diff --git a/layouts/404.html b/layouts/404.html
index 68dca20..1611a41 100644
--- a/layouts/404.html
+++ b/layouts/404.html
@@ -1,3 +1,3 @@
-{{ partial "header.html" . }}
-  <h1 class="title-404">404</h1>
-{{ partial "footer.html" . }}
+{{ define "main" }}
+<h1 class="title-404">404</h1>
+{{ end }}
diff --git a/layouts/_default/baseof.html b/layouts/_default/baseof.html
new file mode 100644
index 0000000..8d6802f
--- /dev/null
+++ b/layouts/_default/baseof.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+
+{{ $social := slice "twitter" "github" "instagram" }}<!---->
+{{ range $key, $val := site.Params }}<!---->
+{{ if in $social $key }}<!---->
+{{ $.Scratch.SetInMap "social-map" $key $val }}<!---->
+{{ end }}<!---->
+{{ end }}<!---->
+
+<html lang="{{ site.LanguageCode }}">
+  {{ partial "head.html" . }}
+
+  <body class="not-ready" data-menu="{{ isset site.Menus `main` }}">
+    {{ partial "header.html" . }}
+
+    <main class="main">{{ block "main" . }}{{ end }}</main>
+
+    {{ partial "footer.html" . }}
+  </body>
+</html>
diff --git a/layouts/_default/list.html b/layouts/_default/list.html
index db4f340..7ec9a4c 100644
--- a/layouts/_default/list.html
+++ b/layouts/_default/list.html
@@ -1,16 +1,17 @@
-{{ partial "header.html" . }}
+{{ define "main" }}
 
+<!-- Main Title -->
 {{ if .Title }}
-<h1 class="page-title">{{ .Title }}</h1>
+<h1 class="main-title">{{ .Title }}</h1>
 {{ end }}
 
+<!-- $pages -->
 {{ $pages := union .RegularPages .Sections }}
-{{ if .IsHome }}
-{{ $pages = where site.RegularPages "Type" "in" site.Params.mainSections }}
+<!---->{{ if .IsHome }} {{ $pages = where site.RegularPages "Type" "in" site.Params.mainSections }}
 {{ end }}
-{{ $paginator := .Paginate $pages }}
 
-{{ range $index, $page := $paginator.Pages }}
+<!-- Articles -->
+{{ $paginator := .Paginate $pages }} {{ range $index, $page := $paginator.Pages }}
 <article class="post-entry">
   <h2>{{ .Title }}</h2>
   <time>{{ .Date.Format "January 2, 2006" }}</time>
@@ -18,15 +19,16 @@
 </article>
 {{ end }}
 
+<!-- Main Nav -->
 {{ if gt $paginator.TotalPages 1 }}
-<nav class="page-nav">
+<nav class="main-nav">
   {{ if $paginator.HasPrev }}
   <a class="prev" href="{{ $paginator.Prev.URL }}">← {{ i18n "prev_page" }}</a>
-  {{ end }}
+  {{ end }}<!---->
   {{ if $paginator.HasNext }}
   <a class="next" href="{{ $paginator.Next.URL }}">{{ i18n "next_page" }} →</a>
   {{ end }}
 </nav>
-{{ end }}
+{{ end }}<!---->
 
-{{ partial "footer.html" . }}
+{{ end }}
diff --git a/layouts/_default/single.html b/layouts/_default/single.html
index c7d1c24..a2db1b7 100644
--- a/layouts/_default/single.html
+++ b/layouts/_default/single.html
@@ -1,4 +1,4 @@
-{{ partial "header.html" . }}
+{{ define "main" }}
 
 <article class="post-single">
   <header class="post-title">
@@ -8,33 +8,32 @@
       <span>{{ .Params.Author | default site.Author.name }}</span>
       {{ end }}
     </aside>
-
     <h1>{{ .Title }}</h1>
   </header>
-
   <section class="post-content">{{ .Content }}</section>
 
+  <!-- Post Tags -->
   {{ if .Params.tags }}
   <footer class="post-tags">
-    {{ range .Params.tags }}
-    {{ $href := print (absURL "tags/") (urlize .) }}
+    {{ range .Params.tags }} {{ $href := print (absURL "tags/") (urlize .) }}
     <a href="{{ $href }}">{{ . }}</a>
     {{ end }}
   </footer>
   {{ end }}
 
-  {{ $pages := where site.RegularPages "Type" "in" site.Params.mainSections }}
+  <!-- Post Nav -->
+  {{ $pages := where site.RegularPages "Type" "in" site.Params.mainSections }}<!---->
   {{ if and (gt (len $pages) 1) (in $pages . ) }}
   <nav class="post-nav">
     {{ with $pages.Next . }}
     <a class="prev" href="{{ .Permalink }}"><span>←</span><span>{{ .Name }}</span></a>
-    {{ end }}
-    {{ with $pages.Prev . }}
+    {{ end }} {{ with $pages.Prev . }}
     <a class="next" href="{{ .Permalink }}"><span>{{ .Name }}</span><span>→</span></a>
     {{ end }}
   </nav>
   {{ end }}
 
+  <!-- Disqus -->
   {{ if and site.DisqusShortname (not (eq .Params.comments false)) }}
   <div id="disqus_thread" class="post-comments"></div>
   <script>
@@ -47,4 +46,4 @@
   {{ end }}
 </article>
 
-{{ partial "footer.html" . }}
+{{ end }}
diff --git a/layouts/partials/footer.html b/layouts/partials/footer.html
index d952c8f..ab5ba9f 100644
--- a/layouts/partials/footer.html
+++ b/layouts/partials/footer.html
@@ -1,8 +1,7 @@
-  </main>
-  <footer class="footer">
-    <p>&copy; {{ now.Year }} <a href="{{ "" | absURL }}">{{ site.Title }}</a></p>
-    <p>Powered by <a href="https://gohugo.io/" rel="noopener" target="_blank">Hugo️️</a>️</p>
-    <p><a href="https://github.com/nanxiaobei/hugo-paper" rel="noopener" target="_blank">Paper 5.0</a></p>
-  </footer>
-  </body>
-</html>
+<footer class="footer">
+  <p>&copy; {{ now.Year }} <a href="{{ `` | absURL }}">{{ site.Title }}</a></p>
+  <p>Powered by <a href="https://gohugo.io/" rel="noopener" target="_blank">Hugo️️</a>️</p>
+  <p>
+    <a href="https://github.com/nanxiaobei/hugo-paper" rel="noopener" target="_blank">Paper 5.0</a>
+  </p>
+</footer>
diff --git a/layouts/partials/head.html b/layouts/partials/head.html
new file mode 100644
index 0000000..91cad2c
--- /dev/null
+++ b/layouts/partials/head.html
@@ -0,0 +1,73 @@
+<head>
+  <meta charset="utf-8" />
+  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no" />
+
+  <!-- Title -->
+  <title>{{ if not .IsHome }}{{ .Title }} - {{ end }}{{ site.Title }}</title>
+
+  <!-- Meta -->
+  {{ if eq .Kind "page" }}
+  <meta name="description" content="{{ .Summary }}" />
+  <meta name="author" content="{{ .Params.Author | default site.Author.name }}" />
+  {{ else }}
+  <meta name="description" content="{{ site.Params.description }}" />
+  <meta name="author" content="{{ site.Author.name }}" />
+  {{ end }}
+
+  <!-- Styles & Scripts -->
+  {{ $app_css := resources.Get "app.css" }}
+  <!---->
+  {{ $custom_css := resources.Get "custom.css" }}
+  <!---->
+  {{ $css := slice $app_css $custom_css | resources.Concat "app.css" | minify }}
+  <link rel="preload stylesheet" as="style" href="{{ $css.Permalink }}" />
+
+  {{ if and .IsPage (not site.Params.disableHLJS) }}
+  <link rel="preload stylesheet" as="style" href="{{ `an-old-hope.min.css` | absURL }}" />
+  <script
+    defer
+    src="{{ `highlight.min.js` | absURL }}"
+    onload="hljs.initHighlightingOnLoad();"
+  ></script>
+  {{ end }}
+
+  <!-- Preload -->
+  <link rel="preload" as="image" href="{{ `theme.png` | absURL }}" />
+
+  {{ range $key, $val := $.Scratch.Get "social-map" }}
+  <link rel="preload" as="image" href="{{ printf `%s.svg` $key | absURL }}" />
+  {{ end }}
+
+  <!-- Favicon -->
+  <link rel="icon" href="{{ `favicon.ico` | absURL }}" />
+  <link rel="apple-touch-icon" href="{{ `apple-touch-icon.png` | absURL }}" />
+
+  <!-- Generator -->
+  {{ hugo.Generator }}
+
+  <!-- RSS -->
+  {{ range .AlternativeOutputFormats }}
+  <link
+    rel="{{ .Rel }}"
+    type="{{ .MediaType.Type }}"
+    href="{{ .Permalink }}"
+    title="{{ site.Title }}"
+  />
+  {{ end }}
+
+  <!-- Misc -->
+  {{ if hugo.IsProduction | eq site.Params.env "production" }}
+  <!---->
+  {{ template "_internal/google_analytics_async.html" . }}
+  <!---->
+  {{ template "_internal/google_news.html" . }}
+  <!---->
+  {{ template "_internal/opengraph.html" . }}
+  <!---->
+  {{ template "_internal/schema.html" . }}
+  <!---->
+  {{ template "_internal/twitter_cards.html" . }}
+  <!---->
+  {{ end }}
+</head>
diff --git a/layouts/partials/header.html b/layouts/partials/header.html
index ef6c353..59534a0 100644
--- a/layouts/partials/header.html
+++ b/layouts/partials/header.html
@@ -1,127 +1,60 @@
-<!DOCTYPE html>
-<html lang="{{ site.LanguageCode }}">
-  <head>
-    <meta charset="utf-8">
-    <meta http-equiv="X-UA-Compatible" content="IE=edge">
-    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
+<header class="header">
+  {{ if .IsHome }}
+  <h1 class="logo">
+    <a class="site-name" href="{{ `` | absURL }}">{{ site.Title }}</a><a class="btn-theme"></a>
+  </h1>
+  {{ else }}
+  <p class="logo">
+    <a class="site-name" href="{{ `` | absURL }}">{{ site.Title }}</a><a class="btn-theme"></a>
+  </p>
+  {{ end }}
 
-    <!-- Title -->
-    <title>{{ if not .IsHome }}{{ .Title }} - {{ end }}{{ site.Title }}</title>
+  <script>
+    let bodyClass = document.body.classList;
+    let buttonDark = document.querySelector('.btn-theme');
+    let schemeDark = window.matchMedia('(prefers-color-scheme: dark)');
 
-    <!-- Meta -->
-    {{ if eq .Kind "page" }}
-    <meta name="description" content="{{ .Summary }}">
-    <meta name="author" content="{{ .Params.Author | default site.Author.name }}">
-    {{ else }}
-    <meta name="description" content="{{ site.Params.description }}">
-    <meta name="author" content="{{ site.Author.name }}">
+    let setDark = () => {
+      bodyClass.add('dark');
+      localStorage.setItem('dark', 'true');
+    };
+    let setLight = () => {
+      bodyClass.remove('dark');
+      localStorage.removeItem('dark');
+    };
+
+    if (schemeDark.matches || localStorage.getItem('dark')) setDark();
+    requestAnimationFrame(() => {
+      bodyClass.remove('not-ready');
+    });
+
+    buttonDark.addEventListener('click', () => {
+      bodyClass.contains('dark') ? setLight() : setDark();
+    });
+    schemeDark.addEventListener('change', event => {
+      event.matches ? setDark() : setLight();
+    });
+  </script>
+
+  {{ $url := .RelPermalink }}<!---->
+  {{ with site.Menus.main }}
+  <nav class="menu">
+    {{ range . }}
+    <a class="{{ if eq .URL $url }}active{{ end }}" href="{{ .URL }}">{{ .Name }}</a>
     {{ end }}
+  </nav>
+  {{ end }}<!---->
 
-    <!-- Styles & Scripts -->
-    {{ $app_css := resources.Get "app.css" }}
-    {{ $custom_css := resources.Get "custom.css" }}
-    {{ $css := slice $app_css $custom_css | resources.Concat "app.css" | minify }}
-    <link rel="preload stylesheet" as="style" href="{{ $css.Permalink }}">
-
-    {{ if and .IsPage (not site.Params.disableHLJS) }}
-    <link rel="preload stylesheet" as="style" href="{{ `an-old-hope.min.css` | absURL }}">
-    <script defer src="{{ `highlight.min.js` | absURL }}" onload="hljs.initHighlightingOnLoad();"></script>
+  {{ with $.Scratch.Get "social-map" }}
+  <nav class="social">
+    {{ range $key, $val := . }}
+    <a
+      class="{{ $key }}"
+      style="--img: url(./{{ printf `%s.svg` $key }})"
+      href="https://{{ $key }}.com/{{ $val }}"
+      target="_blank"
+    ></a>
     {{ end }}
-
-    <!-- Preload -->
-    <link rel="preload" as="image" href="{{ `theme.png` | absURL }}">
-    {{ if site.Params.twitter }}
-    <link rel="preload" as="image" href="{{ `twitter.svg` | absURL }}">
-    {{ end }}
-    {{ if site.Params.github }}
-    <link rel="preload" as="image" href="{{ `github.svg` | absURL }}">
-    {{ end }}
-    {{ if site.Params.instagram }}
-    <link rel="preload" as="image" href="{{ `instagram.svg` | absURL }}">
-    {{ end }}
-
-    <!-- Favicon -->
-    <link rel="icon" href="{{ `favicon.ico` | absURL }}">
-    <link rel="apple-touch-icon" href="{{ `apple-touch-icon.png` | absURL }}">
-
-    <!-- Generator -->
-    {{ hugo.Generator }}
-
-    <!-- RSS -->
-    {{ range .AlternativeOutputFormats }}
-    <link rel="{{ .Rel }}" type="{{ .MediaType.Type }}" href="{{ .Permalink }}" title="{{ site.Title }}">
-    {{ end }}
-
-    <!-- Misc -->
-    {{ if hugo.IsProduction | eq site.Params.env "production" }}
-    {{ template "_internal/google_analytics_async.html" . }}
-    {{ template "_internal/google_news.html" . }}
-    {{ template "_internal/opengraph.html" . }}
-    {{ template "_internal/schema.html" . }}
-    {{ template "_internal/twitter_cards.html" . }}
-    {{ end }}
-  </head>
-
-  <body class="not-ready" data-menu="{{ isset site.Menus `main` }}">
-    <header class="header">
-      {{ $tag := cond .IsHome "h1" "p" }}
-      {{ printf `
-      <%s class="logo">
-        <a class="site-name" href="%s">%s</a>
-        <a class="btn-theme"></a>
-      </%s>
-      ` $tag ("" | absURL) site.Title $tag | safeHTML }}
-
-      <script>
-        let bodyClass = document.body.classList;
-        let schemeDark = window.matchMedia('(prefers-color-scheme: dark)');
-        let buttonDark = document.querySelector('.btn-theme');
-
-        let setDark = () => {
-          bodyClass.add('dark');
-          localStorage.setItem('dark', 'true');
-        };
-
-        let setLight = () => {
-          bodyClass.remove('dark');
-          localStorage.removeItem('dark');
-        };
-
-        if (schemeDark.matches || localStorage.getItem('dark')) setDark();
-
-        requestAnimationFrame(() => {
-          bodyClass.remove('not-ready');
-        });
-
-        schemeDark.addEventListener('change', event => {
-          event.matches ? setDark() : setLight();
-        });
-
-        buttonDark.addEventListener('click', () => {
-          bodyClass.contains('dark') ? setLight() : setDark();
-        });
-      </script>
-
-      {{ if site.Menus.main }}
-      <nav class="menu">
-        {{ $url := .Permalink }}
-        {{ range site.Menus.main }}
-        <a class="{{ if eq $url .URL }}active{{ end }}" href="{{ .URL }}">{{ .Name }}</a>
-        {{ end }}
-      </nav>
-      {{ end }}
-
-      {{ if site.Params.twitter }}
-      <a class="social-icon twitter" href="https://twitter.com/{{ site.Params.twitter }}" target="_blank"></a>
-      {{ end }}
-
-      {{ if site.Params.github }}
-      <a class="social-icon github" href="https://github.com/{{ site.Params.github }}" target="_blank"></a>
-      {{ end }}
-
-      {{ if site.Params.instagram }}
-      <a class="social-icon instagram" href="https://www.instagram.com/{{ site.Params.instagram }}/" target="_blank"></a>
-      {{ end }}
-
-    </header>
-    <main class="main">
+  </nav>
+  {{ end }}
+</header>
diff --git a/layouts/shortcodes/collapse.html b/layouts/shortcodes/collapse.html
index e3984ab..984613d 100644
--- a/layouts/shortcodes/collapse.html
+++ b/layouts/shortcodes/collapse.html
@@ -1,15 +1,9 @@
-{{ if .Get "content" }}
-{{ if .Get "summary" }}
-{{ else }}
-{{ warnf "missing value for param 'summary': %s" .Position }}
-{{ end }}
-{{ else }}
-{{ errorf "missing value for param 'content': %s" .Position }}
-{{ end }}
+<!---->{{ if not (.Get "summary") }}
+<!---->{{ errorf "missing param 'summary': %s" .Position }}
+<!---->{{ else if not (.Get "content") }}{{ warnf "missing param 'content': %s" .Position }}
+<!---->{{ end }}
 
-<p>
-  <details {{ if (eq (.Get "openByDefault") true) }}open=true{{ end }}>
-    <summary markdown="span">{{ .Get "summary" | markdownify }}</summary>
-    {{ .Get "content" | markdownify }}
-  </details>
-</p>
+<details {{ if (eq (.Get `openByDefault`) true) }}open="true" {{ end }}>
+  <summary markdown="span">{{ .Get "summary" | markdownify }}</summary>
+  {{ .Get "content" | markdownify }}
+</details>
