diff --git a/frontend/site/src/components/SiteNav.astro b/frontend/site/src/components/SiteNav.astro
index f0c93d4..05d4b4f 100644
--- a/frontend/site/src/components/SiteNav.astro
+++ b/frontend/site/src/components/SiteNav.astro
@@ -3,6 +3,7 @@ const links = [
   { href: '/', label: '首页' },
   { href: '/archive/', label: '归档' },
   { href: '/tags/', label: '标签' },
+  { href: '/site-map/', label: '站点地图' },
   { href: '/rss.xml', label: 'RSS' }
 ];
 ---
diff --git a/frontend/site/src/components/seo/SeoHead.astro b/frontend/site/src/components/seo/SeoHead.astro
new file mode 100644
index 0000000..ae5b21f
--- /dev/null
+++ b/frontend/site/src/components/seo/SeoHead.astro
@@ -0,0 +1,57 @@
+---
+import { site } from '../../lib/siteConfig';
+import { absoluteUrl } from '../../lib/seo';
+
+type JsonLd = Record<string, unknown> | Record<string, unknown>[];
+
+type Props = {
+  title?: string;
+  description?: string;
+  path?: string;
+  type?: 'website' | 'article';
+  publishedTime?: string;
+  modifiedTime?: string;
+  tags?: string[];
+  jsonLd?: JsonLd;
+};
+
+const {
+  title = site.title,
+  description = site.description,
+  path = '/',
+  type = 'website',
+  publishedTime,
+  modifiedTime,
+  tags = [],
+  jsonLd
+} = Astro.props;
+
+const pageTitle = title === site.title ? site.title : `${title} | ${site.title}`;
+const canonicalUrl = absoluteUrl(path);
+const rssUrl = absoluteUrl('/rss.xml');
+---
+
+<meta charset="utf-8" />
+<meta name="viewport" content="width=device-width" />
+<title>{pageTitle}</title>
+<meta name="description" content={description} />
+<meta name="robots" content="index,follow,max-image-preview:large,max-snippet:-1,max-video-preview:-1" />
+<link rel="canonical" href={canonicalUrl} />
+<link rel="alternate" type="application/rss+xml" title={`${site.title} RSS`} href={rssUrl} />
+<meta property="og:site_name" content={site.title} />
+<meta property="og:title" content={pageTitle} />
+<meta property="og:description" content={description} />
+<meta property="og:type" content={type} />
+<meta property="og:url" content={canonicalUrl} />
+<meta property="og:locale" content={site.language.replace('-', '_')} />
+<meta name="twitter:card" content="summary" />
+<meta name="twitter:title" content={pageTitle} />
+<meta name="twitter:description" content={description} />
+{publishedTime && <meta property="article:published_time" content={publishedTime} />}
+{modifiedTime && <meta property="article:modified_time" content={modifiedTime} />}
+{tags.map((tag) => <meta property="article:tag" content={tag} />)}
+{
+  jsonLd && (
+    <script type="application/ld+json" set:html={JSON.stringify(jsonLd)} />
+  )
+}
diff --git a/frontend/site/src/lib/seo.ts b/frontend/site/src/lib/seo.ts
new file mode 100644
index 0000000..f67a8f3
--- /dev/null
+++ b/frontend/site/src/lib/seo.ts
@@ -0,0 +1,21 @@
+import { site } from './siteConfig';
+import type { Post } from './posts';
+
+export function absoluteUrl(path = '/'): string {
+  const base = site.base_url.replace(/\/+$/, '');
+  const normalizedPath = path.startsWith('/') ? path : `/${path}`;
+  return `${base}${normalizedPath}`;
+}
+
+export function postUpdatedAt(post: Pick<Post, 'updated_at' | 'published_at' | 'created_at' | 'date'>): string {
+  return post.updated_at ?? post.published_at ?? post.created_at ?? post.date ?? '';
+}
+
+export function xmlEscape(value: string): string {
+  return value
+    .replace(/&/g, '&amp;')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&apos;');
+}
diff --git a/frontend/site/src/lib/siteConfig.ts b/frontend/site/src/lib/siteConfig.ts
index 12cf393..ea147b2 100644
--- a/frontend/site/src/lib/siteConfig.ts
+++ b/frontend/site/src/lib/siteConfig.ts
@@ -47,14 +47,26 @@ function loadSiteConfig(): SiteConfig {
   try {
     const file = readFileSync(resolve(siteRoot, 'config/site.yaml'), 'utf8');
     const parsed = YAML.parse(file) ?? {};
+    const siteOverrides = {
+      ...parsed.site,
+      ...(process.env.SITE_URL ? { base_url: process.env.SITE_URL } : {}),
+      ...(process.env.PUBLIC_SITE_URL ? { base_url: process.env.PUBLIC_SITE_URL } : {})
+    };
 
     return {
-      site: { ...defaults.site, ...parsed.site },
+      site: { ...defaults.site, ...siteOverrides },
       content: { ...defaults.content, ...parsed.content },
       build: { ...defaults.build, ...parsed.build }
     };
   } catch {
-    return defaults;
+    return {
+      ...defaults,
+      site: {
+        ...defaults.site,
+        ...(process.env.SITE_URL ? { base_url: process.env.SITE_URL } : {}),
+        ...(process.env.PUBLIC_SITE_URL ? { base_url: process.env.PUBLIC_SITE_URL } : {})
+      }
+    };
   }
 }
 
diff --git a/frontend/site/src/pages/archive/index.astro b/frontend/site/src/pages/archive/index.astro
index bc0ecd1..127d3af 100644
--- a/frontend/site/src/pages/archive/index.astro
+++ b/frontend/site/src/pages/archive/index.astro
@@ -2,21 +2,20 @@
 import '../../styles/normalize.css';
 import DefaultArchive from '../../components/DefaultArchive.astro';
 import YarArchive from '../../components/themes/yar/YarArchive.astro';
+import SeoHead from '../../components/seo/SeoHead.astro';
 import { site } from '../../lib/siteConfig';
 import { getArchiveYears } from '../../lib/posts';
 
 const archiveYears = getArchiveYears();
 const theme = site.theme?.trim().toLowerCase() ?? 'default';
 const ArchiveView = theme === 'yar' ? YarArchive : DefaultArchive;
+const description = `${site.title} 的文章归档`;
 ---
 
 <!doctype html>
 <html lang={site.language}>
   <head>
-    <meta charset="utf-8" />
-    <meta name="viewport" content="width=device-width" />
-    <title>Archive | {site.title}</title>
-    <meta name="description" content={`Archive of ${site.title}`} />
+    <SeoHead title="归档" description={description} path="/archive/" />
   </head>
   <body>
     <ArchiveView archiveYears={archiveYears} />
diff --git a/frontend/site/src/pages/index.astro b/frontend/site/src/pages/index.astro
index 3186872..81c94a6 100644
--- a/frontend/site/src/pages/index.astro
+++ b/frontend/site/src/pages/index.astro
@@ -2,23 +2,30 @@
 import '../styles/normalize.css';
 import DefaultHome from '../components/DefaultHome.astro';
 import YarHome from '../components/themes/yar/YarHome.astro';
+import SeoHead from '../components/seo/SeoHead.astro';
 import { site } from '../lib/siteConfig';
 import { getPaginatedPosts, getPublishedPosts, getTotalPages } from '../lib/posts';
+import { absoluteUrl } from '../lib/seo';
 
 const allPosts = getPublishedPosts();
 const posts = getPaginatedPosts(allPosts, 1);
 const totalPages = getTotalPages(allPosts);
 const theme = site.theme?.trim().toLowerCase() ?? 'default';
 const Home = theme === 'yar' ? YarHome : DefaultHome;
+const jsonLd = {
+  '@context': 'https://schema.org',
+  '@type': 'Blog',
+  name: site.title,
+  description: site.description,
+  url: absoluteUrl('/'),
+  inLanguage: site.language
+};
 ---
 
 <!doctype html>
 <html lang={site.language}>
   <head>
-    <meta charset="utf-8" />
-    <meta name="viewport" content="width=device-width" />
-    <title>{site.title}</title>
-    <meta name="description" content={site.description} />
+    <SeoHead title={site.title} description={site.description} path="/" jsonLd={jsonLd} />
   </head>
   <body>
     <Home posts={posts} currentPage={1} totalPages={totalPages} />
diff --git a/frontend/site/src/pages/page/[page].astro b/frontend/site/src/pages/page/[page].astro
index 91d4101..40070f1 100644
--- a/frontend/site/src/pages/page/[page].astro
+++ b/frontend/site/src/pages/page/[page].astro
@@ -2,6 +2,7 @@
 import '../../styles/normalize.css';
 import DefaultHome from '../../components/DefaultHome.astro';
 import YarHome from '../../components/themes/yar/YarHome.astro';
+import SeoHead from '../../components/seo/SeoHead.astro';
 import { site } from '../../lib/siteConfig';
 import { getPaginatedPosts, getPublishedPosts, getTotalPages } from '../../lib/posts';
 
@@ -24,15 +25,14 @@ const posts = getPaginatedPosts(allPosts, page);
 const totalPages = getTotalPages(allPosts);
 const theme = site.theme?.trim().toLowerCase() ?? 'default';
 const Home = theme === 'yar' ? YarHome : DefaultHome;
+const title = `第 ${page} 页`;
+const description = `${site.title} 的第 ${page} 页文章列表`;
 ---
 
 <!doctype html>
 <html lang={site.language}>
   <head>
-    <meta charset="utf-8" />
-    <meta name="viewport" content="width=device-width" />
-    <title>第 {page} 页 | {site.title}</title>
-    <meta name="description" content={site.description} />
+    <SeoHead title={title} description={description} path={`/page/${page}/`} />
   </head>
   <body>
     <Home posts={posts} currentPage={page} totalPages={totalPages} />
diff --git a/frontend/site/src/pages/posts/[slug].astro b/frontend/site/src/pages/posts/[slug].astro
index eb8b7bf..ba59a19 100644
--- a/frontend/site/src/pages/posts/[slug].astro
+++ b/frontend/site/src/pages/posts/[slug].astro
@@ -2,7 +2,9 @@
 import '../../styles/normalize.css';
 import DefaultPost from '../../components/DefaultPost.astro';
 import YarPost from '../../components/themes/yar/YarPost.astro';
+import SeoHead from '../../components/seo/SeoHead.astro';
 import { site } from '../../lib/siteConfig';
+import { absoluteUrl } from '../../lib/seo';
 
 export function getStaticPaths() {
   const modules = import.meta.glob('../../../../../content/posts/*.md', { eager: true });
@@ -18,15 +20,46 @@ const { post } = Astro.props;
 const title = post.frontmatter.title;
 const theme = site.theme?.trim().toLowerCase() ?? 'default';
 const PostView = theme === 'yar' ? YarPost : DefaultPost;
+const description = post.frontmatter.summary ?? site.description;
+const publishedTime = post.frontmatter.published_at ?? post.frontmatter.created_at;
+const modifiedTime = post.frontmatter.updated_at ?? publishedTime;
+const postUrl = `/posts/${post.frontmatter.slug}/`;
+const tags = post.frontmatter.tags ?? [];
+const jsonLd = {
+  '@context': 'https://schema.org',
+  '@type': 'BlogPosting',
+  headline: title,
+  description,
+  datePublished: publishedTime,
+  dateModified: modifiedTime,
+  url: absoluteUrl(postUrl),
+  mainEntityOfPage: absoluteUrl(postUrl),
+  inLanguage: site.language,
+  author: {
+    '@type': 'Person',
+    name: site.title
+  },
+  publisher: {
+    '@type': 'Organization',
+    name: site.title
+  },
+  ...(tags.length > 0 ? { keywords: tags.join(', ') } : {})
+};
 ---
 
 <!doctype html>
 <html lang={site.language}>
   <head>
-    <meta charset="utf-8" />
-    <meta name="viewport" content="width=device-width" />
-    <title>{title} | {site.title}</title>
-    {post.frontmatter.summary && <meta name="description" content={post.frontmatter.summary} />}
+    <SeoHead
+      title={title}
+      description={description}
+      path={postUrl}
+      type="article"
+      publishedTime={publishedTime}
+      modifiedTime={modifiedTime}
+      tags={tags}
+      jsonLd={jsonLd}
+    />
   </head>
   <body>
     <PostView post={post} />
diff --git a/frontend/site/src/pages/robots.txt.ts b/frontend/site/src/pages/robots.txt.ts
new file mode 100644
index 0000000..cbcf78e
--- /dev/null
+++ b/frontend/site/src/pages/robots.txt.ts
@@ -0,0 +1,14 @@
+import { absoluteUrl } from '../lib/seo';
+
+export function GET() {
+  return new Response(`User-agent: *
+Allow: /
+
+Sitemap: ${absoluteUrl('/sitemap.xml')}
+`, {
+    headers: {
+      'Content-Type': 'text/plain; charset=utf-8',
+      'Cache-Control': 'public, max-age=3600'
+    }
+  });
+}
diff --git a/frontend/site/src/pages/rss.xml.ts b/frontend/site/src/pages/rss.xml.ts
index 0ba5ef2..6a9a483 100644
--- a/frontend/site/src/pages/rss.xml.ts
+++ b/frontend/site/src/pages/rss.xml.ts
@@ -1,6 +1,7 @@
 import rss from '@astrojs/rss';
 import { getPublishedPosts } from '../lib/posts';
 import { site } from '../lib/siteConfig';
+import { absoluteUrl } from '../lib/seo';
 
 export function GET() {
   return rss({
@@ -10,7 +11,7 @@ export function GET() {
     items: getPublishedPosts().map((post) => ({
       title: post.title,
       description: post.summary ?? '',
-      link: post.url,
+      link: absoluteUrl(post.url),
       pubDate: post.date ? new Date(post.date) : undefined,
       categories: post.tags
     }))
diff --git a/frontend/site/src/pages/site-map.astro b/frontend/site/src/pages/site-map.astro
new file mode 100644
index 0000000..03a2759
--- /dev/null
+++ b/frontend/site/src/pages/site-map.astro
@@ -0,0 +1,150 @@
+---
+import '../styles/normalize.css';
+import SiteNav from '../components/SiteNav.astro';
+import SeoHead from '../components/seo/SeoHead.astro';
+import { site } from '../lib/siteConfig';
+import { getArchiveYears, getTagSummaries } from '../lib/posts';
+
+const archiveYears = getArchiveYears();
+const tags = getTagSummaries();
+const description = `${site.title} 的文章、归档和标签站点地图`;
+---
+
+<!doctype html>
+<html lang={site.language}>
+  <head>
+    <SeoHead title="站点地图" description={description} path="/site-map/" />
+  </head>
+  <body>
+    <main class="site-map">
+      <SiteNav />
+      <header>
+        <h1>站点地图</h1>
+        <p>{description}</p>
+      </header>
+
+      <section aria-labelledby="main-pages">
+        <h2 id="main-pages">主要页面</h2>
+        <ul>
+          <li><a href="/">首页</a></li>
+          <li><a href="/archive/">归档</a></li>
+          <li><a href="/tags/">标签</a></li>
+          <li><a href="/rss.xml">RSS</a></li>
+          <li><a href="/sitemap.xml">XML Sitemap</a></li>
+        </ul>
+      </section>
+
+      {tags.length > 0 && (
+        <section aria-labelledby="tag-pages">
+          <h2 id="tag-pages">标签</h2>
+          <ul class="columns">
+            {tags.map((tag) => (
+              <li><a href={`/tags/${tag.slug}/`}>{tag.name}</a> <span>({tag.count})</span></li>
+            ))}
+          </ul>
+        </section>
+      )}
+
+      <section aria-labelledby="post-pages">
+        <h2 id="post-pages">文章</h2>
+        {archiveYears.map((year) => (
+          <div class="year-group">
+            <h3>{year.year}</h3>
+            <ul>
+              {year.posts.map((post) => (
+                <li>
+                  <a href={post.url}>{post.title}</a>
+                  {post.date && <time datetime={post.date}>{new Date(post.date).toLocaleDateString(site.language)}</time>}
+                </li>
+              ))}
+            </ul>
+          </div>
+        ))}
+      </section>
+    </main>
+  </body>
+</html>
+
+<style>
+  .site-map {
+    width: min(860px, calc(100% - 32px));
+    margin: 0 auto;
+    padding: 48px 0 80px;
+    color: #20201d;
+    font-family:
+      Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
+      sans-serif;
+  }
+
+  .site-map :global(.site-nav) {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px 18px;
+    margin-bottom: 36px;
+    color: #625a50;
+    font-size: 0.95rem;
+  }
+
+  a {
+    color: inherit;
+    text-underline-offset: 4px;
+  }
+
+  header {
+    border-bottom: 1px solid #d8d1c3;
+    margin-bottom: 32px;
+    padding-bottom: 24px;
+  }
+
+  h1 {
+    margin: 0 0 12px;
+    font-size: 2.5rem;
+    line-height: 1.1;
+  }
+
+  h2 {
+    margin: 32px 0 12px;
+    font-size: 1.35rem;
+  }
+
+  h3 {
+    margin: 20px 0 8px;
+    color: #625a50;
+    font-size: 1rem;
+  }
+
+  p {
+    margin: 0;
+    color: #5b554d;
+    line-height: 1.7;
+  }
+
+  ul {
+    display: grid;
+    gap: 10px;
+    margin: 0;
+    padding-left: 1.2rem;
+  }
+
+  .columns {
+    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
+  }
+
+  li {
+    line-height: 1.6;
+  }
+
+  time,
+  span {
+    color: #766e63;
+    font-size: 0.9rem;
+  }
+
+  time {
+    margin-left: 10px;
+  }
+
+  .year-group + .year-group {
+    margin-top: 16px;
+  }
+</style>
diff --git a/frontend/site/src/pages/sitemap.xml.ts b/frontend/site/src/pages/sitemap.xml.ts
new file mode 100644
index 0000000..df2e9e8
--- /dev/null
+++ b/frontend/site/src/pages/sitemap.xml.ts
@@ -0,0 +1,73 @@
+import { getPublishedPosts, getTagSummaries, getTotalPages } from '../lib/posts';
+import { absoluteUrl, postUpdatedAt, xmlEscape } from '../lib/seo';
+import { site } from '../lib/siteConfig';
+
+type SitemapEntry = {
+  path: string;
+  lastmod?: string;
+  changefreq?: 'daily' | 'weekly' | 'monthly' | 'yearly';
+  priority?: string;
+};
+
+function formatLastmod(value?: string): string | undefined {
+  if (!value) {
+    return undefined;
+  }
+
+  const date = new Date(value);
+  if (Number.isNaN(date.getTime())) {
+    return undefined;
+  }
+
+  return date.toISOString();
+}
+
+export function GET() {
+  const posts = getPublishedPosts();
+  const latestPostDate = posts.map(postUpdatedAt).sort().at(-1);
+  const entries: SitemapEntry[] = [
+    { path: '/', lastmod: latestPostDate, changefreq: 'daily', priority: '1.0' },
+    { path: '/archive/', lastmod: latestPostDate, changefreq: 'weekly', priority: '0.7' },
+    { path: '/tags/', lastmod: latestPostDate, changefreq: 'weekly', priority: '0.6' },
+    { path: '/site-map/', lastmod: latestPostDate, changefreq: 'weekly', priority: '0.5' },
+    ...Array.from({ length: Math.max(0, getTotalPages(posts) - 1) }, (_, index) => ({
+      path: `/page/${index + 2}/`,
+      lastmod: latestPostDate,
+      changefreq: 'weekly' as const,
+      priority: '0.6'
+    })),
+    ...getTagSummaries().map((tag) => ({
+      path: `/tags/${tag.slug}/`,
+      lastmod: latestPostDate,
+      changefreq: 'weekly' as const,
+      priority: '0.5'
+    })),
+    ...posts.map((post) => ({
+      path: post.url,
+      lastmod: postUpdatedAt(post),
+      changefreq: 'monthly' as const,
+      priority: '0.8'
+    }))
+  ];
+
+  const body = `<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+${entries
+  .map((entry) => {
+    const lastmod = formatLastmod(entry.lastmod);
+    return `  <url>
+    <loc>${xmlEscape(absoluteUrl(entry.path))}</loc>${lastmod ? `\n    <lastmod>${lastmod}</lastmod>` : ''}
+    <changefreq>${entry.changefreq ?? 'weekly'}</changefreq>
+    <priority>${entry.priority ?? '0.5'}</priority>
+  </url>`;
+  })
+  .join('\n')}
+</urlset>`;
+
+  return new Response(body, {
+    headers: {
+      'Content-Type': 'application/xml; charset=utf-8',
+      'Cache-Control': 'public, max-age=3600'
+    }
+  });
+}
diff --git a/frontend/site/src/pages/tags/[tag].astro b/frontend/site/src/pages/tags/[tag].astro
index 9c547c0..6e38870 100644
--- a/frontend/site/src/pages/tags/[tag].astro
+++ b/frontend/site/src/pages/tags/[tag].astro
@@ -2,6 +2,7 @@
 import '../../styles/normalize.css';
 import DefaultTagPosts from '../../components/DefaultTagPosts.astro';
 import YarTagPosts from '../../components/themes/yar/YarTagPosts.astro';
+import SeoHead from '../../components/seo/SeoHead.astro';
 import { site } from '../../lib/siteConfig';
 import { getPostsByTag, getTagSummaries } from '../../lib/posts';
 
@@ -16,15 +17,13 @@ const { tag } = Astro.props;
 const posts = getPostsByTag(tag.slug);
 const theme = site.theme?.trim().toLowerCase() ?? 'default';
 const TagPostsView = theme === 'yar' ? YarTagPosts : DefaultTagPosts;
+const description = `${site.title} 中带有「${tag.name}」标签的文章`;
 ---
 
 <!doctype html>
 <html lang={site.language}>
   <head>
-    <meta charset="utf-8" />
-    <meta name="viewport" content="width=device-width" />
-    <title>{tag.name} | {site.title}</title>
-    <meta name="description" content={`Posts tagged ${tag.name}`} />
+    <SeoHead title={tag.name} description={description} path={`/tags/${tag.slug}/`} />
   </head>
   <body>
     <TagPostsView tag={tag} posts={posts} />
diff --git a/frontend/site/src/pages/tags/index.astro b/frontend/site/src/pages/tags/index.astro
index 3557cd8..0729cb5 100644
--- a/frontend/site/src/pages/tags/index.astro
+++ b/frontend/site/src/pages/tags/index.astro
@@ -2,21 +2,20 @@
 import '../../styles/normalize.css';
 import DefaultTags from '../../components/DefaultTags.astro';
 import YarTags from '../../components/themes/yar/YarTags.astro';
+import SeoHead from '../../components/seo/SeoHead.astro';
 import { site } from '../../lib/siteConfig';
 import { getTagSummaries } from '../../lib/posts';
 
 const tags = getTagSummaries();
 const theme = site.theme?.trim().toLowerCase() ?? 'default';
 const TagsView = theme === 'yar' ? YarTags : DefaultTags;
+const description = `${site.title} 的全部文章标签`;
 ---
 
 <!doctype html>
 <html lang={site.language}>
   <head>
-    <meta charset="utf-8" />
-    <meta name="viewport" content="width=device-width" />
-    <title>Tags | {site.title}</title>
-    <meta name="description" content={`Tags on ${site.title}`} />
+    <SeoHead title="标签" description={description} path="/tags/" />
   </head>
   <body>
     <TagsView tags={tags} />