improve utilities workspace navigation

app/components/toolkit/ToolShell.tsx

@@ -1,4 +1,3 @@
-import Link from "next/link";
 import { cn } from "@/lib/utils";
 
 type ToolShellProps = {
@@ -19,31 +18,23 @@ export default function ToolShell({
   subtitle,
   className,
   children,
-  backHref = "/laser-toolkit",
-  backLabel = "Back to Toolkit",
 }: ToolShellProps) {
   const desc = description ?? subtitle;
 
   return (
-    <div className={cn("mx-auto w-full max-w-5xl px-4 py-6", className)}>
-      <div className="mb-6 flex items-start justify-between gap-4">
+    <div className={cn("w-full p-4 sm:p-5", className)}>
+      <div className="mb-4 flex items-start justify-between gap-4 border-b border-border/50 pb-4">
         <div>
-          <h1 className="text-2xl font-semibold tracking-tight">{title}</h1>
+          <div className="mb-1 text-[10px] uppercase tracking-[0.18em] text-accent">laser.calc</div>
+          <h1 className="text-xl font-semibold tracking-tight">{title}</h1>
           {desc ? (
             <p className="mt-1 text-sm text-muted-foreground">{desc}</p>
           ) : null}
         </div>
 
-        <Link
-          href={backHref}
-          className="inline-flex h-9 items-center rounded-md border border-input bg-background px-3 text-sm shadow-sm transition-colors hover:bg-accent hover:text-accent-foreground"
-        >
-          {backLabel}
-        </Link>
       </div>
 
       {children}
     </div>
   );
 }
-