body {
  font-family: "Zen Old Mincho", serif;
  font-weight: 400;
  font-style: normal;
  line-height: 1.8;
  letter-spacing: 0.1em;
  margin: 0;
  padding: 0;
  background: #000;
  color: #fff;
  font-size: clamp(15px, 1.5vw, 20px);
}

.container {
  max-width: 1300px;
  margin: 0 auto;
  padding: 20px;
}

header.title {
  position: fixed;
  top: 5px;
  left: 25px;
}

/* header.title h1 {
  font-size: 2.5rem;
  margin-bottom: 10px;
  letter-spacing: 0.2em;
} */

header.title h1 img {
  width: 250px;
}

.subtitle {
  font-size: 1.4rem;
  color: #009999;
  font-weight: bold;
}

.intro {
  text-align: center;
  margin-top: 66vh;
}

.intro p {
  font-size: 1.2rem;
  margin-bottom: 1em;
}

.monthly {
  color: #009999;
  font-weight: bold;
  text-align: right;
}

.info {
  background: rgba(255, 255, 255, 0.8);
  /* border-radius: 10px; */
  /* border-radius: 50px 0; */
  padding: 30px 50px;
  color: #000;
  width: 90%;
  margin: 50px auto;
  max-width: 900px;
  border: 16px solid #fff;
  box-sizing: border-box;
}

.info h2 {
  font-size: 1.5rem;
  border-bottom: 2px solid #fff;
  margin-bottom: 2em;
  text-align: center;
}

.info ul {
  list-style: none;
  padding: 0;
}

.info li {
  margin-bottom: 1.5em;
}

li.scedule {
  margin: 36px auto;
  background: #fff;
  padding: 10px 20px;
  font-size: 1.1rem;
  /* border-radius: 10px; */
  /* border: 1px dotted #ccc; */
}

li.scedule .date {
  font-weight: 700;
  display: inline-block;
  width: 19em;
}

.notice {
  font-size: 0.9rem;
}

.qrcode {
  width: 160px;
  margin-top: 10px;
  margin-left: 20px;
}

footer.contact {
  margin-top: 40px;

  padding-top: 20px;
}

footer.contact a {
  color: #009999;
  text-decoration: none;
}

.note {
  margin-top: 1em;
  font-size: 0.95em;
  color: #666;
}

.yt-bg {
  position: fixed;
  inset: 0;
  z-index: -2;
  overflow: hidden;
  background: #000;
  /* 読み込み前の保険 */
}

/* 16:9のiframeを画面いっぱいに「はみ出してOK」でカバー */
.yt-bg iframe {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 100vw;
  height: 56.25vw;
  /* 9/16 * 100 = 56.25 */
  min-width: 177.78vh;
  /* 16/9 * 100 = 177.78 */
  min-height: 100vh;
  transform: translate(-50%, -50%);
  pointer-events: none;
  /* 背景なのでクリックできない */
  border: 0;
}

/* 文字が読めるように暗幕 */
.yt-overlay {
  position: fixed;
  inset: 0;
  z-index: -1;
  background: rgba(0, 0, 0, 0.6);
  /* 好みで調整 */
}

#soundBtn {
  position: fixed;
  top: 50px;
  right: 50px;
  width: 75px;
  cursor: pointer;
  transition-duration: 0.5s;
}

#soundBtn:hover {
  opacity: 0.7;
}

#soundBtn .on {
  display: none;
}

#soundBtn .off {
  display: block;
}

#soundBtn.on .on {
  display: block;
}

#soundBtn.on .off {
  display: none;
}

#soundBtn img {
  width: 100%;
}

@media (max-width: 800px) {
  .subtitle {
    font-size: 1.2rem;
  }

  header.title {
    top: 0px;
    left: 15px;
  }

  header.title h1 img {
    width: 100px;
  }

  #soundBtn {
    top: 20px;
    right: 15px;
    width: 50px;
  }

  .container {
    padding: 15px;
  }

  .intro p {
    font-size: 1.0rem;
    text-align: left;
    padding: 10px;
  }

  .info {
    padding: 0 15px;
    width: 100%;
  }

  li.scedule .date {
    width: auto;
  }

  .info h2 {
    font-size: 1.3rem;
  }
}