feat: add onboarding modal

frontend/app/page.tsx

@@ -17,6 +17,8 @@ interface EscrowItem {
   status: "Locked" | "Executed" | "Refunded";
 }
 
+import OnboardingModal from "@/components/OnboardingModal";
+
 export default function Home() {
   const { address, connect } = useWallet();
   const { createEscrow, isPending: isCreating } = useCreateEscrow();
@@ -123,6 +125,7 @@ export default function Home() {
 
   return (
     <div className="min-h-screen bg-[#0A0E05] text-white selection:bg-[#8FA828]/30 selection:text-white">
+      <OnboardingModal />
       <Navbar />
 
       <main className="max-w-7xl mx-auto px-6 pt-32 pb-24 grid grid-cols-1 lg:grid-cols-12 gap-12 items-start">

frontend/components/OnboardingModal.tsx

@@ -0,0 +1,134 @@
+"use client";
+
+import { useState, useEffect } from "react";
+import { motion, AnimatePresence } from "framer-motion";
+import { Zap, ShieldCheck, Clock, CheckCircle2, X } from "lucide-react";
+
+const slides = [
+  {
+    id: 1,
+    title: "Welcome to EpochSend",
+    description: "The next generation of intent-based conditional payments built securely on the Stellar network.",
+    icon: <Zap size={48} className="text-[#8FA828]" />,
+  },
+  {
+    id: 2,
+    title: "Time-Locked Escrows",
+    description: "Easily lock digital assets on-chain. Funds are automatically released to the recipient only when the exact timestamp is reached.",
+    icon: <Clock size={48} className="text-[#8FA828]" />,
+  },
+  {
+    id: 3,
+    title: "Trusted Arbiters",
+    description: "Need human intervention? Assign a trusted third-party arbiter to manually release or refund payments when conditions are met.",
+    icon: <ShieldCheck size={48} className="text-[#8FA828]" />,
+  },
+  {
+    id: 4,
+    title: "Fully Decentralized",
+    description: "Powered entirely by Soroban smart contracts. No middlemen, no hidden fees, and complete transparency.",
+    icon: <CheckCircle2 size={48} className="text-[#8FA828]" />,
+  },
+];
+
+export default function OnboardingModal() {
+  const [isOpen, setIsOpen] = useState(false);
+  const [currentSlide, setCurrentSlide] = useState(0);
+
+  useEffect(() => {
+    // Check local storage to see if user has seen onboarding
+    const hasSeenOnboarding = localStorage.getItem("hasSeenEpochSendOnboarding");
+    if (!hasSeenOnboarding) {
+      setIsOpen(true);
+    }
+  }, []);
+
+  const handleClose = () => {
+    localStorage.setItem("hasSeenEpochSendOnboarding", "true");
+    setIsOpen(false);
+  };
+
+  const nextSlide = () => {
+    if (currentSlide < slides.length - 1) {
+      setCurrentSlide(currentSlide + 1);
+    } else {
+      handleClose();
+    }
+  };
+
+  if (!isOpen) return null;
+
+  return (
+    <AnimatePresence>
+      {isOpen && (
+        <div className="fixed inset-0 z-50 flex items-center justify-center px-4 bg-black/60 backdrop-blur-sm">
+          <motion.div
+            initial={{ opacity: 0, scale: 0.95, y: 20 }}
+            animate={{ opacity: 1, scale: 1, y: 0 }}
+            exit={{ opacity: 0, scale: 0.95, y: 20 }}
+            className="bg-[#0A0E05] border border-white/10 shadow-2xl shadow-[#8FA828]/10 rounded-3xl p-8 max-w-md w-full relative overflow-hidden"
+          >
+            {/* Background Glow */}
+            <div className="absolute -top-24 -right-24 w-48 h-48 bg-[#8FA828]/20 rounded-full blur-3xl pointer-events-none" />
+
+            {/* Close Button */}
+            <button
+              onClick={handleClose}
+              className="absolute top-4 right-4 p-2 text-gray-500 hover:text-white transition-colors rounded-full hover:bg-white/5"
+            >
+              <X size={20} />
+            </button>
+
+            {/* Slide Content */}
+            <AnimatePresence mode="wait">
+              <motion.div
+                key={currentSlide}
+                initial={{ opacity: 0, x: 20 }}
+                animate={{ opacity: 1, x: 0 }}
+                exit={{ opacity: 0, x: -20 }}
+                transition={{ duration: 0.2 }}
+                className="flex flex-col items-center text-center mt-4 mb-8 space-y-6"
+              >
+                <div className="p-4 bg-white/5 rounded-full border border-white/10 inline-flex shadow-lg shadow-[#8FA828]/5">
+                  {slides[currentSlide].icon}
+                </div>
+
+                <div className="space-y-3">
+                  <h2 className="text-2xl font-black text-white tracking-tight">
+                    {slides[currentSlide].title}
+                  </h2>
+                  <p className="text-sm text-gray-400 leading-relaxed max-w-[280px] mx-auto">
+                    {slides[currentSlide].description}
+                  </p>
+                </div>
+              </motion.div>
+            </AnimatePresence>
+
+            {/* Navigation & Progress */}
+            <div className="flex flex-col space-y-6">
+              {/* Dots */}
+              <div className="flex justify-center space-x-2">
+                {slides.map((_, index) => (
+                  <div
+                    key={index}
+                    className={`h-1.5 rounded-full transition-all duration-300 ${
+                      index === currentSlide ? "w-6 bg-[#8FA828]" : "w-1.5 bg-white/20"
+                    }`}
+                  />
+                ))}
+              </div>
+
+              {/* Action Button */}
+              <button
+                onClick={nextSlide}
+                className="w-full py-3.5 bg-[#8FA828] text-black font-black text-xs uppercase tracking-widest rounded-xl hover:bg-[#a3c22e] active:scale-[0.99] transition-all shadow-lg shadow-[#8FA828]/20"
+              >
+                {currentSlide === slides.length - 1 ? "Get Started" : "Continue"}
+              </button>
+            </div>
+          </motion.div>
+        </div>
+      )}
+    </AnimatePresence>
+  );
+}