Initial commit

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/components/common/back-button.tsx

@@ -0,0 +1,19 @@
+"use client";
+
+import { useRouter } from "next/navigation";
+
+export function BackButton({ fallback = "/", className = "" }: { fallback?: string; className?: string }) {
+  const router = useRouter();
+  const goBack = () => {
+    if (window.history.length > 1) router.back();
+    else router.push(fallback);
+  };
+
+  return (
+    <button data-component="back-button" type="button" aria-label="返回" onClick={goBack} className={`cursor-pointer size-6 ${className}`}>
+      <svg viewBox="0 0 24 24" className="size-full" aria-hidden="true">
+        <path d="M15 5l-7 7 7 7" fill="none" stroke="white" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" />
+      </svg>
+    </button>
+  );
+}