*{
margin:0;
padding:0;
box-sizing:border-box;
}

body{
font-family:Arial, sans-serif;
background:#f4f4f4;
}

header{
background:#1e3a5f;
color:white;
text-align:center;
padding:20px;
}

nav{
margin-top:10px;
}

nav a{
color:white;
text-decoration:none;
margin:0 10px;
}

main{
max-width:900px;
margin:auto;
padding:40px 20px;
}

.card{
background:white;
padding:20px;
margin:15px 0;
border-radius:5px;
}

.btn{
display:inline-block;
margin-top:15px;
padding:10px 20px;
background:#1e3a5f;
color:white;
text-decoration:none;
}

.imagen{
    width:100%;
    max-width:700px;
    display:block;
    margin:20px auto;
    border-radius:8px;
}

input,
textarea{
width:100%;
padding:10px;
margin:10px 0;
}

button{
padding:10px 20px;
}

footer{
background:#1e3a5f;
color:white;
text-align:center;
padding:20px;
margin-top:40px;
}

@media(max-width:768px){

nav a{
display:block;
margin:10px 0;
}

}