body {  
    margin: 0;
    font-family: sans-serif;
    display: flex;
    flex-direction: column;
    align-items: start;
    min-height: 100vh;
}

.contenedor { 
    width: 100%;
    height: 100%;
}

.principal, header, footer { 
    width: 100%;
}

div, body, header, nav, ul, footer { 
    box-sizing: border-box;
}

.nav {
    background-color: #141254;
    opacity: 55%;
}

.nav_1 {
    background-color: #141254;
    opacity: 75%;
}

.nav_list { 
    margin: 0;
    text-align: center;
}

.header {
    margin: 0;
    flex: 1;
    background-image: url('imagenes/titulo.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

header h2 { 
    color: aliceblue;
    margin: auto;
    padding: 10px;
    text-align: center;
}

.nav_item { 
    display: inline-block;
}

.nav_link {
    min-width: 10%;
    text-decoration: none;
    color: aliceblue;
    text-decoration: none;
    display: inline-block;
    padding: 12px;
    background-color: #223b7e;
    margin: 5px 15px;
    border-radius: 10px;
    border: none; 
}

.nav_link:hover { 
    background-color: #59e;
    text-decoration: none;
}

.link--buttom {
    background-color: #0f2540;
    padding: 16px;
    color: aliceblue;
    border-radius: 10px;
    text-decoration: none;
    margin-bottom: 10px;
}

.link--buttom:hover { 
    background: #59e;
    color: aliceblue;
}

.principal {
    display: flex;
    flex-grow: 1;
    flex-wrap: wrap;
}

.principal aside { 
    flex: 1 1 200px;
}

.principal a { 
    text-decoration: none;
}

.secundario { 
    flex: 1;
    text-align: left;
    background-color: #91a5d8;
    margin: 0;
}

aside, main {
    padding: 12px;
}

main { 
    margin: 10px 90px;
    flex: 2 1 700px;
}

.secundario ul { 
    padding: 0;
    margin: 0;
}

.secundario li { 
    list-style: none;
    margin: 0;
}

.secundario a {
    color: #24263b;
    display: inline-block;
    padding: 10px;
    width: 94%;
    border-radius: 14px;
}

.secundario a:hover { 
    background-color: #46e;
    color: aliceblue;
}

footer {
    margin-top: auto;
    background-color: #24263b;
    color: aliceblue;
    padding: 20px;
    text-align: center;
    font-size: 1.2em;
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
}

.izquierda {
    flex: 1 1 250px;
    background-color: #91a5d8;
}

.element_izquierda {
    margin: 0;
    padding: 20px;
}

img {
    text-align: center;
    min-width: 100%;
    max-height: 270px;
    box-shadow: 0px 0px 45px #0006;
    border-radius: 28px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

img:hover {
    transform: scale(1.05); 
    box-shadow: 0px 0px 60px #0008;
}
.top3 {
    width: 50%;
    max-width: 800px;
    margin: 20px auto;
    border-collapse: collapse;
}

.top3 th, .top3 td {
    padding: 10px;
    text-align: center;
    border: 1px solid #ddd;
}

.top3 th {
    background-color: #f4b400;
    color: #fff;
}

.top3 tr:nth-child(even) {
    background-color: #f9f9f9;
}

.top3 tr:hover {
    background-color: #ffeeba;
}

mark {
    background-color: #59e;
    border-radius: 8px;
    padding: 5px;
}