.logo,
.circle {
    transform: translate(-50%, -50%) translateZ(0);
}

html,
body {
    overflow: hidden;
}

body {
    margin: 0;
    background: #fff;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    overflow-y: scroll;
}

body.noscroll {
    overflow: hidden;
}

.white-bg {
    overflow: hidden;
    /* 初回だけ隠す */
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: #fff;
    z-index: 10;
    animation: whiteFadeOut 1s ease-in 3s forwards;
}

.circle {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 30vw;
    max-width: 350px;
    min-width: 200px;
    height: 30vw;
    max-height: 350px;
    min-height: 200px;
    background-color: #e94819;
    border-radius: 50%;
    animation: expand 1s ease-out forwards, fadeOut 1s ease-in 3s forwards;
    z-index: 100;
}

@keyframes fadeOut {
    from {
    opacity: 1;
    }

    to {
    opacity: 0;
    }
}

@keyframes expand {
    0% {
    transform: translate(-50%, -50%) scale(0.1);
    -webkit-transform: translate(-50%, -50%) scale(0.1);
    opacity: 1;
    }

    100% {
    transform: translate(-50%, -50%) scale(1);
    -webkit-transform: translate(-50%, -50%) scale(1);
    opacity: 1;
    }
}

.logo {
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    position: absolute;
    top: 50%;
    left: 50%;
    opacity: 0;
    z-index: 2;
    width: 30vw;
    max-width: 350px;
    min-width: 200px;
    height: 30vw;
    max-height: 350px;
    min-height: 200px;
    animation: logoFadeIn 1.2s ease-out 1.2s forwards, logoFadeOut 3s ease-out 4s forwards;
    ;
    z-index: 100;
}

@keyframes logoFadeIn {
    0% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(1);
    -webkit-transform: translate(-50%, -50%) scale(1);
    }

    100% {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1);
    -webkit-transform: translate(-50%, -50%) scale(1);
    }
}

@keyframes logoFadeOut {
    from {
    opacity: 1;
    }

    to {
    opacity: 0;
    }
}

.mainwrapper {
    opacity: 0;
    transition: opacity 1.5s ease;
}

body.content-visible .mainwrapper {
    opacity: 1;
}

@keyframes whiteFadeOut {
    0% {
    opacity: 1;
    }

    100% {
    opacity: 0;
    }
}