diff --git a/book.toml b/book.toml
index 91ee231..935cb0e 100644
--- a/book.toml
+++ b/book.toml
@@ -7,4 +7,9 @@ src = "src"
 
 [output.html]
 theme = "src/theme"
+default-theme = "rust"
 git-repository-url = "https://git.oyd.org.tr/oyd/guvenlik"
+
+[output.html.search]
+enable = true
+
diff --git a/src/theme/css/variables.css b/src/theme/css/variables.css
new file mode 100644
index 0000000..1f23035
--- /dev/null
+++ b/src/theme/css/variables.css
@@ -0,0 +1,246 @@
+
+/* Globals */
+
+:root {
+    --sidebar-width: 300px;
+    --page-padding: 15px;
+    --content-max-width: 750px;
+    --menu-bar-height: 50px;
+}
+
+/* Themes */
+
+.ayu {
+    --bg: hsl(210, 25%, 8%);
+    --fg: #c5c5c5;
+
+    --sidebar-bg: #14191f;
+    --sidebar-fg: #c8c9db;
+    --sidebar-non-existant: #5c6773;
+    --sidebar-active: #ffb454;
+    --sidebar-spacer: #2d334f;
+
+    --scrollbar: var(--sidebar-fg);
+
+    --icons: #737480;
+    --icons-hover: #b7b9cc;
+
+    --links: #0096cf;
+
+    --inline-code-color: #ffb454;
+
+    --theme-popup-bg: #14191f;
+    --theme-popup-border: #5c6773;
+    --theme-hover: #191f26;
+
+    --quote-bg: hsl(226, 15%, 17%);
+    --quote-border: hsl(226, 15%, 22%);
+
+    --table-border-color: hsl(210, 25%, 13%);
+    --table-header-bg: hsl(210, 25%, 28%);
+    --table-alternate-bg: hsl(210, 25%, 11%);
+
+    --searchbar-border-color: #848484;
+    --searchbar-bg: #424242;
+    --searchbar-fg: #fff;
+    --searchbar-shadow-color: #d4c89f;
+    --searchresults-header-fg: #666;
+    --searchresults-border-color: #888;
+    --searchresults-li-bg: #252932;
+    --search-mark-bg: #e3b171;
+}
+
+.coal {
+    --bg: hsl(200, 7%, 8%);
+    --fg: #98a3ad;
+
+    --sidebar-bg: #292c2f;
+    --sidebar-fg: #a1adb8;
+    --sidebar-non-existant: #505254;
+    --sidebar-active: #3473ad;
+    --sidebar-spacer: #393939;
+
+    --scrollbar: var(--sidebar-fg);
+
+    --icons: #43484d;
+    --icons-hover: #b3c0cc;
+
+    --links: #2b79a2;
+
+    --inline-code-color: #c5c8c6;;
+
+    --theme-popup-bg: #141617;
+    --theme-popup-border: #43484d;
+    --theme-hover: #1f2124;
+
+    --quote-bg: hsl(234, 21%, 18%);
+    --quote-border: hsl(234, 21%, 23%);
+
+    --table-border-color: hsl(200, 7%, 13%);
+    --table-header-bg: hsl(200, 7%, 28%);
+    --table-alternate-bg: hsl(200, 7%, 11%);
+
+    --searchbar-border-color: #aaa;
+    --searchbar-bg: #b7b7b7;
+    --searchbar-fg: #000;
+    --searchbar-shadow-color: #aaa;
+    --searchresults-header-fg: #666;
+    --searchresults-border-color: #98a3ad;
+    --searchresults-li-bg: #2b2b2f;
+    --search-mark-bg: #355c7d;
+}
+
+.light {
+    --bg: hsl(0, 0%, 100%);
+    --fg: #333333;
+
+    --sidebar-bg: #fafafa;
+    --sidebar-fg: #364149;
+    --sidebar-non-existant: #aaaaaa;
+    --sidebar-active: #008cff;
+    --sidebar-spacer: #f4f4f4;
+
+    --scrollbar: #cccccc;
+
+    --icons: #cccccc;
+    --icons-hover: #333333;
+
+    --links: #4183c4;
+
+    --inline-code-color: #6e6b5e;
+
+    --theme-popup-bg: #fafafa;
+    --theme-popup-border: #cccccc;
+    --theme-hover: #e6e6e6;
+
+    --quote-bg: hsl(197, 37%, 96%);
+    --quote-border: hsl(197, 37%, 91%);
+
+    --table-border-color: hsl(0, 0%, 95%);
+    --table-header-bg: hsl(0, 0%, 80%);
+    --table-alternate-bg: hsl(0, 0%, 97%);
+
+    --searchbar-border-color: #aaa;
+    --searchbar-bg: #fafafa;
+    --searchbar-fg: #000;
+    --searchbar-shadow-color: #aaa;
+    --searchresults-header-fg: #666;
+    --searchresults-border-color: #888;
+    --searchresults-li-bg: #e4f2fe;
+    --search-mark-bg: #a2cff5;
+}
+
+.navy {
+    --bg: hsl(226, 23%, 11%);
+    --fg: #bcbdd0;
+
+    --sidebar-bg: #282d3f;
+    --sidebar-fg: #c8c9db;
+    --sidebar-non-existant: #505274;
+    --sidebar-active: #2b79a2;
+    --sidebar-spacer: #2d334f;
+
+    --scrollbar: var(--sidebar-fg);
+
+    --icons: #737480;
+    --icons-hover: #b7b9cc;
+
+    --links: #2b79a2;
+
+    --inline-code-color: #c5c8c6;;
+
+    --theme-popup-bg: #161923;
+    --theme-popup-border: #737480;
+    --theme-hover: #282e40;
+
+    --quote-bg: hsl(226, 15%, 17%);
+    --quote-border: hsl(226, 15%, 22%);
+
+    --table-border-color: hsl(226, 23%, 16%);
+    --table-header-bg: hsl(226, 23%, 31%);
+    --table-alternate-bg: hsl(226, 23%, 14%);
+
+    --searchbar-border-color: #aaa;
+    --searchbar-bg: #aeaec6;
+    --searchbar-fg: #000;
+    --searchbar-shadow-color: #aaa;
+    --searchresults-header-fg: #5f5f71;
+    --searchresults-border-color: #5c5c68;
+    --searchresults-li-bg: #242430;
+    --search-mark-bg: #a2cff5;
+}
+
+.rust {
+    --bg: #e0d7de;
+    --fg: #262625;
+    --sidebar-bg: #4c2447;
+    --sidebar-fg: #c8c9db;
+    --sidebar-non-existant: #505254;
+    --sidebar-active: #83577D;
+    --sidebar-spacer: #45373a;
+    --scrollbar: var(--sidebar-fg);
+    --icons: #737480;
+    --icons-hover: #262625;
+    --links: #2b79a2;
+    --inline-code-color: #6e6b5e;
+    --theme-popup-bg: #e1e1db;
+    --theme-popup-border: #b38f6b;
+    --theme-hover: #99908a;
+    --quote-bg: hsl(60, 5%, 75%);
+    --quote-border: hsl(60, 5%, 70%);
+    --table-border-color: hsl(60, 9%, 82%);
+    --table-header-bg: #83577D;
+    --table-alternate-bg: hsl(60, 9%, 84%);
+    --searchbar-border-color: #aaa;
+    --searchbar-bg: #fafafa;
+    --searchbar-fg: #000;
+    --searchbar-shadow-color: #aaa;
+    --searchresults-header-fg: #666;
+    --searchresults-border-color: #888;
+    --searchresults-li-bg: #dec2a2;
+    --search-mark-bg: #e69f67;
+}
+
+@media (prefers-color-scheme: dark) {
+    .light.no-js {
+        --bg: hsl(200, 7%, 8%);
+        --fg: #98a3ad;
+
+        --sidebar-bg: #292c2f;
+        --sidebar-fg: #a1adb8;
+        --sidebar-non-existant: #505254;
+        --sidebar-active: #3473ad;
+        --sidebar-spacer: #393939;
+
+        --scrollbar: var(--sidebar-fg);
+
+        --icons: #43484d;
+        --icons-hover: #b3c0cc;
+
+        --links: #2b79a2;
+
+        --inline-code-color: #c5c8c6;;
+
+        --theme-popup-bg: #141617;
+        --theme-popup-border: #43484d;
+        --theme-hover: #1f2124;
+
+        --quote-bg: hsl(234, 21%, 18%);
+        --quote-border: hsl(234, 21%, 23%);
+
+        --table-border-color: hsl(200, 7%, 13%);
+        --table-header-bg: hsl(200, 7%, 28%);
+        --table-alternate-bg: hsl(200, 7%, 11%);
+
+        --searchbar-border-color: #aaa;
+        --searchbar-bg: #b7b7b7;
+        --searchbar-fg: #000;
+        --searchbar-shadow-color: #aaa;
+        --searchresults-header-fg: #666;
+        --searchresults-border-color: #98a3ad;
+        --searchresults-li-bg: #2b2b2f;
+        --search-mark-bg: #355c7d;
+    }
+}
+
+
diff --git a/src/theme/favicon.ico b/src/theme/favicon.ico
new file mode 100644
index 0000000..5f2bb85
Binary files /dev/null and b/src/theme/favicon.ico differ
diff --git a/src/theme/head.hbs b/src/theme/head.hbs
new file mode 100644
index 0000000..6ea29c0
--- /dev/null
+++ b/src/theme/head.hbs
@@ -0,0 +1,12 @@
+<meta property="og:title" content="{{chapter_title}} - Özgür Yazılım Derneği Güvenlik Rehberi" />
+<meta property="og:type" content="article" />
+<meta property="og:url" content="https://guvenlik.oyd.org.tr" />
+<meta property="og:description" content="{{chapter_title}} - Güvenlik Rehberi" />
+<meta property="og:image" content="/oyd_social.png?v=2" />
+<meta property="og:site_name" content="Özgür Yazılım Derneği Güvenlik Rehberi" />
+<meta name="twitter:card" content="summary_image" />
+<meta name="twitter:site" content="@oydorgtr" />
+<meta name="twitter:title" content="{{chapter_title}} - Özgür Yazılım Derneği Güvenlik Rehberi">
+<meta name="twitter:description" content="{{chapter_title}} - Güvenlik Rehberi">
+<meta name="twitter:creator" content="@oydorgtr" />
+<meta name="twitter:image" content="https://oyd.org.tr/oyd_social.png?48123">
\ No newline at end of file