html, body {
    margin: 0;
    padding: 0;
    background-attachment: fixed;
    background-position: 50% 50%;
    background-size: cover;
}

a {
    text-decoration: underline;
}

    a:hover {
        text-decoration: none;
    }

.bg-red {
    background-image: url(../img/bg-red.jpg);
}

.bg-orange {
    background-image: url(../img/bg-orange.jpg);
}

.bg-yellow {
    background-image: url(../img/bg-yellow.jpg);
}

.bg-green {
    background-image: url(../img/bg-green.jpg);
}

.bg-cyan {
    background-image: url(../img/bg-cyan.jpg);
}

.bg-blue {
    background-image: url(../img/bg-blue.jpg);
}

.bg-purple {
    background-image: url(../img/bg-purple.jpg);
}

.bg-pink {
    background-image: url(../img/bg-pink.jpg);
}

.bg-black {
    background-image: url(../img/bg-black.jpg);
}

.body {
    max-width: 600px;
    margin: 0 auto;
    padding: 40px;
}

.body-s {
    max-width: 400px;
}

@media screen and (max-width: 600px) {
    .body {
        padding: 20px;
    }
}

.menubtn {
    float: right;
    text-decoration: none;
    margin: 0 10px 0 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    padding: 1.5px 10px;
    background: #2da5da;
    color: #FFF;
    opacity: 0.8;
}

    .menubtn:hover {
        opacity: 1;
    }