diff --git a/assets/css/custom.css b/assets/css/custom.css
new file mode 100644
index 0000000..9fcb354
--- /dev/null
+++ b/assets/css/custom.css
@@ -0,0 +1,128 @@
+
+:root {
+  --primary-color: #4F46E5;
+  --secondary-color: #10B981;
+  --background-color: #F3F4F6;
+  --surface-color: #FFFFFF;
+  --text-color: #111827;
+}
+
+body {
+  font-family: 'Inter', sans-serif;
+  background-color: var(--background-color);
+  color: var(--text-color);
+}
+
+.sidebar {
+  position: fixed;
+  top: 0;
+  left: 0;
+  height: 100vh;
+  width: 80px;
+  background-color: var(--surface-color);
+  padding: 1rem 0;
+  transition: width 0.3s ease;
+  z-index: 1000;
+  overflow-x: hidden;
+  display: flex;
+  flex-direction: column;
+  border-right: 1px solid #e5e7eb;
+}
+
+.sidebar.expanded {
+  width: 250px;
+}
+
+.sidebar .nav-link {
+  display: flex;
+  align-items: center;
+  padding: 0.75rem 1.5rem;
+  color: #6b7280;
+  text-decoration: none;
+  white-space: nowrap;
+}
+
+.sidebar .nav-link .icon {
+  width: 1.5rem;
+  height: 1.5rem;
+  margin-right: 1rem;
+  flex-shrink: 0;
+}
+
+.sidebar .nav-link .link-text {
+  opacity: 0;
+  transition: opacity 0.2s ease-in-out;
+}
+
+.sidebar.expanded .nav-link .link-text {
+  opacity: 1;
+}
+
+.sidebar .nav-link:hover {
+  color: var(--primary-color);
+  background-color: #f9fafb;
+}
+
+.sidebar .logo-container {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    padding: 1rem;
+    margin-bottom: 1rem;
+}
+
+.sidebar .logo {
+    width: 40px;
+    height: 40px;
+    background-color: var(--primary-color);
+    border-radius: 50%;
+    color: white;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    font-weight: bold;
+    font-size: 1.5rem;
+    flex-shrink: 0;
+}
+
+
+.sidebar-toggle {
+  position: absolute;
+  bottom: 1rem;
+  left: 1.5rem;
+  background: none;
+  border: none;
+  color: #6b7280;
+  padding: 0.5rem;
+}
+
+.sidebar.expanded .sidebar-toggle {
+    left: auto;
+    right: 1rem;
+}
+
+.main-content {
+  margin-left: 80px;
+  padding: 2rem;
+  transition: margin-left 0.3s ease;
+}
+
+.main-content.expanded {
+  margin-left: 250px;
+}
+
+@media (max-width: 768px) {
+  .sidebar {
+    width: 0;
+    padding: 0;
+  }
+  .sidebar.expanded {
+    width: 250px;
+  }
+  .main-content {
+    margin-left: 0;
+  }
+  .main-content.expanded {
+    margin-left: 0; /* Or a semi-transparent overlay */
+  }
+}
diff --git a/assets/js/main.js b/assets/js/main.js
new file mode 100644
index 0000000..7595b8c
--- /dev/null
+++ b/assets/js/main.js
@@ -0,0 +1,20 @@
+document.addEventListener('DOMContentLoaded', function () {
+    const sidebar = document.querySelector('.sidebar');
+    const mainContent = document.querySelector('.main-content');
+    const sidebarToggle = document.querySelector('.sidebar-toggle');
+
+    if (sidebarToggle) {
+        sidebarToggle.addEventListener('click', () => {
+            sidebar.classList.toggle('expanded');
+            mainContent.classList.toggle('expanded');
+        });
+    }
+
+    // Mobile toggle for off-canvas menu
+    const mobileMenuButton = document.querySelector('.mobile-menu-button');
+    if(mobileMenuButton) {
+        mobileMenuButton.addEventListener('click', () => {
+            sidebar.classList.toggle('expanded');
+        });
+    }
+});
diff --git a/index.php b/index.php
index 6f7ffab..e2f9f44 100644
--- a/index.php
+++ b/index.php
@@ -1,131 +1,76 @@
-<?php
-declare(strict_types=1);
-@ini_set('display_errors', '1');
-@error_reporting(E_ALL);
-@date_default_timezone_set('UTC');
-
-$phpVersion = PHP_VERSION;
-$now = date('Y-m-d H:i:s');
-?>
-<!doctype html>
+<!DOCTYPE html>
 <html lang="en">
 <head>
-  <meta charset="utf-8" />
-  <meta name="viewport" content="width=device-width, initial-scale=1" />
-  <title>New Style</title>
-  <link rel="preconnect" href="https://fonts.googleapis.com">
-  <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
-  <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;700&display=swap" rel="stylesheet">
-  <style>
-    :root {
-      --bg-color-start: #6a11cb;
-      --bg-color-end: #2575fc;
-      --text-color: #ffffff;
-      --card-bg-color: rgba(255, 255, 255, 0.01);
-      --card-border-color: rgba(255, 255, 255, 0.1);
-    }
-    body {
-      margin: 0;
-      font-family: 'Inter', sans-serif;
-      background: linear-gradient(45deg, var(--bg-color-start), var(--bg-color-end));
-      color: var(--text-color);
-      display: flex;
-      justify-content: center;
-      align-items: center;
-      min-height: 100vh;
-      text-align: center;
-      overflow: hidden;
-      position: relative;
-    }
-    body::before {
-      content: '';
-      position: absolute;
-      top: 0;
-      left: 0;
-      width: 100%;
-      height: 100%;
-      background-image: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="100" height="100" viewBox="0 0 100 100"><path d="M-10 10L110 10M10 -10L10 110" stroke-width="1" stroke="rgba(255,255,255,0.05)"/></svg>');
-      animation: bg-pan 20s linear infinite;
-      z-index: -1;
-    }
-    @keyframes bg-pan {
-      0% { background-position: 0% 0%; }
-      100% { background-position: 100% 100%; }
-    }
-    main {
-      padding: 2rem;
-    }
-    .card {
-      background: var(--card-bg-color);
-      border: 1px solid var(--card-border-color);
-      border-radius: 16px;
-      padding: 2rem;
-      backdrop-filter: blur(20px);
-      -webkit-backdrop-filter: blur(20px);
-      box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.1);
-    }
-    .loader {
-      margin: 1.25rem auto 1.25rem;
-      width: 48px;
-      height: 48px;
-      border: 3px solid rgba(255, 255, 255, 0.25);
-      border-top-color: #fff;
-      border-radius: 50%;
-      animation: spin 1s linear infinite;
-    }
-    @keyframes spin {
-      from { transform: rotate(0deg); }
-      to   { transform: rotate(360deg); }
-    }
-    .hint {
-      opacity: 0.9;
-    }
-    .sr-only {
-      position: absolute;
-      width: 1px; height: 1px;
-      padding: 0; margin: -1px;
-      overflow: hidden;
-      clip: rect(0, 0, 0, 0);
-      white-space: nowrap; border: 0;
-    }
-    h1 {
-      font-size: 3rem;
-      font-weight: 700;
-      margin: 0 0 1rem;
-      letter-spacing: -1px;
-    }
-    p {
-      margin: 0.5rem 0;
-      font-size: 1.1rem;
-    }
-    code {
-      background: rgba(0,0,0,0.2);
-      padding: 2px 6px;
-      border-radius: 4px;
-      font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
-    }
-    footer {
-      position: absolute;
-      bottom: 1rem;
-      font-size: 0.8rem;
-      opacity: 0.7;
-    }
-  </style>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>CRM Dashboard</title>
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css" rel="stylesheet">
+    <link rel="stylesheet" href="https://unpkg.com/heroicons@2.1.3/24/outline/css/heroicons.min.css">
+    <link rel="stylesheet" href="assets/css/custom.css?v=<?php echo time(); ?>">
+    <link rel="preconnect" href="https://fonts.googleapis.com">
+    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
+    <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap" rel="stylesheet">
 </head>
 <body>
-  <main>
-    <div class="card">
-      <h1>Analyzing your requirements and generating your website…</h1>
-      <div class="loader" role="status" aria-live="polite" aria-label="Applying initial changes">
-        <span class="sr-only">Loading…</span>
-      </div>
-      <p class="hint"><?= ($_SERVER['HTTP_HOST'] ?? '') === 'appwizzy.com' ? 'AppWiZZy' : 'Flatlogic' ?> AI is collecting your requirements and applying the first changes.</p>
-      <p class="hint">This page will update automatically as the plan is implemented.</p>
-      <p>Runtime: PHP <code><?= htmlspecialchars($phpVersion) ?></code> — UTC <code><?= htmlspecialchars($now) ?></code></p>
+
+    <div class="sidebar">
+        <div class="logo-container">
+            <div class="logo">C</div>
+        </div>
+        <nav class="nav flex-column">
+            <a class="nav-link" href="#">
+                <i class="icon hi-outline hi-home"></i>
+                <span class="link-text">Dashboard</span>
+            </a>
+            <a class="nav-link" href="#">
+                <i class="icon hi-outline hi-view-columns"></i>
+                <span class="link-text">Oportunidades</span>
+            </a>
+            <a class="nav-link" href="#">
+                <i class="icon hi-outline hi-user-group"></i>
+                <span class="link-text">Clientes</span>
+            </a>
+            <a class="nav-link" href="#">
+                <i class="icon hi-outline hi-chart-pie"></i>
+                <span class="link-text">Relatórios</span>
+            </a>
+            <a class="nav-link" href="#">
+                <i class="icon hi-outline hi-cog"></i>
+                <span class="link-text">Configurações</span>
+            </a>
+        </nav>
+        <button class="sidebar-toggle">
+            <i class="icon hi-outline hi-chevron-double-right"></i>
+        </button>
     </div>
-  </main>
-  <footer>
-    Page updated: <?= htmlspecialchars($now) ?> (UTC)
-  </footer>
+
+    <div class="main-content">
+        <header class="d-flex justify-content-between align-items-center mb-4">
+            <button class="btn d-md-none mobile-menu-button">
+                <i class="icon hi-outline hi-bars-3"></i>
+            </button>
+            <h1 class="h3 mb-0">Dashboard</h1>
+            <div class="d-flex align-items-center">
+                <span class="me-3">Admin</span>
+                <img src="https://picsum.photos/seed/user/40/40" class="rounded-circle" alt="User avatar">
+            </div>
+        </header>
+
+        <div class="container-fluid">
+            <div class="row">
+                <div class="col-12">
+                    <div class="card shadow-sm border-0">
+                        <div class="card-body">
+                            <h5 class="card-title">Bem-vindo ao seu CRM!</h5>
+                            <p class="card-text">Este é o painel principal. As funcionalidades serão adicionadas aqui.</p>
+                        </div>
+                    </div>
+                </div>
+            </div>
+        </div>
+    </div>
+
+    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js"></script>
+    <script src="assets/js/main.js?v=<?php echo time(); ?>"></script>
 </body>
-</html>
+</html>
\ No newline at end of file
