diff --git a/index.html b/index.html
index d3ea868..ce00fb9 100644
--- a/index.html
+++ b/index.html
@@ -1,8 +1,8 @@
 <!DOCTYPE html>
-<html lang="en">
+<html lang='en'>
 <head>
-    <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <meta charset='UTF-8'>
+    <meta name='viewport' content='width=device-width, initial-scale=1.0'>
     <title>Arduino Remote Web</title>
     <style>
         :root {
@@ -110,7 +110,7 @@
             }
         }
     </style>
-    <script type="application/javascript">
+    <script type='application/javascript'>
         function sendButtonSignal(buttonCode) {
           fetch('/sendSignal', {
           method: 'POST',
@@ -121,49 +121,49 @@
     </script>
 </head>
 <body>
-    <div id="buttons" class="flex-container">
-        <div id="power" onclick="sendButtonSignal(0x15)">Power</div>
-        <div id="exit" onclick="sendButtonSignal(0x13)">Exit</div>
-        <div id="guide" onclick="sendButtonSignal(0x47)">Guide</div>
-        <div id="mute" onclick="sendButtonSignal(0x16)">Mute</div>
-        <div id="source" onclick="sendButtonSignal(0x12)">Source</div>
+    <div id='buttons' class='flex-container'>
+        <div id='power' onclick='sendButtonSignal(0x15)'>Power</div>
+        <div id='exit' onclick='sendButtonSignal(0x13)'>Exit</div>
+        <div id='guide' onclick='sendButtonSignal(0x47)'>Guide</div>
+        <div id='mute' onclick='sendButtonSignal(0x16)'>Mute</div>
+        <div id='source' onclick='sendButtonSignal(0x12)'>Source</div>
     </div>
-    <div class="flex-container">
-        <div id="volume" class="flex-container-column">
-            <div id="volume-up" onclick="sendButtonSignal(0x1B)">Volume up</div>
-            <div id="volume-down" onclick="sendButtonSignal(0x1A)">Volume down</div>
+    <div class='flex-container'>
+        <div id='volume' class='flex-container-column'>
+            <div id='volume-up' onclick='sendButtonSignal(0x1B)'>Volume up</div>
+            <div id='volume-down' onclick='sendButtonSignal(0x1A)'>Volume down</div>
         </div>
-        <div id="channel" class="flex-container-column">
-            <div id="channel-up" onclick="sendButtonSignal(0x19)">Channel up</div>
-            <div id="channel-down" onclick="sendButtonSignal(0x18)">Channel down</div>
+        <div id='channel' class='flex-container-column'>
+            <div id='channel-up' onclick='sendButtonSignal(0x19)'>Channel up</div>
+            <div id='channel-down' onclick='sendButtonSignal(0x18)'>Channel down</div>
         </div>
     </div>
-    <div id="numpad">
-        <div id="numpad-row-1" class="flex-container">
-            <div id="number-1" onclick="sendButtonSignal(0x1)">1</div>
-            <div id="number-2" onclick="sendButtonSignal(0x2)">2</div>
-            <div id="number-3" onclick="sendButtonSignal(0x3)">3</div>
+    <div id='numpad'>
+        <div id='numpad-row-1' class='flex-container'>
+            <div id='number-1' onclick='sendButtonSignal(0x1)'>1</div>
+            <div id='number-2' onclick='sendButtonSignal(0x2)'>2</div>
+            <div id='number-3' onclick='sendButtonSignal(0x3)'>3</div>
         </div>
-        <div id="numpad-row-2" class="flex-container">
-            <div id="number-4" onclick="sendButtonSignal(0x4)">4</div>
-            <div id="number-5" onclick="sendButtonSignal(0x5)">5</div>
-            <div id="number-6" onclick="sendButtonSignal(0x6)">6</div>
+        <div id='numpad-row-2' class='flex-container'>
+            <div id='number-4' onclick='sendButtonSignal(0x4)'>4</div>
+            <div id='number-5' onclick='sendButtonSignal(0x5)'>5</div>
+            <div id='number-6' onclick='sendButtonSignal(0x6)'>6</div>
         </div>
-        <div id="numpad-row-3" class="flex-container">
-            <div id="number-7" onclick="sendButtonSignal(0x7)">7</div>
-            <div id="number-8" onclick="sendButtonSignal(0x8)">8</div>
-            <div id="number-9" onclick="sendButtonSignal(0x9)">9</div>
+        <div id='numpad-row-3' class='flex-container'>
+            <div id='number-7' onclick='sendButtonSignal(0x7)'>7</div>
+            <div id='number-8' onclick='sendButtonSignal(0x8)'>8</div>
+            <div id='number-9' onclick='sendButtonSignal(0x9)'>9</div>
         </div>
-        <div id="numpad-row-4" class="flex-container">
-            <div id="number-0" onclick="sendButtonSignal(0x0)">0</div>
+        <div id='numpad-row-4' class='flex-container'>
+            <div id='number-0' onclick='sendButtonSignal(0x0)'>0</div>
         </div>
     </div>
-    <div id="arrows" class="flex-container">
-      <div id="Up" onclick="sendButtonSignal(0xC)">Up</div>
-      <div id="Down" onclick="sendButtonSignal(0xD)">Down</div>
-      <div id="Left" onclick="sendButtonSignal(0xF)">Left</div>
-      <div id="Right" onclick="sendButtonSignal(0xE)">Right</div>
-      <div id="Enter" onclick="sendButtonSignal(0x10)">Enter</div>
+    <div id='arrows' class='flex-container'>
+      <div id='Up' onclick='sendButtonSignal(0xC)'>Up</div>
+      <div id='Down' onclick='sendButtonSignal(0xD)'>Down</div>
+      <div id='Left' onclick='sendButtonSignal(0xF)'>Left</div>
+      <div id='Right' onclick='sendButtonSignal(0xE)'>Right</div>
+      <div id='Enter' onclick='sendButtonSignal(0x10)'>Enter</div>
     </div>
 </body>
 </html>
