.hero {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}
.navbar .btn-primary {
    background-color: #007bff;
    border-color: #007bff;
}
footer {
    margin-top: auto;
}
body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}
main {
    flex: 1;
}