html {
    scroll-behavior: smooth;
}

.pagetop {
    box-shadow: 0 4px 6px rgb(0 0 0 / 30%);
    height: 50px;
    width: 50px;
    position: fixed;
    right: 30px;
    bottom: 30px;
    background: #fff;
    border: solid 2px #000;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2;
    opacity: 0;
}

.pagetop__arrow {
    height: 10px;
    width: 10px;
    border-top: 3px solid #000;
    border-right: 3px solid #000;
    transform: translateY(20%) rotate(-45deg);
    opacity: 1;
}

.in_Anime {
    animation: fadeInAnime;
    animation-duration: 1s;
    animation-fill-mode: forwards;
    opacity: 0;
}

.out_Anime {
    animation: fadeOutAnime;
    animation-duration: 1s;
    animation-fill-mode: forwards;
    opacity: 0;
}

@keyframes fadeInAnime {
    from {
        opacity: 0;
    }

    to {
        opacity: 0.7;
    }
}

@keyframes fadeOutAnime {
    from {
        opacity: 0.7;
    }

    to {
        opacity: 0;
    }
}