- Gemfile explicitly pinned base64/benchmark/bigdecimal/csv/logger/ostruct
  as 'standard library that ships as a bundled gem from Ruby 3.4/4.0
  onward' — leftover from Jekyll's much larger dependency tree. Nothing
  in lib/build.rb or script/build_design_bundle.rb uses any of them, and
  removing them still resolves and builds cleanly (Gemfile.lock now lists
  exactly kramdown, kramdown-parser-gfm, rake, rexml, webrick).
- .ad-callout--danger/--success were never referenced by any page (only
  the bare .ad-callout is used, ten times, with no tone variant).
- assets/js/system.js's setUpLoadingDemo wired up a data-demo-loading
  attribute that doesn't appear in any component page — a demo that got
  rewritten at some point without removing its handler.

Verified: bundle install + rake build + rake design all still succeed
with 26 pages and 23 design-bundle cards.

diff --git a/Gemfile b/Gemfile
index ce189f5..9afea84 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,20 +5,12 @@ source "https://rubygems.org"
 # This site is built on Ruby 4.0.
 # ruby "~> 4.0" # temporarily disabled for local verification under ruby 3.3.6
 
-# Markdown rendering (GFM) for the ERB-rendered pages — see
-# lib/arbitrary_definitions/site_builder.rb. No syntax highlighter: code
-# blocks render as plain, unhighlighted <pre><code>.
+# Markdown rendering (GFM) for the ERB-rendered pages — see lib/build.rb.
+# No syntax highlighter: code blocks render as plain, unhighlighted
+# <pre><code>.
 gem "kramdown", "~> 2.5"
 gem "kramdown-parser-gfm", "~> 1.1"
 
 gem "rake", "~> 13.2"
 gem "webrick", "~> 1.9"
 
-# Standard library that ships as a bundled gem from Ruby 3.4/4.0 onward, but
-# still has to be declared explicitly rather than assumed.
-gem "base64", "~> 0.2"
-gem "benchmark", "~> 0.4"
-gem "bigdecimal", "~> 3.1"
-gem "csv", "~> 3.3"
-gem "logger", "~> 1.6"
-gem "ostruct", "~> 0.6"
diff --git a/Gemfile.lock b/Gemfile.lock
index d023d42..2d65ff3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,16 +1,10 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    base64 (0.3.0)
-    benchmark (0.5.0)
-    bigdecimal (3.3.1)
-    csv (3.3.6)
     kramdown (2.5.2)
       rexml (>= 3.4.4)
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
-    logger (1.7.0)
-    ostruct (0.6.3)
     rake (13.4.2)
     rexml (3.4.4)
     webrick (1.9.2)
@@ -35,27 +29,15 @@ PLATFORMS
   x86_64-linux-musl
 
 DEPENDENCIES
-  base64 (~> 0.2)
-  benchmark (~> 0.4)
-  bigdecimal (~> 3.1)
-  csv (~> 3.3)
   kramdown (~> 2.5)
   kramdown-parser-gfm (~> 1.1)
-  logger (~> 1.6)
-  ostruct (~> 0.6)
   rake (~> 13.2)
   webrick (~> 1.9)
 
 CHECKSUMS
-  base64 (0.3.0) sha256=27337aeabad6ffae05c265c450490628ef3ebd4b67be58257393227588f5a97b
-  benchmark (0.5.0) sha256=465df122341aedcb81a2a24b4d3bd19b6c67c1530713fd533f3ff034e419236c
-  bigdecimal (3.3.1) sha256=eaa01e228be54c4f9f53bf3cc34fe3d5e845c31963e7fcc5bedb05a4e7d52218
   bundler (4.0.16) sha256=d6ca5dd440c24f9abce9844cf44cc8e18c6a553de65a47efb4544137af92c47d
-  csv (3.3.6) sha256=aba61e7e507a66f03d45cb1f3c4b6359861c3504038b422962875dce099e4456
   kramdown (2.5.2) sha256=1ba542204c66b6f9111ff00dcc26075b95b220b07f2905d8261740c82f7f02fa
   kramdown-parser-gfm (1.1.0) sha256=fb39745516427d2988543bf01fc4cf0ab1149476382393e0e9c48592f6581729
-  logger (1.7.0) sha256=196edec7cc44b66cfb40f9755ce11b392f21f7967696af15d274dde7edff0203
-  ostruct (0.6.3) sha256=95a2ed4a4bd1d190784e666b47b2d3f078e4a9efda2fccf18f84ddc6538ed912
   rake (13.4.2) sha256=cb825b2bd5f1f8e91ca37bddb4b9aaf345551b4731da62949be002fa89283701
   rexml (3.4.4) sha256=19e0a2c3425dfbf2d4fc1189747bdb2f849b6c5e74180401b15734bc97b5d142
   webrick (1.9.2) sha256=beb4a15fc474defed24a3bda4ffd88a490d517c9e4e6118c3edce59e45864131
diff --git a/_sass/site/tokens-docs.css b/_sass/site/tokens-docs.css
index f03fee4..dd9d962 100644
--- a/_sass/site/tokens-docs.css
+++ b/_sass/site/tokens-docs.css
@@ -162,9 +162,6 @@
   border-radius: var(--ad-radius-md);
   background: var(--ad-color-surface-fill);
 }
-.ad-callout--danger { border-left-color: var(--ad-color-danger); }
-.ad-callout--success { border-left-color: var(--ad-color-success); }
-
 /* Generic reference tables (component APIs, alias tables, the contrast
    contract). `<table>` IS a table — no class needed to say so. Every table
    on this site uses the one compact density, so there is no separate
diff --git a/assets/js/system.js b/assets/js/system.js
index fc9f6ee..85ae6a6 100644
--- a/assets/js/system.js
+++ b/assets/js/system.js
@@ -121,21 +121,7 @@
     });
   }
 
-  // Demo-only: the buttons page shows a loading state that resolves itself.
-  function setUpLoadingDemo() {
-    document.addEventListener("click", function (event) {
-      var button = event.target.closest("[data-demo-loading]");
-      if (!button || button.dataset.loading === "true") return;
-
-      button.dataset.loading = "true";
-      window.setTimeout(function () {
-        button.dataset.loading = "false";
-      }, 1800);
-    });
-  }
-
   setUpTheme();
   setUpTabs();
   setUpNavToggle();
-  setUpLoadingDemo();
 })();