html {
    font-family: 'Cantarell', sans-serif;
    color: whitesmoke;
}

header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 2.8rem;
    display: flex;
    /*flex-direction: row;*/
    /*flex-wrap: nowrap;*/
    /*flex-flow: row nowrap;*/
    justify-content: center;
    align-items: center;
    /* formatting */
    background-color: rgba(0,0,0,.6);
}

header div, header nav {
    width: 100%;
    height: 80%;
    display: flex;
    align-items: center;
}

header nav, header nav a, header svg {
    display: none;
}

header a {
    height: 100%;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}


header a:hover {
    color: #9dbb88;
}

header div a h1 {
    font-size: 1rem;
    margin-left: .5rem;
}

#idx-atf {
    /* layout */
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    /* background */
    background-color: #5b5b5b;
    background-image: url("../img/background-photo-mobile-devices.jpg");
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover;
    /*background-origin: border-box;*/
    background-attachment: fixed;
    /* formatting */
}

#idx-atf > div {
    height: 85vh;
}

.idx-center-spacebetween {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
    margin-top: 1.5rem;
}

.idx-center-center {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

#idx-atf h1 {
    font-size: 2rem;
    text-align: center;
}

#idx-atf h2 {
    font-size: 1.4rem;
    font-weight: 700;
    text-align: center;
}

#idx-atf h3 {
    font-size: 1.4rem;
    text-align: center;
    margin-top: .8rem;
    line-height: 1.2;
}

#idx-atf button {
    color: rgb(202, 250, 234);
    font-size: 1.4rem;
    font-weight: 700;
    border: 1px solid rgb(202, 250, 234);
    padding: .7rem 1.2rem;
    border-radius: 3px;
}

footer {
    font-size: 1.6rem;
}

footer nav {
    display: flex;
    flex-direction: column;
}

footer nav a {
    display: flex;
    align-items: center;
    padding-left: 3rem;
    background-color: deepskyblue;
    border-top: 1px solid rgba(255,255,255,0.3);
    border-bottom: 1px solid rgba(0,0,0,0.1);
}

footer nav a:last-child {
    border-bottom: none;
}

footer nav a:hover {
    background-color: royalblue;
}

footer nav a svg {
    padding-right: 1.7rem;
}