fix: Add internationalization support for various pages by updating text elements with data-i18n attributes for better localization

src/pages/validate-signature-pdf.html

@@ -147,7 +147,12 @@
               >
               <span data-i18n="upload.orDragAndDrop">or drag and drop</span>
             </p>
-            <p class="text-xs text-gray-500">PDF Documents</p>
+            <p
+              class="text-xs text-gray-500"
+              data-i18n="upload.hints.pdfDocuments"
+            >
+              PDF Documents
+            </p>
             <p class="text-xs text-gray-500" data-i18n="upload.filesNeverLeave">
               Your files never leave your device.
             </p>
@@ -241,7 +246,10 @@
 
     <!-- How It Works Section -->
     <section class="max-w-4xl mx-auto px-4 py-12">
-      <h2 class="text-2xl md:text-3xl font-bold text-white mb-8 text-center">
+      <h2
+        class="text-2xl md:text-3xl font-bold text-white mb-8 text-center"
+        data-i18n="howItWorks.title"
+      >
         How It Works
       </h2>
       <div class="space-y-6">
@@ -294,7 +302,10 @@
 
     <!-- Related Tools Section -->
     <section class="max-w-6xl mx-auto px-4 py-12">
-      <h2 class="text-2xl md:text-3xl font-bold text-white mb-6 text-center">
+      <h2
+        class="text-2xl md:text-3xl font-bold text-white mb-6 text-center"
+        data-i18n="relatedTools.title"
+      >
         Related PDF Tools
       </h2>
       <div class="grid grid-cols-2 md:grid-cols-3 lg:grid-cols-6 gap-4">
@@ -324,7 +335,10 @@
 
     <!-- FAQ Section -->
     <section class="max-w-4xl mx-auto px-4 py-12">
-      <h2 class="text-2xl md:text-3xl font-bold text-white mb-6 text-center">
+      <h2
+        class="text-2xl md:text-3xl font-bold text-white mb-6 text-center"
+        data-i18n="faq.sectionTitle"
+      >
         Frequently Asked Questions
       </h2>
       <div class="space-y-4">