feat: BLACK HEART DANCE HOUSE landing page

Landing page with Hero, About, Team, Classes, and Contact sections.
Light/dark mode, scroll reveal animations, Yandex Maps, responsive design.
Next.js 16 + Tailwind v4 + TypeScript.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/ui/Reveal.tsx

@@ -0,0 +1,45 @@
+"use client";
+
+import { useEffect, useRef, useState } from "react";
+
+interface RevealProps {
+  children: React.ReactNode;
+  className?: string;
+}
+
+export function Reveal({ children, className = "" }: RevealProps) {
+  const ref = useRef<HTMLDivElement>(null);
+  const [visible, setVisible] = useState(false);
+
+  useEffect(() => {
+    const el = ref.current;
+    if (!el) return;
+
+    const observer = new IntersectionObserver(
+      ([entry]) => {
+        if (entry.isIntersecting) {
+          setVisible(true);
+          observer.unobserve(el);
+        }
+      },
+      { threshold: 0.1, rootMargin: "0px 0px -50px 0px" },
+    );
+
+    observer.observe(el);
+    return () => observer.disconnect();
+  }, []);
+
+  return (
+    <div
+      ref={ref}
+      className={className}
+      style={{
+        opacity: visible ? 1 : 0,
+        transform: visible ? "translateY(0)" : "translateY(30px)",
+        transition: "opacity 0.7s ease-out, transform 0.7s ease-out",
+      }}
+    >
+      {children}
+    </div>
+  );
+}