diff --git a/CHANGELOG.md b/CHANGELOG.md
index 02d75ca..2351a17 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,11 @@ This format follows Keep a Changelog principles and aims for Semantic Versioning
 
 ## [Unreleased]
 ### Added
+- **Template Validation Tests**: Comprehensive test suite for HTML/Jinja2 templates
+  - Validates Jinja2 syntax across all templates
+  - Checks HTML structure (balanced tags, unique IDs, proper attributes)
+  - Basic accessibility validation (alt text, form labels, button types)
+  - Regression prevention thresholds to maintain code quality
 - **Code Quality Tools**: Enhanced development tooling for maintainability
   - Automated utilities for code cleanup
   - Improved type checking configuration
@@ -81,6 +86,10 @@ This format follows Keep a Changelog principles and aims for Semantic Versioning
   - Optimized linting rules for development workflow
 
 ### Fixed
+- **Template Quality**: Resolved HTML structure issues found by validation tests
+  - Fixed duplicate ID attributes in build wizard and theme picker templates
+  - Removed erroneous block tags from component documentation
+  - Corrected template structure for HTMX fragments
 - **Code Quality**: Resolved type checking warnings and improved code maintainability
   - Fixed type annotation inconsistencies
   - Cleaned up redundant code quality suppressions
diff --git a/RELEASE_NOTES_TEMPLATE.md b/RELEASE_NOTES_TEMPLATE.md
index e21aec0..f03d5c5 100644
--- a/RELEASE_NOTES_TEMPLATE.md
+++ b/RELEASE_NOTES_TEMPLATE.md
@@ -3,9 +3,14 @@
 ## [Unreleased]
 
 ### Summary
-Web UI improvements with Tailwind CSS migration, TypeScript conversion, component library, enhanced code quality tools, and optional card image caching for faster performance and better maintainability.
+Web UI improvements with Tailwind CSS migration, TypeScript conversion, component library, template validation tests, enhanced code quality tools, and optional card image caching for faster performance and better maintainability.
 
 ### Added
+- **Template Validation Tests**: Comprehensive test suite ensuring HTML/template quality
+  - Validates Jinja2 syntax and structure
+  - Checks for common HTML issues (duplicate IDs, balanced tags)
+  - Basic accessibility validation
+  - Prevents regression in template quality
 - **Code Quality Tools**: Enhanced development tooling for maintainability
   - Automated utilities for code cleanup
   - Improved type checking configuration
@@ -78,6 +83,10 @@ Web UI improvements with Tailwind CSS migration, TypeScript conversion, componen
 _None_
 
 ### Fixed
+- **Template Quality**: Resolved HTML structure issues
+  - Fixed duplicate ID attributes in templates
+  - Removed erroneous template block tags
+  - Corrected structure for HTMX fragments
 - **Code Quality**: Resolved type checking warnings and improved code maintainability
   - Fixed type annotation inconsistencies
   - Cleaned up redundant code quality suppressions
diff --git a/code/web/templates/build/_step1.html b/code/web/templates/build/_step1.html
index 0f54ecd..dfea715 100644
--- a/code/web/templates/build/_step1.html
+++ b/code/web/templates/build/_step1.html
@@ -66,8 +66,8 @@
   {% endif %}
 
   {% if (query is defined and query and (not candidates or (candidates|length == 0))) and not inspect %}
-    <div id="candidate-grid" class="muted" style="margin-top:.5rem;" aria-live="polite">
-      No results for “{{ query }}”. Try a shorter name or a different spelling.
+    <div id="no-results-message" class="muted" style="margin-top:.5rem;" aria-live="polite">
+      No results for "{{ query }}". Try a shorter name or a different spelling.
     </div>
   {% endif %}
 
diff --git a/code/web/templates/docs/components.html b/code/web/templates/docs/components.html
index e8cca98..a6d83f5 100644
--- a/code/web/templates/docs/components.html
+++ b/code/web/templates/docs/components.html
@@ -33,7 +33,6 @@
   <!-- BUTTONS -->
   <section id="buttons" class="section-spacing">
     {% call panel(title='Buttons', padding='lg') %}
-      {% block body %}
         
         <h4 style="margin-top: 0;">Button Variants</h4>
         <div class="btn-group content-spacing-lg">
@@ -76,16 +75,14 @@
         <div class="btn-group">
           {{ button('Go Home', href='/', variant='ghost') }}
           {{ button('Build Deck', href='/build', variant='primary') }}
-        </div>
+        </code></pre>
 
-      {% endblock %}
     {% endcall %}
   </section>
 
   <!-- MODALS -->
   <section id="modals" style="margin-top: 2rem;">
     {% call panel(title='Modals', padding='lg') %}
-      {% block body %}
         
         <p style="margin-top: 0; color: var(--muted);">Click buttons to see modal examples</p>
 
@@ -104,14 +101,12 @@
           {{ button('XLarge (960px)', onclick='showSizedModal("xl")') }}
         </div>
 
-      {% endblock %}
     {% endcall %}
   </section>
 
   <!-- FORMS -->
   <section id="forms" style="margin-top: 2rem;">
     {% call panel(title='Form Components', padding='lg') %}
-      {% block body %}
         
         <form onsubmit="event.preventDefault(); alert('Form submitted!');" style="max-width: 600px;">
           
@@ -147,14 +142,12 @@
           </div>
         </form>
 
-      {% endblock %}
     {% endcall %}
   </section>
 
   <!-- CARD DISPLAY -->
   <section id="cards" style="margin-top: 2rem;">
     {% call panel(title='Card Display Components', padding='lg') %}
-      {% block body %}
         
         <h4 style="margin-top: 0;">Card Thumbnail Sizes</h4>
         <div style="display: flex; gap: 1rem; flex-wrap: wrap; align-items: flex-start; margin-bottom: 2rem;">
@@ -179,14 +172,12 @@
           {'name': 'Birds of Paradise', 'role': 'ramp', 'tags': ['Ramp', 'Creature']}
         ], size='medium', columns=3) }}
 
-      {% endblock %}
     {% endcall %}
   </section>
 
   <!-- PANELS -->
   <section id="panels" style="margin-top: 2rem;">
     {% call panel(title='Panel Components', padding='lg') %}
-      {% block body %}
         
         <h4 style="margin-top: 0;">Panel Variants</h4>
         {{ simple_panel(title='Default Panel', content='<p>This is a default panel with standard background.</p>', variant='default') }}
@@ -232,14 +223,12 @@
 
         <h4 style="margin-top: 2rem;">Collapsible Panel</h4>
         {% call collapsible_panel(title='Advanced Options', expanded=False) %}
-          {% block body %}
             <p>These are advanced settings that are hidden by default.</p>
             <ul>
               <li>Option 1: Enable feature X</li>
               <li>Option 2: Adjust threshold Y</li>
               <li>Option 3: Configure behavior Z</li>
             </ul>
-          {% endblock %}
         {% endcall %}
 
         <h4 style="margin-top: 2rem;">Empty State</h4>
@@ -254,7 +243,6 @@
         <h4 style="margin-top: 2rem;">Loading State</h4>
         {{ loading_panel(message='Building deck...', spinner=True) }}
 
-      {% endblock %}
     {% endcall %}
   </section>
 
diff --git a/code/web/templates/partials/_forms.html b/code/web/templates/partials/_forms.html
index 560c807..6a47c55 100644
--- a/code/web/templates/partials/_forms.html
+++ b/code/web/templates/partials/_forms.html
@@ -17,9 +17,9 @@
   
   Examples:
     {% call form_field('Email', 'email', required=True) %}
-      {% block body %}
+
         <input type="email" name="email" />
-      {% endblock %}
+
     {% endcall %}
 #}
 {% macro form_field(label='', name='', required=False, help_text='', error='', classes='') %}
@@ -72,7 +72,7 @@
 #}
 {% macro text_input(name, label='', type='text', value='', placeholder='', required=False, disabled=False, readonly=False, help_text='', error='', classes='', attrs='') %}
   {% call form_field(label, name, required, help_text, error, classes) %}
-    {% block body %}
+
       <input type="{{ type }}"
              id="{{ name }}"
              name="{{ name }}"
@@ -83,7 +83,7 @@
              {% if disabled %}disabled{% endif %}
              {% if readonly %}readonly{% endif %}
              {{ attrs|safe }} />
-    {% endblock %}
+
   {% endcall %}
 {% endmacro %}
 
@@ -110,7 +110,7 @@
 #}
 {% macro textarea(name, label='', value='', placeholder='', rows=4, required=False, disabled=False, readonly=False, help_text='', error='', classes='', attrs='') %}
   {% call form_field(label, name, required, help_text, error, classes) %}
-    {% block body %}
+
       <textarea id="{{ name }}"
                 name="{{ name }}"
                 class="form-textarea"
@@ -120,7 +120,7 @@
                 {% if disabled %}disabled{% endif %}
                 {% if readonly %}readonly{% endif %}
                 {{ attrs|safe }}>{{ value }}</textarea>
-    {% endblock %}
+
   {% endcall %}
 {% endmacro %}
 
@@ -148,7 +148,7 @@
 #}
 {% macro select(name, label='', options=[], value='', required=False, disabled=False, help_text='', error='', classes='', attrs='') %}
   {% call form_field(label, name, required, help_text, error, classes) %}
-    {% block body %}
+
       <select id="{{ name }}"
               name="{{ name }}"
               class="form-select"
@@ -163,7 +163,7 @@
           </option>
         {% endfor %}
       </select>
-    {% endblock %}
+
   {% endcall %}
 {% endmacro %}
 
@@ -295,7 +295,7 @@
 #}
 {% macro number_input(name, label='', value='', min='', max='', step=1, placeholder='', required=False, disabled=False, help_text='', error='', classes='', attrs='') %}
   {% call form_field(label, name, required, help_text, error, classes) %}
-    {% block body %}
+
       <input type="number"
              id="{{ name }}"
              name="{{ name }}"
@@ -308,7 +308,7 @@
              {% if required %}required{% endif %}
              {% if disabled %}disabled{% endif %}
              {{ attrs|safe }} />
-    {% endblock %}
+
   {% endcall %}
 {% endmacro %}
 
@@ -333,7 +333,7 @@
 #}
 {% macro file_input(name, label='', accept='', multiple=False, required=False, disabled=False, help_text='', error='', classes='', attrs='') %}
   {% call form_field(label, name, required, help_text, error, classes) %}
-    {% block body %}
+
       <input type="file"
              id="{{ name }}"
              name="{{ name }}"
@@ -343,7 +343,7 @@
              {% if required %}required{% endif %}
              {% if disabled %}disabled{% endif %}
              {{ attrs|safe }} />
-    {% endblock %}
+
   {% endcall %}
 {% endmacro %}
 
diff --git a/code/web/templates/themes/picker.html b/code/web/templates/themes/picker.html
index c596ad5..374ddd7 100644
--- a/code/web/templates/themes/picker.html
+++ b/code/web/templates/themes/picker.html
@@ -77,7 +77,6 @@
     {% endif %}
   </div>
   <div id="theme-preview-host"></div>
-  <div id="filter-chips" class="filter-chips" aria-label="Active filters"></div>
 </div>
 <style>
 .theme-picker-controls { display:flex; flex-wrap:wrap; gap:.5rem; margin-bottom:.75rem; }