diff --git a/README.md b/README.md
index 8276d5d..f84285b 100644
--- a/README.md
+++ b/README.md
@@ -54,6 +54,7 @@ Markdown content (posts & pages) lives in a separate repository and is consumed
 
 - **Blog index** (`/blog`)
   - Uses `PostListWithControls`:
+    - Keyword search filters posts by title, tags, and excerpt with instant feedback.
     - Sort order: new→old or old→new.
     - Pagination using `siteConfig.postsPerPage`.
 
@@ -62,6 +63,7 @@ Markdown content (posts & pages) lives in a separate repository and is consumed
   - Top: published date, large title, colored tags.
   - Body: `prose` typography with tuned light/dark colors, images, blockquotes, code.
   - Top bar: reading progress indicator.
+  - Bottom: "相關文章" cards suggesting up to three related posts that share overlapping tags.
 
 - **Right sidebar** (on large screens)
   - Top hero:
@@ -77,6 +79,29 @@ Markdown content (posts & pages) lives in a separate repository and is consumed
 - **Misc**
   - Floating "back to top" button on long pages.
 
+## Motion & Interaction Guidelines
+
+- Keep motion subtle and purposeful:
+  - Use small translations (±2–4px) and short durations (200–400ms, `ease-out`).
+  - Prefer fade/slide-in over large bounces or rotations.
+- Respect user preferences:
+  - Animations that run on their own are wrapped with `motion-safe:` so they are disabled when `prefers-reduced-motion` is enabled.
+- Reading experience first:
+  - Scroll-based reveals are used sparingly (e.g. post header and article body), not on every small element.
+  - TOC and reading progress bar emphasize orientation, not decoration.
+- Hover & focus:
+  - Use light elevation (shadow + tiny translateY) and accent color changes to indicate interactivity.
+  - Focus states remain visible and are not replaced by motion-only cues.
+
+### Implemented Visual Touches
+
+- Reading progress bar with a soft gradient glow at the top of post pages.
+- Scroll reveal for post header + article body (`ScrollReveal` component).
+- Hover elevation + gradient accents for post cards, list items, sidebar author card, and tag chips.
+- Smooth theme toggle with icon rotation and global `transition-colors` on the page background.
+- TOC smooth scrolling + short-lived highlight on the target heading.
+- Subtle hover elevation for `blockquote` and `pre` blocks inside `.prose` content.
+
 ## Prerequisites
 
 - Node.js **18+**
diff --git a/app/blog/[slug]/page.tsx b/app/blog/[slug]/page.tsx
index 541bb50..3e22248 100644
--- a/app/blog/[slug]/page.tsx
+++ b/app/blog/[slug]/page.tsx
@@ -2,10 +2,12 @@ import Link from 'next/link';
 import { notFound } from 'next/navigation';
 import type { Metadata } from 'next';
 import { allPosts } from 'contentlayer/generated';
-import { getPostBySlug } from '@/lib/posts';
+import { getPostBySlug, getRelatedPosts } from '@/lib/posts';
 import { siteConfig } from '@/lib/config';
 import { ReadingProgress } from '@/components/reading-progress';
 import { PostToc } from '@/components/post-toc';
+import { ScrollReveal } from '@/components/scroll-reveal';
+import { PostCard } from '@/components/post-card';
 
 export function generateStaticParams() {
   return allPosts.map((post) => ({
@@ -34,6 +36,8 @@ export default function BlogPostPage({ params }: Props) {
 
   if (!post) return notFound();
 
+  const relatedPosts = getRelatedPosts(post, 3);
+
   return (
     <>
       <ReadingProgress />
@@ -41,46 +45,71 @@ export default function BlogPostPage({ params }: Props) {
         <aside className="hidden shrink-0 lg:block lg:w-44">
           <PostToc />
         </aside>
-        <div className="flex-1">
-          <header className="mb-6 space-y-2">
-            {post.published_at && (
-              <p className="text-xs text-slate-500 dark:text-slate-500">
-                {new Date(post.published_at).toLocaleDateString(
-                  siteConfig.defaultLocale
-                )}
-              </p>
-            )}
-            <h1 className="text-2xl font-bold leading-tight text-slate-900 sm:text-3xl dark:text-slate-50">
-              {post.title}
-            </h1>
-            {post.tags && (
-              <div className="flex flex-wrap gap-2 pt-1">
-                {post.tags.map((t) => (
-                  <Link
-                    key={t}
-                    href={`/tags/${encodeURIComponent(
-                      t.toLowerCase().replace(/\s+/g, '-')
-                    )}`}
-                    className="rounded-full bg-accent-soft px-2 py-0.5 text-xs text-accent-textLight transition hover:bg-accent hover:text-white dark:bg-slate-800 dark:text-slate-100 dark:hover:bg-slate-700"
-                  >
-                    #{t}
-                  </Link>
-                ))}
-              </div>
-            )}
-          </header>
-          <article className="prose prose-lg prose-slate max-w-none dark:prose-dark">
-            {post.feature_image && (
-              // feature_image is stored as "../assets/xyz", serve from "/assets/xyz"
-              // eslint-disable-next-line @next/next/no-img-element
-              <img
-                src={post.feature_image.replace('../assets', '/assets')}
-                alt={post.title}
-                className="my-4 rounded"
-              />
-            )}
-            <div dangerouslySetInnerHTML={{ __html: post.body.html }} />
-          </article>
+        <div className="flex-1 space-y-6">
+          <ScrollReveal>
+            <header className="mb-2 space-y-2">
+              {post.published_at && (
+                <p className="text-xs text-slate-500 dark:text-slate-500">
+                  {new Date(post.published_at).toLocaleDateString(
+                    siteConfig.defaultLocale
+                  )}
+                </p>
+              )}
+              <h1 className="text-2xl font-bold leading-tight text-slate-900 sm:text-3xl dark:text-slate-50">
+                {post.title}
+              </h1>
+              {post.tags && (
+                <div className="flex flex-wrap gap-2 pt-1">
+                  {post.tags.map((t) => (
+                    <Link
+                      key={t}
+                      href={`/tags/${encodeURIComponent(
+                        t.toLowerCase().replace(/\s+/g, '-')
+                      )}`}
+                      className="rounded-full bg-accent-soft px-2 py-0.5 text-xs text-accent-textLight transition hover:bg-accent hover:text-white dark:bg-slate-800 dark:text-slate-100 dark:hover:bg-slate-700"
+                    >
+                      #{t}
+                    </Link>
+                  ))}
+                </div>
+              )}
+            </header>
+          </ScrollReveal>
+
+          <ScrollReveal>
+            <article className="prose prose-lg prose-slate max-w-none dark:prose-dark">
+              {post.feature_image && (
+                // feature_image is stored as "../assets/xyz", serve from "/assets/xyz"
+                // eslint-disable-next-line @next/next/no-img-element
+                <img
+                  src={post.feature_image.replace('../assets', '/assets')}
+                  alt={post.title}
+                  className="my-4 rounded"
+                />
+              )}
+              <div dangerouslySetInnerHTML={{ __html: post.body.html }} />
+            </article>
+          </ScrollReveal>
+
+          {relatedPosts.length > 0 && (
+            <ScrollReveal>
+              <section className="space-y-4 rounded-xl border border-slate-200 bg-white/80 p-4 shadow-sm dark:border-slate-800 dark:bg-slate-900/50">
+                <div className="flex items-center justify-between gap-2">
+                  <h2 className="text-base font-semibold text-slate-900 dark:text-slate-50">
+                    相關文章
+                  </h2>
+                  <p className="text-xs text-slate-500 dark:text-slate-400">
+                    為你挑選相似主題
+                  </p>
+                </div>
+                <div className="grid gap-4 md:grid-cols-2 lg:grid-cols-3">
+                  {relatedPosts.map((related) => (
+                    <PostCard key={related._id} post={related} />
+                  ))}
+                </div>
+              </section>
+            </ScrollReveal>
+          )}
         </div>
       </div>
     </>
diff --git a/components/post-list-with-controls.tsx b/components/post-list-with-controls.tsx
index c06f34b..cbdf231 100644
--- a/components/post-list-with-controls.tsx
+++ b/components/post-list-with-controls.tsx
@@ -1,6 +1,6 @@
 'use client';
 
-import { useMemo, useState } from 'react';
+import { useEffect, useMemo, useState } from 'react';
 import type { Post } from 'contentlayer/generated';
 import { siteConfig } from '@/lib/config';
 import { PostListItem } from './post-list-item';
@@ -15,11 +15,31 @@ type SortOrder = 'new' | 'old';
 export function PostListWithControls({ posts, pageSize }: Props) {
   const [sortOrder, setSortOrder] = useState<SortOrder>('new');
   const [page, setPage] = useState(1);
+  const [searchTerm, setSearchTerm] = useState('');
 
   const size = pageSize ?? siteConfig.postsPerPage ?? 5;
 
+  const normalizedQuery = searchTerm.trim().toLowerCase();
+
+  const filteredPosts = useMemo(() => {
+    if (!normalizedQuery) return posts;
+
+    return posts.filter((post) => {
+      const haystack = [
+        post.title,
+        post.description,
+        post.custom_excerpt,
+        post.tags?.join(' ')
+      ]
+        .filter(Boolean)
+        .join(' ')
+        .toLowerCase();
+      return haystack.includes(normalizedQuery);
+    });
+  }, [posts, normalizedQuery]);
+
   const sortedPosts = useMemo(() => {
-    const arr = [...posts];
+    const arr = [...filteredPosts];
     arr.sort((a, b) => {
       const aDate = a.published_at
         ? new Date(a.published_at).getTime()
@@ -30,13 +50,17 @@ export function PostListWithControls({ posts, pageSize }: Props) {
       return sortOrder === 'new' ? bDate - aDate : aDate - bDate;
     });
     return arr;
-  }, [posts, sortOrder]);
+  }, [filteredPosts, sortOrder]);
 
   const totalPages = Math.max(1, Math.ceil(sortedPosts.length / size));
   const currentPage = Math.min(page, totalPages);
   const start = (currentPage - 1) * size;
   const currentPosts = sortedPosts.slice(start, start + size);
 
+  useEffect(() => {
+    setPage(1);
+  }, [normalizedQuery]);
+
   const handleChangeSort = (order: SortOrder) => {
     setSortOrder(order);
     setPage(1);
@@ -49,7 +73,7 @@ export function PostListWithControls({ posts, pageSize }: Props) {
 
   return (
     <div className="space-y-4">
-      <div className="flex items-center justify-between gap-4 text-xs text-slate-500 dark:text-slate-400">
+      <div className="flex flex-col gap-4 text-xs text-slate-500 dark:text-slate-400 sm:flex-row sm:items-center sm:justify-between">
         <div className="flex items-center gap-2">
           <span>排序：</span>
           <button
@@ -75,18 +99,50 @@ export function PostListWithControls({ posts, pageSize }: Props) {
             舊到新
           </button>
         </div>
-        <div>
-          第 {currentPage} / {totalPages} 頁
+        <div className="flex w-full items-center gap-2 text-sm sm:w-auto">
+          <label htmlFor="post-search" className="text-xs">
+            搜尋：
+          </label>
+          <input
+            id="post-search"
+            type="search"
+            placeholder="輸入標題或標籤"
+            value={searchTerm}
+            onChange={(event) => setSearchTerm(event.target.value)}
+            className="w-full rounded-full border border-slate-200 bg-white px-3 py-1.5 text-sm text-slate-700 shadow-sm transition focus:border-blue-500 focus:outline-none focus:ring-2 focus:ring-blue-200 dark:border-slate-700 dark:bg-slate-900 dark:text-slate-100 dark:focus:ring-blue-500 sm:w-56"
+          />
         </div>
       </div>
 
-      <ul className="space-y-3">
-        {currentPosts.map((post) => (
-          <PostListItem key={post._id} post={post} />
-        ))}
-      </ul>
+      <div className="flex items-center justify-between text-xs text-slate-500 dark:text-slate-400">
+        <p>
+          第 {currentPage} / {totalPages} 頁 · 共 {sortedPosts.length} 篇
+          {normalizedQuery && `（搜尋「${searchTerm}」）`}
+        </p>
+        {normalizedQuery && sortedPosts.length === 0 && (
+          <button
+            type="button"
+            onClick={() => setSearchTerm('')}
+            className="text-blue-600 underline-offset-2 hover:underline dark:text-blue-400"
+          >
+            清除搜尋
+          </button>
+        )}
+      </div>
 
-      {totalPages > 1 && (
+      {currentPosts.length === 0 ? (
+        <div className="rounded-lg border border-dashed border-slate-200 p-6 text-center text-sm text-slate-500 dark:border-slate-700 dark:text-slate-400">
+          找不到符合關鍵字的文章，換個詞再試試？
+        </div>
+      ) : (
+        <ul className="space-y-3">
+          {currentPosts.map((post) => (
+            <PostListItem key={post._id} post={post} />
+          ))}
+        </ul>
+      )}
+
+      {totalPages > 1 && currentPosts.length > 0 && (
         <nav className="flex items-center justify-center gap-3 text-xs text-slate-600 dark:text-slate-300">
           <button
             type="button"
@@ -129,4 +185,3 @@ export function PostListWithControls({ posts, pageSize }: Props) {
     </div>
   );
 }
-
diff --git a/lib/posts.ts b/lib/posts.ts
index d9c26db..e3eeda7 100644
--- a/lib/posts.ts
+++ b/lib/posts.ts
@@ -47,3 +47,43 @@ export function getAllTagsWithCount(): { tag: string; slug: string; count: numbe
       return b.count - a.count;
     });
 }
+
+export function getRelatedPosts(target: Post, limit = 3): Post[] {
+  const targetTags = new Set(target.tags?.map((tag) => tag.toLowerCase()) ?? []);
+  const candidates = getAllPostsSorted().filter((post) => post._id !== target._id);
+
+  if (candidates.length === 0) return [];
+
+  const scored = candidates
+    .map((post) => {
+      const sharedTags = (post.tags ?? []).reduce((acc, tag) => {
+        return acc + (targetTags.has(tag.toLowerCase()) ? 1 : 0);
+      }, 0);
+      return { post, score: sharedTags };
+    })
+    .filter((entry) => entry.score > 0)
+    .sort((a, b) => {
+      if (b.score === a.score) {
+        const aDate = a.post.published_at
+          ? new Date(a.post.published_at).getTime()
+          : 0;
+        const bDate = b.post.published_at
+          ? new Date(b.post.published_at).getTime()
+          : 0;
+        return bDate - aDate;
+      }
+      return b.score - a.score;
+    })
+    .slice(0, limit)
+    .map((entry) => entry.post);
+
+  if (scored.length >= limit) {
+    return scored;
+  }
+
+  const fallback = candidates.filter(
+    (post) => !scored.some((existing) => existing._id === post._id)
+  );
+
+  return [...scored, ...fallback.slice(0, limit - scored.length)].slice(0, limit);
+}