* {
    box-sizing: border-box;
    font-family: sans-serif;
    margin: 0;
    padding: 0;
}

body {
    align-items: center;
    background: url("./img/background.jpg") no-repeat;
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: 100vh;
}

.fade-in {
    animation: fade-in 0.5s linear;
    animation-fill-mode: both;
}

.fade-out {
    animation: fade-out 0.5s linear;
    animation-fill-mode: both;
}

.hidden {
    visibility: hidden;
}

@keyframes fade-in {
    0% {
        opacity: 0;
    }

    100% {
        opacity: 1;
    }
}

@keyframes fade-out {
    0% {
        opacity: 1;
    }

    100% {
        opacity: 0;
    }
}