diff --git a/index.html b/index.html
index 85b991c..67053de 100644
--- a/index.html
+++ b/index.html
@@ -1,11 +1,309 @@
 <!doctype html>
+
 <html lang="en">
-  <head>
-    <meta charset="UTF-8" />
-    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <title>Hello World</title>
-  </head>
-  <body>
-    <h1>Hello world</h1>
-  </body>
+<head>
+  <meta charset="utf-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1, viewport-fit=cover" />
+  <title>ChatGPT — Mobile Clone (Light)</title>
+  <!-- Tailwind CSS CDN -->
+  <script src="https://cdn.tailwindcss.com"></script>
+  <style>
+    /* iOS safe area for the input dock */
+    :root { --safe-bottom: env(safe-area-inset-bottom); }
+    ::-webkit-scrollbar { height: 8px; width: 8px; }
+    ::-webkit-scrollbar-thumb { background: #e5e7eb; border-radius: 999px; }
+    .no-scrollbar::-webkit-scrollbar { display: none; }
+    .no-scrollbar { -ms-overflow-style: none; scrollbar-width: none; }
+  </style>
+</head>
+<body class="bg-white text-gray-900 selection:bg-amber-200/60">
+  <!-- App Shell -->
+  <div class="flex flex-col h-dvh max-h-dvh">
+    <!-- Header -->
+    <header class="sticky top-0 z-10 bg-white/80 backdrop-blur border-b border-gray-200">
+      <div class="mx-auto w-full max-w-2xl px-4 py-3 flex items-center justify-between">
+        <button id="newChatBtn" class="text-sm font-medium px-3 py-1.5 rounded-xl bg-gray-100 hover:bg-gray-200 active:scale-[.99] transition">
+          New chat
+        </button>
+        <div class="text-sm text-gray-600 truncate" id="modelBadge">
+          Model: <span class="font-semibold" id="modelName">openai/gpt-4o</span>
+        </div>
+        <div class="flex items-center gap-2">
+          <span class="text-[11px] text-gray-400" id="status">offline</span>
+        </div>
+      </div>
+    </header><!-- Messages -->
+<main id="chat" class="flex-1 overflow-y-auto no-scrollbar">
+  <div id="messages" class="mx-auto w-full max-w-2xl px-4 py-4 sm:py-6 space-y-4">
+    <!-- Placeholder intro -->
+    <div class="flex gap-3">
+      <div class="shrink-0 h-8 w-8 rounded-full bg-emerald-100 text-emerald-700 flex items-center justify-center">🤖</div>
+      <div class="bg-gray-100 rounded-2xl px-4 py-3 text-[15px] leading-relaxed">
+        <div class="font-semibold text-gray-800 mb-1">Hello!</div>
+        I’m a lightweight ChatGPT-style demo. Type below to chat. Set an OpenRouter API key (bottom-left) to go online; otherwise I’ll reply locally.
+      </div>
+    </div>
+  </div>
+  <div class="h-24"></div> <!-- spacer so last message isn't hidden under input dock -->
+</main>
+
+<!-- Input Dock -->
+<footer class="sticky bottom-0 bg-gradient-to-t from-white via-white/95 to-white/40 pt-3 pb-[calc(12px+var(--safe-bottom))] border-t border-gray-200">
+  <div class="mx-auto w-full max-w-2xl px-4">
+    <form id="composer" class="group relative flex items-end gap-2">
+      <textarea id="input" rows="1" placeholder="Send a message" spellcheck="true"
+        class="flex-1 resize-none rounded-2xl border border-gray-300 bg-white px-4 py-3 text-[15px] leading-6 placeholder:text-gray-400 focus:outline-none focus:ring-2 focus:ring-amber-300/80 focus:border-gray-300 max-h-40"></textarea>
+      <button id="sendBtn" type="submit" aria-label="Send"
+        class="shrink-0 rounded-2xl bg-amber-500 text-white h-10 w-10 inline-flex items-center justify-center shadow-sm hover:bg-amber-600 active:scale-[.98] transition disabled:opacity-40 disabled:cursor-not-allowed">
+        <!-- Send icon -->
+        <svg viewBox="0 0 24 24" class="h-5 w-5" fill="none" stroke="currentColor" stroke-width="1.8">
+          <path stroke-linecap="round" stroke-linejoin="round" d="M5 12h14M12 5l7 7-7 7"/>
+        </svg>
+      </button>
+    </form>
+    <div class="mt-2 flex items-center justify-between text-xs text-gray-500">
+      <div class="flex items-center gap-1.5">
+        <kbd class="px-1.5 py-0.5 rounded border bg-gray-50">Enter</kbd>
+        to send • <kbd class="px-1.5 py-0.5 rounded border bg-gray-50">Shift</kbd>+<kbd class="px-1.5 py-0.5 rounded border bg-gray-50">Enter</kbd> for newline
+      </div>
+      <button id="clearBtn" class="underline decoration-dotted hover:text-gray-700">Clear</button>
+    </div>
+  </div>
+</footer>
+
+<!-- Corner Controls (bottom-left) -->
+<div class="fixed bottom-[calc(68px+var(--safe-bottom))] left-3 flex flex-col gap-2">
+  <button id="setApiBtn" title="Set OpenRouter API key" class="h-10 w-10 rounded-full bg-gray-100 border border-gray-200 shadow-sm hover:bg-gray-200 active:scale-[.98] transition flex items-center justify-center">
+    <!-- User icon -->
+    <svg viewBox="0 0 24 24" class="h-5 w-5 text-gray-700" fill="none" stroke="currentColor" stroke-width="1.6">
+      <path stroke-linecap="round" stroke-linejoin="round" d="M15.75 6.75a3.75 3.75 0 11-7.5 0 3.75 3.75 0 017.5 0z"/>
+      <path stroke-linecap="round" stroke-linejoin="round" d="M4.5 20.25a8.25 8.25 0 0115 0"/>
+    </svg>
+  </button>
+  <button id="setModelBtn" title="Set model" class="h-10 w-10 rounded-full bg-emerald-50 border border-emerald-200 shadow-sm hover:bg-emerald-100 active:scale-[.98] transition flex items-center justify-center">
+    <!-- Bot icon -->
+    <svg viewBox="0 0 24 24" class="h-5 w-5 text-emerald-700" fill="none" stroke="currentColor" stroke-width="1.6">
+      <path stroke-linecap="round" stroke-linejoin="round" d="M9 7h6M4 11h16v4a5 5 0 01-5 5H9a5 5 0 01-5-5v-4z"/>
+      <path stroke-linecap="round" stroke-linejoin="round" d="M9 3h6v4H9z"/>
+      <circle cx="9" cy="14" r="1"/><circle cx="15" cy="14" r="1"/>
+    </svg>
+  </button>
+</div>
+
+  </div>  <script>
+    // === State ===
+    const el = {
+      chat: document.getElementById('chat'),
+      messages: document.getElementById('messages'),
+      composer: document.getElementById('composer'),
+      input: document.getElementById('input'),
+      sendBtn: document.getElementById('sendBtn'),
+      clearBtn: document.getElementById('clearBtn'),
+      newChatBtn: document.getElementById('newChatBtn'),
+      status: document.getElementById('status'),
+      modelName: document.getElementById('modelName'),
+      modelBadge: document.getElementById('modelBadge'),
+      setApiBtn: document.getElementById('setApiBtn'),
+      setModelBtn: document.getElementById('setModelBtn'),
+    };
+
+    const store = {
+      get apiKey() { return localStorage.getItem('openrouter_api_key') || ''; },
+      set apiKey(v) { localStorage.setItem('openrouter_api_key', v || ''); updateStatus(); },
+      get model() { return localStorage.getItem('openrouter_model') || 'openai/gpt-4o'; },
+      set model(v) { localStorage.setItem('openrouter_model', v || 'openai/gpt-4o'); el.modelName.textContent = store.model; },
+    };
+
+    const state = {
+      messages: [], // {role: 'user'|'assistant'|'system', content: string}
+      busy: false,
+      controller: null,
+    };
+
+    // === UI Helpers ===
+    function addMessage(role, content) {
+      const row = document.createElement('div');
+      row.className = 'flex gap-3';
+
+      const avatar = document.createElement('div');
+      avatar.className = 'shrink-0 h-8 w-8 rounded-full flex items-center justify-center ' + (role === 'user' ? 'bg-blue-100 text-blue-700' : 'bg-emerald-100 text-emerald-700');
+      avatar.textContent = role === 'user' ? '🧑' : '🤖';
+
+      const bubble = document.createElement('div');
+      bubble.className = 'rounded-2xl px-4 py-3 text-[15px] leading-relaxed whitespace-pre-wrap ' + (role === 'user' ? 'bg-blue-50 border border-blue-100' : 'bg-gray-100');
+      bubble.textContent = content;
+
+      row.appendChild(avatar);
+      row.appendChild(bubble);
+      el.messages.appendChild(row);
+
+      // Keep internal transcript (for API calls)
+      state.messages.push({ role, content });
+
+      // Auto-scroll
+      queueMicrotask(() => el.chat.scrollTo({ top: el.chat.scrollHeight, behavior: 'smooth' }));
+
+      return bubble;
+    }
+
+    function addThinkingBubble() {
+      const row = document.createElement('div');
+      row.className = 'flex gap-3';
+      const avatar = document.createElement('div');
+      avatar.className = 'shrink-0 h-8 w-8 rounded-full flex items-center justify-center bg-emerald-100 text-emerald-700';
+      avatar.textContent = '🤖';
+      const bubble = document.createElement('div');
+      bubble.className = 'rounded-2xl px-4 py-3 text-[15px] leading-relaxed bg-gray-100 text-gray-700';
+      bubble.innerHTML = '<span class="inline-flex items-center gap-1">Thinking<span class="inline-block w-1 h-1 bg-gray-500 rounded-full animate-bounce [animation-delay:-0.2s]"></span><span class="inline-block w-1 h-1 bg-gray-500 rounded-full animate-bounce [animation-delay:-0.1s]"></span><span class="inline-block w-1 h-1 bg-gray-500 rounded-full animate-bounce"></span></span>';
+      row.appendChild(avatar);
+      row.appendChild(bubble);
+      el.messages.appendChild(row);
+      queueMicrotask(() => el.chat.scrollTo({ top: el.chat.scrollHeight }));
+      return bubble;
+    }
+
+    function clearChat(intro = true) {
+      state.messages = [];
+      el.messages.innerHTML = '';
+      if (intro) {
+        const introRow = document.createElement('div');
+        introRow.className = 'flex gap-3';
+        introRow.innerHTML = `
+          <div class="shrink-0 h-8 w-8 rounded-full bg-emerald-100 text-emerald-700 flex items-center justify-center">🤖</div>
+          <div class="bg-gray-100 rounded-2xl px-4 py-3 text-[15px] leading-relaxed">
+            <div class="font-semibold text-gray-800 mb-1">New chat</div>
+            You're in a fresh conversation. Ask away.
+          </div>`;
+        el.messages.appendChild(introRow);
+      }
+    }
+
+    function updateStatus() {
+      const online = !!store.apiKey;
+      el.status.textContent = online ? 'online' : 'offline';
+      el.status.className = 'text-[11px] ' + (online ? 'text-emerald-600' : 'text-gray-400');
+    }
+
+    // === Comms ===
+    async function askOpenRouter() {
+      const apiKey = store.apiKey;
+      const model = store.model;
+      if (!apiKey) {
+        // Local demo reply
+        return {
+          ok: true,
+          text: localDemoReply(state.messages[state.messages.length - 1]?.content || '')
+        };
+      }
+
+      try {
+        state.controller = new AbortController();
+        const res = await fetch('https://openrouter.ai/api/v1/chat/completions', {
+          method: 'POST',
+          headers: {
+            'Content-Type': 'application/json',
+            'Authorization': 'Bearer ' + apiKey,
+          },
+          body: JSON.stringify({
+            model,
+            messages: state.messages.filter(m => m.role !== 'system'),
+            stream: false,
+          }),
+          signal: state.controller.signal,
+        });
+        if (!res.ok) {
+          const err = await res.text();
+          throw new Error(err || ('HTTP ' + res.status));
+        }
+        const data = await res.json();
+        const choice = data.choices?.[0]?.message?.content?.trim() || '(no content)';
+        return { ok: true, text: choice };
+      } catch (e) {
+        console.error(e);
+        return { ok: false, text: 'Request failed. Using local demo instead.\n\n' + localDemoReply(state.messages[state.messages.length - 1]?.content || '') };
+      } finally {
+        state.controller = null;
+      }
+    }
+
+    function localDemoReply(prompt) {
+      // Very tiny offline echo with a dash of personality
+      const tips = [
+        'Tip: set an OpenRouter API key (bottom-left) to go truly online.',
+        'Pro move: tap the bot icon to pick a different model.',
+        'New chats are stateless here—no history is kept.',
+      ];
+      const tip = tips[Math.floor(Math.random() * tips.length)];
+      const mirrored = prompt.split(/\s+/).slice(0, 24).join(' ');
+      return `Local demo mode. You said: "${mirrored}"\n\n${tip}`;
+    }
+
+    // === Events ===
+    el.composer.addEventListener('submit', async (e) => {
+      e.preventDefault();
+      if (state.busy) return;
+      const text = el.input.value.trim();
+      if (!text) return;
+      el.input.value = '';
+      el.input.style.height = 'auto';
+
+      addMessage('user', text);
+      state.busy = true;
+      el.sendBtn.disabled = true;
+      const thinking = addThinkingBubble();
+
+      const res = await askOpenRouter();
+      thinking.textContent = res.text;
+
+      // Replace thinking bubble with final assistant bubble style
+      thinking.className = 'rounded-2xl px-4 py-3 text-[15px] leading-relaxed bg-gray-100 text-gray-800 whitespace-pre-wrap';
+      state.messages[state.messages.length - 1] = { role: 'assistant', content: res.text };
+
+      el.sendBtn.disabled = false;
+      state.busy = false;
+      queueMicrotask(() => el.chat.scrollTo({ top: el.chat.scrollHeight, behavior: 'smooth' }));
+    });
+
+    // Auto-resize textarea
+    el.input.addEventListener('input', () => {
+      el.input.style.height = 'auto';
+      const h = Math.min(el.input.scrollHeight, 160); // cap at 160px
+      el.input.style.height = h + 'px';
+    });
+
+    // Enter to send, Shift+Enter for new line
+    el.input.addEventListener('keydown', (e) => {
+      if (e.key === 'Enter' && !e.shiftKey) {
+        e.preventDefault();
+        el.composer.requestSubmit();
+      }
+    });
+
+    // Clear chat
+    el.clearBtn.addEventListener('click', () => clearChat(false));
+
+    // New chat (fresh intro)
+    el.newChatBtn.addEventListener('click', () => clearChat(true));
+
+    // Set API key
+    el.setApiBtn.addEventListener('click', () => {
+      const current = store.apiKey ? '********' : '';
+      const input = prompt('Enter OpenRouter API key (stored locally):', current);
+      if (input === null) return; // cancel
+      store.apiKey = input === '********' ? store.apiKey : (input.trim());
+      alert(store.apiKey ? 'API key saved locally.' : 'API key cleared.');
+    });
+
+    // Set Model
+    el.setModelBtn.addEventListener('click', () => {
+      const input = prompt('Enter model name (e.g., openai/gpt-4o):', store.model);
+      if (input === null) return;
+      const name = input.trim() || 'openai/gpt-4o';
+      store.model = name;
+    });
+
+    // Init
+    updateStatus();
+    el.modelName.textContent = store.model;
+  </script></body>
 </html>
