diff --git a/public/banner.js b/public/banner.js
index 2216db4..4192c42 100644
--- a/public/banner.js
+++ b/public/banner.js
@@ -66,27 +66,50 @@
   var params = getScriptParams();
 
   // ── Determine locale ──────────────────────────────────────────────────
-  function resolveLocale(tag) {
-    if (!tag) return "en";
-    if (messages[tag]) return tag;
-    var lower = tag.toLowerCase();
-    for (var key in messages) {
-      if (key.toLowerCase() === lower) return key;
-    }
-    var base = tag.split("-")[0].toLowerCase();
-    if (messages[base]) return base;
-    for (var key2 in messages) {
-      if (key2.toLowerCase().split("-")[0] === base) return key2;
+  function resolveLocale(tags) {
+    var preferences = tags.map(tag => {
+      try { return new Intl.Locale(tag); } catch (e) {}
+    });
+
+    var best = null;
+    var bestWeight = null;
+    for (var k in messages) {
+      var key = new Intl.Locale(k);
+      var script = key.script || key.maximize().script;
+      var preferred = -1;
+      var preference = null;
+      for (var p = 0; p < preferences.length; p++) {
+        tag = preferences[p];
+        if (tag && key.language === tag.language && script === (tag.script || tag.maximize().script)) {
+          preferred = p;
+          preference = tag;
+          break;
+        }
+      }
+      if (preferred < 0) continue;
+      var country = key.region;
+      var weight = preferred << 4;
+      if ((script && preference.script || country && preference.region) && country === preference.region) {
+        weight |= !script | !country << 1 | !(script === preference.script) << 2;
+      } else {
+        weight |= 8 | !!country << 2 | !!script << 1 | (country && country !== new Intl.Locale(preference.language, { script: script }).maximize().region);
+      }
+      if (bestWeight === null || weight < bestWeight) {
+        best = key;
+        bestWeight = weight;
+      }
     }
-    return "en";
+    return best;
   }
 
-  var locale = resolveLocale(
-    params.lang ||
+  var locales = navigator.languages;
+  var prefer = params.lang ||
     document.documentElement.lang ||
     navigator.language ||
-    navigator.userLanguage
-  );
+    navigator.userLanguage;
+  if (!locales || !locales.length || prefer !== locales[0]) locales = [...prefer.split(',').map(p => p.trim()), ...locales];
+
+  var locale = messages[locales[0]] ? locales[0] : resolveLocale(locales) || 'en';
 
   // ── Size variant ──────────────────────────────────────────────────────
   var size = params.size === "mini" ? "mini" : "normal";
@@ -295,10 +318,10 @@
     }
   }
 
-  cacheFormattingInfo(1, "day");
-  cacheFormattingInfo(2, "hour");
-  cacheFormattingInfo(3, "minute");
-  cacheFormattingInfo(4, "second");
+  cacheFormattingInfo(11, "day");
+  cacheFormattingInfo(22, "hour");
+  cacheFormattingInfo(33, "minute");
+  cacheFormattingInfo(44, "second");
 
   function getLocalizedUnit(value, unit, trimConjunction, trimSuffix) {
     var offset = getOffset(unit);
@@ -306,8 +329,8 @@
     var p = pfx[offset];
     var s = sfx[offset];
     return string.slice(
-      trimConjunction && p || (p == 1 && string[0] === "+") ? pfx[offset] : 0,
-      trimSuffix && s ? -sfx[offset] : string.length
+      trimConjunction && p || (p == 1 && string[0] === "+") ? p : 0,
+      trimSuffix && s ? -s : string.length
     );
   }
 
@@ -319,6 +342,11 @@
     var now = new Date().getTime();
     var distance = countDownDate - now;
 
+    if (distance < 0) {
+      clearInterval(timer);
+      return;
+    }
+
     var days = Math.floor(distance / (1000 * 60 * 60 * 24));
     var hours = Math.floor(
       (distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60)
@@ -342,10 +370,6 @@
     remaining[6] = getLocalizedUnit(seconds, "second", parts++, false);
 
     countdownSpan.textContent = remaining.join("");
-
-    if (distance < 0) {
-      clearInterval(timer);
-    }
   }
 
   timer = setInterval(updateBanner, 1000);