diff --git a/.theme/assets/styles/theme.css b/.theme/assets/styles/theme.css
new file mode 100644
index 0000000..3e23ae7
--- /dev/null
+++ b/.theme/assets/styles/theme.css
@@ -0,0 +1,502 @@
+:root {
+  color-scheme: dark;
+  --bg: #111314;
+  --surface: #191c1d;
+  --surface-raised: #202425;
+  --text: #f1eee6;
+  --muted: #aaa99f;
+  --line: #34393a;
+  --accent: #d9a75c;
+  --accent-strong: #f2c57d;
+  --focus: #8fd3ff;
+  --max-width: 72rem;
+  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
+  font-synthesis: none;
+}
+
+* {
+  box-sizing: border-box;
+}
+
+html {
+  scroll-behavior: smooth;
+}
+
+body {
+  margin: 0;
+  background:
+    radial-gradient(circle at 10% 0%, rgb(217 167 92 / 10%), transparent 28rem),
+    var(--bg);
+  color: var(--text);
+  font-size: 1rem;
+  line-height: 1.65;
+}
+
+a {
+  color: var(--accent-strong);
+  text-underline-offset: 0.2em;
+  text-decoration-thickness: 0.08em;
+}
+
+a:hover {
+  color: #ffe1ad;
+}
+
+:focus-visible {
+  outline: 0.2rem solid var(--focus);
+  outline-offset: 0.2rem;
+}
+
+.shell {
+  width: min(calc(100% - 2rem), var(--max-width));
+  margin-inline: auto;
+}
+
+.skip-link {
+  position: fixed;
+  z-index: 10;
+  top: 0.75rem;
+  left: 0.75rem;
+  padding: 0.65rem 0.9rem;
+  transform: translateY(-160%);
+  border-radius: 0.35rem;
+  background: var(--text);
+  color: var(--bg);
+}
+
+.skip-link:focus {
+  transform: translateY(0);
+}
+
+.site-header {
+  border-bottom: 1px solid var(--line);
+  background: rgb(17 19 20 / 88%);
+}
+
+.header-inner {
+  min-height: 4.75rem;
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 1.5rem;
+}
+
+.brand {
+  display: inline-flex;
+  align-items: center;
+  gap: 0.7rem;
+  color: var(--text);
+  font-weight: 750;
+  letter-spacing: -0.02em;
+  text-decoration: none;
+}
+
+.brand-mark {
+  width: 2rem;
+  height: 2rem;
+  display: grid;
+  place-items: center;
+  border: 1px solid var(--accent);
+  border-radius: 50%;
+  color: var(--accent-strong);
+  font-family: Georgia, "Times New Roman", serif;
+  font-style: italic;
+}
+
+.site-nav {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.25rem;
+}
+
+.site-nav a {
+  padding: 0.45rem 0.7rem;
+  border-radius: 0.35rem;
+  color: var(--muted);
+  font-size: 0.9rem;
+  font-weight: 650;
+  text-decoration: none;
+}
+
+.site-nav a:hover,
+.site-nav a[aria-current="page"] {
+  background: var(--surface-raised);
+  color: var(--text);
+}
+
+main.shell {
+  min-height: 68vh;
+  padding-block: clamp(3.5rem, 8vw, 7rem);
+}
+
+h1,
+h2,
+h3 {
+  margin-top: 0;
+  font-family: Georgia, "Times New Roman", serif;
+  font-weight: 500;
+  line-height: 1.08;
+  letter-spacing: -0.035em;
+}
+
+h1 {
+  max-width: 13ch;
+  margin-bottom: 1.25rem;
+  font-size: clamp(3rem, 9vw, 6.5rem);
+}
+
+h2 {
+  font-size: clamp(2rem, 5vw, 3.25rem);
+}
+
+h3 {
+  font-size: 1.5rem;
+}
+
+.eyebrow,
+.card-kind,
+.content-meta,
+.footer-meta {
+  color: var(--accent);
+  font-family: ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
+  font-size: 0.78rem;
+  font-weight: 700;
+  letter-spacing: 0.12em;
+  text-transform: uppercase;
+}
+
+.hero {
+  max-width: 62rem;
+}
+
+.hero h1 {
+  max-width: 11ch;
+}
+
+.hero-summary,
+.lede {
+  max-width: 48rem;
+  color: #d2d0c8;
+  font-size: clamp(1.2rem, 2.5vw, 1.55rem);
+  line-height: 1.5;
+}
+
+.hero-copy {
+  margin-top: 3rem;
+}
+
+.section-block,
+.listing {
+  margin-top: clamp(4rem, 9vw, 7rem);
+  padding-top: 2rem;
+  border-top: 1px solid var(--line);
+}
+
+.section-heading {
+  margin-bottom: 2rem;
+}
+
+.section-heading h2 {
+  margin-bottom: 0;
+}
+
+.card-grid {
+  display: grid;
+  grid-template-columns: repeat(2, minmax(0, 1fr));
+  gap: 1rem;
+}
+
+.card {
+  min-height: 18rem;
+  display: flex;
+  flex-direction: column;
+  padding: clamp(1.35rem, 3vw, 2rem);
+  border: 1px solid var(--line);
+  border-radius: 0.75rem;
+  background: linear-gradient(145deg, var(--surface-raised), var(--surface));
+}
+
+.card h2,
+.card h3 {
+  margin-bottom: 0.8rem;
+}
+
+.card h2 a,
+.card h3 a,
+.listing-item h2 a {
+  color: var(--text);
+  text-decoration: none;
+}
+
+.card p:not(.card-kind) {
+  color: var(--muted);
+}
+
+.card .text-link {
+  margin-top: auto;
+  padding-top: 1.5rem;
+}
+
+.text-link {
+  width: fit-content;
+  font-weight: 750;
+  text-decoration: none;
+}
+
+.page-intro,
+.content-header {
+  margin-bottom: clamp(3rem, 8vw, 5.5rem);
+}
+
+.page-intro h1,
+.content-header h1 {
+  font-size: clamp(3rem, 8vw, 5.5rem);
+}
+
+.listing {
+  display: grid;
+}
+
+.listing-item {
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) auto;
+  align-items: end;
+  gap: 2rem;
+  padding-block: 2rem;
+  border-bottom: 1px solid var(--line);
+}
+
+.listing-item h2 {
+  margin-bottom: 0.6rem;
+  font-size: clamp(1.75rem, 4vw, 2.5rem);
+}
+
+.listing-item p {
+  max-width: 46rem;
+  margin-bottom: 0;
+  color: var(--muted);
+}
+
+.content-page {
+  max-width: 56rem;
+}
+
+.prose {
+  max-width: 46rem;
+  color: #d5d3cb;
+  font-size: 1.05rem;
+}
+
+.prose > * + * {
+  margin-top: 1.35em;
+}
+
+.prose h2,
+.prose h3 {
+  margin-top: 2em;
+  color: var(--text);
+}
+
+.prose h2 {
+  font-size: 2rem;
+}
+
+.prose h3 {
+  font-size: 1.4rem;
+}
+
+.prose code {
+  padding: 0.12em 0.32em;
+  border: 1px solid var(--line);
+  border-radius: 0.25rem;
+  background: var(--surface);
+  font-family: ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
+  font-size: 0.9em;
+}
+
+.prose pre {
+  overflow-x: auto;
+  padding: 1.25rem;
+  border: 1px solid var(--line);
+  border-radius: 0.5rem;
+  background: #0b0d0e;
+}
+
+.prose pre code {
+  padding: 0;
+  border: 0;
+  background: none;
+}
+
+.prose blockquote {
+  margin-inline: 0;
+  padding-left: 1.25rem;
+  border-left: 0.2rem solid var(--accent);
+  color: var(--muted);
+}
+
+.project-facts {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 1rem;
+  margin-top: 2rem;
+}
+
+.project-facts div {
+  min-width: 9rem;
+  padding: 0.8rem 1rem;
+  border: 1px solid var(--line);
+  border-radius: 0.5rem;
+  background: var(--surface);
+}
+
+.project-facts dt {
+  color: var(--muted);
+  font-size: 0.75rem;
+  font-weight: 700;
+  text-transform: uppercase;
+}
+
+.project-facts dd {
+  margin: 0.2rem 0 0;
+}
+
+.tag-list {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.5rem;
+  margin: 1.5rem 0 0;
+  padding: 0;
+  list-style: none;
+}
+
+.tag-list li {
+  padding: 0.32rem 0.6rem;
+  border: 1px solid var(--line);
+  border-radius: 999px;
+  color: var(--muted);
+  font-size: 0.82rem;
+}
+
+.content-tags {
+  margin-top: 3rem;
+  padding-top: 1.5rem;
+  border-top: 1px solid var(--line);
+}
+
+.button-link {
+  display: inline-block;
+  margin-top: 1.5rem;
+  padding: 0.75rem 1rem;
+  border: 1px solid var(--accent);
+  border-radius: 0.4rem;
+  text-decoration: none;
+}
+
+.error-page {
+  max-width: 48rem;
+}
+
+.error-page p:not(.eyebrow) {
+  color: var(--muted);
+  font-size: 1.2rem;
+}
+
+.empty-state {
+  color: var(--muted);
+}
+
+.site-footer {
+  padding-block: 2.5rem;
+  border-top: 1px solid var(--line);
+  color: var(--muted);
+}
+
+.footer-inner {
+  display: flex;
+  justify-content: space-between;
+  gap: 2rem;
+}
+
+.footer-inner p {
+  margin: 0;
+}
+
+.visually-hidden {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  padding: 0;
+  overflow: hidden;
+  clip: rect(0, 0, 0, 0);
+  white-space: nowrap;
+  border: 0;
+}
+
+@media (max-width: 44rem) {
+  .header-inner,
+  .footer-inner {
+    align-items: flex-start;
+    flex-direction: column;
+  }
+
+  .header-inner {
+    padding-block: 1rem;
+  }
+
+  .card-grid {
+    grid-template-columns: 1fr;
+  }
+
+  .listing-item {
+    grid-template-columns: 1fr;
+    align-items: start;
+    gap: 1rem;
+  }
+}
+
+@media (prefers-reduced-motion: reduce) {
+  html {
+    scroll-behavior: auto;
+  }
+}
+
+@media (prefers-color-scheme: light) {
+  :root {
+    color-scheme: light;
+    --bg: #f4f0e7;
+    --surface: #ebe5da;
+    --surface-raised: #fffaf0;
+    --text: #202323;
+    --muted: #5f625f;
+    --line: #cbc4b7;
+    --accent: #87591b;
+    --accent-strong: #704713;
+    --focus: #075b9b;
+  }
+
+  body {
+    background:
+      radial-gradient(circle at 10% 0%, rgb(135 89 27 / 11%), transparent 28rem),
+      var(--bg);
+  }
+
+  a:hover {
+    color: #4e2d04;
+  }
+
+  .site-header {
+    background: rgb(244 240 231 / 90%);
+  }
+
+  .hero-summary,
+  .lede,
+  .prose {
+    color: #3d413f;
+  }
+
+  .prose pre {
+    background: #242728;
+    color: #f7f3eb;
+  }
+}
diff --git a/.theme/templates/404.liquid b/.theme/templates/404.liquid
new file mode 100644
index 0000000..030c63f
--- /dev/null
+++ b/.theme/templates/404.liquid
@@ -0,0 +1,6 @@
+<section class="error-page">
+  <p class="eyebrow">Error 404</p>
+  <h1>That route does not exist.</h1>
+  <p>The page may have moved, or the address may be incomplete.</p>
+  <a class="button-link" href="/">Return home</a>
+</section>
diff --git a/.theme/templates/content/article.liquid b/.theme/templates/content/article.liquid
new file mode 100644
index 0000000..23debe5
--- /dev/null
+++ b/.theme/templates/content/article.liquid
@@ -0,0 +1,25 @@
+<article class="content-page">
+  <header class="content-header">
+    <p class="eyebrow">Article</p>
+    <h1>{{ page.title }}</h1>
+    {% if page.summary %}
+      <p class="lede">{{ page.summary }}</p>
+    {% endif %}
+    {% if page.published %}
+      <p class="content-meta">Published {{ page.published }}</p>
+    {% endif %}
+  </header>
+  <div class="prose">
+    {{ page.renderedContent | safe_content }}
+  </div>
+  {% if page.tags.size > 0 %}
+    <footer class="content-tags">
+      <p class="visually-hidden">Topics</p>
+      <ul class="tag-list">
+        {% for tag in page.tags %}
+          <li>{{ tag }}</li>
+        {% endfor %}
+      </ul>
+    </footer>
+  {% endif %}
+</article>
diff --git a/.theme/templates/content/page.liquid b/.theme/templates/content/page.liquid
new file mode 100644
index 0000000..222750b
--- /dev/null
+++ b/.theme/templates/content/page.liquid
@@ -0,0 +1,12 @@
+<article class="content-page">
+  <header class="content-header">
+    <p class="eyebrow">Page</p>
+    <h1>{{ page.title }}</h1>
+    {% if page.summary %}
+      <p class="lede">{{ page.summary }}</p>
+    {% endif %}
+  </header>
+  <div class="prose">
+    {{ page.renderedContent | safe_content }}
+  </div>
+</article>
diff --git a/.theme/templates/content/project.liquid b/.theme/templates/content/project.liquid
new file mode 100644
index 0000000..815b488
--- /dev/null
+++ b/.theme/templates/content/project.liquid
@@ -0,0 +1,33 @@
+<article class="content-page project-page">
+  <header class="content-header">
+    <p class="eyebrow">Project</p>
+    <h1>{{ page.title }}</h1>
+    {% if page.summary %}
+      <p class="lede">{{ page.summary }}</p>
+    {% endif %}
+    <dl class="project-facts">
+      {% if page.metadata.version %}
+        <div><dt>Version</dt><dd>{{ page.metadata.version }}</dd></div>
+      {% endif %}
+      {% if page.metadata.license %}
+        <div><dt>License</dt><dd>{{ page.metadata.license }}</dd></div>
+      {% endif %}
+      {% if page.metadata.stack.size > 0 %}
+        <div><dt>Stack</dt><dd>{{ page.metadata.stack | join: ", " }}</dd></div>
+      {% endif %}
+    </dl>
+  </header>
+  <div class="prose">
+    {{ page.renderedContent | safe_content }}
+  </div>
+  {% if page.tags.size > 0 %}
+    <footer class="content-tags">
+      <p class="visually-hidden">Topics</p>
+      <ul class="tag-list">
+        {% for tag in page.tags %}
+          <li>{{ tag }}</li>
+        {% endfor %}
+      </ul>
+    </footer>
+  {% endif %}
+</article>
diff --git a/.theme/templates/home.liquid b/.theme/templates/home.liquid
new file mode 100644
index 0000000..28b61a2
--- /dev/null
+++ b/.theme/templates/home.liquid
@@ -0,0 +1,29 @@
+<section class="hero">
+  <p class="eyebrow">Configuration-first publishing</p>
+  <h1>{{ page.title }}</h1>
+  {% if page.summary %}
+    <p class="hero-summary">{{ page.summary }}</p>
+  {% endif %}
+  <div class="prose hero-copy">
+    {{ page.renderedContent | safe_content }}
+  </div>
+</section>
+
+{% if collection.items.size > 0 %}
+  <section class="section-block" aria-labelledby="latest-heading">
+    <div class="section-heading">
+      <p class="eyebrow">From the repository</p>
+      <h2 id="latest-heading">Latest work</h2>
+    </div>
+    <div class="card-grid">
+      {% for item in collection.items %}
+        <article class="card">
+          <p class="card-kind">{{ item.contentModel }}</p>
+          <h3><a href="{{ item.route }}">{{ item.title }}</a></h3>
+          <p>{{ item.summary }}</p>
+          <a class="text-link" href="{{ item.route }}">Read more <span aria-hidden="true">→</span></a>
+        </article>
+      {% endfor %}
+    </div>
+  </section>
+{% endif %}
diff --git a/.theme/templates/layout.liquid b/.theme/templates/layout.liquid
new file mode 100644
index 0000000..6907809
--- /dev/null
+++ b/.theme/templates/layout.liquid
@@ -0,0 +1,44 @@
+<!doctype html>
+<html lang="{{ site.language }}">
+  <head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <meta name="description" content="{{ page.summary }}">
+    <meta name="color-scheme" content="dark light">
+    {% if page.type == "home" %}
+      <title>{{ site.title }}</title>
+    {% else %}
+      <title>{{ page.title }} · {{ site.title }}</title>
+    {% endif %}
+    {% for stylesheet in theme.styles %}
+      <link rel="stylesheet" href="{{ stylesheet }}">
+    {% endfor %}
+  </head>
+  <body>
+    <a class="skip-link" href="#main-content">Skip to content</a>
+    <header class="site-header">
+      <div class="shell header-inner">
+        <a class="brand" href="/" aria-label="{{ site.title }} home">
+          <span class="brand-mark" aria-hidden="true">L</span>
+          <span>{{ site.title }}</span>
+        </a>
+        <nav class="site-nav" aria-label="Primary navigation">
+          {% for item in navigation %}
+            <a href="{{ item.route }}"{% if item.route == page.route %} aria-current="page"{% endif %}>{{ item.label }}</a>
+          {% endfor %}
+        </nav>
+      </div>
+    </header>
+
+    <main id="main-content" class="shell">
+      {{ page.body | safe_page_body }}
+    </main>
+
+    <footer class="site-footer">
+      <div class="shell footer-inner">
+        <p><strong>{{ site.title }}</strong> turns Git-owned configuration and content into a dependable website.</p>
+        <p class="footer-meta">Built from immutable sources.</p>
+      </div>
+    </footer>
+  </body>
+</html>
diff --git a/.theme/templates/sections/articles.liquid b/.theme/templates/sections/articles.liquid
new file mode 100644
index 0000000..08588d8
--- /dev/null
+++ b/.theme/templates/sections/articles.liquid
@@ -0,0 +1,22 @@
+<section class="page-intro">
+  <p class="eyebrow">Writing</p>
+  <h1>{{ page.title }}</h1>
+  {% if page.summary %}
+    <p class="lede">{{ page.summary }}</p>
+  {% endif %}
+</section>
+
+<section class="listing" aria-label="{{ page.title }}">
+  {% for item in collection.items %}
+    <article class="listing-item">
+      <div>
+        <p class="card-kind">{{ item.contentModel }}</p>
+        <h2><a href="{{ item.route }}">{{ item.title }}</a></h2>
+        <p>{{ item.summary }}</p>
+      </div>
+      <a class="text-link" href="{{ item.route }}" aria-label="Read {{ item.title }}">Read <span aria-hidden="true">→</span></a>
+    </article>
+  {% else %}
+    <p class="empty-state">No articles have been published yet.</p>
+  {% endfor %}
+</section>
diff --git a/.theme/templates/sections/projects.liquid b/.theme/templates/sections/projects.liquid
new file mode 100644
index 0000000..6233706
--- /dev/null
+++ b/.theme/templates/sections/projects.liquid
@@ -0,0 +1,27 @@
+<section class="page-intro">
+  <p class="eyebrow">Projects</p>
+  <h1>{{ page.title }}</h1>
+  {% if page.summary %}
+    <p class="lede">{{ page.summary }}</p>
+  {% endif %}
+</section>
+
+<section class="card-grid" aria-label="{{ page.title }}">
+  {% for item in collection.items %}
+    <article class="card project-card">
+      <p class="card-kind">{{ item.contentModel }}</p>
+      <h2><a href="{{ item.route }}">{{ item.title }}</a></h2>
+      <p>{{ item.summary }}</p>
+      {% if item.tags.size > 0 %}
+        <ul class="tag-list" aria-label="Technologies and topics">
+          {% for tag in item.tags %}
+            <li>{{ tag }}</li>
+          {% endfor %}
+        </ul>
+      {% endif %}
+      <a class="text-link" href="{{ item.route }}">View project <span aria-hidden="true">→</span></a>
+    </article>
+  {% else %}
+    <p class="empty-state">No projects have been published yet.</p>
+  {% endfor %}
+</section>
diff --git a/.theme/theme.yml b/.theme/theme.yml
new file mode 100644
index 0000000..cfca5b7
--- /dev/null
+++ b/.theme/theme.yml
@@ -0,0 +1,28 @@
+protocol: labyricorn-theme/v1
+id: labyricorn-default
+version: 1.0.0
+engine: liquid
+
+templates:
+  layout: templates/layout.liquid
+  home: templates/home.liquid
+  notFound: templates/404.liquid
+  sections:
+    articles: templates/sections/articles.liquid
+    projects: templates/sections/projects.liquid
+  content:
+    page: templates/content/page.liquid
+    article: templates/content/article.liquid
+    project: templates/content/project.liquid
+
+assets:
+  styles:
+    - assets/styles/theme.css
+  scripts: []
+  files: []
+  fonts: []
+
+security:
+  allowScripts: false
+  allowExternalAssets: false
+  allowedExternalOrigins: []
diff --git a/README.md b/README.md
index 7396e80..0c29545 100644
--- a/README.md
+++ b/README.md
@@ -7,8 +7,10 @@ publishing path before more content or integrations are added.
 ## Source of truth
 
 This repository is authoritative for the site content it contains. Labyricorn
-reads `.labyricorn/site.yml`, discovers the configured content, builds the
-website, and publishes the completed output to the local canonical site.
+reads the repository participation policy in `.labyricorn/site.yml`, resolves
+the canonical site definition in `site.yml`, validates the `.theme/` package,
+discovers the configured content, builds the website, and publishes the
+completed output to the local canonical site.
 
 Generated website files do not belong in this repository.
 
@@ -16,6 +18,10 @@ Generated website files do not belong in this repository.
 
 ```text
 .labyricorn/site.yml  Repository participation and publishing policy
+site.yml              Canonical site definition and theme selection
+navigation.yml        Public navigation and section-template selection
+projects.yml          Allowlisted project-page declarations
+.theme/                Strict Liquid templates and declared static assets
 pages/                Standalone website pages
 articles/             Article source documents
 projects/             Project source documents
@@ -30,6 +36,7 @@ The first deployment includes:
 - one homepage;
 - one introductory article;
 - one project page;
+- a repository-owned, script-free Liquid theme;
 - local publication through Labyricorn.
 
 It does not yet include:
diff --git a/articles/welcome.md b/articles/welcome.md
index f1e52df..65f07ee 100644
--- a/articles/welcome.md
+++ b/articles/welcome.md
@@ -2,6 +2,7 @@
 model: article
 title: Welcome to Labyricorn
 slug: welcome
+route: /articles/welcome/
 date: 2026-07-23
 status: published
 summary: Why the first deployment is intentionally small and locally hosted.
@@ -11,8 +12,6 @@ tags:
   - git
 ---
 
-# Welcome to Labyricorn
-
 Labyricorn is a configuration-first, Git-driven site builder. Repositories
 provide content and configuration; the builder turns those sources into a
 coherent website; the generated local site is the canonical runtime copy.
diff --git a/docs/DEPLOYMENT.md b/docs/DEPLOYMENT.md
index be8babd..3cd7805 100644
--- a/docs/DEPLOYMENT.md
+++ b/docs/DEPLOYMENT.md
@@ -17,15 +17,19 @@ Cloudflare Pages, Docker, or a public Control Plane.
 2. Add that Gitea repository as the remote for this local repository.
 3. Push the default branch to Gitea.
 4. Connect the repository in the Labyricorn Control Plane.
-5. Synchronize it and confirm `.labyricorn/site.yml` is valid.
-6. Confirm that the `page`, `article`, and `project` models are installed and
+5. Synchronize it and confirm `.labyricorn/site.yml` and the root `site.yml`
+   are valid.
+6. Validate `.theme/theme.yml`, every referenced Liquid template, and the
+   declared stylesheet before creating a release.
+7. Confirm that the `page`, `article`, and `project` models are installed and
    enabled in Labyricorn.
-7. Confirm discovery finds the three Markdown documents in this repository.
-8. Preview the generated routes and resolve any validation errors.
-9. Build the site.
-10. Publish the completed build to the local canonical site.
-11. Verify the homepage, article, and project page from a browser.
-12. Record the deployed Git revision and active local release.
+8. Confirm discovery finds the three Markdown documents in this repository.
+9. Preview the generated routes and resolve any validation errors.
+10. Build the site.
+11. Publish the completed build to the local canonical site.
+12. Verify the homepage, article, project index, and project page from a
+    browser.
+13. Record the deployed Git revision and active local release.
 
 ## Required proof
 
@@ -33,6 +37,7 @@ The initial deployment is successful only when all of the following are true:
 
 - the repository revision shown by Labyricorn matches Gitea;
 - configuration validation uses the committed `site.yml`;
+- theme validation uses the committed `.theme/theme.yml` and declared files;
 - all three source documents are discovered without filename heuristics;
 - generated routes come from configured model behavior;
 - the public pages are served from the activated local release;
diff --git a/navigation.yml b/navigation.yml
new file mode 100644
index 0000000..33e3122
--- /dev/null
+++ b/navigation.yml
@@ -0,0 +1,22 @@
+navigation:
+  - id: home
+    label: Home
+    route: /
+    iconName: Home
+    contentModel: page
+
+  - id: articles
+    label: Articles
+    route: /articles/
+    iconName: FileText
+    contentModel: article
+    presentation:
+      sectionTemplate: articles
+
+  - id: projects
+    label: Projects
+    route: /projects/
+    iconName: Boxes
+    contentModel: project
+    presentation:
+      sectionTemplate: projects
diff --git a/pages/index.md b/pages/index.md
index d9a40db..96cbdfa 100644
--- a/pages/index.md
+++ b/pages/index.md
@@ -7,8 +7,6 @@ status: published
 summary: A configuration-first, Git-driven home for projects, articles, and documentation.
 ---
 
-# Build once. Understand every part.
-
 Labyricorn brings project information, articles, and documentation together
 without replacing Git as the source of truth.
 
diff --git a/projects.yml b/projects.yml
new file mode 100644
index 0000000..30d5270
--- /dev/null
+++ b/projects.yml
@@ -0,0 +1,19 @@
+projects:
+  - id: labyricorn
+    source: site-definition
+    route: /projects/labyricorn/
+    title: Labyricorn
+    summary: A configuration-first, Git-driven static-site builder and control plane.
+    license: Proprietary
+    tags:
+      - labyricorn
+      - git
+      - static-site
+    stack:
+      - TypeScript
+      - React
+      - Liquid
+      - Nginx
+    presentation:
+      detailTemplate: project
+    publishedFiles: []
diff --git a/projects/labyricorn.md b/projects/labyricorn.md
index ff05f8b..37ecd7b 100644
--- a/projects/labyricorn.md
+++ b/projects/labyricorn.md
@@ -2,6 +2,7 @@
 model: project
 title: Labyricorn
 slug: labyricorn
+route: /projects/labyricorn/
 status: published
 summary: A configuration-first, Git-driven site builder and its administrative control plane.
 repository_url: https://git.labyricorn.com
@@ -11,8 +12,6 @@ tags:
   - static-site
 ---
 
-# Labyricorn
-
 Labyricorn builds and hosts locally generated sites from Git repositories.
 Content models, routes, navigation, styles, themes, and integrations derive
 their meaning from configuration rather than hardcoded content-type names.
diff --git a/site.yml b/site.yml
new file mode 100644
index 0000000..b3c49e0
--- /dev/null
+++ b/site.yml
@@ -0,0 +1,52 @@
+protocol: labyricorn-site/v1
+
+site:
+  id: labyricorn
+  title: Labyricorn
+  baseUrl: https://labyricorn.com
+  language: en-US
+
+navigationFile: ./navigation.yml
+projectsFile: ./projects.yml
+
+theme:
+  source: site-definition
+  path: .theme
+
+markdown:
+  dialect: labyricorn-commonmark-v1
+  rawHtmlPolicy: disabled
+  rawHtmlEnabled: false
+  extensions:
+    tables: true
+    taskLists: true
+    footnotes: true
+    definitionLists: true
+    headingAnchors: true
+    fencedCode: true
+    syntaxHighlighting: true
+    callouts: true
+    youtube: false
+    wikipediaLinks: true
+
+hosting:
+  engine: nginx
+  production:
+    enabled: true
+    hostname: labyricorn.com
+    listen: 80
+  staging:
+    enabled: true
+    hostname: preview.labyricorn.com
+    listen: 8080
+  releases:
+    retainCount: 10
+
+buildPolicy:
+  staging:
+    enabled: true
+    requireApproval: true
+  localActivation:
+    automatic: false
+  push:
+    automatic: false