diff --git a/000.md b/000.md
index 7dc7027b..e45dadff 100644
--- a/000.md
+++ b/000.md
@@ -8,7 +8,7 @@ title:  "GitHub Page Configuration Files"
 
 ```
 title: Operating Systems - Sistem Operasi
-version:     "613a---23-Jul-2024"
+version:     "613b---23-Jul-2024"
 copyright:   "2018-2024"
 description: This is the Operating System course site,
       a GitHub Page, hosted at GitHub.com (thank you!).
@@ -42,16 +42,24 @@ github:           [metadata]
 ### Gemfile
 
 ```
-source 'https://rubygems.org'
+source "https://rubygems.org"
 
-gem 'jekyll-sitemap'
-gem 'github-pages', group: :jekyll_plugins
+group :jekyll_plugins do
 gem "addressable"
-gem "nokogiri"
 gem "faraday-retry"
-gem 'webrick'
-gem "minitest"
 gem "ffi"
+gem "github-pages"
+gem "jekyll"
+gem "jekyll-sitemap"
+gem "jekyll-seo-tag"
+gem "jekyll-feed"
+gem "jekyll-paginate"
+gem "minitest"
+gem "nokogiri"
+gem "readline-ext"
+gem "tzinfo-data"
+gem "webrick"
+end
 
 ```
 
@@ -157,11 +165,12 @@ ALL: 000.md
 
 ```
 {% raw %}
-<!-- File _includes/navbar.html           -->
-<!-- (c) 2021 - 2021 VauLSMorg            -->
-<!-- REV02: Thu 26 Aug 2021 16:35:26 WIB  -->
-<!-- START: Wed 17 Feb 2021 19:48:31 WIB  -->
-<!-- This is a free HTML file             -->
+<!-- File _includes/navbar.html   -->
+<!-- (c) 2021 - 2024 VauLSMorg    -->
+<!-- REV03: Tue 23 Jul 2024 13:00 -->
+<!-- REV02: Thu 26 Aug 2021 16:00 -->
+<!-- START: Wed 17 Feb 2021 19:00 -->
+<!-- This is a free HTML file     -->
 <nav class="navbar">
   <ul>
     <li class='listitem'><a href='{{ site.baseurl }}/'>HOME</a></li>
@@ -211,10 +220,14 @@ ALL: 000.md
 
 .plainclass1 h1 {
   color:            hsl(100, 50%, 50%);
+  font-size:        1.9em;
+  font-weight:      bold;
 }
 
 .plainclass1 h2 {
   color:            hsl(100, 50%, 50%);
+  font-size:        1.4em;
+  font-weight:      bold;
 }
 
 .plainclass1 h3 {
@@ -240,6 +253,10 @@ ALL: 000.md
   color: #f0f0f0;
 }
 
+.textleft {
+  text-align:   left;
+}
+
 .row {
 }
 
@@ -315,6 +332,16 @@ ALL: 000.md
   clear: both;
 }
 
+td {
+  padding-top:      3px;
+  padding-bottom:   3px;
+}
+
+li {
+  padding-top:      3px;
+  padding-bottom:   3px;
+}
+
 .navbar {
   background-color: #101010;
   color:            #FFFFFF;
@@ -340,10 +367,15 @@ ALL: 000.md
 }
 
 pre {
-  border:        3px solid rgba(255, 255, 255, 0.15);
-  padding:       10px; 
-  color:         #b5e853;
-  border-radius: 2px;
+  background-color: hsla(0,     0%,    0%, 1);
+  border:           1px solid hsla(0,    50%,   20%, 1);
+  padding:          10px;
+  font-size:        16px;
+  color:            hsla(0,   100%,  100%, 1);
+  border-radius:    2px;
+  word-wrap:        normal;
+  overflow:         auto;
+  overflow-y:       hidden;
 }
 
 table {
diff --git a/Gemfile b/Gemfile
index 15372814..b52f7718 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,11 +1,19 @@
-source 'https://rubygems.org'
+source "https://rubygems.org"
 
-gem 'jekyll-sitemap'
-gem 'github-pages', group: :jekyll_plugins
+group :jekyll_plugins do
 gem "addressable"
-gem "nokogiri"
 gem "faraday-retry"
-gem 'webrick'
-gem "minitest"
 gem "ffi"
+gem "github-pages"
+gem "jekyll"
+gem "jekyll-sitemap"
+gem "jekyll-seo-tag"
+gem "jekyll-feed"
+gem "jekyll-paginate"
+gem "minitest"
+gem "nokogiri"
+gem "readline-ext"
+gem "tzinfo-data"
+gem "webrick"
+end
 
diff --git a/_config.yml b/_config.yml
index fb43f3de..8e5fa355 100644
--- a/_config.yml
+++ b/_config.yml
@@ -1,5 +1,5 @@
 title: Operating Systems - Sistem Operasi
-version:     "613a---23-Jul-2024"
+version:     "613b---23-Jul-2024"
 copyright:   "2018-2024"
 description: This is the Operating System course site,
       a GitHub Page, hosted at GitHub.com (thank you!).
diff --git a/_includes/navbar.html b/_includes/navbar.html
index 72a95a1a..c7543ac8 100644
--- a/_includes/navbar.html
+++ b/_includes/navbar.html
@@ -1,8 +1,9 @@
-<!-- File _includes/navbar.html           -->
-<!-- (c) 2021 - 2021 VauLSMorg            -->
-<!-- REV02: Thu 26 Aug 2021 16:35:26 WIB  -->
-<!-- START: Wed 17 Feb 2021 19:48:31 WIB  -->
-<!-- This is a free HTML file             -->
+<!-- File _includes/navbar.html   -->
+<!-- (c) 2021 - 2024 VauLSMorg    -->
+<!-- REV03: Tue 23 Jul 2024 13:00 -->
+<!-- REV02: Thu 26 Aug 2021 16:00 -->
+<!-- START: Wed 17 Feb 2021 19:00 -->
+<!-- This is a free HTML file     -->
 <nav class="navbar">
   <ul>
     <li class='listitem'><a href='{{ site.baseurl }}/'>HOME</a></li>
diff --git a/assets/css/style.css b/assets/css/style.css
index bd4f2136..3d644528 100644
--- a/assets/css/style.css
+++ b/assets/css/style.css
@@ -28,10 +28,14 @@
 
 .plainclass1 h1 {
   color:            hsl(100, 50%, 50%);
+  font-size:        1.9em;
+  font-weight:      bold;
 }
 
 .plainclass1 h2 {
   color:            hsl(100, 50%, 50%);
+  font-size:        1.4em;
+  font-weight:      bold;
 }
 
 .plainclass1 h3 {
@@ -57,6 +61,10 @@
   color: #f0f0f0;
 }
 
+.textleft {
+  text-align:   left;
+}
+
 .row {
 }
 
@@ -132,6 +140,16 @@
   clear: both;
 }
 
+td {
+  padding-top:      3px;
+  padding-bottom:   3px;
+}
+
+li {
+  padding-top:      3px;
+  padding-bottom:   3px;
+}
+
 .navbar {
   background-color: #101010;
   color:            #FFFFFF;
@@ -157,10 +175,15 @@
 }
 
 pre {
-  border:        3px solid rgba(255, 255, 255, 0.15);
-  padding:       10px; 
-  color:         #b5e853;
-  border-radius: 2px;
+  background-color: hsla(0,     0%,    0%, 1);
+  border:           1px solid hsla(0,    50%,   20%, 1);
+  padding:          10px;
+  font-size:        16px;
+  color:            hsla(0,   100%,  100%, 1);
+  border-radius:    2px;
+  word-wrap:        normal;
+  overflow:         auto;
+  overflow-y:       hidden;
 }
 
 table {