style.css

body, html {
    width: 100%;
    height: 100%;
}

body {
    /*background-position: center;*/
    /*background-image: url("laptop.jpg");*/
    /*background-repeat: no-repeat;*/
    max-height:100%;
    max-width:100%;
    font-family: 'Lucida Sans Unicode';
}

header.startup {
    background-position: center;
    background-image: url("laptop.jpg");
    background-size: cover;
    height: 100%;
}

header.startup h1 {
    font-size: 2rem;
}

.btn {
    font-weight: 700;
    text-transform: uppercase;
    border-radius: 300px;
    font-family: 'Lucida Sans Unicode';
}

.btn-xl {
    padding: 1rem 2rem;
}

.button1 {
    margin-top: 510px;
    margin-right: 5px;
}

.btn-primary {
    background-color: orange;
    border-color: orange;
    transition: all 1s;
}

.btn-primary:hover {
    background-color: whitesmoke;
    border-color: whitesmoke;
    transform: scale(1.1);
}