@charset "utf-8";

html {
    font-size: 16px;
}

/* 「*」はユニバーサルセレクタ(すべての要素を対象にするセレクタ)でbox-sizing: border-box;を指定 */
/* この指定(してい)はborderとpaddingをボックスサイズ(widthとheight)の中に含めて算出するので、スタイリングがしやすい*/
*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    margin: 0;
    line-height: normal;
    /*ブラウザが自動的に行間を決める*/
    font-family: "Helvetica Neue",
        Arial,
        "Hiragino Kaku Gothic ProN",
        "Hiragino Sans",
        Meiryo,
        sans-serif;
    background-image: url(../img/moi.jpeg);
    background-size: auto;
    overflow: hidden;
}

p {
    margin: 0;
    padding: 0;
}

header {
    margin-top: 8px;
    color: rgb(244, 155, 220);
    font-size: 38px;
    font-weight: bold;
    text-align: center;
}

.wrapper {
    position: relative;
    max-width: 100vw;
    min-height: 100vh;
    margin: 0;
    padding: 0;
    padding-bottom: 23px;
    text-align: center;
}

#btn1 {
    position: relative;
    margin: 20px auto;
    width: 250px;
    height: 250px;
    line-height: 250px;
    border-radius: 125px;
    color: rgb(255, 0, 212);
    font-weight: bold;
    font-size: 40px;
    text-align: center;
    text-shadow: 1px 1px 1px rgba(255, 255, 255, 0.65);
    background: linear-gradient(#6795fd 0%, #afeeee 100%);
    box-shadow: 0 10px 0 grey;
    justify-content: center;
    cursor: grab;
    user-select: none;
}

#btn1:hover {
    background: linear-gradient(#da70d6 0%, pink 100%);
}

#btn1:active {
    position: relative;
    top: 5px;
    left: 5px;
    box-shadow: 0 10px 0 grey;
}

.back{
    text-align: left;
}

#btn99{
    padding: 0.5rem;
    border-radius: 1rem;
    color: whitesmoke;
    font-size: 1.5rem;
    background: rgb(81, 231, 231);
    cursor: pointer;
}

footer {
    position: absolute;
    bottom: 5px;
    width: 100%;
    margin: 0px;
    padding: 1px;
    color: whitesmoke;
    font: 16px Rajidhani;
    text-align: center;
    background: rgba(1, 24, 31, 0.7);

}

.shutter {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 9999;
    margin: 0em;
    padding: 0em;
    background-color: #1e1e1e;
    animation: byeShutter 2.5s forwards;
}

.shutter::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    width: 0;
    margin: auto;
    background-color: #fff;
    animation: shutterOpen 2.5s forwards;
}

@keyframes byeShutter {
    70% {
        opacity: 1;
    }

    100% {
        opacity: 0;
        display: none;
        z-index: -1;
    }
}

@keyframes shutterOpen {
    0% {
        width: 0;
        height: 0.05em;
    }

    50% {
        width: 100%;
        height: 0.05em;
    }

    90% {
        width: 100%;
        height: 100%;
    }

    100% {
        width: 100%;
        height: 100%;
    }
}

@media screen and (max-width:480px) {
    body {
        background-position: 75% 0%;
        background-size: auto 1000px;
    }

}