Add Navigation component & added offline mode

components/Navigation/ActiveLink.tsx

@@ -0,0 +1,56 @@
+import { useRouter } from "next/router";
+import Link, { LinkProps } from "next/link";
+import React, { useState, useEffect, ReactElement, Children } from "react";
+type ActiveLinkProps = LinkProps & {
+  children: ReactElement;
+  activeClassName: string;
+};
+const ActiveLink = ({
+  children,
+  activeClassName,
+  ...props
+}: ActiveLinkProps) => {
+  const { asPath, isReady, pathname } = useRouter();
+  const child = Children.only(children);
+  const childClassName = child.props.className || "";
+  const [className, setClassName] = useState(childClassName);
+  useEffect(() => {
+    // Check if the router fields are updated client-side
+    if (isReady) {
+      // Dynamic route will be matched via props.as
+      // Static route will be matched via props.href
+      const linkPathname = new URL(
+        (props.as || props.href) as string,
+        location.href
+      ).pathname;
+      // Using URL().pathname to get rid of query and hash
+      const activePathname = new URL(asPath, location.href).pathname;
+      const newClassName =
+        linkPathname === activePathname
+          ? `${childClassName} ${activeClassName}`.trim()
+          : childClassName;
+      if (newClassName !== className) {
+        setClassName(newClassName);
+      }
+    }
+  }, [
+    asPath,
+    isReady,
+    props.as,
+    props.href,
+    childClassName,
+    activeClassName,
+    setClassName,
+    className,
+  ]);
+  return (
+    <Link {...props}>
+      <a>
+        {React.cloneElement(child, {
+          className: className || null,
+        })}
+      </a>
+    </Link>
+  );
+};
+export default ActiveLink;

components/Navigation/NavLink.tsx

@@ -0,0 +1,15 @@
+import Link from "next/link";
+type NavLinkProps = {
+  href: string;
+  children: React.ReactNode;
+};
+
+const NavLink = ({ children, href }: NavLinkProps) => {
+  return (
+    <Link href={href} shallow>
+      <a>{children}</a>
+    </Link>
+  );
+};
+
+export default NavLink;

pages/_offline.tsx

@@ -0,0 +1,5 @@
+const Offline = () => {
+  return <p className="text-3xl font-bold">Кажется, вы оффлайн!</p>;
+};
+
+export default Offline;