body {
    padding: 60px 30px 60px;
    width: 100%;
    background-image: url(../imagenes/biblioteca.jpg);
    padding: 80px 50px, 20px;
    text-align: center;
}

#login-form {
    background-color: white;
    width: 60em;
    height: 25em;
    margin: 2em auto;
    text-align: center;
    font-weight: bold;
    padding: 1.5em;
    border-radius: 10px;
}

#btn {
    width: 240px;
    height: 40px;
    font-size: 13px;
    margin: 5px 3px;
    text-align: center;
    padding: 10px 20px;
}

.h2 {
    color: #337ab7;
}

.img {
    max-width: 100%;
    max-height: 100%;
}

.BtnD {
    appearance: none;
    background-color: #337ab7;
    color: white;
    padding: 10px 16px;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    cursor: pointer;
    font-family: Arial;
    font-weight: 300;
    text-align: center;
    width: 230px;
}

.dropdown {
    position: relative;
    display: inline-block;
}

.dropbtn {
    background-color: #337ab7; /* azul */
    color: white;
    padding: 10px 20px;
    font-size: 16px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 300;
    width: 230px;
    text-align: center;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: white;
    min-width: 230px;
    border-radius: 6px;
    box-shadow: 0px 8px 16px rgba(0,0,0,0.2);
    z-index: 1;
    right: 0; /* 👈 aparece a la derecha */
}

    .dropdown-content a {
        color: black;
        padding: 10px 16px;
        text-decoration: none;
        display: block;
        font-size: 15px;
    }

        .dropdown-content a:hover {
            background-color: #f1f1f1;
        }

.dropdown:hover .dropdown-content {
    display: block;