feat: add landing page components and API enhancements

packages/ui/src/app/app/page.tsx

@@ -0,0 +1,148 @@
+"use client";
+
+import { useState } from "react";
+import { fetchTransaction, fetchAccount, getErrorMessage } from "@/lib/api";
+import type { TransactionExplanation, AccountExplanation, Tab } from "@/types";
+import { TabSwitcher } from "@/components/TabSwitcher";
+import { SearchBar } from "@/components/SearchBar";
+import { TransactionResult } from "@/components/TransactionResult";
+import { AccountResult } from "@/components/AccountResult";
+
+export default function Home() {
+  const [tab, setTab] = useState<Tab>("tx");
+
+  // Each tab has its own independent input + result — switching tabs
+  // preserves whatever was last searched on each side.
+  const [txInput, setTxInput] = useState("");
+  const [accountInput, setAccountInput] = useState("");
+
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [txResult, setTxResult] = useState<TransactionExplanation | null>(null);
+  const [accountResult, setAccountResult] = useState<AccountExplanation | null>(
+    null,
+  );
+
+  const input = tab === "tx" ? txInput : accountInput;
+  const setInput = tab === "tx" ? setTxInput : setAccountInput;
+
+  async function handleExplain() {
+    const trimmed = input.trim();
+    if (!trimmed) return;
+
+    setLoading(true);
+    setError(null);
+
+    try {
+      if (tab === "tx") {
+        setTxResult(null);
+        const data = await fetchTransaction(trimmed);
+        setTxResult(data);
+      } else {
+        setAccountResult(null);
+        const data = await fetchAccount(trimmed);
+        setAccountResult(data);
+      }
+    } catch (err) {
+      setError(getErrorMessage(err));
+    } finally {
+      setLoading(false);
+    }
+  }
+
+  const hasResult = tab === "tx" ? !!txResult : !!accountResult;
+
+  return (
+    <div
+      className="min-h-screen bg-[#080c12] text-white"
+      style={{ fontFamily: "'IBM Plex Mono', 'Fira Code', monospace" }}
+    >
+      {/* grid background */}
+      <div
+        className="fixed inset-0 pointer-events-none"
+        style={{
+          backgroundImage:
+            "linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px)",
+          backgroundSize: "40px 40px",
+        }}
+      />
+
+      {/* horizon glow */}
+      <div
+        className="fixed top-0 left-1/2 -translate-x-1/2 w-[700px] h-[300px] pointer-events-none"
+        style={{
+          background:
+            "radial-gradient(ellipse at 50% 0%, rgba(56,189,248,0.06) 0%, transparent 70%)",
+        }}
+      />
+
+      <div className="relative z-10 max-w-2xl mx-auto px-4 pt-16 pb-24">
+        {/* header */}
+        <div className="mb-12">
+          <div className="flex items-center gap-3 mb-3">
+            <div className="w-7 h-7 rounded-lg bg-sky-400/10 border border-sky-400/30 flex items-center justify-center">
+              <svg
+                width="14"
+                height="14"
+                viewBox="0 0 24 24"
+                fill="none"
+                stroke="currentColor"
+                strokeWidth="2"
+                className="text-sky-400"
+              >
+                <circle cx="12" cy="12" r="3" />
+                <path d="M12 2v3m0 14v3M2 12h3m14 0h3m-3.5-6.5-2 2m-9 9-2 2m0-13 2 2m9 9 2 2" />
+              </svg>
+            </div>
+            <h1
+              className="text-lg font-semibold tracking-tight text-white/90"
+              style={{ fontFamily: "'IBM Plex Sans', system-ui, sans-serif" }}
+            >
+              Stellar Explain
+            </h1>
+          </div>
+          <p
+            className="text-sm text-white/35 leading-relaxed"
+            style={{ fontFamily: "'IBM Plex Sans', system-ui, sans-serif" }}
+          >
+            Plain-English explanations for Stellar blockchain operations.
+          </p>
+        </div>
+
+        <TabSwitcher active={tab} onChange={setTab} />
+
+        <SearchBar
+          tab={tab}
+          value={input}
+          loading={loading}
+          onChange={setInput}
+          onSubmit={handleExplain}
+        />
+
+        {/* error */}
+        {error && (
+          <div className="mb-6 px-4 py-3 rounded-lg bg-red-900/20 border border-red-700/30 text-red-300 text-xs font-mono">
+            {error}
+          </div>
+        )}
+
+        {/* results */}
+        {tab === "tx" && txResult && <TransactionResult data={txResult} />}
+        {tab === "account" && accountResult && (
+          <AccountResult data={accountResult} />
+        )}
+
+        {/* empty state */}
+        {!hasResult && !error && !loading && (
+          <div className="text-center py-20">
+            <p className="text-white/15 text-xs font-mono">
+              {tab === "tx"
+                ? "enter a transaction hash to decode it"
+                : "enter an account address to inspect it"}
+            </p>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}

packages/ui/src/app/globals.css

@@ -1,26 +1,34 @@
 @import "tailwindcss";
 
 :root {
-  --background: #ffffff;
-  --foreground: #171717;
+  --background: #080c12;
+  --foreground: #e8eaf0;
 }
 
 @theme inline {
   --color-background: var(--background);
   --color-foreground: var(--foreground);
-  --font-sans: var(--font-geist-sans);
-  --font-mono: var(--font-geist-mono);
-}
-
-@media (prefers-color-scheme: dark) {
-  :root {
-    --background: #0a0a0a;
-    --foreground: #ededed;
-  }
+  --font-sans: var(--font-sans);
+  --font-mono: var(--font-mono);
 }
 
 body {
   background: var(--background);
   color: var(--foreground);
-  font-family: Arial, Helvetica, sans-serif;
 }
+
+@keyframes animate-in {
+  from { opacity: 0; transform: translateY(8px); }
+  to   { opacity: 1; transform: translateY(0); }
+}
+
+.animate-in {
+  animation: animate-in 0.25s ease-out forwards;
+}
+@keyframes fadeSlideUp {
+  from { opacity: 0; transform: translateY(8px); }
+  to   { opacity: 1; transform: translateY(0); }
+}
+.animate-fadeSlideUp {
+  animation: fadeSlideUp 0.35s ease forwards;
+}

packages/ui/src/app/layout.tsx

@@ -1,20 +1,22 @@
 import type { Metadata } from "next";
-import { Geist, Geist_Mono } from "next/font/google";
+import { IBM_Plex_Mono, IBM_Plex_Sans } from "next/font/google";
 import "./globals.css";
 
-const geistSans = Geist({
-  variable: "--font-geist-sans",
+const ibmPlexMono = IBM_Plex_Mono({
+  variable: "--font-mono",
   subsets: ["latin"],
+  weight: ["400", "500", "600"],
 });
 
-const geistMono = Geist_Mono({
-  variable: "--font-geist-mono",
+const ibmPlexSans = IBM_Plex_Sans({
+  variable: "--font-sans",
   subsets: ["latin"],
+  weight: ["400", "500", "600"],
 });
 
 export const metadata: Metadata = {
-  title: "Create Next App",
-  description: "Generated by create next app",
+  title: "Stellar Explain",
+  description: "Plain-English explanations for Stellar blockchain operations.",
 };
 
 export default function RootLayout({
@@ -24,11 +26,9 @@ export default function RootLayout({
 }>) {
   return (
     <html lang="en">
-      <body
-        className={`${geistSans.variable} ${geistMono.variable} antialiased`}
-      >
+      <body className={`${ibmPlexMono.variable} ${ibmPlexSans.variable} antialiased`}>
         {children}
       </body>
     </html>
   );
-}
+}

packages/ui/src/app/page.tsx

@@ -1,103 +1,56 @@
-import Image from "next/image";
+'use client";'
+import Navbar from "@/components/landing/Navbar";
+import HeroSection from "@/components/landing/HeroSection";
+import HowItWorksSection from "@/components/landing/HowItWorksSection";
+import WhatWeDecodeSection from "@/components/landing/WhatWeDecodeSection";
+import OpenSourceSection from "@/components/landing/OpenSourceSection";
+import Footer from "@/components/landing/Footer";
 
-export default function Home() {
+export default function LandingPage() {
   return (
-    <div className="font-sans grid grid-rows-[20px_1fr_20px] items-center justify-items-center min-h-screen p-8 pb-20 gap-16 sm:p-20">
-      <main className="flex flex-col gap-[32px] row-start-2 items-center sm:items-start">
-        <Image
-          className="dark:invert"
-          src="/next.svg"
-          alt="Next.js logo"
-          width={180}
-          height={38}
-          priority
-        />
-        <ol className="font-mono list-inside list-decimal text-sm/6 text-center sm:text-left">
-          <li className="mb-2 tracking-[-.01em]">
-            Get started by editing{" "}
-            <code className="bg-black/[.05] dark:bg-white/[.06] font-mono font-semibold px-1 py-0.5 rounded">
-              src/app/page.tsx
-            </code>
-            .
-          </li>
-          <li className="tracking-[-.01em]">
-            Save and see your changes instantly.
-          </li>
-        </ol>
+    <div
+      className="min-h-screen bg-[#080c12] text-white overflow-x-hidden"
+      style={{ fontFamily: "'IBM Plex Sans', system-ui, sans-serif" }}
+    >
+      {/* ── Background layers ── */}
+      <div
+        className="fixed inset-0 pointer-events-none"
+        style={{
+          backgroundImage:
+            "linear-gradient(rgba(255,255,255,0.018) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,0.018) 1px, transparent 1px)",
+          backgroundSize: "48px 48px",
+        }}
+      />
+      <div
+        className="fixed inset-0 pointer-events-none opacity-30"
+        style={{
+          backgroundImage:
+            "linear-gradient(135deg, rgba(56,189,248,0.03) 25%, transparent 25%), linear-gradient(225deg, rgba(56,189,248,0.03) 25%, transparent 25%)",
+          backgroundSize: "96px 96px",
+        }}
+      />
+      <div
+        className="fixed top-0 left-1/2 -translate-x-1/2 w-[900px] h-[500px] pointer-events-none"
+        style={{
+          background:
+            "radial-gradient(ellipse at 50% 0%, rgba(56,189,248,0.08) 0%, transparent 65%)",
+        }}
+      />
+      <div
+        className="fixed bottom-0 left-0 w-[500px] h-[400px] pointer-events-none"
+        style={{
+          background:
+            "radial-gradient(ellipse at 0% 100%, rgba(56,189,248,0.04) 0%, transparent 60%)",
+        }}
+      />
+
+      <Navbar />
+      <HeroSection />
+      <HowItWorksSection />
+      <WhatWeDecodeSection />
+      <OpenSourceSection />
+      <Footer />
 
-        <div className="flex gap-4 items-center flex-col sm:flex-row">
-          <a
-            className="rounded-full border border-solid border-transparent transition-colors flex items-center justify-center bg-foreground text-background gap-2 hover:bg-[#383838] dark:hover:bg-[#ccc] font-medium text-sm sm:text-base h-10 sm:h-12 px-4 sm:px-5 sm:w-auto"
-            href="https://vercel.com/new?utm_source=create-next-app&utm_medium=appdir-template-tw&utm_campaign=create-next-app"
-            target="_blank"
-            rel="noopener noreferrer"
-          >
-            <Image
-              className="dark:invert"
-              src="/vercel.svg"
-              alt="Vercel logomark"
-              width={20}
-              height={20}
-            />
-            Deploy now
-          </a>
-          <a
-            className="rounded-full border border-solid border-black/[.08] dark:border-white/[.145] transition-colors flex items-center justify-center hover:bg-[#f2f2f2] dark:hover:bg-[#1a1a1a] hover:border-transparent font-medium text-sm sm:text-base h-10 sm:h-12 px-4 sm:px-5 w-full sm:w-auto md:w-[158px]"
-            href="https://nextjs.org/docs?utm_source=create-next-app&utm_medium=appdir-template-tw&utm_campaign=create-next-app"
-            target="_blank"
-            rel="noopener noreferrer"
-          >
-            Read our docs
-          </a>
-        </div>
-      </main>
-      <footer className="row-start-3 flex gap-[24px] flex-wrap items-center justify-center">
-        <a
-          className="flex items-center gap-2 hover:underline hover:underline-offset-4"
-          href="https://nextjs.org/learn?utm_source=create-next-app&utm_medium=appdir-template-tw&utm_campaign=create-next-app"
-          target="_blank"
-          rel="noopener noreferrer"
-        >
-          <Image
-            aria-hidden
-            src="/file.svg"
-            alt="File icon"
-            width={16}
-            height={16}
-          />
-          Learn
-        </a>
-        <a
-          className="flex items-center gap-2 hover:underline hover:underline-offset-4"
-          href="https://vercel.com/templates?framework=next.js&utm_source=create-next-app&utm_medium=appdir-template-tw&utm_campaign=create-next-app"
-          target="_blank"
-          rel="noopener noreferrer"
-        >
-          <Image
-            aria-hidden
-            src="/window.svg"
-            alt="Window icon"
-            width={16}
-            height={16}
-          />
-          Examples
-        </a>
-        <a
-          className="flex items-center gap-2 hover:underline hover:underline-offset-4"
-          href="https://nextjs.org?utm_source=create-next-app&utm_medium=appdir-template-tw&utm_campaign=create-next-app"
-          target="_blank"
-          rel="noopener noreferrer"
-        >
-          <Image
-            aria-hidden
-            src="/globe.svg"
-            alt="Globe icon"
-            width={16}
-            height={16}
-          />
-          Go to nextjs.org →
-        </a>
-      </footer>
     </div>
   );
 }