diff --git a/assets/css/custom.css b/assets/css/custom.css
new file mode 100644
index 0000000..554fa1a
--- /dev/null
+++ b/assets/css/custom.css
@@ -0,0 +1,107 @@
+@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');
+
+body {
+    font-family: 'Inter', sans-serif;
+    background-color: #F3F4F6;
+    color: #111827;
+    display: flex;
+    margin: 0;
+}
+
+.sidebar {
+    width: 260px;
+    background-color: #FFFFFF;
+    padding: 1.5rem;
+    height: 100vh;
+    position: fixed;
+    top: 0;
+    left: 0;
+    display: flex;
+    flex-direction: column;
+    border-right: 1px solid #E5E7EB;
+}
+
+.sidebar .school-logo {
+    font-size: 1.5rem;
+    font-weight: 700;
+    color: #4F46E5;
+    margin-bottom: 2.5rem;
+    text-align: center;
+}
+
+.sidebar .nav-menu {
+    list-style: none;
+    padding: 0;
+    margin: 0;
+    flex-grow: 1;
+}
+
+.sidebar .nav-menu .nav-item a {
+    display: block;
+    padding: 0.8rem 1rem;
+    border-radius: 0.375rem;
+    text-decoration: none;
+    color: #374151;
+    font-weight: 500;
+    margin-bottom: 0.5rem;
+    transition: background-color 0.2s ease, color 0.2s ease;
+}
+
+.sidebar .nav-menu .nav-item a:hover {
+    background-color: #EEF2FF;
+    color: #4F46E5;
+}
+
+.sidebar .nav-menu .nav-item a.active {
+    background-color: #4F46E5;
+    color: #FFFFFF;
+    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
+}
+
+.main-content {
+    margin-left: 260px;
+    flex-grow: 1;
+    padding: 2rem;
+    display: flex;
+    flex-direction: column;
+}
+
+.main-header {
+    display: flex;
+    justify-content: flex-end;
+    align-items: center;
+    margin-bottom: 2rem;
+}
+
+.user-profile {
+    display: flex;
+    align-items: center;
+    gap: 0.75rem;
+}
+
+.user-profile img {
+    width: 40px;
+    height: 40px;
+    border-radius: 50%;
+}
+
+.user-profile .user-name {
+    font-weight: 600;
+}
+
+.content-body {
+    flex-grow: 1;
+}
+
+.card {
+    background-color: #FFFFFF;
+    border-radius: 0.5rem;
+    padding: 1.5rem;
+    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.05), 0 1px 2px 0 rgba(0, 0, 0, 0.02);
+}
+
+.card-title {
+    font-size: 1.25rem;
+    font-weight: 600;
+    margin-bottom: 1rem;
+}
diff --git a/assets/js/main.js b/assets/js/main.js
new file mode 100644
index 0000000..122310b
--- /dev/null
+++ b/assets/js/main.js
@@ -0,0 +1 @@
+// Future JavaScript interactions will go here.
diff --git a/index.php b/index.php
index 6f7ffab..f984d31 100644
--- a/index.php
+++ b/index.php
@@ -1,131 +1,87 @@
-<?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>
-<html lang="en">
+<!DOCTYPE html>
+<html lang="es">
 <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>Dashboard - Gestión Escolar</title>
+    <meta name="description" content="Panel de administración para la gestión de alumnos, profesores y materias.">
+    <!-- Open Graph / Facebook -->
+    <meta property="og:type" content="website">
+    <meta property="og:url" content="URL_DEL_SITIO">
+    <meta property="og:title" content="Dashboard - Gestión Escolar">
+    <meta property="og:description" content="Panel de administración para la gestión de alumnos, profesores y materias.">
+    <meta property="og:image" content="URL_DE_IMAGEN_PREVIEW">
+
+    <!-- Twitter -->
+    <meta property="twitter:card" content="summary_large_image">
+    <meta property="twitter:url" content="URL_DEL_SITIO">
+    <meta property="twitter:title" content="Dashboard - Gestión Escolar">
+    <meta property="twitter:description" content="Panel de administración para la gestión de alumnos, profesores y materias.">
+    <meta property="twitter:image" content="URL_DE_IMAGEN_PREVIEW">
+
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.css" rel="stylesheet">
+    <link rel="stylesheet" href="assets/css/custom.css?v=<?php echo time(); ?>">
 </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>
+
+    <aside class="sidebar">
+        <div class="school-logo">
+            EscuelaWeb
+        </div>
+        <ul class="nav-menu">
+            <li class="nav-item"><a href="#" class="active">Dashboard</a></li>
+            <li class="nav-item"><a href="#">Alumnos</a></li>
+            <li class="nav-item"><a href="#">Profesores</a></li>
+            <li class="nav-item"><a href="#">Materias</a></li>
+        </ul>
+    </aside>
+
+    <div class="main-content">
+        <header class="main-header">
+            <div class="user-profile">
+                <span class="user-name">Admin User</span>
+                <img src="https://i.pravatar.cc/40?u=admin" alt="Admin User Avatar">
+            </div>
+        </header>
+
+        <main class="content-body">
+            <h1>Bienvenido al Dashboard</h1>
+            <p class="text-secondary mb-4">Selecciona una opción del menú para comenzar a gestionar.</p>
+            
+            <div class="card">
+                <h5 class="card-title">Vista Rápida</h5>
+                <p>Aquí se mostrarán estadísticas y accesos directos importantes.</p>
+                <div class="row">
+                    <div class="col-md-4">
+                        <div class="card bg-light">
+                            <div class="card-body">
+                                <h6 class="card-subtitle mb-2 text-muted">Total Alumnos</h6>
+                                <p class="card-text fs-4 fw-bold">-</p>
+                            </div>
+                        </div>
+                    </div>
+                    <div class="col-md-4">
+                        <div class="card bg-light">
+                            <div class="card-body">
+                                <h6 class="card-subtitle mb-2 text-muted">Total Profesores</h6>
+                                <p class="card-text fs-4 fw-bold">-</p>
+                            </div>
+                        </div>
+                    </div>
+                    <div class="col-md-4">
+                        <div class="card bg-light">
+                            <div class="card-body">
+                                <h6 class="card-subtitle mb-2 text-muted">Total Materias</h6>
+                                <p class="card-text fs-4 fw-bold">-</p>
+                            </div>
+                        </div>
+                    </div>
+                </div>
+            </div>
+        </main>
     </div>
-  </main>
-  <footer>
-    Page updated: <?= htmlspecialchars($now) ?> (UTC)
-  </footer>
+
+    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/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
