body {
    margin: 0;
    padding: 0;
    background: #f4f4f4;
}

.contenedor {
    width: 80vw;
    margin: 30px auto;
    background: #fff;
    display: flex;
    flex-direction: column;
    min-height: 80vh;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

.header, .footer {
    background: #ccc;
    color: #222;
    text-align: center;
    padding: 20px 0;
    font-size: 1.2em;
}

.contenido {
    display: flex;
    flex: 1 1 auto;
    min-height: 400px;
}

.menu {
    width: 15%;
    background: #b3e0ff;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px 0;
    box-sizing: border-box;
}

.menu h2 {
    margin: 0 0 20px 0;
    text-align: center;
}

.menu ul {
    list-style: none;
    padding: 0;
    margin: 0;
    width: 100%;
}

.menu li {
    width: 100%;
    margin-bottom: 15px;
    display: flex;
    justify-content: center;
}

.menu a {
    display: block;
    width: 80%;
    padding: 10px;
    border: none;
    border-radius: 6px;
    background: #e0e0e0;
    color: #222;
    font-size: 1em;
    text-align: center;
    text-decoration: none;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
}

.menu a:hover {
    background: #0074d9;
    color: #fff;
}

.iframe-contenido {
    width: 85%;
    padding: 0;
    box-sizing: border-box;
    display: flex;
    align-items: stretch;
}

.iframe-contenido iframe {
    width: 100%;
    height: 100%;
    min-height: 400px;
    border: none;
    background: #fff;
}