html, body {
    height: 100%;
}

body {
    background: rgb(50, 50, 50);
}

nav {
    background: rgb(70, 70, 70);
    position: absolute;
}

.nav-link, .navbar-brand {
    color: #fff;
}

main {
    height: 100%;
    color: #fff;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

main > div {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    background: rgba(200, 200, 200, 0.3);
    padding: 20px 10px;
    width: 520px;
    height: 240px;
    border-radius: 10px;
    margin: 10px;
}

h1 {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 10px;
    width: 300px;
    margin-bottom: 20px;
}

h2 {
    margin-bottom: 20px;
    text-align: center;
}

form {
    display: flex;
    align-items: center;
    justify-content: center;
}

input {
    padding: 5px;
    height: 40px;
}

button {
    background-color: rgba(0, 0, 0, 0.5);
    color: #fff;
    transition: .2s;
    padding: 0 10px 0 10px;
    border: 0;
    border-radius: 10px;
    height: 40px;
    margin: 0 10px;
}

button:hover {
    background-color: rgba(0, 0, 0, 0.4);
}

.response {
    text-align: center;
    font-size: 1.2em;
    padding: 5px 10px;
    border-radius: 10px;
    margin: 0;
}

.navbar-nav {
    justify-content: center;
    align-items: center;
}