chore: optimized popup text

Author: Junyi-99

webapp/_webapp/src/views/extension-popup/app.css

@@ -80,4 +80,19 @@
   font-size: 12px;
   color: #6c757d;
   margin-top: 12px;
+}
+
+.noselect {
+  -webkit-touch-callout: none;
+  /* iOS Safari */
+  -webkit-user-select: none;
+  /* Safari */
+  -khtml-user-select: none;
+  /* Konqueror HTML */
+  -moz-user-select: none;
+  /* Firefox */
+  -ms-user-select: none;
+  /* Internet Explorer/Edge */
+  user-select: none;
+  /* Non-prefixed version, currently supported by Chrome and Opera */
 }

webapp/_webapp/src/views/extension-popup/components/ExtensionPopup.tsx

@@ -42,7 +42,7 @@ export const ExtensionPopup = () => {
     "/settings.html";
 
   return (
-    <div className="popup-shell">
+    <div className="popup-shell noselect">
       <h1 className="title">PaperDebugger</h1>
       <h2 className="subtitle">How to use</h2>
       <Steps steps={steps} />