diff --git a/src/app/layout.tsx b/src/app/layout.tsx
index dba4fe5..998bcd4 100644
--- a/src/app/layout.tsx
+++ b/src/app/layout.tsx
@@ -75,40 +75,44 @@ export default function RootLayout({
           enableSystem
           disableTransitionOnChange
         >
-          <header className="border-border/50 bg-background/80 sticky top-0 z-40 flex h-12 items-center justify-between border-b px-4 backdrop-blur-xl sm:px-6">
-            <div className="flex items-center gap-2">
-              <span className="text-lg font-semibold tracking-tight">
-                zipkit
-              </span>
-              <span className="text-muted-foreground hidden text-base sm:inline">
-                /
-              </span>
-              <span className="text-muted-foreground hidden text-base sm:inline">
-                {"地址英譯"}
-              </span>
-            </div>
-            <div className="flex items-center gap-1">
-              <a
-                href="https://github.com/ronload/zipkit"
-                target="_blank"
-                rel="noopener noreferrer"
-                aria-label="GitHub"
-                className="text-muted-foreground hover:bg-secondary hover:text-foreground flex h-7 w-7 items-center justify-center rounded-md transition-colors"
-              >
-                <svg
-                  viewBox="0 0 16 16"
-                  fill="currentColor"
-                  className="h-4 w-4"
+          <header className="border-border/50 bg-background/80 sticky top-0 z-40 h-12 border-b backdrop-blur-xl">
+            <div className="mx-auto flex h-full w-full max-w-3xl items-center justify-between px-4 sm:px-6">
+              <div className="flex items-center gap-2">
+                <span className="text-lg font-semibold tracking-tight">
+                  zipkit
+                </span>
+                <span className="text-muted-foreground hidden text-base sm:inline">
+                  /
+                </span>
+                <span className="text-muted-foreground hidden text-base sm:inline">
+                  {"地址英譯"}
+                </span>
+              </div>
+              <div className="flex items-center gap-1">
+                <a
+                  href="https://github.com/ronload/zipkit"
+                  target="_blank"
+                  rel="noopener noreferrer"
+                  aria-label="GitHub"
+                  className="text-muted-foreground hover:bg-secondary hover:text-foreground flex h-7 w-7 items-center justify-center rounded-md transition-colors"
                 >
-                  <path d="M8 0C3.58 0 0 3.58 0 8c0 3.54 2.29 6.53 5.47 7.59.4.07.55-.17.55-.38 0-.19-.01-.82-.01-1.49-2.01.37-2.53-.49-2.69-.94-.09-.23-.48-.94-.82-1.13-.28-.15-.68-.52-.01-.53.63-.01 1.08.58 1.23.82.72 1.21 1.87.87 2.33.66.07-.52.28-.87.51-1.07-1.78-.2-3.64-.89-3.64-3.95 0-.87.31-1.59.82-2.15-.08-.2-.36-1.02.08-2.12 0 0 .67-.21 2.2.82.64-.18 1.32-.27 2-.27s1.36.09 2 .27c1.53-1.04 2.2-.82 2.2-.82.44 1.1.16 1.92.08 2.12.51.56.82 1.27.82 2.15 0 3.07-1.87 3.75-3.65 3.95.29.25.54.73.54 1.48 0 1.07-.01 1.93-.01 2.2 0 .21.15.46.55.38A8.01 8.01 0 0016 8c0-4.42-3.58-8-8-8z" />
-                </svg>
-              </a>
-              <ModeToggle />
+                  <svg
+                    viewBox="0 0 16 16"
+                    fill="currentColor"
+                    className="h-4 w-4"
+                  >
+                    <path d="M8 0C3.58 0 0 3.58 0 8c0 3.54 2.29 6.53 5.47 7.59.4.07.55-.17.55-.38 0-.19-.01-.82-.01-1.49-2.01.37-2.53-.49-2.69-.94-.09-.23-.48-.94-.82-1.13-.28-.15-.68-.52-.01-.53.63-.01 1.08.58 1.23.82.72 1.21 1.87.87 2.33.66.07-.52.28-.87.51-1.07-1.78-.2-3.64-.89-3.64-3.95 0-.87.31-1.59.82-2.15-.08-.2-.36-1.02.08-2.12 0 0 .67-.21 2.2.82.64-.18 1.32-.27 2-.27s1.36.09 2 .27c1.53-1.04 2.2-.82 2.2-.82.44 1.1.16 1.92.08 2.12.51.56.82 1.27.82 2.15 0 3.07-1.87 3.75-3.65 3.95.29.25.54.73.54 1.48 0 1.07-.01 1.93-.01 2.2 0 .21.15.46.55.38A8.01 8.01 0 0016 8c0-4.42-3.58-8-8-8z" />
+                  </svg>
+                </a>
+                <ModeToggle />
+              </div>
             </div>
           </header>
           <main className="flex-1">{children}</main>
-          <footer className="border-border/50 text-muted-foreground/70 border-t px-4 py-3 text-xs sm:px-6">
-            {"地址英譯僅供參考。資料來源：中華郵政。"}
+          <footer className="border-border/50 text-muted-foreground/70 border-t text-xs">
+            <div className="mx-auto w-full max-w-3xl px-4 py-3 sm:px-6">
+              {"地址英譯僅供參考。資料來源：中華郵政。"}
+            </div>
           </footer>
           <Toaster
             toastOptions={{