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

src/pages/adjust-colors.html

@@ -139,7 +139,9 @@
               >
               <span data-i18n="upload.orDragAndDrop">or drag and drop</span>
             </p>
-            <p class="text-xs text-gray-500">A single PDF file</p>
+            <p class="text-xs text-gray-500" data-i18n="upload.hints.singlePdf">
+              A single PDF file
+            </p>
             <p class="text-xs text-gray-500" data-i18n="upload.filesNeverLeave">
               Your files never leave your device.
             </p>
@@ -387,7 +389,10 @@
     </div>
 
     <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">
@@ -432,7 +437,10 @@
     </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">
@@ -475,7 +483,10 @@
     </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">