body {
    background-color: #000;
    color: #fff;
    font-family: "ＭＳ ゴシック";
    line-height: 150%;
}

#container {
    width: 100%;
    max-width: 360px;
    margin-right: auto;
    margin-left: auto;
}

.display-none {
    display: none;
}

.footer-content a {
    color: #00bfff;
}

.footer-content a:hover {
    color: #f00;
}
#start-buttons {
    width: 100%;
    position: absolute;
    left: 0px;
    top: 100px;
    text-align: center;
}
#field {
    width: 100%;
    position: relative;
}
#start, #go-ranking {
    font-weight: bold;
    text-align: center;
	font-size: 18px;
	width: 280px;
    border: none;
    font-size: 16px;
    background-color: #1DA1F2;
    padding: 10px 32px;
    border-radius: 100vh;
    color: white;
    cursor: pointer;
}

#start {
    margin-bottom:15px;
}

#go-ranking {
    margin-top:30px;
}

#zxButtons {
    margin-top: 30px;
    margin-bottom: 15px;
    text-align: center;
}

#zButton {
    width: 100px;
    height: 50px;
    margin-right: 10px;
}

#xButton {
    width: 100px;
    height: 50px;
    margin-left: 10px;
}

#volume-ctrl {
    margin-top: 30px;
}