Refactor: Improve i18n support and fix multiplication steps layout

- Integrate i18n translations for difficulty descriptions
- Fix intermediate steps alignment in long multiplication display
- Simplify spacing calculations for better layout consistency
- Update translation files for all supported languages (en, es, el, sv)

index.html

@@ -62,7 +62,7 @@
             <section class="score-section">
                 <div class="score-box">
                     <p class="score-label">Points:</p>
-                    <p class="score-value" id="points-score">0/20</p>
+                    <p class="score-value" id="points-score">0/10</p>
                 </div>
             </section>
 
@@ -83,4 +83,4 @@
     <script src="translations.js"></script>
     <script src="script.js"></script>
 </body>
-</html>
+</html>