.masthead {
    height: 100vh;
    min-height: 500px;
    background-image: url(https://source.unsplash.com/BtbjCFUvBXs/1920x1080);
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

.esquinas_redondeadas {
    border-radius: 20px;
}