diff --git a/README.md b/README.md
index 0f56398ce..614bf6211 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 <p align="center">
   <a href="https://www.hello-algo.com/">
-    <img src="https://www.hello-algo.com/index.assets/hello_algo_header.png" width="450"></a>
+    <img src="/docs/index.assets/hello_algo_header.png" width="450"></a>
 </p>
 
 <p align="center">
@@ -11,30 +11,30 @@
 
 <p align="center">
   <a href="https://www.hello-algo.com/">
-    <img src="https://www.hello-algo.com/index.assets/btn_read_online_dark.svg" height="45"></a>
+    <img src="/docs/index.assets/btn_read_online_dark.svg" height="45"></a>
   <a href="https://github.com/krahets/hello-algo/releases">
-    <img src="https://www.hello-algo.com/index.assets/btn_download_pdf_epub_dark.svg" height="45"></a>
+    <img src="/docs/index.assets/btn_download_pdf_epub_dark.svg" height="45"></a>
 </p>
 
 <p align="center">
-  <img src="https://www.hello-algo.com/index.assets/animation.gif" width="395">
-  <img src="https://www.hello-algo.com/index.assets/running_code.gif" width="395">
+  <img src="/docs/index.assets/animation.gif" width="395">
+  <img src="/docs/index.assets/running_code.gif" width="395">
 </p>
 
 <p align="center">
-  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB" alt="" />
-  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02" alt="" />
-  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C" alt="" />
-  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC" alt="" />
-  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4" alt="" />
-  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30" alt="" />
-  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8" alt="" />
-  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138" alt="" />
-  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000" alt="" />
-  <img src="https://img.shields.io/badge/Ruby-snow?logo=ruby&logoColor=CC342D" alt="" />
-  <img src="https://img.shields.io/badge/Kotlin-snow?logo=kotlin&logoColor=7F52FF" alt="" />
-  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6" alt="" />
-  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2" alt="" />
+  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB" alt="Python" />
+  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02" alt="Java" />
+  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C" alt="C++" />
+  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC" alt="C" />
+  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4" alt="C#" />
+  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30" alt="JavaScript" />
+  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8" alt="Go" />
+  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138" alt="Swift" />
+  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000" alt="Rust" />
+  <img src="https://img.shields.io/badge/Ruby-snow?logo=ruby&logoColor=CC342D" alt="Ruby" />
+  <img src="https://img.shields.io/badge/Kotlin-snow?logo=kotlin&logoColor=7F52FF" alt="Kotlin" />
+  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6" alt="TypeScript" />
+  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2" alt="Dart" />
 </p>
 
 <p align="center">
diff --git a/en/README.md b/en/README.md
index e58d03ccf..dc2e66110 100644
--- a/en/README.md
+++ b/en/README.md
@@ -1,6 +1,6 @@
 <p align="center">
   <a href="https://www.hello-algo.com/en/">
-    <img src="https://www.hello-algo.com/en/index.assets/hello_algo_header.png" width="450"></a>
+    <img src="/en/docs/index.assets/hello_algo_header.png" width="450"></a>
 </p>
 
 <p align="center">
@@ -11,30 +11,30 @@
 
 <p align="center">
   <a href="https://www.hello-algo.com/en/">
-    <img src="https://www.hello-algo.com/en/index.assets/btn_read_online_dark.svg" height="45"></a>
+    <img src="/en/docs/index.assets/btn_read_online_dark.svg" height="45"></a>
   <a href="https://github.com/krahets/hello-algo/releases">
-    <img src="https://www.hello-algo.com/en/index.assets/btn_download_pdf_epub_dark.svg" height="45"></a>
+    <img src="/en/docs/index.assets/btn_download_pdf_epub_dark.svg" height="45"></a>
 </p>
 
 <p align="center">
-  <img src="https://www.hello-algo.com/index.assets/animation.gif" width="395">
-  <img src="https://www.hello-algo.com/index.assets/running_code.gif" width="395">
+  <img src="/en/docs/index.assets/animation.gif" width="395">
+  <img src="/en/docs/index.assets/running_code.gif" width="395">
 </p>
 
 <p align="center">
-  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB" alt="" />
-  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02" alt="" />
-  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C" alt="" />
-  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC" alt="" />
-  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4" alt="" />
-  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30" alt="" />
-  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8" alt="" />
-  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138" alt="" />
-  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000" alt="" />
-  <img src="https://img.shields.io/badge/Ruby-snow?logo=ruby&logoColor=CC342D" alt="" />
-  <img src="https://img.shields.io/badge/Kotlin-snow?logo=kotlin&logoColor=7F52FF" alt="" />
-  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6" alt="" />
-  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2" alt="" />
+  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB" alt="Python" />
+  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02" alt="Java" />
+  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C" alt="C++" />
+  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC" alt="C" />
+  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4" alt="C#" />
+  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30" alt="JavaScript" />
+  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8" alt="Go" />
+  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138" alt="Swift" />
+  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000" alt="Rust" />
+  <img src="https://img.shields.io/badge/Ruby-snow?logo=ruby&logoColor=CC342D" alt="Ruby" />
+  <img src="https://img.shields.io/badge/Kotlin-snow?logo=kotlin&logoColor=7F52FF" alt="Kotlin" />
+  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6" alt="TypeScript" />
+  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2" alt="Dart" />
 </p>
 
 <p align="center">
diff --git a/ja/README.md b/ja/README.md
index fd2011aa3..6f7109b2b 100644
--- a/ja/README.md
+++ b/ja/README.md
@@ -1,6 +1,6 @@
 <p align="center">
   <a href="https://www.hello-algo.com/ja/">
-    <img src="https://www.hello-algo.com/en/index.assets/hello_algo_header.png" width="450"></a>
+    <img src="/ja/docs/index.assets/hello_algo_header.png" width="450"></a>
 </p>
 
 <p align="center">
@@ -11,30 +11,30 @@
 
 <p align="center">
   <a href="https://www.hello-algo.com/ja/">
-    <img src="https://www.hello-algo.com/en/index.assets/btn_read_online_dark.svg" height="45"></a>
+    <img src="/ja/docs/index.assets/btn_read_online_dark.svg" height="45"></a>
   <a href="https://github.com/krahets/hello-algo/releases">
-    <img src="https://www.hello-algo.com/en/index.assets/btn_download_pdf_epub_dark.svg" height="45"></a>
+    <img src="/ja/docs/index.assets/btn_download_pdf_epub_dark.svg" height="45"></a>
 </p>
 
 <p align="center">
-  <img src="https://www.hello-algo.com/index.assets/animation.gif" width="395">
-  <img src="https://www.hello-algo.com/index.assets/running_code.gif" width="395">
+  <img src="/ja/docs/index.assets/animation.gif" width="395">
+  <img src="/ja/docs/index.assets/running_code.gif" width="395">
 </p>
 
 <p align="center">
-  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB" alt="" />
-  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02" alt="" />
-  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C" alt="" />
-  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC" alt="" />
-  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4" alt="" />
-  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30" alt="" />
-  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8" alt="" />
-  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138" alt="" />
-  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000" alt="" />
-  <img src="https://img.shields.io/badge/Ruby-snow?logo=ruby&logoColor=CC342D" alt="" />
-  <img src="https://img.shields.io/badge/Kotlin-snow?logo=kotlin&logoColor=7F52FF" alt="" />
-  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6" alt="" />
-  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2" alt="" />
+  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB" alt="Python" />
+  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02" alt="Java" />
+  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C" alt="C++" />
+  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC" alt="C" />
+  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4" alt="C#" />
+  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30" alt="JavaScript" />
+  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8" alt="Go" />
+  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138" alt="Swift" />
+  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000" alt="Rust" />
+  <img src="https://img.shields.io/badge/Ruby-snow?logo=ruby&logoColor=CC342D" alt="Ruby" />
+  <img src="https://img.shields.io/badge/Kotlin-snow?logo=kotlin&logoColor=7F52FF" alt="Kotlin" />
+  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6" alt="TypeScript" />
+  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2" alt="Dart" />
 </p>
 
 <p align="center">
diff --git a/ru/README.md b/ru/README.md
index 7285dbb6f..8f04428fe 100644
--- a/ru/README.md
+++ b/ru/README.md
@@ -1,6 +1,6 @@
 <p align="center">
   <a href="https://www.hello-algo.com/ru/">
-    <img src="https://www.hello-algo.com/index.assets/hello_algo_header.png" width="450"></a>
+    <img src="/docs/index.assets/hello_algo_header.png" width="450"></a>
 </p>
 
 <p align="center">
@@ -16,24 +16,24 @@
 </p>
 
 <p align="center">
-  <img src="https://www.hello-algo.com/index.assets/animation.gif" width="395">
-  <img src="https://www.hello-algo.com/index.assets/running_code.gif" width="395">
+  <img src="/ru/docs/index.assets/animation.gif" width="395">
+  <img src="/ru/docs/index.assets/running_code.gif" width="395">
 </p>
 
 <p align="center">
-  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB" alt="" />
-  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02" alt="" />
-  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C" alt="" />
-  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC" alt="" />
-  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4" alt="" />
-  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30" alt="" />
-  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8" alt="" />
-  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138" alt="" />
-  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000" alt="" />
-  <img src="https://img.shields.io/badge/Ruby-snow?logo=ruby&logoColor=CC342D" alt="" />
-  <img src="https://img.shields.io/badge/Kotlin-snow?logo=kotlin&logoColor=7F52FF" alt="" />
-  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6" alt="" />
-  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2" alt="" />
+  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB" alt="Python" />
+  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02" alt="Java" />
+  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C" alt="C++" />
+  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC" alt="C" />
+  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4" alt="C#" />
+  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30" alt="JavaScript" />
+  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8" alt="Go" />
+  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138" alt="Swift" />
+  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000" alt="Rust" />
+  <img src="https://img.shields.io/badge/Ruby-snow?logo=ruby&logoColor=CC342D" alt="Ruby" />
+  <img src="https://img.shields.io/badge/Kotlin-snow?logo=kotlin&logoColor=7F52FF" alt="Kotlin" />
+  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6" alt="TypeScript" />
+  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2" alt="Dart" />
 </p>
 
 <p align="center">
diff --git a/zh-hant/README.md b/zh-hant/README.md
index b9a4efc4f..beed08ace 100644
--- a/zh-hant/README.md
+++ b/zh-hant/README.md
@@ -1,6 +1,6 @@
 <p align="center">
   <a href="https://www.hello-algo.com/">
-    <img src="https://www.hello-algo.com/index.assets/hello_algo_header.png" width="450"></a>
+    <img src="/zh-hant/docs/index.assets/hello_algo_header.png" width="450"></a>
 </p>
 
 <p align="center">
@@ -11,30 +11,30 @@
 
 <p align="center">
   <a href="https://www.hello-algo.com/zh-hant/">
-    <img src="https://www.hello-algo.com/zh-hant/index.assets/btn_read_online_dark.svg" height="45"></a>
+    <img src="/zh-hant/docs/index.assets/btn_read_online_dark.svg" height="45"></a>
   <a href="https://github.com/krahets/hello-algo/releases">
-    <img src="https://www.hello-algo.com/zh-hant/index.assets/btn_download_pdf_epub_dark.svg" height="45"></a>
+    <img src="/zh-hant/docs/index.assets/btn_download_pdf_epub_dark.svg" height="45"></a>
 </p>
 
 <p align="center">
-  <img src="https://www.hello-algo.com/index.assets/animation.gif" width="395">
-  <img src="https://www.hello-algo.com/index.assets/running_code.gif" width="395">
+  <img src="/zh-hant/docs/index.assets/animation.gif" width="395">
+  <img src="/zh-hant/docs/index.assets/running_code.gif" width="395">
 </p>
 
 <p align="center">
-  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB" alt="" />
-  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02" alt="" />
-  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C" alt="" />
-  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC" alt="" />
-  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4" alt="" />
-  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30" alt="" />
-  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8" alt="" />
-  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138" alt="" />
-  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000" alt="" />
-  <img src="https://img.shields.io/badge/Ruby-snow?logo=ruby&logoColor=CC342D" alt="" />
-  <img src="https://img.shields.io/badge/Kotlin-snow?logo=kotlin&logoColor=7F52FF" alt="" />
-  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6" alt="" />
-  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2" alt="" />
+  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB" alt="Python" />
+  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02" alt="Java" />
+  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C" alt="C++" />
+  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC" alt="C" />
+  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4" alt="C#" />
+  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30" alt="JavaScript" />
+  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8" alt="Go" />
+  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138" alt="Swift" />
+  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000" alt="Rust" />
+  <img src="https://img.shields.io/badge/Ruby-snow?logo=ruby&logoColor=CC342D" alt="Ruby" />
+  <img src="https://img.shields.io/badge/Kotlin-snow?logo=kotlin&logoColor=7F52FF" alt="Kotlin" />
+  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6" alt="TypeScript" />
+  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2" alt="Dart" />
 </p>
 
 <p align="center">