: 14px;
+    font-weight: 500;
+    color: var(--color-text);
+  }
+
+  .time .done {
+    font-size: 11px;
+    color: var(--color-success);
+    font-family: var(--font-family-display);
+    letter-spacing: 0.02em;
+  }
+
+  .controls {
+    display: flex;
+    flex-direction: column;
+    gap: 4px;
+    opacity: 0;
+    transition: opacity 180ms ease;
+  }
+
+  .focus-timer:hover .controls,
+  .focus-timer:focus-within .controls,
+  .focus-timer.completed .controls {
+    opacity: 1;
+  }
+
+  .icon-btn {
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    width: 22px;
+    height: 22px;
+    padding: 0;
+    border: 0;
+    border-radius: var(--radius-sm);
+    background: transparent;
+    color: var(--color-text-secondary);
+    cursor: pointer;
+    transition: background 150ms ease, color 150ms ease;
+  }
+
+  .icon-btn:hover {
+    background: var(--color-hover);
+    color: var(--color-text);
+  }
+
+  .icon-btn:focus-visible {
+    outline: 2px solid var(--color-accent);
+    outline-offset: 1px;
+  }
+
+  .label {
+    max-width: 140px;
+    font-size: 12px;
+    color: var(--color-text-secondary);
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+  }
+
+  :global([data-reduce-motion="true"]) .focus-timer circle {
+    transition: none !important;
+  }
+</style>
diff --git a/src/lib/components/WipTaskList.svelte b/src/lib/components/WipTaskList.svelte
index fe416e6..eca3863 100644
--- a/src/lib/components/WipTaskList.svelte
+++ b/src/lib/components/WipTaskList.svelte
@@ -1,7 +1,13 @@
 <script lang="ts">
   import { tasks, addTask, completeTask, uncompleteTask, deleteTask } from '$lib/stores/page.svelte.js';
   import MicroSteps from '$lib/components/MicroSteps.svelte';
-  import { ChevronDown, ChevronRight } from 'lucide-svelte';
+  import { ChevronDown, ChevronRight, Timer } from 'lucide-svelte';
+
+  function startFocusTimer(task: { id: string; text: string }) {
+    window.dispatchEvent(new CustomEvent('kon:start-timer', {
+      detail: { taskId: task.id, seconds: 300, label: task.text }
+    }));
+  }
 
   let { wipLimit = 3 } = $props();
 
@@ -68,6 +74,16 @@
               aria-label="Complete task"
             ></button>
             <span class="text-[13px] text-text flex-1 min-w-0 truncate">{task.text}</span>
+            <!-- 5-min focus timer — the "just-start" button from the brief -->
+            <button
+              class="opacity-0 group-hover:opacity-100 text-text-tertiary hover:text-accent"
+              onclick={() => startFocusTimer(task)}
+              aria-label="Start 5-minute focus timer for this task"
+              title="Start 5-minute focus timer"
+              style="transition: opacity var(--duration-ui)"
+            >
+              <Timer size={12} aria-hidden="true" />
+            </button>
             <!-- Expand/collapse micro-steps toggle -->
             <button
               class="opacity-0 group-hover:opacity-100 text-text-tertiary hover:text-accent"
diff --git a/src/lib/stores/focusTimer.svelte.ts b/src/lib/stores/focusTimer.svelte.ts
new file mode 100644
index 0000000..776e0db
--- /dev/null
+++ b/src/lib/stores/focusTimer.svelte.ts
@@ -0,0 +1,230 @@
+// Focus timer store. Single active timer at a time — the "just-start"
+// 2/5/10/15-minute countdown paired with micro-steps. Exposes:
+//   - focusTimer.active: whether a timer is currently running
+//   - focusTimer.progress: 0..1 fraction of elapsed time
+//   - focusTimer.remainingMs: milliseconds until completion
+//   - focusTimer.label / focusTimer.taskId: what this timer is for
+//   - start(seconds, opts) / cancel() / extend(seconds)
+//
+// Survives window close + reopen via localStorage, because a timer
+// that loses its clock when the user alt-tabs is a timer that nobody
+// trusts. On rehydrate after expiry, fires completion then clears —
+// so closing the window mid-timer still gets you the "done" signal
+// on next launch.
+
+const STORAGE_KEY = "kon.focusTimer.v1";
+const TICK_INTERVAL_MS = 250;
+
+export type FocusTimerPersisted = {
+  startedAt: number;
+  durationMs: number;
+  taskId: string | null;
+  label: string | null;
+};
+
+function readPersisted(): FocusTimerPersisted | null {
+  if (typeof window === "undefined") return null;
+  try {
+    const raw = window.localStorage.getItem(STORAGE_KEY);
+    if (!raw) return null;
+    const parsed = JSON.parse(raw);
+    if (
+      typeof parsed?.startedAt !== "number" ||
+      typeof parsed?.durationMs !== "number"
+    ) return null;
+    return {
+      startedAt: parsed.startedAt,
+      durationMs: parsed.durationMs,
+      taskId: parsed.taskId ?? null,
+      label: parsed.label ?? null,
+    };
+  } catch {
+    return null;
+  }
+}
+
+function writePersisted(state: FocusTimerPersisted | null): void {
+  if (typeof window === "undefined") return;
+  try {
+    if (state === null) window.localStorage.removeItem(STORAGE_KEY);
+    else window.localStorage.setItem(STORAGE_KEY, JSON.stringify(state));
+  } catch { /* storage may be disabled; non-fatal */ }
+}
+
+function createFocusTimerStore() {
+  let startedAt = $state<number | null>(null);
+  let durationMs = $state<number>(0);
+  let taskId = $state<string | null>(null);
+  let label = $state<string | null>(null);
+  let now = $state<number>(Date.now());
+  let completionFlashUntil = $state<number>(0);
+
+  let interval: ReturnType<typeof setInterval> | null = null;
+
+  const active = $derived(startedAt !== null);
+  const elapsedMs = $derived(startedAt === null ? 0 : Math.max(0, now - startedAt));
+  const remainingMs = $derived(Math.max(0, durationMs - elapsedMs));
+  const progress = $derived(durationMs === 0 ? 0 : Math.min(1, elapsedMs / durationMs));
+  const finished = $derived(active && remainingMs === 0);
+  const showingCompletionFlash = $derived(now < completionFlashUntil);
+
+  // Internal completion + flash bookkeeping. We track whether we have
+  // already fired the completion chime for the current timer so a
+  // second tick does not re-fire it. Reset whenever a new timer starts.
+  let completionFired = false;
+
+  function tick() {
+    now = Date.now();
+    // Fire completion once, the first tick after we cross remaining=0.
+    if (startedAt !== null && !completionFired && now - startedAt >= durationMs) {
+      completionFired = true;
+      completionFlashUntil = now + 3000;
+      fireCompletion();
+    }
+    // After the 3 s flash window, clear everything and stop ticking.
+    if (completionFlashUntil > 0 && now >= completionFlashUntil) {
+      clear();
+    }
+  }
+
+  function startTick() {
+    if (interval !== null) return;
+    interval = setInterval(tick, TICK_INTERVAL_MS);
+  }
+
+  function stopTick() {
+    if (interval !== null) {
+      clearInterval(interval);
+      interval = null;
+    }
+  }
+
+  function clear() {
+    startedAt = null;
+    durationMs = 0;
+    taskId = null;
+    label = null;
+    completionFlashUntil = 0;
+    completionFired = false;
+    writePersisted(null);
+    stopTick();
+  }
+
+  function start(seconds: number, opts?: { taskId?: string | null; label?: string | null }): void {
+    if (!Number.isFinite(seconds) || seconds <= 0) return;
+    now = Date.now();
+    startedAt = now;
+    durationMs = Math.floor(seconds * 1000);
+    taskId = opts?.taskId ?? null;
+    label = opts?.label ?? null;
+    completionFlashUntil = 0;
+    completionFired = false;
+    writePersisted({ startedAt, durationMs, taskId, label });
+    startTick();
+  }
+
+  function cancel(): void {
+    clear();
+  }
+
+  function extend(seconds: number): void {
+    if (startedAt === null) return;
+    if (!Number.isFinite(seconds) || seconds <= 0) return;
+    durationMs += Math.floor(seconds * 1000);
+    writePersisted({ startedAt, durationMs, taskId, label });
+  }
+
+  function dismissCompletionFlash(): void {
+    completionFlashUntil = 0;
+    clear();
+  }
+
+  function fireCompletion(): void {
+    if (typeof window === "undefined") return;
+    // Gentle chime — WebAudio so we do not ship a bundled asset.
+    // A 440 Hz fall into 330 Hz over 220 ms, low volume, no sustain.
+    try {
+      type AudioCtx = typeof AudioContext;
+      const win = window as unknown as { AudioContext?: AudioCtx; webkitAudioContext?: AudioCtx };
+      const Ctx = win.AudioContext ?? win.webkitAudioContext;
+      if (!Ctx) return;
+      const ctx = new Ctx();
+      const osc = ctx.createOscillator();
+      const gain = ctx.createGain();
+      osc.type = "sine";
+      osc.frequency.setValueAtTime(440, ctx.currentTime);
+      osc.frequency.exponentialRampToValueAtTime(330, ctx.currentTime + 0.22);
+      gain.gain.setValueAtTime(0.0001, ctx.currentTime);
+      gain.gain.exponentialRampToValueAtTime(0.15, ctx.currentTime + 0.02);
+      gain.gain.exponentialRampToValueAtTime(0.0001, ctx.currentTime + 0.28);
+      osc.connect(gain);
+      gain.connect(ctx.destination);
+      osc.start();
+      osc.stop(ctx.currentTime + 0.3);
+      osc.onended = () => ctx.close().catch(() => {});
+    } catch { /* audio is a nicety; never fatal */ }
+
+    window.dispatchEvent(new CustomEvent("kon:focus-timer-complete", {
+      detail: { taskId, label },
+    }));
+  }
+
+  // Rehydrate on first touch. If the persisted timer has already
+  // expired, fire completion then clear so the user still gets the
+  // "done" signal they missed while the window was closed.
+  function rehydrate(): void {
+    const persisted = readPersisted();
+    if (!persisted) return;
+    const age = Date.now() - persisted.startedAt;
+    if (age >= persisted.durationMs) {
+      // Already expired while the window was closed. Fire a completion
+      // event so downstream listeners (nudges, UI flourishes) can react.
+      taskId = persisted.taskId;
+      label = persisted.label;
+      durationMs = persisted.durationMs;
+      startedAt = persisted.startedAt;
+      now = persisted.startedAt + persisted.durationMs;
+      // Flash briefly so the user knows it happened.
+      completionFlashUntil = Date.now() + 3000;
+      completionFired = true;
+      fireCompletion();
+      startTick();
+      return;
+    }
+    startedAt = persisted.startedAt;
+    durationMs = persisted.durationMs;
+    taskId = persisted.taskId;
+    label = persisted.label;
+    now = Date.now();
+    startTick();
+  }
+
+  // Exposed as frozen object. Getters so derivations stay reactive.
+  return {
+    get active() { return active; },
+    get progress() { return progress; },
+    get elapsedMs() { return elapsedMs; },
+    get remainingMs() { return remainingMs; },
+    get durationMs() { return durationMs; },
+    get taskId() { return taskId; },
+    get label() { return label; },
+    get showingCompletionFlash() { return showingCompletionFlash; },
+    start,
+    cancel,
+    extend,
+    rehydrate,
+    dismissCompletionFlash,
+  };
+}
+
+export const focusTimer = createFocusTimerStore();
+
+// Preset durations surfaced in the UI. 2 / 5 / 10 / 15 minutes match
+// the brief's guidance for the "just-start" timer and cover common
+// Pomodoro / shorter-focus preferences.
+export const FOCUS_TIMER_PRESETS_SECONDS: ReadonlyArray<{ label: string; seconds: number }> = [
+  { label: "2 min", seconds: 120 },
+  { label: "5 min", seconds: 300 },
+  { label: "10 min", seconds: 600 },
+  { label: "15 min", seconds: 900 },
+];
diff --git a/src/routes/+layout.svelte b/src/routes/+layout.svelte
index 28f1836..31ce059 100644
--- a/src/routes/+layout.svelte
+++ b/src/routes/+layout.svelte
@@ -8,6 +8,7 @@
   import Titlebar from "$lib/components/Titlebar.svelte";
   import ToastViewport from "$lib/components/ToastViewport.svelte";
   import ResizeHandles from "$lib/components/ResizeHandles.svelte";
+  import FocusTimer from "$lib/components/FocusTimer.svelte";
   import { hasTauriRuntime } from "$lib/utils/runtime.js";
   import { loadOsInfo, isLinux } from "$lib/utils/osInfo.js";
   import { page, settings, saveSettings } from "$lib/stores/page.svelte.js";
@@ -396,6 +397,13 @@
      in the bottom-right of the viewport. (Day 3 of the upgrade plan) -->
 <ToastViewport />
 
+<!-- Global focus-timer overlay. Renders nothing until a `kon:start-timer`
+     event fires; then pins a shrinking colour ring to the top-right.
+     Phase 1 of the 2026-04-23 feature-complete roadmap — closes the
+     visual-time-representation gap from docs/brief/feature-set.md and
+     wires the dangling emit in MicroSteps.svelte. -->
+<FocusTimer />
+
 <!-- Invisible resize margins for frameless (macOS/Windows). On Linux we
      use native decorations, so ResizeHandles would compete with the
      compositor's own resize and is suppressed. -->