*{
    margin: 0px;
    padding: 0px;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

header{
    background-color: #8ba3c5;
    color: #02122f;
    padding: 15px 10px;
    font-size: 15px;
    text-align: center;
}

nav{
    background-color: #23354d;
    text-align: center;
    padding: 10px 5px;
}

nav a{
    color: #ffffff;
    font-weight: bold;
    text-decoration: none;
    margin: 0 15px;
}

nav select {
    background-color: #f0ecdd;
    color: #495b7d;        
    font-weight: bold;
    padding: 6px 10px;   
    border-radius: 4px; 
    border: 1px solid #ffffff; 
}

main {
    background-color: #ffffff;     
    max-width: 900px;               
    margin: 40px auto;             
    padding: 30px 40px;            
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08); 
}

.btn-volver {
    display: inline-block;
    background-color: #23354d;
    color: #ffffff;
    padding: 10px 20px;
    margin: 20px;
    text-decoration: none;
    border-radius: 5px;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    font-weight: bold;
}

.btn-volver:hover {
    background-color: #8ba3c5;
    color: #02122f;
}

footer{
    background-color: #23354d;
    font-weight: bold;
    color: #ffffff;
    text-align: center;
    padding: 10px;
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
}