body {
margin: 20px;
}
header {
    background-color: red;
    height: 80px;
    display: flex;
    justify-content: space-between;
    padding-top: 30px;
    padding-left: 30px;
    padding-right: 30px;
}
header a {
    color: white;
    font-size: 50px;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}
nav a {
    text-align: center;
}
main {
    background-color: gray;
    height: 700px;
}
h1 {
    text-align: center;
    color: white;
}
p {
    color: white;
}
.Divpai1 {
    display: flex;
    justify-content: space-between;
    padding-left: 60px;
    padding-right: 60px;
}
.Divfilho1 {
    background-color: red;
    height: 400px;
    width: 400px;
    background-image:url(10-predios-mais-altos-do-Brasil.jpg) ;
}
.Divfilho2 {
    background-color: red;
    height: 400px;
    width: 400px;
    background-image:url(142461\,muralhas-a-beira-mar-predios-de-ate-21-andares-na-orla-de-salvador-prejudicam-lazer-e-bem-estar-da-cidade-3.jpg) ;
}
.Divfilho3 {
    background-color: red;
    height: 400px;
    width: 400px;
    background-image:url(hospital-da-bahia.jpg) ;
}
footer {
    background-color: red;
    height: 100px;
}
footer a {
    color: white;
    display: flex;
    justify-content: center;
    font-size: 60px;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}