Add compatibility note for itemcache.wdb in HTML and style updates for compatibility message

Author: CyberMist2

index.html

@@ -60,6 +60,10 @@ <h1>Itemcache to SQL Exporter</h1>
         </form>
 
         <p id="export-msg" class="status-msg" role="status" aria-live="polite"></p>
+        <p class="compat-note">
+          Compatible only with <code>itemcache.wdb</code> from World of Warcraft:
+          The Burning Crusade 2.4.3 (build 8606).
+        </p>
         <footer class="helper-text">
           Tip: Use absolute paths for best compatibility.
         </footer>

src/styles.css

@@ -201,6 +201,24 @@ button:disabled {
   color: #ff7b72;
 }
 
+.compat-note {
+  margin: 10px 0 0;
+  padding: 10px 12px;
+  font-size: 0.85rem;
+  line-height: 1.45;
+  color: #d29922;
+  background: rgba(210, 153, 34, 0.12);
+  border: 1px solid rgba(210, 153, 34, 0.35);
+  border-radius: 8px;
+}
+
+.compat-note code {
+  color: #ffd58f;
+  background: rgba(210, 153, 34, 0.22);
+  padding: 1px 5px;
+  border-radius: 5px;
+}
+
 .helper-text {
   margin-top: 10px;
   font-size: 0.82rem;