diff --git a/src/app.css b/src/app.css
deleted file mode 100644
index 61ba367..0000000
--- a/src/app.css
+++ /dev/null
@@ -1,79 +0,0 @@
-:root {
-  font-family: system-ui, Avenir, Helvetica, Arial, sans-serif;
-  line-height: 1.5;
-  font-weight: 400;
-
-  color-scheme: light dark;
-  color: rgba(255, 255, 255, 0.87);
-  background-color: #242424;
-
-  font-synthesis: none;
-  text-rendering: optimizeLegibility;
-  -webkit-font-smoothing: antialiased;
-  -moz-osx-font-smoothing: grayscale;
-}
-
-a {
-  font-weight: 500;
-  color: #646cff;
-  text-decoration: inherit;
-}
-a:hover {
-  color: #535bf2;
-}
-
-body {
-  margin: 0;
-  display: flex;
-  place-items: center;
-  min-width: 320px;
-  min-height: 100vh;
-}
-
-h1 {
-  font-size: 3.2em;
-  line-height: 1.1;
-}
-
-.card {
-  padding: 2em;
-}
-
-#app {
-  max-width: 1280px;
-  margin: 0 auto;
-  padding: 2rem;
-  text-align: center;
-}
-
-button {
-  border-radius: 8px;
-  border: 1px solid transparent;
-  padding: 0.6em 1.2em;
-  font-size: 1em;
-  font-weight: 500;
-  font-family: inherit;
-  background-color: #1a1a1a;
-  cursor: pointer;
-  transition: border-color 0.25s;
-}
-button:hover {
-  border-color: #646cff;
-}
-button:focus,
-button:focus-visible {
-  outline: 4px auto -webkit-focus-ring-color;
-}
-
-@media (prefers-color-scheme: light) {
-  :root {
-    color: #213547;
-    background-color: #ffffff;
-  }
-  a:hover {
-    color: #747bff;
-  }
-  button {
-    background-color: #f9f9f9;
-  }
-}
diff --git a/src/app/app.css b/src/app/app.css
new file mode 100644
index 0000000..b67f2fd
--- /dev/null
+++ b/src/app/app.css
@@ -0,0 +1,3 @@
+@import "@picocss/pico/css/pico.classless.jade.min.css";
+@import "./styles/base.css";
+@import "./styles/countdown.css";
diff --git a/src/app/styles/base.css b/src/app/styles/base.css
new file mode 100644
index 0000000..4fb733e
--- /dev/null
+++ b/src/app/styles/base.css
@@ -0,0 +1,16 @@
+:root {
+    --pico-border-radius: 0.5rem;
+    --pico-typography-spacing-vertical: 1.5rem;
+    --pico-form-element-spacing-vertical: 1rem;
+    --pico-form-element-spacing-horizontal: 1.25rem;
+}
+
+h1 {
+    --pico-font-family: Pacifico, cursive;
+    --pico-font-weight: 400;
+    --pico-typography-spacing-vertical: 0.5rem;
+}
+
+button {
+    --pico-font-weight: 700;
+}
\ No newline at end of file
diff --git a/src/app/styles/countdown.css b/src/app/styles/countdown.css
new file mode 100644
index 0000000..5153b8f
--- /dev/null
+++ b/src/app/styles/countdown.css
@@ -0,0 +1,10 @@
+.countdown-actions {
+    display: flex;
+    gap: 0.5rem;
+}
+
+.countdown-error {
+    min-height: 1.25rem;
+    color: #b00020;
+    margin: 0.25rem 0;
+}
diff --git a/src/features/countdown/api.ts b/src/features/countdown/api.ts
new file mode 100644
index 0000000..96c3cb2
--- /dev/null
+++ b/src/features/countdown/api.ts
@@ -0,0 +1,45 @@
+import {invokeCommand} from "../../shared/tauri/invoke";
+import {CountdownCommand, CountdownSnapshot, CountdownState, Duration} from "./types";
+import {millisToDuration} from "./helper.ts";
+
+type CountdownSnapshotDto = {
+    id: number;
+    label: string;
+    duration: number;
+    state: CountdownState;
+    start_epoch_ms: number | null;
+    target_epoch_ms: number | null;
+};
+
+export async function fetchCountdownSnapshot(): Promise<CountdownSnapshot> {
+    let temp = await invokeCommand<CountdownSnapshotDto>("countdown_snapshot");
+    const duration: Duration = millisToDuration(temp.duration);
+    return {
+        id: temp.id,
+        label: temp.label,
+        duration: duration,
+        state: temp.state,
+        start_epoch: temp.start_epoch_ms !== null ? new Date(temp.start_epoch_ms) : null,
+        target_epoch: temp.target_epoch_ms !== null ? new Date(temp.target_epoch_ms) : null,
+    };
+}
+
+async function invokeCountdownCommand(command: CountdownCommand): Promise<void> {
+    await invokeCommand<void>(command);
+}
+
+export async function startCountdown(): Promise<void> {
+    await invokeCountdownCommand("countdown_start");
+}
+
+export async function pauseCountdown(): Promise<void> {
+    await invokeCountdownCommand("countdown_pause");
+}
+
+export async function resumeCountdown(): Promise<void> {
+    await invokeCountdownCommand("countdown_resume");
+}
+
+export async function resetCountdown(): Promise<void> {
+    await invokeCountdownCommand("countdown_reset");
+}
diff --git a/src/features/countdown/controller.ts b/src/features/countdown/controller.ts
new file mode 100644
index 0000000..025d1d9
--- /dev/null
+++ b/src/features/countdown/controller.ts
@@ -0,0 +1,48 @@
+import {
+  fetchCountdownSnapshot,
+  pauseCountdown,
+  resetCountdown,
+  resumeCountdown,
+  startCountdown,
+} from "./api";
+import { createCountdownView } from "./view";
+
+export async function initCountdownController(container: HTMLElement): Promise<void> {
+  const view = createCountdownView(container);
+
+  const refreshSnapshot = async (): Promise<void> => {
+    try {
+      const snapshot = await fetchCountdownSnapshot();
+      view.setSnapshot(snapshot);
+    } catch (error) {
+      view.setError(`snapshot error: ${String(error)}`);
+    }
+  };
+
+  const runAction = async (action: () => Promise<void>): Promise<void> => {
+    try {
+      await action();
+      await refreshSnapshot();
+    } catch (error) {
+      view.setError(`command error: ${String(error)}`);
+    }
+  };
+
+  view.onStart(() => {
+    void runAction(startCountdown);
+  });
+  view.onPause(() => {
+    void runAction(pauseCountdown);
+  });
+  view.onResume(() => {
+    void runAction(resumeCountdown);
+  });
+  view.onReset(() => {
+    void runAction(resetCountdown);
+  });
+  view.onRefresh(() => {
+    void refreshSnapshot();
+  });
+
+  await refreshSnapshot();
+}
diff --git a/src/features/countdown/types.ts b/src/features/countdown/types.ts
new file mode 100644
index 0000000..d206929
--- /dev/null
+++ b/src/features/countdown/types.ts
@@ -0,0 +1,18 @@
+import type {Duration} from "../../shared/time/duration";
+
+export type CountdownState = "Idle" | "Running" | "Paused" | "Finished";
+
+export type CountdownSnapshot = {
+    id: number;
+    label: string;
+    duration: Duration;
+    state: CountdownState;
+    start_epoch: Date | null;
+    target_epoch: Date | null;
+}
+
+export type CountdownCommand =
+    | "countdown_start"
+    | "countdown_pause"
+    | "countdown_resume"
+    | "countdown_reset";
diff --git a/src/features/countdown/view.ts b/src/features/countdown/view.ts
new file mode 100644
index 0000000..7dff44e
--- /dev/null
+++ b/src/features/countdown/view.ts
@@ -0,0 +1,79 @@
+import {formatDuration} from "./helper.ts";
+import {CountdownSnapshot} from "./types.ts";
+
+export type CountdownView = {
+    onStart: (handler: () => void) => void;
+    onResume: (handler: () => void) => void;
+    onPause: (handler: () => void) => void;
+    onReset: (handler: () => void) => void;
+    onRefresh: (handler: () => void) => void;
+    setSnapshot: (snapshot: CountdownSnapshot) => void;
+    setError: (message: string) => void;
+};
+
+function makeButton(label: string): HTMLButtonElement {
+    const button = document.createElement("button");
+    button.id = "cd-btn-" + label.toLowerCase();
+    button.className = "countdown-btn"
+    button.type = "button";
+    button.textContent = label;
+    return button;
+}
+
+export function createCountdownView(container: HTMLElement): CountdownView {
+    const panel = document.createElement("section");
+    panel.className = "countdown-panel";
+
+    const title = document.createElement("h2");
+    title.textContent = "Countdown Controls";
+
+    const actions = document.createElement("div");
+    actions.className = "countdown-actions";
+
+    const startButton = makeButton("Start");
+    const resumeButton = makeButton("Resume");
+    const pauseButton = makeButton("Pause");
+    const resetButton = makeButton("Reset");
+    const refreshButton = makeButton("Refresh");
+
+    actions.append(startButton, resumeButton, pauseButton, resetButton, refreshButton);
+
+    const summary = document.createElement("p");
+    summary.className = "countdown-summary";
+    summary.textContent = "Waiting for snapshot...";
+
+    const error = document.createElement("p");
+    error.className = "countdown-error";
+
+    const snapshot = document.createElement("pre");
+    snapshot.className = "countdown-snapshot";
+
+    panel.append(title, actions, summary, error, snapshot);
+    container.appendChild(panel);
+
+    return {
+        onStart(handler) {
+            startButton.addEventListener("click", handler);
+        },
+        onResume(handler) {
+            resumeButton.addEventListener("click", handler);
+        },
+        onPause(handler) {
+            pauseButton.addEventListener("click", handler);
+        },
+        onReset(handler) {
+            resetButton.addEventListener("click", handler);
+        },
+        onRefresh(handler) {
+            refreshButton.addEventListener("click", handler);
+        },
+        setSnapshot(value) {
+            error.textContent = "";
+            summary.textContent = `State: ${value.state} | Remaining: ${formatDuration(value.duration)}`;
+            snapshot.textContent = JSON.stringify(value, null, 2);
+        },
+        setError(message) {
+            error.textContent = message;
+        },
+    };
+}
diff --git a/src/main.ts b/src/main.ts
index 664a057..d219507 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1,9 +1,9 @@
-import { mount } from 'svelte'
-import './app.css'
+import {mount} from 'svelte'
+import './app/app.css'
 import App from './App.svelte'
 
 const app = mount(App, {
-  target: document.getElementById('app')!,
+    target: document.getElementById('app')!,
 })
 
 export default app
diff --git a/src/shared/tauri/invoke.ts b/src/shared/tauri/invoke.ts
new file mode 100644
index 0000000..980ffab
--- /dev/null
+++ b/src/shared/tauri/invoke.ts
@@ -0,0 +1,8 @@
+import { invoke } from "@tauri-apps/api/core";
+
+export async function invokeCommand<T>(
+  command: string,
+  payload?: Record<string, unknown>
+): Promise<T> {
+  return invoke<T>(command, payload);
+}
diff --git a/src/shared/time/duration.ts b/src/shared/time/duration.ts
new file mode 100644
index 0000000..466eb35
--- /dev/null
+++ b/src/shared/time/duration.ts
@@ -0,0 +1,19 @@
+export type Duration = {
+    hours: number;
+    minutes: number;
+    seconds: number;
+    millis: number;
+}
+
+export function formatDuration(duration: Duration): string {
+    return `${duration.hours.toString().padStart(2, '0')}:${duration.minutes.toString().padStart(2, '0')}:${duration.seconds.toString().padStart(2, '0')}.${duration.millis.toString().padStart(3, '0')}`;
+}
+
+export function millisToDuration(millis: number): Duration {
+    return {
+        hours: Math.floor(millis / 3600000),
+        minutes: Math.floor((millis % 3600000) / 60000),
+        seconds: Math.floor((millis % 60000) / 1000),
+        millis: millis % 1000,
+    }
+}