diff --git a/.eslintrc.json b/.eslintrc.json
index c6d0760..8ad7011 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -1,25 +1,22 @@
 {
-    "env": {
-        "browser": true,
-        "es2021": true
-    },
-    "extends": [
-        "airbnb",
-        "plugin:react/recommended",
-        "plugin:prettier/recommended"
-    ],
-    "overrides": [
-    ],
-    "parserOptions": {
-        "ecmaVersion": "latest",
-        "sourceType": "module"
-    },
-    "plugins": [
-        "react"
-    ],
-    "rules": {
-        "no-console": "warn",
-        "react/react-in-jsx-scope": "off",
-        "react/jsx-filename-extension": [1, { "extensions": [".js", ".jsx"] }]
-    }
+  "env": {
+    "browser": true,
+    "es2021": true
+  },
+  "extends": [
+    "airbnb",
+    "plugin:react/recommended",
+    "plugin:prettier/recommended"
+  ],
+  "overrides": [],
+  "parserOptions": {
+    "ecmaVersion": "latest",
+    "sourceType": "module"
+  },
+  "plugins": ["react"],
+  "rules": {
+    "no-console": "warn",
+    "react/react-in-jsx-scope": "off",
+    "react/jsx-filename-extension": [1, { "extensions": [".js", ".jsx"] }]
+  }
 }
diff --git a/.prettierrc b/.prettierrc
index 59e99c0..d649697 100644
--- a/.prettierrc
+++ b/.prettierrc
@@ -1,11 +1,11 @@
 {
-    "tabWidth": 2,
-    "semi": true,
-    "singleQuote": true,
-    "jsxSingleQuote": true,
-    "printWidth": 80,
-    "trailingComma": "none",
-    "bracketSpacing": true,
-    "bracketSameLine": false,
-    "arrowParens": "always"
-  }
\ No newline at end of file
+  "tabWidth": 2,
+  "semi": true,
+  "singleQuote": true,
+  "jsxSingleQuote": true,
+  "printWidth": 80,
+  "trailingComma": "none",
+  "bracketSpacing": true,
+  "bracketSameLine": false,
+  "arrowParens": "always"
+}
diff --git a/README.md b/README.md
index 38da585..1dd0746 100644
--- a/README.md
+++ b/README.md
@@ -1 +1 @@
-# gdsc-cicd-example
\ No newline at end of file
+# gdsc-cicd-example
diff --git a/package.json b/package.json
index ee4cfe1..2285e1c 100644
--- a/package.json
+++ b/package.json
@@ -41,4 +41,4 @@
     "eslint-plugin-react-hooks": "^4.6.0",
     "prettier": "2.8.8"
   }
-}
\ No newline at end of file
+}
diff --git a/src/App.css b/src/App.css
index dcf6d74..10e4996 100644
--- a/src/App.css
+++ b/src/App.css
@@ -36,4 +36,4 @@
   to {
     transform: rotate(360deg);
   }
-}
\ No newline at end of file
+}
diff --git a/src/App.js b/src/App.js
index 3784575..66a440c 100644
--- a/src/App.js
+++ b/src/App.js
@@ -3,17 +3,18 @@ import './App.css';
 
 function App() {
   return (
-    <div className="App">
-      <header className="App-header">
-        <img src={logo} className="App-logo" alt="logo" />
+    <div className='App'>
+      <header className='App-header'>
+        <img src={logo} className='App-logo' alt='logo' />
         <p>
-          Edit <code>src/App.js</code> and save to reload.
+          This is example page for seminar of CI/CD with{' '}
+          <code>GitHub Actions</code>.
         </p>
         <a
-          className="App-link"
-          href="https://reactjs.org"
-          target="_blank"
-          rel="noopener noreferrer"
+          className='App-link'
+          href='https://reactjs.org'
+          target='_blank'
+          rel='noopener noreferrer'
         >
           Learn React
         </a>
diff --git a/src/reportWebVitals.js b/src/reportWebVitals.js
index 5253d3a..532f29b 100644
--- a/src/reportWebVitals.js
+++ b/src/reportWebVitals.js
@@ -1,4 +1,4 @@
-const reportWebVitals = onPerfEntry => {
+const reportWebVitals = (onPerfEntry) => {
   if (onPerfEntry && onPerfEntry instanceof Function) {
     import('web-vitals').then(({ getCLS, getFID, getFCP, getLCP, getTTFB }) => {
       getCLS(onPerfEntry);