diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000..ef538c2
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+3.1.2
diff --git a/Gemfile b/Gemfile
index 3a443fc..7b5a425 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,4 @@
 source 'http://rubygems.org'
 
-require 'json'
-require 'open-uri'
-versions = JSON.parse(open('https://pages.github.com/versions.json').read)
-
-gem 'github-pages', versions['github-pages']
+gem "webrick"
+gem 'github-pages', group: :jekyll_plugins
diff --git a/css/main.css b/css/main.css
index 7ebb656..dd77e27 100755
--- a/css/main.css
+++ b/css/main.css
@@ -48,7 +48,18 @@ a {
 }
 
 p {
-  margin: 0 0 10px;
+  margin: 0 0 12px;
+  font-size: 1rem;
+  line-height: 1.45rem;
+}
+
+img + em {
+  display: block;
+  margin-top: 4px;
+}
+
+li {
+  margin-bottom: 12px;
 }
 
 table {
@@ -377,6 +388,33 @@ a.rss img {
   }
 }
 
+.post .row {
+  display: flex;
+  align: center;
+  justify-content: center;
+  gap: 8px 8px;
+  flex-wrap: wrap;
+}
+
+.post .row figure {
+  flex-basis: calc(50% - 8px);
+}
+
+@media (max-width: 40rem) {
+  .post .row {
+    flex-direction: column;
+  }
+}
+
+.post figure {
+  margin: 0;
+}
+
+.post figure figurecaption {
+  display: block;
+  margin-top: 4px;
+}
+
 /*****************************************************************************/
 /*
 /* Subscribe form