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/Button.tsx

@@ -0,0 +1,41 @@
+import Link from "next/link";
+
+interface ButtonProps {
+  href?: string;
+  variant?: "primary" | "outline" | "ghost";
+  size?: "sm" | "md" | "lg";
+  children: React.ReactNode;
+  className?: string;
+  onClick?: () => void;
+}
+
+const sizes = {
+  sm: "px-4 py-2 text-sm",
+  md: "px-6 py-3 text-base",
+  lg: "px-8 py-4 text-lg",
+};
+
+export function Button({
+  href,
+  variant = "primary",
+  size = "md",
+  children,
+  className = "",
+  onClick,
+}: ButtonProps) {
+  const classes = `btn-${variant} ${sizes[size]} ${className}`;
+
+  if (href) {
+    return (
+      <Link href={href} className={classes}>
+        {children}
+      </Link>
+    );
+  }
+
+  return (
+    <button onClick={onClick} className={classes}>
+      {children}
+    </button>
+  );
+}