diff --git a/Gemfile b/Gemfile
index 65ff651..a6d0f88 100644
--- a/Gemfile
+++ b/Gemfile
@@ -13,6 +13,7 @@ gem 'html-proofer'
 gem 'scss_lint'
 
 group :jekyll_plugins do
+  gem 'jekyll-assets'
   gem 'jekyll-multiple-languages-plugin'
   gem 'jekyll-sitemap'
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 3af0d7d..619875a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -17,6 +17,9 @@ GEM
     ethon (0.11.0)
       ffi (>= 1.3.0)
     eventmachine (1.2.7)
+    extras (0.3.0)
+      forwardable-extended (~> 2.5)
+    fastimage (2.1.4)
     ffi (1.9.25)
     forwardable-extended (2.6.0)
     html-proofer (3.9.2)
@@ -44,6 +47,14 @@ GEM
       pathutil (~> 0.9)
       rouge (>= 1.7, < 4)
       safe_yaml (~> 1.0)
+    jekyll-assets (2.4.0)
+      concurrent-ruby (~> 1.0)
+      extras (~> 0.2)
+      fastimage (~> 2.0, >= 1.8)
+      jekyll (~> 3.1, >= 3.0)
+      pathutil (>= 0.8)
+      rack (~> 1.6)
+      sprockets (~> 3.3, < 3.8)
     jekyll-feed (0.10.0)
       jekyll (~> 3.3)
     jekyll-multiple-languages-plugin (1.5.1)
@@ -95,6 +106,9 @@ GEM
     scss_lint (0.57.0)
       rake (>= 0.9, < 13)
       sass (~> 3.5.5)
+    sprockets (3.7.2)
+      concurrent-ruby (~> 1.0)
+      rack (> 1, < 3)
     thread_safe (0.3.6)
     typhoeus (1.3.0)
       ethon (>= 0.9.0)
@@ -108,6 +122,7 @@ PLATFORMS
 DEPENDENCIES
   html-proofer
   jekyll (>= 3.7.4)
+  jekyll-assets
   jekyll-multiple-languages-plugin
   jekyll-sitemap
   minima
diff --git a/_config.production.yml b/_config.production.yml
index 06e32e3..b4b7d5b 100644
--- a/_config.production.yml
+++ b/_config.production.yml
@@ -16,6 +16,7 @@ exclude_from_localizations: ['javascript', 'images', 'css']
 markdown: kramdown
 theme: minima
 plugins:
+  - jekyll-assets
   - jekyll-feed
   - jekyll-multiple-languages-plugin
   - jekyll-sitemap
@@ -26,3 +27,17 @@ counters:
     webmaster: 'XXXXXXXXXXXXXXXX'
   google:
     analytics: 'XX-XXXXXXXXX-X'
+
+assets:
+  destination: '/assets'
+  source_maps: false
+  compression: true
+  gzip: true
+  defaults:
+    js: { integrity: true }
+    css: { integrity: true }
+    img: { integrity: true }
+  caching:
+    path: '.jekyll-cache/assets'
+    type: memory
+    enabled: true
diff --git a/_config.staging.yml b/_config.staging.yml
index 0f26813..01e612a 100644
--- a/_config.staging.yml
+++ b/_config.staging.yml
@@ -16,6 +16,21 @@ exclude_from_localizations: ['javascript', 'images', 'css']
 markdown: kramdown
 theme: minima
 plugins:
+  - jekyll-assets
   - jekyll-feed
   - jekyll-multiple-languages-plugin
   - jekyll-sitemap
+
+assets:
+  destination: '/assets'
+  source_maps: false
+  compression: true
+  gzip: true
+  defaults:
+    js: { integrity: true }
+    css: { integrity: true }
+    img: { integrity: true }
+  caching:
+    path: '.jekyll-cache/assets'
+    type: memory
+    enabled: true
diff --git a/_config.yml b/_config.yml
index 3a00669..c47b734 100644
--- a/_config.yml
+++ b/_config.yml
@@ -3,7 +3,7 @@ encoding: utf-8
 collections:
   pages:
     output: true
-    permalink: /:path
+    permalink: /:slug
 
 languages:
   - en
@@ -14,6 +14,21 @@ exclude_from_localizations: ['javascript', 'images', 'css']
 markdown: kramdown
 theme: minima
 plugins:
+  - jekyll-assets
   - jekyll-feed
   - jekyll-multiple-languages-plugin
   - jekyll-sitemap
+
+assets:
+  destination: '/assets'
+  source_maps: false
+  compression: true
+  gzip: false
+  defaults:
+    js: { integrity: false }
+    css: { integrity: false }
+    img: { integrity: false }
+  caching:
+    path: '.jekyll-cache/assets'
+    type: mempry
+    enabled: true
diff --git a/_i18n/en.yml b/_i18n/en.yml
index 0492aec..52b79b8 100644
--- a/_i18n/en.yml
+++ b/_i18n/en.yml
@@ -43,6 +43,7 @@ sidebar:
           - queue
           - deque
           - singly_linked_list
+          - doubly_linked_list
           - ordered_list
           - hash_table
           - binary_tree
diff --git a/_includes/algorithm_complexity_header.html b/_includes/algorithm_complexity_header.html
index c905aba..fd553c4 100644
--- a/_includes/algorithm_complexity_header.html
+++ b/_includes/algorithm_complexity_header.html
@@ -1,4 +1,4 @@
-<thead style="font-weight: bold; text-align: center">
+<thead class="table complexity">
   <tr>
     <td>{% t pages.algorithms.complexity.best %}</td>
     <td>{% t pages.algorithms.complexity.average %}</td>
diff --git a/_includes/data_structure_complexity_header.html b/_includes/data_structure_complexity_header.html
index fd7f993..e64ccdd 100644
--- a/_includes/data_structure_complexity_header.html
+++ b/_includes/data_structure_complexity_header.html
@@ -1,4 +1,4 @@
-<thead style="font-weight: bold; text-align: center">
+<thead style="table complexity">
   <tr>
     <td>Average Access</td>
     <td>Average Search</td>
diff --git a/_includes/head.html b/_includes/head.html
index 7d826b3..e21e447 100644
--- a/_includes/head.html
+++ b/_includes/head.html
@@ -1,4 +1,6 @@
-<title>{% t head.title %}</title>
+{% assign key = page.url | remove_first: '/' %}
+{% assign title = site.translations[site.lang].pages[key].title %}
+<title>{% t head.title %} - {{ title }}</title>
 
 <meta charset="utf-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=edge"/>
@@ -16,9 +18,11 @@
 {% endif %}
 
 <!-- Favicons -->
-<!-- <link rel="shortcut icon" type="image/png" href="/favicon.png"> -->
+<link rel="shortcut icon" type="image/png" href="/favicon.png">
 <link rel="icon" href="/favicon.ico">
 
+<link rel="canonical" href="{{ site.url }}{{ page.url | remove: 'index' }}">
+
 <!-- Styles -->
 <link rel="stylesheet" href="/css/main.css">
 
diff --git a/_includes/sidebar.html b/_includes/sidebar.html
index 3d9803e..0227989 100644
--- a/_includes/sidebar.html
+++ b/_includes/sidebar.html
@@ -20,12 +20,13 @@
           {%- endif -%}
         {%- endcapture -%}
         {% assign location = page.url | replace: '/', '' %}
+        {% assign link = link | replace: '_', '-' %}
         {%- if location == link -%}
           <li class='menu-item menu__submenus'>
-            <a class='menu__link menu__link--current' id='{{ link }}' href='{{ link }}'>{{ menu.title }}</a>
+            <a class='menu__link menu__link--current' id='{{ link }}' href='/{{ link }}'>{{ menu.title }}</a>
         {%- else -%}
           <li class='menu-item'>
-            <a class='menu__link' id='{{ link }}' href='{{ link }}'>{{ menu.title }}</a>
+            <a class='menu__link' id='{{ link }}' href='/{{ link }}'>{{ menu.title }}</a>
         {%- endif -%}
           <ul class="submenus">
             {%- for submenu in menu.submenus -%}
@@ -35,7 +36,7 @@ <h4>{{ site.translations[site.lang].pages[menu.url][submenu.key].title }}</h4>
                   {% assign subs = submenu.submenus %}
                   {%- for sub in subs -%}
                   <li>
-                    <a href="/{{ link }}#{{ sub }}">
+                    <a href="/{{ link }}#{{ sub | replace: '_', '-' }}">
                       {{ site.translations[site.lang].pages[menu.url][submenu.key][sub].title }}
                     </a>
                   </li>
@@ -43,7 +44,7 @@ <h4>{{ site.translations[site.lang].pages[menu.url][submenu.key].title }}</h4>
                 </ul>
               {%- else -%}
                 <li>
-                  <a href="/{{ link }}#{{ submenu }}">
+                  <a href="/{{ link }}#{{ submenu | replace: '_', '-' }}">
                     {{ site.translations[site.lang].pages[menu.url][submenu].title }}
                   </a>
                 </li>
diff --git a/_includes/sponsors/234x60.html b/_includes/sponsors/234x60.html
index d85ecd9..a480cd2 100644
--- a/_includes/sponsors/234x60.html
+++ b/_includes/sponsors/234x60.html
@@ -1,3 +1,3 @@
 <div class="sponsor-block with-size-234x60">
-  <a href="https://www.givemepoc.org"><img src="images/{{ site.lang }}/poc.png"/></a>
+  <a href="https://www.givemepoc.org"><img src="images/{{ site.lang }}/poc.png" alt="givmepoc.org"/></a>
 </div>
diff --git a/_pages/algorithms.html b/_pages/algorithms.html
index 8ac6fe6..8d10223 100644
--- a/_pages/algorithms.html
+++ b/_pages/algorithms.html
@@ -14,9 +14,9 @@ <h2>{% t pages.algorithms.sorting.title %}</h2>
   </article>
 
   <article>
-    <h3 id="bubble_sort">{% t pages.algorithms.sorting.bubble_sort.title %}</h3>
+    <h3 id="bubble-sort">{% t pages.algorithms.sorting.bubble_sort.title %}</h3>
     <p>{% t pages.algorithms.sorting.bubble_sort.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="complexity text-align-center">
       {% include algorithm_complexity_header.html %}
       <tbody>
         <tr>
@@ -86,9 +86,9 @@ <h3 id="bubble_sort">{% t pages.algorithms.sorting.bubble_sort.title %}</h3>
   </article>
 
   <article>
-    <h3 id="insertion_sort">{% t pages.algorithms.sorting.insertion_sort.title %}</h3>
+    <h3 id="insertion-sort">{% t pages.algorithms.sorting.insertion_sort.title %}</h3>
     <p>{% t pages.algorithms.sorting.insertion_sort.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="complexity text-align-center">
       {% include algorithm_complexity_header.html %}
       <tbody>
         <tr>
@@ -128,9 +128,9 @@ <h3 id="insertion_sort">{% t pages.algorithms.sorting.insertion_sort.title %}</h
   {% include sponsors/728x90.html %}
 
   <article>
-    <h3 id="selection_sort">{% t pages.algorithms.sorting.selection_sort.title %}</h3>
+    <h3 id="selection-sort">{% t pages.algorithms.sorting.selection_sort.title %}</h3>
     <p>{% t pages.algorithms.sorting.selection_sort.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="complexity text-align-center">
       {% include algorithm_complexity_header.html %}
       <tbody>
         <tr>
@@ -185,9 +185,9 @@ <h3 id="selection_sort">{% t pages.algorithms.sorting.selection_sort.title %}</h
   </article>
 
   <article>
-    <h3 id="shell_sort">{% t pages.algorithms.sorting.shell_sort.title %}</h3>
+    <h3 id="shell-sort">{% t pages.algorithms.sorting.shell_sort.title %}</h3>
     <p>{% t pages.algorithms.sorting.shell_sort.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="complexity text-align-center">
       {% include algorithm_complexity_header.html %}
       <tbody>
         <tr>
@@ -229,9 +229,9 @@ <h3 id="shell_sort">{% t pages.algorithms.sorting.shell_sort.title %}</h3>
   {% include sponsors/728x90.html %}
 
   <article>
-    <h3 id="heap_sort">{% t pages.algorithms.sorting.heap_sort.title %}</h3>
+    <h3 id="heap-sort">{% t pages.algorithms.sorting.heap_sort.title %}</h3>
     <p>{% t pages.algorithms.sorting.heap_sort.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="complexity text-align-center">
       {% include algorithm_complexity_header.html %}
       <tbody>
         <tr>
@@ -287,9 +287,9 @@ <h3 id="heap_sort">{% t pages.algorithms.sorting.heap_sort.title %}</h3>
   </article>
 
   <article>
-    <h3 id="merge_sort">{% t pages.algorithms.sorting.merge_sort.title %}</h3>
+    <h3 id="merge-sort">{% t pages.algorithms.sorting.merge_sort.title %}</h3>
     <p>{% t pages.algorithms.sorting.merge_sort.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="complexity text-align-center">
       {% include algorithm_complexity_header.html %}
       <tbody>
         <tr>
@@ -327,9 +327,9 @@ <h3 id="merge_sort">{% t pages.algorithms.sorting.merge_sort.title %}</h3>
   </article>
 
   <article>
-    <h3 id="quick_sort">{% t pages.algorithms.sorting.quick_sort.title %}</h3>
+    <h3 id="quick-sort">{% t pages.algorithms.sorting.quick_sort.title %}</h3>
     <p>{% t pages.algorithms.sorting.quick_sort.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="complexity text-align-center">
       {% include algorithm_complexity_header.html %}
       <tbody>
         <tr>
@@ -382,10 +382,10 @@ <h2>{% t pages.algorithms.searching.title %}</h2>
   </article>
 
   <article>
-    <h3 id="binary_search">{% t pages.algorithms.searching.binary_search.title %}</h3>
+    <h3 id="binary-search">{% t pages.algorithms.searching.binary_search.title %}</h3>
     <p>{% t pages.algorithms.searching.binary_search.description %}</p>
-    <table class="complexity" style="text-align: center">
-      <thead style="font-weight: bold; text-align: center">
+    <table class="table complexity text-align-center">
+      <thead>
         <tr>
           <td>{% t pages.algorithms.complexity.best %}</td>
           <td>{% t pages.algorithms.complexity.average %}</td>
@@ -437,7 +437,7 @@ <h3 id="binary_search">{% t pages.algorithms.searching.binary_search.title %}</h
   {% include sponsors/728x90.html %}
 
   <article>
-    <h3 id="knuth_moriss_pratt_search">{% t pages.algorithms.searching.knuth_moriss_pratt_search.title %}</h3>
+    <h3 id="knuth-moriss-pratt-search">{% t pages.algorithms.searching.knuth_moriss_pratt_search.title %}</h3>
     <p>{% t pages.algorithms.searching.knuth_moriss_pratt_search.description %}</p>
     <a href="https://en.wikipedia.org/wiki/Binary_search_algorithm">{% t pages.wiki %}</a>
   </article>
diff --git a/_pages/data_structures.html b/_pages/data_structures.html
index 0cee186..f1be7b8 100644
--- a/_pages/data_structures.html
+++ b/_pages/data_structures.html
@@ -15,7 +15,7 @@ <h2>{% t pages.data_structures.axioms.title %}</h2>
   </article>
 
   <article>
-    <h3 id="fetch_store">{% t pages.data_structures.axioms.fetch_store.title %}</h3>
+    <h3 id="fetch-store">{% t pages.data_structures.axioms.fetch_store.title %}</h3>
     <p>{% t pages.data_structures.axioms.fetch_store.description1 %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.data_structures.axioms.fetch_store.title %}</p>
@@ -47,7 +47,7 @@ <h3>{% t pages.data_structures.axioms.elementary_operations.title %}</h3>
   </article>
 
   <article>
-    <h3 id="call_method">{% t pages.data_structures.axioms.call_method.title %}</h3>
+    <h3 id="call-method">{% t pages.data_structures.axioms.call_method.title %}</h3>
     <p>{% t pages.data_structures.axioms.call_method.description1 %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.data_structures.axioms.call_method.title %}</p>
@@ -111,7 +111,7 @@ <h2>{% t pages.data_structures.implementations.title %}</h2>
   <article>
     <h3 id="stack">{% t pages.data_structures.implementations.stack.title %}</h3>
     <p>{% t pages.data_structures.implementations.stack.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
       {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
@@ -268,7 +268,7 @@ <h3 id="stack">{% t pages.data_structures.implementations.stack.title %}</h3>
   <article>
     <h3 id="queue">{% t pages.data_structures.implementations.queue.title %}</h3>
     <p>{% t pages.data_structures.implementations.queue.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
       {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
@@ -367,7 +367,7 @@ <h3 id="queue">{% t pages.data_structures.implementations.queue.title %}</h3>
   <article>
     <h3 id="deque">{% t pages.data_structures.implementations.deque.title %}</h3>
     <p>{% t pages.data_structures.implementations.deque.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
       {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
@@ -472,9 +472,9 @@ <h3 id="deque">{% t pages.data_structures.implementations.deque.title %}</h3>
   </article>
 
   <article>
-    <h3 id="singly_linked_list">{% t pages.data_structures.implementations.singly_linked_list.title %}</h3>
+    <h3 id="singly-linked-list">{% t pages.data_structures.implementations.singly_linked_list.title %}</h3>
     <p>{% t pages.data_structures.implementations.singly_linked_list.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
       {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
@@ -620,9 +620,9 @@ <h3 id="singly_linked_list">{% t pages.data_structures.implementations.singly_li
   </article>
 
   <article>
-    <h3>{% t pages.data_structures.implementations.doubly_linked_list.title %}</h3>
+    <h3 id="doubly-linked-list">{% t pages.data_structures.implementations.doubly_linked_list.title %}</h3>
     <p>{% t pages.data_structures.implementations.doubly_linked_list.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
       {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
@@ -711,9 +711,9 @@ <h3>{% t pages.data_structures.implementations.doubly_linked_list.title %}</h3>
   </article>
 
   <article>
-    <h3 id="ordered_list">{% t pages.data_structures.implementations.ordered_list.title %}</h3>
+    <h3 id="ordered-list">{% t pages.data_structures.implementations.ordered_list.title %}</h3>
     <p>{% t pages.data_structures.implementations.ordered_list.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
      {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
@@ -830,9 +830,9 @@ <h3 id="ordered_list">{% t pages.data_structures.implementations.ordered_list.ti
   </article>
 
   <article>
-    <h3 id="hash_table">{% t pages.data_structures.implementations.hash_table.title %}</h3>
+    <h3 id="hash-table">{% t pages.data_structures.implementations.hash_table.title %}</h3>
     <p>{% t pages.data_structures.implementations.hash_table.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
       {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
@@ -920,9 +920,9 @@ <h3 id="hash_table">{% t pages.data_structures.implementations.hash_table.title
   {% include sponsors/728x90.html %}
 
   <article>
-    <h3 id="binary_tree">{% t pages.data_structures.implementations.binary_tree.title %}</h3>
+    <h3 id="binary-tree">{% t pages.data_structures.implementations.binary_tree.title %}</h3>
     <p>{% t pages.data_structures.implementations.binary_tree.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
       {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
@@ -1010,9 +1010,9 @@ <h3 id="binary_tree">{% t pages.data_structures.implementations.binary_tree.titl
   </article>
 
   <article>
-    <h3 id="binary_search_tree">{% t pages.data_structures.implementations.binary_search_tree.title %}</h3>
+    <h3 id="binary-search-tree">{% t pages.data_structures.implementations.binary_search_tree.title %}</h3>
     <p>{% t pages.data_structures.implementations.binary_search_tree.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
       {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
@@ -1112,9 +1112,9 @@ <h3 id="binary_search_tree">{% t pages.data_structures.implementations.binary_se
   </article>
 
   <article>
-    <h3 id="b_tree">{% t pages.data_structures.implementations.b_tree.title %}</h3>
+    <h3 id="b-tree">{% t pages.data_structures.implementations.b_tree.title %}</h3>
     <p>{% t pages.data_structures.implementations.b_tree.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
       {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
@@ -1193,9 +1193,9 @@ <h3 id="b_tree">{% t pages.data_structures.implementations.b_tree.title %}</h3>
     </div>
   </article>
   <article>
-    <h3 id="binary_heap">{% t pages.data_structures.implementations.binary_heap.title %}</h3>
+    <h3 id="binary-heap">{% t pages.data_structures.implementations.binary_heap.title %}</h3>
     <p>{% t pages.data_structures.implementations.binary_heap.description %}</p>
-    <table class="complexity" style="text-align: center">
+    <table class="table complexity text-align-center">
       {% include data_structure_complexity_header.html %}
       <tbody>
         <tr>
diff --git a/_pages/design_patterns.html b/_pages/design_patterns.html
index ad3ff0a..9a2895a 100644
--- a/_pages/design_patterns.html
+++ b/_pages/design_patterns.html
@@ -15,7 +15,7 @@ <h2>{% t pages.design_patterns.creational.title %}</h2>
   </article>
 
   <article>
-    <h3 id="abstract_factory">{% t pages.design_patterns.creational.abstract_factory.title %}</h3>
+    <h3 id="abstract-factory">{% t pages.design_patterns.creational.abstract_factory.title %}</h3>
     <p>{% t pages.design_patterns.creational.abstract_factory.description %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.design_patterns.creational.abstract_factory.title %}</p>
@@ -706,7 +706,7 @@ <h2>{% t pages.design_patterns.behavioral.title %}</h2>
   </article>
 
   <article>
-    <h3 id="chain_of_responsobility">{% t pages.design_patterns.behavioral.chain_of_responsobility.title %}</h3>
+    <h3 id="chain-of-responsobility">{% t pages.design_patterns.behavioral.chain_of_responsobility.title %}</h3>
     <p>{% t pages.design_patterns.behavioral.chain_of_responsobility.description %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.design_patterns.behavioral.chain_of_responsobility.title %}</p>
diff --git a/_pages/functional_programming.html b/_pages/functional_programming.html
index d8b0a20..bf361ff 100644
--- a/_pages/functional_programming.html
+++ b/_pages/functional_programming.html
@@ -18,7 +18,7 @@ <h1 class="post-title">{% t pages.functional_programming.title %}</h1>
   </article>
 
   <article>
-    <h3 id="pure_functions">{% t pages.functional_programming.pure_functions.title %}</h3>
+    <h3 id="pure-functions">{% t pages.functional_programming.pure_functions.title %}</h3>
     <p>{% t pages.functional_programming.pure_functions.description %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.functional_programming.pure_functions.title %}</p>
diff --git a/_pages/gotchas.html b/_pages/gotchas.html
index 37e7e2a..7477b82 100644
--- a/_pages/gotchas.html
+++ b/_pages/gotchas.html
@@ -91,7 +91,7 @@ <h3 id="twue">{% t pages.gotchas.twue.title %}</h3>
   </article>
 
   <article>
-    <h3 id="symbols_and_strings">{% t pages.gotchas.symbols_and_strings.title %}</h3>
+    <h3 id="symbols-and-strings">{% t pages.gotchas.symbols_and_strings.title %}</h3>
     <p>{% t pages.gotchas.symbols_and_strings.description %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.gotchas.symbols_and_strings.title %}</p>
@@ -112,7 +112,7 @@ <h3 id="symbols_and_strings">{% t pages.gotchas.symbols_and_strings.title %}</h3
   </article>
 
   <article>
-    <h3 id="string_or_nothing">{% t pages.gotchas.string_or_nothing.title %}</h3>
+    <h3 id="string-or-nothing">{% t pages.gotchas.string_or_nothing.title %}</h3>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.gotchas.string_or_nothing.title %}</p>
 {% highlight ruby %}
@@ -615,7 +615,7 @@ <h3 id="freeze">{% t pages.gotchas.freeze.title %}</h3>
   {% include sponsors/728x90.html %}
 
   <article>
-    <h3 id="one_is_one">{% t pages.gotchas.one_is_one.title %}</h3>
+    <h3 id="one-is-one">{% t pages.gotchas.one_is_one.title %}</h3>
     <p>{% t pages.gotchas.one_is_one.description %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.gotchas.one_is_one.title %}</p>
@@ -755,7 +755,7 @@ <h3 id="rescue">{% t pages.gotchas.rescue.title %}</h3>
   </article>
 
   <article>
-    <h3 id="to_str">{% t pages.gotchas.to_str.title %}</h3>
+    <h3 id="to-str">{% t pages.gotchas.to_str.title %}</h3>
     <p>{% t pages.gotchas.to_str.description %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.gotchas.to_str.title %}</p>
diff --git a/_pages/index.html b/_pages/index.html
index e7b08df..2296e54 100644
--- a/_pages/index.html
+++ b/_pages/index.html
@@ -1,6 +1,7 @@
 ---
 layout: default
 priority: 1
+permalink: /
 ---
 
 <div class="content">
diff --git a/_pages/meta_programming.html b/_pages/meta_programming.html
index 2e034c6..ecffd33 100644
--- a/_pages/meta_programming.html
+++ b/_pages/meta_programming.html
@@ -10,7 +10,7 @@ <h1 class="post-title">{% t pages.meta_programming.title %}</h1>
   </article>
 
   <article>
-   <h3 id="dynamic_dispatch">{% t pages.meta_programming.dynamic_dispatch.title %}</h3>
+   <h3 id="dynamic-dispatch">{% t pages.meta_programming.dynamic_dispatch.title %}</h3>
     <p>{% t pages.meta_programming.dynamic_dispatch.description %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.meta_programming.dynamic_dispatch.title %}</p>
@@ -26,7 +26,7 @@ <h3 id="dynamic_dispatch">{% t pages.meta_programming.dynamic_dispatch.title %}<
   </article>
 
   <article>
-    <h3 id="dynamic_method">{% t pages.meta_programming.dynamic_method.title %}</h3>
+    <h3 id="dynamic-method">{% t pages.meta_programming.dynamic_method.title %}</h3>
     <p>{% t pages.meta_programming.dynamic_method.description %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.meta_programming.dynamic_method.title %}</p>
@@ -140,7 +140,7 @@ <h3 id="dynamic_method">{% t pages.meta_programming.dynamic_method.title %}</h3>
   </article>
 
   <article>
-    <h3 id="dynamic_proxies">{% t pages.meta_programming.dynamic_proxies.title %}</h3>
+    <h3 id="dynamic-proxies">{% t pages.meta_programming.dynamic_proxies.title %}</h3>
     <p>{% t pages.meta_programming.dynamic_proxies.description %}</p>
     <div class="code-block">
       <p class="spec-title spec-correct">{% t pages.meta_programming.dynamic_proxies.title %}</p>
diff --git a/_pages/solid_principles.html b/_pages/solid_principles.html
index d7ce506..edc01ac 100644
--- a/_pages/solid_principles.html
+++ b/_pages/solid_principles.html
@@ -83,7 +83,7 @@ <h3 id="single">{% t pages.solid_principles.single.title %}</h3>
   </article>
 
   <article>
-    <h3 id="open_close">{% t pages.solid_principles.open_close.title %}</h3>
+    <h3 id="open-close">{% t pages.solid_principles.open_close.title %}</h3>
     <p>{% t pages.solid_principles.open_close.description %}</p>
     <div class="code-block">
       <p class="spec-title spec-wrong">{% t pages.solid_principles.bad %}</p>
diff --git a/_sass/_base.scss b/_sass/_base.scss
index 9761d9f..90d9049 100644
--- a/_sass/_base.scss
+++ b/_sass/_base.scss
@@ -721,3 +721,14 @@ article,
     background-color: $c-bg;
   }
 }
+
+.table {
+  &.complexity {
+    font-weight: bold;
+    text-align: center;
+  }
+}
+
+.text-align-center {
+  text-align: center;
+}
diff --git a/favicon.ico b/favicon.ico
new file mode 100644
index 0000000..708dc70
Binary files /dev/null and b/favicon.ico differ
diff --git a/javascripts/vendor/classie.js b/javascripts/vendor/classie.js
index 32af54c..d5d04d6 100644
--- a/javascripts/vendor/classie.js
+++ b/javascripts/vendor/classie.js
@@ -1,72 +1 @@
-/*!
- * classie v1.0.1
- * class helper functions
- * from bonzo https://github.com/ded/bonzo
- * MIT license
- *
- * classie.has( elem, 'my-class' ) -> true/false
- * classie.add( elem, 'my-new-class' )
- * classie.remove( elem, 'my-unwanted-class' )
- * classie.toggle( elem, 'my-class' )
- */
-
-/* jshint browser: true, strict: true, undef: true, unused: true */
-/* global define: false, module: false */
-
-(function(window) {
-  'use strict';
-
-  function classReg(className) {
-    return new RegExp('(^|\\s+)' + className + '(\\s+|$)');
-  }
-  var hasClass, addClass, removeClass;
-
-  if ('classList' in window.document.documentElement) {
-    hasClass = function(elem, c) {
-      return elem.classList.contains(c);
-    };
-    addClass = function(elem, c) {
-      elem.classList.add(c);
-    };
-    removeClass = function(elem, c) {
-      elem.classList.remove(c);
-    };
-  }
-  else {
-    hasClass = function(elem, c) {
-      return classReg(c).test(elem.className);
-    };
-    addClass = function(elem, c) {
-      if (!hasClass(elem, c)) {
-        elem.className = elem.className + ' ' + c;
-      }
-    };
-    removeClass = function(elem, c) {
-      elem.className = elem.className.replace(classReg(c), ' ');
-    };
-  }
-
-  function toggleClass(elem, c) {
-    var fn = hasClass(elem, c) ? removeClass : addClass;
-    fn(elem, c);
-  }
-
-  var classie = {
-    hasClass: hasClass,
-    addClass: addClass,
-    removeClass: removeClass,
-    toggleClass: toggleClass,
-    has: hasClass,
-    add: addClass,
-    remove: removeClass,
-    toggle: toggleClass
-  };
-
-  if (typeof define === 'function' && define.amd) {
-    define(classie);
-  } else if (typeof exports === 'object') {
-    module.exports = classie;
-  } else {
-    window.classie = classie;
-  }
-})(window);
+!function(s){"use strict";function e(s){return new RegExp("(^|\\s+)"+s+"(\\s+|$)")}var n,t,a;function c(s,e){(n(s,e)?a:t)(s,e)}"classList"in s.document.documentElement?(n=function(s,e){return s.classList.contains(e)},t=function(s,e){s.classList.add(e)},a=function(s,e){s.classList.remove(e)}):(n=function(s,n){return e(n).test(s.className)},t=function(s,e){n(s,e)||(s.className=s.className+" "+e)},a=function(s,n){s.className=s.className.replace(e(n)," ")});var o={hasClass:n,addClass:t,removeClass:a,toggleClass:c,has:n,add:t,remove:a,toggle:c};"function"==typeof define&&define.amd?define(o):"object"==typeof exports?module.exports=o:s.classie=o}(window);
\ No newline at end of file