diff --git a/cabecera.php b/cabecera.php
index 21d2e7d..0bf9863 100644
--- a/cabecera.php
+++ b/cabecera.php
@@ -1,68 +1,310 @@
-<?php
-if (session_status() === PHP_SESSION_NONE) {
-    session_start();
-}
-
-// Comprobación de sesión
-$isLoggedIn = isset($_SESSION['usuario']) && !empty($_SESSION['usuario']);
-$username = $isLoggedIn ? $_SESSION['usuario'] : '';
-?>
-
-<!-- Bootstrap 5 CSS -->
-<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.css" rel="stylesheet">
-<!-- FontAwesome para iconos -->
-<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.2/css/all.min.css">
-<!-- Google Fonts para estilo Kahoot -->
-<link href="https://fonts.googleapis.com/css2?family=Fredoka:wght@400;600;700&display=swap" rel="stylesheet">
-<link rel="stylesheet" href="/css/index.css">
-<style>
-
-</style>
-
-<nav class="navbar navbar-expand-lg navbar-kahoot py-3 mb-4">
-    <div class="container">
-        <a class="navbar-brand" href="index.php">
-            <i class="fa-solid fa-gamepad me-2"></i>TRIVIAGMÁTICO
-        </a>
-        <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarContent">
-            <span class="navbar-toggler-icon"></span>
-        </button>
-
-        <div class="collapse navbar-collapse" id="navbarContent">
-            <ul class="navbar-nav me-auto mb-2 mb-lg-0"></ul>
-            
-            <div class="d-flex align-items-center gap-3">
-                <?php if ($isLoggedIn): ?>
-                    <!-- Menú desplegable -->
-                    <div class="dropdown">
-                        <button class="btn user-dropdown-btn dropdown-toggle d-flex align-items-center gap-2" 
-                                type="button" 
-                                id="userDropdown" 
-                                data-bs-toggle="dropdown" 
-                                aria-expanded="false">
-                            <i class="fa-solid fa-circle-user fa-lg text-warning"></i>
-                            <span><?= htmlspecialchars($username) ?></span>
-                        </button>
-                        <ul class="dropdown-menu dropdown-menu-end user-dropdown-menu" aria-labelledby="userDropdown">
-                            <li>
-                                <a class="dropdown-item d-flex align-items-center gap-2" href="perfil.php">
-                                    <i class="fa-solid fa-user text-primary"></i> Perfil
-                                </a>
-                            </li>
-                            <li><hr class="dropdown-divider"></li>
-                            <li>
-                                <a class="dropdown-item logout-item d-flex align-items-center gap-2" href="logout.php">
-                                    <i class="fa-solid fa-right-from-bracket"></i> Cerrar Sesión
-                                </a>
-                            </li>
-                        </ul>
-                    </div>
-                <?php else: ?>
-                    <a href="login.php" class="btn btn-kahoot-login rounded-pill px-4">
-                        <i class="fa-solid fa-right-to-bracket me-1"></i> Iniciar Sesión
-                    </a>
-                <?php endif; ?>
-            </div>
-        </div>
-    </div>
-</nav>
\ No newline at end of file
+<?php
+if (session_status() === PHP_SESSION_NONE) {
+    session_start();
+}
+
+// Comprobación de sesión
+$isLoggedIn = isset($_SESSION['usuario']) && !empty($_SESSION['usuario']);
+$username = $isLoggedIn ? $_SESSION['usuario'] : '';
+?>
+
+<!-- Bootstrap 5 CSS -->
+<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.css" rel="stylesheet">
+<!-- FontAwesome para iconos -->
+<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.2/css/all.min.css">
+<!-- Google Fonts para estilo Kahoot -->
+<link href="https://fonts.googleapis.com/css2?family=Fredoka:wght@400;600;700&display=swap" rel="stylesheet">
+<link rel="stylesheet" href="/css/index.css">
+<style>
+
+    :root {
+        --kahoot-purple: #46178f;
+        --kahoot-blue: #1368ce;
+        --kahoot-red: #e21b3c;
+        --kahoot-yellow: #ffa602;
+        --kahoot-green: #26890c;
+        --kahoot-green-hover: #1f6f09;
+    }
+
+    body {
+        font-family: 'Fredoka', sans-serif;
+        background-color: #f2f2f2;
+        min-height: 100vh;
+    }
+
+    .navbar-kahoot {
+        background-color: var(--kahoot-purple);
+        box-shadow: 0 4px 12px rgba(0,0,0,0.15);
+    }
+
+    .navbar-brand {
+        font-weight: 700;
+        font-size: 1.8rem;
+        color: #fff !important;
+        letter-spacing: 1px;
+        text-shadow: 2px 2px 0px rgba(0, 0, 0, 0.2);
+    }
+
+    .btn-kahoot-login {
+        background-color: var(--kahoot-blue);
+        color: white;
+        font-weight: 600;
+        border: none;
+        border-bottom: 4px solid #0c4891;
+        transition: all 0.2s ease;
+    }
+
+    .btn-kahoot-login:hover {
+        background-color: #0f56ab;
+        color: white;
+        transform: translateY(-2px);
+    }
+
+    .btn-kahoot-register {
+        background-color: var(--kahoot-green);
+        color: white;
+        font-weight: 600;
+        border: none;
+        border-bottom: 4px solid var(--kahoot-green-hover);
+        transition: all 0.2s ease;
+    }
+
+    .btn-kahoot-register:hover {
+        background-color: #2bb00f;
+        color: white;
+        transform: translateY(-2px);
+    }
+
+    .user-dropdown-btn {
+        background: rgba(255, 255, 255, 0.15);
+        color: white;
+        border: 2px solid rgba(255, 255, 255, 0.3);
+        border-radius: 50px;
+        padding: 8px 18px;
+        font-weight: 600;
+        transition: all 0.2s ease;
+    }
+
+    .user-dropdown-btn:hover, 
+    .user-dropdown-btn:focus,
+    .user-dropdown-btn.show {
+        background: rgba(255, 255, 255, 0.3);
+        color: white;
+        border-color: #fff;
+        box-shadow: none;
+    }
+
+    .user-dropdown-menu {
+        border-radius: 15px;
+        border: none;
+        box-shadow: 0 10px 25px rgba(0,0,0,0.2);
+        padding: 10px;
+        min-width: 200px;
+        margin-top: 10px !important;
+    }
+
+    .user-dropdown-menu .dropdown-item {
+        border-radius: 10px;
+        font-weight: 600;
+        padding: 10px 15px;
+        transition: all 0.15s ease;
+    }
+
+    .user-dropdown-menu .dropdown-item:hover {
+        background-color: #f0eafb;
+        color: var(--kahoot-purple);
+    }
+
+    .user-dropdown-menu .dropdown-item.logout-item {
+        color: var(--kahoot-red);
+    }
+
+    .user-dropdown-menu .dropdown-item.logout-item:hover {
+        background-color: #fde8ea;
+        color: var(--kahoot-red);
+    }
+
+    .btn-play-kahoot {
+        background-color: var(--kahoot-green);
+        color: white;
+        font-size: 2.2rem;
+        font-weight: 700;
+        width: 100%;
+        padding: 30px 20px;
+        border-radius: 20px;
+        border: none;
+        border-bottom: 8px solid var(--kahoot-green-hover);
+        box-shadow: 0 8px 15px rgba(0,0,0,0.2);
+        transition: all 0.1s ease;
+        display: flex;
+        align-items: center;
+        justify-content: center;
+        gap: 15px;
+    }
+
+    .btn-play-kahoot:hover {
+        background-color: #2bb00f;
+        color: white;
+        transform: translateY(-3px);
+        box-shadow: 0 12px 20px rgba(0,0,0,0.25);
+    }
+
+    .btn-play-kahoot:active {
+        transform: translateY(4px);
+        border-bottom: 2px solid var(--kahoot-green-hover);
+    }
+
+    .ranking-card {
+        border-radius: 20px;
+        border: none;
+        box-shadow: 0 8px 20px rgba(0,0,0,0.08);
+        overflow: hidden;
+    }
+
+    .ranking-header {
+        background-color: var(--kahoot-yellow);
+        color: #333;
+        padding: 15px 20px;
+        font-weight: 700;
+    }
+
+    .trophy-icon {
+        font-size: 3rem;
+        color: var(--kahoot-yellow);
+        margin-bottom: 10px;
+    }
+
+    /* Estilos modales */
+    .modal-content {
+        border-radius: 20px;
+        overflow: hidden;
+    }
+</style>
+
+<nav class="navbar navbar-expand-lg navbar-kahoot py-3 mb-4">
+    <div class="container">
+        <a class="navbar-brand" href="index.php">
+            <i class="fa-solid fa-gamepad me-2"></i>TRIVIAGMÁTICO
+        </a>
+        <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarContent">
+            <span class="navbar-toggler-icon"></span>
+        </button>
+
+        <div class="collapse navbar-collapse" id="navbarContent">
+            <ul class="navbar-nav me-auto mb-2 mb-lg-0"></ul>
+            
+            <div class="d-flex align-items-center gap-3">
+                <?php if ($isLoggedIn): ?>
+                    <!-- Menú desplegable cuando la sesión está iniciada -->
+                    <div class="dropdown">
+                        <button class="btn user-dropdown-btn dropdown-toggle d-flex align-items-center gap-2" 
+                                type="button" 
+                                id="userDropdown" 
+                                data-bs-toggle="dropdown" 
+                                aria-expanded="false">
+                            <i class="fa-solid fa-circle-user fa-lg text-warning"></i>
+                            <span><?= htmlspecialchars($username) ?></span>
+                        </button>
+                        <ul class="dropdown-menu dropdown-menu-end user-dropdown-menu" aria-labelledby="userDropdown">
+                            <li>
+                                <a class="dropdown-item d-flex align-items-center gap-2" href="perfil.php">
+                                    <i class="fa-solid fa-user text-primary"></i> Perfil
+                                </a>
+                            </li>
+                            <li><hr class="dropdown-divider"></li>
+                            <li>
+                                <a class="dropdown-item logout-item d-flex align-items-center gap-2" href="logout.php">
+                                    <i class="fa-solid fa-right-from-bracket"></i> Cerrar Sesión
+                                </a>
+                            </li>
+                        </ul>
+                    </div>
+                <?php else: ?>
+                    <!-- Botones que abren los modales cuando NO hay sesión iniciada -->
+                    <button type="button" class="btn btn-kahoot-login rounded-pill px-4" data-bs-toggle="modal" data-bs-target="#modalLogin">
+                        <i class="fa-solid fa-right-to-bracket me-1"></i> Iniciar Sesión
+                    </button>
+                    <button type="button" class="btn btn-kahoot-register rounded-pill px-4" data-bs-toggle="modal" data-bs-target="#modalRegistro">
+                        <i class="fa-solid fa-user-plus me-1"></i> Registrarse
+                    </button>
+                <?php endif; ?>
+            </div>
+        </div>
+    </div>
+</nav>
+
+<!-- MODAL DE LOGIN -->
+<div class="modal fade" id="modalLogin" tabindex="-1" aria-labelledby="loginModalLabel" aria-hidden="true">
+    <div class="modal-dialog modal-dialog-centered">
+        <div class="modal-content border-dark">
+            <div class="modal-header">
+                <h1 class="modal-title fs-5 fw-bold" id="loginModalLabel">
+                    <i class="fa-solid fa-right-to-bracket text-primary me-2"></i>Iniciar sesión
+                </h1>
+                <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Cerrar"></button>
+            </div>
+            <div class="modal-body">
+                <form id="formLogin">
+                    <div class="form-floating mb-3">
+                        <input type="email" class="form-control border-dark" id="loginEmail" name="email" placeholder="Correo electrónico" required>
+                        <label for="loginEmail">Correo electrónico</label>
+                    </div>
+                    <div class="form-floating mb-3">
+                        <input type="password" class="form-control border-dark" id="loginPassword" name="password" placeholder="Contraseña" required>
+                        <label for="loginPassword">Contraseña</label>
+                    </div>
+                    <div class="form-check">
+                        <input class="form-check-input" id="recordar" name="recordar" type="checkbox" />
+                        <label for="recordar" class="small">Recuérdeme durante 10 días</label>
+                    </div>
+                    <input type="hidden" name="orden" value="validar">
+                </form>
+                <div id="errorLogin" class="text-danger fw-bold mt-2"></div>
+            </div>
+            <div class="modal-footer">
+                <button type="button" class="btn btn-secondary rounded-pill px-3" data-bs-dismiss="modal">Cancelar</button>
+                <button type="button" class="btn btn-primary rounded-pill px-4" id="botonAceptarLogin">Entrar</button>
+            </div>
+        </div>
+    </div>
+</div>
+
+<!-- MODAL DE REGISTRO -->
+<div class="modal fade" id="modalRegistro" tabindex="-1" aria-labelledby="registroModalLabel" aria-hidden="true">
+    <div class="modal-dialog modal-dialog-centered">
+        <div class="modal-content border-dark">
+            <div class="modal-header">
+                <h1 class="modal-title fs-5 fw-bold" id="registroModalLabel">
+                    <i class="fa-solid fa-user-plus text-success me-2"></i>Registrarse
+                </h1>
+                <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Cerrar"></button>
+            </div>
+            <div class="modal-body">
+                <form id="formRegistro">
+                    <div class="form-floating mb-3">
+                        <input type="text" class="form-control border-dark" id="regNombre" name="nombre" placeholder="Nombre" required>
+                        <label for="regNombre">Nombre</label>
+                    </div>
+                    <div class="form-floating mb-3">
+                        <input type="email" class="form-control border-dark" id="regEmail" name="email" placeholder="Correo electrónico" required>
+                        <label for="regEmail">Correo electrónico</label>
+                    </div>
+                    <div class="form-floating mb-3">
+                        <input type="password" class="form-control border-dark" id="regPassword" name="password" placeholder="Contraseña" required>
+                        <label for="regPassword">Contraseña</label>
+                    </div>
+                    <div class="form-floating mb-3">
+                        <input type="password" class="form-control border-dark" id="regPasswordConfirm" name="passwordConfirm" placeholder="Confirmar contraseña" required>
+                        <label for="regPasswordConfirm">Confirmar contraseña</label>
+                    </div>
+                    <input type="hidden" name="orden" value="registrar">
+                </form>
+                <div id="errorRegistro" class="text-danger fw-bold mt-2"></div>
+            </div>
+            <div class="modal-footer">
+                <button type="button" class="btn btn-secondary rounded-pill px-3" data-bs-dismiss="modal">Cancelar</button>
+                <button type="button" class="btn btn-success rounded-pill px-4" id="botonAceptarRegistro">Registrarse</button>
+            </div>
+        </div>
+    </div>
+</div>
\ No newline at end of file