html {
    scroll-behavior: smooth;
}

.header {
    background-image: url('../images/nasa-Q1p7bh3SHj8-unsplash.jpg');
    background-size: cover;
    background-position: center;
    position: relative;
}

.overlay {
    position: absolute;
    min-height: 100%;
    min-width: 100%;
    left: 0;
    top: 0;
    background: rgba(0, 0, 0, 0.6);
}

.description {
    left: 50%;
    position: absolute;
    top: 45%;
    transform: translate(-50%, -55%);
    text-align: center;
}
.description h1 {
    color: #6ab446;
}
.description p {
    color: #fff;
    font-size: 1.3rem;
    line-height: 1.5;
}

.description button {
    border:1px solid #6ab446;
    background:#6ab446;
    border-radius: 0;
    color:#fff;
}
.description button:hover {
    border:1px solid #fff;
    background:#fff;
    color:#000;
}

.features {
    margin: 4em auto;
    padding: 1em;
    position: relative;
}
.feature-title {
    color: #333;
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 20px;
    text-transform: uppercase;
}
.features img {
    -webkit-box-shadow: 1px 1px 4px rgba(0, 0, 0, 0.4);
    -moz-box-shadow: 1px 1px 4px rgba(0, 0, 0, 0.4);
    box-shadow: 1px 1px 4px rgba(0, 0, 0, 0.4);
    margin-bottom: 16px;
}

.page-footer {
    background-color: #222;
    color: #ccc;
    padding: 20px 0 20px;
}
.footer-copyright {
    color: #666;
    padding: 20px 0;
}