diff --git a/tests/blog-carousel.test.mjs b/tests/blog-carousel.test.mjs
new file mode 100644
index 00000000..adb15233
--- /dev/null
+++ b/tests/blog-carousel.test.mjs
@@ -0,0 +1,236 @@
+import assert from 'node:assert/strict';
+import { beforeEach, afterEach, describe, test } from 'node:test';
+
+import { advanceSlide, createCarousel, destroyCarousel } from '../js/blog/carousel.js';
+import { mountProgressBar } from '../js/blog/progressBar.js';
+import {
+  createBlogDomEnvironment,
+  createSpy,
+  readDynamicStyleRules,
+} from './test-helpers/blog-dom.mjs';
+
+const CAROUSEL_HTML = `
+  <div data-carousel>
+    <div data-carousel-track>
+      <article data-slide="0">Slide 1</article>
+      <article data-slide="1">Slide 2</article>
+      <article data-slide="2">Slide 3</article>
+    </div>
+    <button type="button" data-carousel-prev>Prev</button>
+    <button type="button" data-carousel-next>Next</button>
+  </div>
+`;
+
+const PROGRESS_HTML = '<div id="progress-root"></div>';
+
+describe('blog carousel', () => {
+  let env;
+  let container;
+  let track;
+  let slides;
+  let prevButton;
+  let nextButton;
+
+  beforeEach(() => {
+    env = createBlogDomEnvironment(CAROUSEL_HTML);
+    const doc = env.document;
+    container = doc.querySelector('[data-carousel]');
+    track = container.querySelector('[data-carousel-track]');
+    slides = Array.from(track.children);
+    prevButton = container.querySelector('[data-carousel-prev]');
+    nextButton = container.querySelector('[data-carousel-next]');
+
+    env.inlineStyleGuard.guard(container);
+    env.inlineStyleGuard.guard(track);
+    env.inlineStyleGuard.guard(prevButton);
+    env.inlineStyleGuard.guard(nextButton);
+    slides.forEach((slide) => env.inlineStyleGuard.guard(slide));
+  });
+
+  afterEach(() => {
+    env.cleanup();
+  });
+
+  test('initializes slides with dynamic styling and accessibility state', () => {
+    const state = createCarousel(container, {
+      perPage: 1,
+      loop: true,
+      controls: { prev: prevButton, next: nextButton },
+    });
+
+    assert.ok(state, 'state should be created when container markup is valid');
+    assert.strictEqual(state.perPage, 1);
+    assert.strictEqual(state.slides.length, 3);
+    assert.ok(container.classList.contains('splide'));
+    assert.ok(container.classList.contains('is-initialized'));
+    assert.ok(container.classList.contains('is-active'));
+
+    const trackDynamicClasses = Array.from(track.classList).filter((className) => className.startsWith('bvds-'));
+    assert.ok(trackDynamicClasses.length >= 1, 'track should receive dynamic style classes');
+
+    for (const slide of slides) {
+      assert.ok(slide.classList.contains('splide__slide'));
+      const dynamicClasses = Array.from(slide.classList).filter((className) => className.startsWith('bvds-'));
+      assert.ok(dynamicClasses.length >= 1, 'slide should receive dynamic sizing styles');
+    }
+
+    assert.strictEqual(slides[0].getAttribute('aria-hidden'), 'false');
+    assert.strictEqual(slides[1].getAttribute('aria-hidden'), 'true');
+    assert.strictEqual(slides[2].getAttribute('aria-hidden'), 'true');
+
+    state.goTo(2);
+    assert.strictEqual(state.index, 2);
+    assert.strictEqual(slides[2].getAttribute('aria-hidden'), 'false');
+    assert.strictEqual(slides[0].getAttribute('aria-hidden'), 'true');
+
+    destroyCarousel(state);
+  });
+
+  test('control buttons advance slides and respect looping', () => {
+    const state = createCarousel(container, {
+      perPage: 1,
+      loop: true,
+      controls: { prev: prevButton, next: nextButton },
+    });
+
+    nextButton.dispatchEvent(new env.window.MouseEvent('click', { bubbles: true }));
+    assert.strictEqual(state.index, 1);
+    nextButton.dispatchEvent(new env.window.MouseEvent('click', { bubbles: true }));
+    assert.strictEqual(state.index, 2);
+    nextButton.dispatchEvent(new env.window.MouseEvent('click', { bubbles: true }));
+    assert.strictEqual(state.index, 0, 'looping should wrap forward navigation to the first slide');
+
+    prevButton.dispatchEvent(new env.window.MouseEvent('click', { bubbles: true }));
+    assert.strictEqual(state.index, 2, 'looping should wrap backward navigation to the last slide');
+
+    destroyCarousel(state);
+  });
+
+  test('auto play progress resets when navigation occurs', () => {
+    const state = createCarousel(container, {
+      perPage: 1,
+      controls: { prev: prevButton, next: nextButton },
+    });
+    const events = [];
+    const progress = {
+      reset: () => events.push('reset'),
+      start: (duration) => events.push(['start', duration]),
+      destroy: () => events.push('destroy'),
+    };
+    state.setProgress(progress);
+    state.autoPlayInterval = 4200;
+
+    state.goTo(1);
+    assert.deepStrictEqual(events, ['reset', ['start', 4200]]);
+
+    events.length = 0;
+    state.goTo(2, { restartProgress: false });
+    assert.deepStrictEqual(events, [], 'progress should not restart when restartProgress is false');
+
+    destroyCarousel(state);
+  });
+
+  test('destroyCarousel tears down listeners and progress state', () => {
+    const state = createCarousel(container, {
+      perPage: 1,
+      controls: { prev: prevButton, next: nextButton },
+    });
+    const progressEvents = [];
+    const progress = {
+      reset: () => progressEvents.push('reset'),
+      start: () => progressEvents.push('start'),
+      destroy: () => progressEvents.push('destroy'),
+    };
+    state.setProgress(progress);
+    state.autoPlayInterval = 2000;
+    state.goTo(1);
+
+    destroyCarousel(state);
+    assert.ok(progressEvents.includes('destroy'), 'progress.destroy should be called during teardown');
+    assert.ok(!container.classList.contains('is-initialized'));
+    assert.ok(!container.classList.contains('is-active'));
+    assert.strictEqual(state.cleanup.length, 0);
+
+    const previousIndex = state.index;
+    nextButton.dispatchEvent(new env.window.MouseEvent('click', { bubbles: true }));
+    assert.strictEqual(state.index, previousIndex, 'clicks after destroy should not change the index');
+  });
+
+  test('advanceSlide delegates to goTo with relative offsets', () => {
+    const state = createCarousel(container, { perPage: 1 });
+    const goToSpy = createSpy();
+    state.goTo = goToSpy;
+    state.index = 2;
+
+    advanceSlide(state, -1, { restartProgress: false });
+    assert.strictEqual(goToSpy.callCount, 1);
+    assert.deepStrictEqual(goToSpy.calls[0], [1, { restartProgress: false }]);
+  });
+});
+
+
+describe('progress bar', () => {
+  let env;
+  let container;
+
+  beforeEach(() => {
+    env = createBlogDomEnvironment(PROGRESS_HTML);
+    container = env.document.getElementById('progress-root');
+    env.inlineStyleGuard.guard(container);
+  });
+
+  afterEach(() => {
+    env.cleanup();
+  });
+
+  test('mountProgressBar renders structure with dynamic width styles', () => {
+    const progress = mountProgressBar(container, { initialDuration: 500, autoStart: false });
+    assert.ok(progress, 'progress instance should be returned');
+
+    const wrapper = container.querySelector('.splide__progress');
+    assert.ok(wrapper, 'wrapper element should be appended');
+    const fill = wrapper.querySelector('.splide__progress__bar');
+    assert.ok(fill, 'fill element should be created');
+
+    progress.reset();
+    const cssRules = readDynamicStyleRules(env.document);
+    assert.match(cssRules, /width:\s*0%/);
+  });
+
+  test('autoStart runs animation and triggers completion callback', () => {
+    const onComplete = createSpy();
+    const progress = mountProgressBar(container, { initialDuration: 600, autoStart: true, onComplete });
+    const wrapper = progress.element;
+    const fill = wrapper.querySelector('.splide__progress__bar');
+    assert.ok(Array.from(fill.classList).some((className) => className.startsWith('bvds-')));
+
+    env.raf.step(0);
+    env.raf.step(300);
+    assert.strictEqual(onComplete.callCount, 0);
+
+    env.raf.step(300);
+    assert.strictEqual(onComplete.callCount, 1);
+
+    const cssRules = readDynamicStyleRules(env.document);
+    assert.match(cssRules, /width:\s*100%/);
+  });
+
+  test('manual controls support stop, restart, and cleanup', () => {
+    const onComplete = createSpy();
+    const progress = mountProgressBar(container, { initialDuration: 800, onComplete });
+
+    progress.start(800);
+    env.raf.step(0);
+    env.raf.step(400);
+    progress.stop();
+    env.raf.step(600);
+    assert.strictEqual(onComplete.callCount, 0, 'stop should cancel pending completion');
+
+    progress.setOnComplete(onComplete);
+    progress.start(0);
+    assert.strictEqual(onComplete.callCount, 1, 'zero duration should fire completion immediately');
+
+    progress.destroy();
+    assert.strictEqual(container.children.length, 0, 'destroy should remove wrapper from DOM');
+  });
+});
diff --git a/tests/test-helpers/blog-dom.mjs b/tests/test-helpers/blog-dom.mjs
new file mode 100644
index 00000000..b7eefed0
--- /dev/null
+++ b/tests/test-helpers/blog-dom.mjs
@@ -0,0 +1,178 @@
+import { JSDOM } from 'jsdom';
+
+const DOM_GLOBALS = [
+  'window',
+  'document',
+  'HTMLElement',
+  'HTMLStyleElement',
+  'Element',
+  'Node',
+  'Event',
+  'MouseEvent',
+  'CustomEvent',
+  'KeyboardEvent',
+  'MutationObserver',
+  'getComputedStyle',
+];
+
+export function createSpy(implementation = () => {}) {
+  function spy(...args) {
+    spy.calls.push(args);
+    spy.callCount += 1;
+    return implementation(...args);
+  }
+  spy.calls = [];
+  spy.callCount = 0;
+  return spy;
+}
+
+export function createAnimationFrameStub() {
+  let now = 0;
+  let handle = 0;
+  const queue = new Map();
+
+  function requestAnimationFrame(callback) {
+    handle += 1;
+    const id = handle;
+    queue.set(id, callback);
+    return id;
+  }
+
+  function cancelAnimationFrame(id) {
+    queue.delete(id);
+  }
+
+  function step(elapsed = 0) {
+    now += elapsed;
+    const callbacks = Array.from(queue.entries());
+    queue.clear();
+    for (const [, callback] of callbacks) {
+      callback(now);
+    }
+  }
+
+  return {
+    requestAnimationFrame,
+    cancelAnimationFrame,
+    step,
+    get now() {
+      return now;
+    },
+    get pending() {
+      return queue.size;
+    },
+  };
+}
+
+export function installInlineStyleGuard(document) {
+  const originalCreateElement = document.createElement.bind(document);
+  const guardedElements = new WeakSet();
+
+  function guard(element) {
+    if (!element || typeof element !== 'object') {
+      return element;
+    }
+
+    if (guardedElements.has(element)) {
+      return element;
+    }
+
+    Object.defineProperty(element, 'style', {
+      get() {
+        throw new Error(
+          'Inline style access is disabled in blog widget tests. Use applyDynamicStyles or CSS class toggles instead.',
+        );
+      },
+      set() {
+        throw new Error(
+          'Inline style assignment is disabled in blog widget tests. Use applyDynamicStyles or CSS class toggles instead.',
+        );
+      },
+      configurable: true,
+    });
+
+    guardedElements.add(element);
+
+    if (element.children?.length) {
+      Array.from(element.children).forEach((child) => guard(child));
+    }
+
+    return element;
+  }
+
+  document.createElement = function createElementGuarded(...args) {
+    const element = originalCreateElement(...args);
+    guard(element);
+    return element;
+  };
+
+  return {
+    guard,
+    restore() {
+      document.createElement = originalCreateElement;
+    },
+  };
+}
+
+export function readDynamicStyleRules(document) {
+  const styleElement = document.getElementById('bitvid-style-system');
+  const sheet = styleElement?.sheet;
+  if (!sheet) {
+    return '';
+  }
+
+  try {
+    return Array.from(sheet.cssRules)
+      .map((rule) => rule.cssText)
+      .join('\n');
+  } catch (error) {
+    return '';
+  }
+}
+
+export function createBlogDomEnvironment(html) {
+  const dom = new JSDOM(html, { url: 'https://example.com' });
+  const { window } = dom;
+  const previousGlobals = new Map();
+
+  for (const key of DOM_GLOBALS) {
+    previousGlobals.set(key, globalThis[key]);
+    const nextValue = window[key];
+    if (typeof nextValue !== 'undefined') {
+      globalThis[key] = nextValue;
+    } else {
+      delete globalThis[key];
+    }
+  }
+
+  const inlineStyleGuard = installInlineStyleGuard(window.document);
+  const raf = createAnimationFrameStub();
+
+  previousGlobals.set('requestAnimationFrame', globalThis.requestAnimationFrame);
+  previousGlobals.set('cancelAnimationFrame', globalThis.cancelAnimationFrame);
+
+  globalThis.requestAnimationFrame = raf.requestAnimationFrame;
+  globalThis.cancelAnimationFrame = raf.cancelAnimationFrame;
+  window.requestAnimationFrame = raf.requestAnimationFrame;
+  window.cancelAnimationFrame = raf.cancelAnimationFrame;
+
+  return {
+    window,
+    document: window.document,
+    dom,
+    raf,
+    inlineStyleGuard,
+    cleanup() {
+      inlineStyleGuard.restore();
+      dom.window.close();
+
+      for (const [key, value] of previousGlobals) {
+        if (typeof value === 'undefined') {
+          delete globalThis[key];
+        } else {
+          globalThis[key] = value;
+        }
+      }
+    },
+  };
+}