#header {
    text-align: center;
    display: flex;
    height: 100%;
    position: absolute;
    width: 100%;
    justify-content: center;
    flex-direction: column;
}
#header h1 {
    font-size: 15em;
    font-weight: 900;
    background-image: url('images/clouds.jpg');
    background-size: auto 100%;
    -webkit-text-fill-color: transparent;
    -webkit-background-clip: text;
    color: grey;
    animation: slide 20s infinite alternate ease-in-out;

    line-height: 1.2;
    margin: 0;
    font-size: calc(8vw + 8vh + 4vmin);
}

@keyframes slide {
    0% {
        background-position: left center;
        font-weight: 100;
    }
    100% {
        background-position: right center;
        font-weight: 900;
    }
}
@keyframes breathing {
    0% {
        transform: scale(.9);
        opacity: .9;
    }
    25% {
        transform: scale(1.1);
    }
    60% {
        transform: scale(.9);
    }
    100% {
        transform: scale(.9);
        opacity: .9;
    }
}

@media (prefers-color-scheme: dark) {
    body {
        background-color: #000;
        color: #fff;
    }
}