html, body {
    padding: 0;
    margin: 0;
}

.main-div {
    width: 100vw; 
    height: 100vh;
    padding: 0;
    margin: 0;
} 

.back-img{
    background-image: url('../img/background_cidall.jpg');
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover; 
}

.back-img::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
}

.navigation-div {
    margin: 0;
    padding: 0;
    position: relative;
    height: 100px;
}


.heading {
    float: left;
    height: 100%;
    width: 40%;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

.heading-nav-main:hover {
    color: brown;
}


.nav-div {
    float: right;
    height: 100%;
    width: 50%;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
}


.nav-div a:hover {
    color: brown;
}

.heading-nav-main {
    margin: 0;
    padding: 0;
    font-family: sans-serif;
    font-weight: 700;
    font-size: 30px;
    color: #FFF;
    text-decoration: none;
}

.link-nav-main {
    text-decoration: none;
    font-size: 18px;
    font-family: sans-serif;
    color: #FFF;
    text-align: center;
    margin-left: 5px;
    margin-right: 5px;
}

.center {
    z-index: 1;
    top: 50%;
    left: 50%;
    position: absolute;
    transform: translate(-50%, -50%);
    text-align: center;
    width: 600px;
}

.center h1 a {
    text-decoration: none;
    color: #FFF;
    font-size: 80px;
    font-family: sans-serif;
}

.center p {
    color: #FFF;
    font-size: 18px;
    font-family: sans-serif;
}

hr {
    width: 70%;
}

/* LAS OTRAS PÁGINAS */

.submain-div {
    padding-left: 4%;
    padding-right: 4%;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.title-link {
    color: #0A0A50;
    text-align: center;
    font-family: sans-serif;
    font-size: 12px;
    font-weight: 700;
    margin-top: 40px;
    margin-bottom: 60px;
}

.subtitle-link {
    background-color: #ABB8C3;
    padding: 12px;
}

.subtitle-link h2 {
    padding-left: 5%;
    color: #444;
    font-family: sans-serif;
}

.description {
    padding: 12px;
    margin-bottom: 50px;
}

.subdescription {
    margin-bottom: 50px;
}

.description h3 {
    padding-left: 5%;
    font-family: sans-serif;
}

.description p{
    line-height: 1.9;
    color: #444;
    font-family: sans-serif;
    letter-spacing: 0.5px;
    text-align: justify;
}

.description .phrase {
    text-align: center;
    font-size: 15px;
}

ul {
    padding-left: 0;
}

ul li {
    line-height: 1.9;
    color: #444;
    font-family: sans-serif;
    letter-spacing: 0.5px;
    text-align: justify;
}

div.origen-sismo {
    text-align: center;
    margin-bottom: 70px;
}

div.img-res img{
    margin-left: auto;
    margin-right: auto;
    display: block;
    width: 100%;
}

div.img-res-center img {
    width: 50%;
} 

div.acelerografo {
    margin-bottom: 40px;
}

div.img-res-w70 img {
    width: 70%;
} 

figcaption {
    color: #444;
    font-family: sans-serif;
    font-size: 15px;
}

figcaption a, div.subdescription a {
    color: #0BB4AA;
}

div.seismoprocessor img, div.microtremorsoft img {
    margin-bottom: 70px;
}

/* FORMULARIO */

.form-section {
    width: 70%;
    margin-bottom: 20px;
}

.form-section input{
    width: 80%;
    height: 25px;
}

.form-section label {
    padding-left: 10px;
    color: #333;
}

.form-section button {
    width: 82%;
    height: 30px;
    background-color: #0A0A50;
    color: #FFF;
}

.form-section select {
    width: 82%;
    height: 25px;
}

.alerta {
    width: 58%;
    color: #FFF;
    text-transform: uppercase;
    height: 20px;
    margin-top: 10px;
    margin-bottom: 10px;
    text-align: center;
}

.alerta-error {
    background-color: red;
}

.alerta-good {
    background-color: rgb(64, 255, 47);
}

/* menu desplegable*/
/* Agrega este estilo para el menú desplegable */
.dropdown-content-menu, .dropdown-content-menu2 {
    position: relative; /* Establece el menú desplegable como relativo */
    display: inline-block; /* Para que el contenido flote alrededor de él */
}

.dropdown-content {
    position: absolute; /* Establece el menú desplegable como absoluto */
    z-index: 1; /* Asegura que esté por encima de otros elementos */
    display: none; /* Oculta el menú por defecto */
    background-color: #f9f9f9;
    opacity: 0.1;
    width: 100%;
    min-width: 160px;
}

.dropdown-content-menu:hover .dropdown-content {
    display: block; /* Muestra el menú cuando pasas el ratón sobre el enlace "Enlaces de Interes" */
    opacity: 0.5;
}

.dropdown-content-menu2:hover .dropdown-content {
    display: block;
    opacity: 1;
}

.dropdown-content a {
    font-size: 18px;
    font-family: sans-serif;
    color: #000;
    text-align: center;
    text-decoration: none;
    display: block;
    line-height: 35px;
}

.dropdown-content a:hover {
    background-color: #000;
    color: #FFF;
}

@media screen and (max-width: 1400px) {

    .heading, .nav-div {
        float: none;
        width: 100%;
    }

    .nav-div {
        display: block;
        width: 100%;
    }

    .heading:hover {
        background-color: #000;
    }

    .navigation-div {
        margin: 0;
        padding: 0;
        height: auto;
        width: 100%;
        background-color: rgba(0, 0, 0, 0.5);
    }

    .nav-div a {
        display: block;
        width: 100%;
        margin: auto 0;
        padding: 0;
        line-height: 30px;
    }

    .nav-div a:hover {
        background-color: #000;
    }

    .dropdown-content-menu, .dropdown-content-menu2 {
        width: 100%;
        display: block;
    }

    .dropdown-content-menu:hover .dropdown-content, .dropdown-content-menu2:hover .dropdown-content {
        z-index: 0;
        position: relative;
        opacity: 0.5;
    }

    .center {
        top: 60%;
        left: 50%;
        transform: translate(-50%, -50%);
    }

}

@media screen and (max-width: 492px){
    .center {
        top: 60%;
        left: 50%;
        transform: translate(-50%, -50%);  
        width: 450px;     
    }
    .center h1 a {
        font-size: 60px;
    }
    
    .center p {
        color: #FFF;
        font-size: 16px;
        font-family: sans-serif;
    }
}

@media screen and (max-width: 375px){
    .center {
        top: 60%;
        left: 50%;
        transform: translate(-50%, -50%);  
        width: 300px;     
    }
    .center h1 a {
        font-size: 40px;
    } 
    .center p {
        color: #FFF;
        font-size: 12px;
        font-family: sans-serif;
    }
}

@media screen and (max-height: 720px){
    .center {
        display: none;
    }
}