html, body, * {
  font-size: 110%;
}

/* =========================
   PC レイアウト
========================= */
@media screen and (min-width: 720px) {
  body {
    background:
      repeating-linear-gradient(0deg, #000 0, #000 2px, #111 2px, #111 4px),
      repeating-linear-gradient(90deg, #000 0, #000 2px, #111 2px, #111 4px);
    background-size: 4px 4px;
    background-attachment: fixed;

    padding: 130px 10px 100px 10px;
    letter-spacing: 0.05em;
    font-size: 130%;
  }
}

/* =========================
   SP レイアウト
========================= */
@media screen and (max-width: 720px) {
  body {
    background:
      repeating-linear-gradient(0deg, #000 0, #000 2px, #111 2px, #111 4px),
      repeating-linear-gradient(90deg, #000 0, #000 2px, #111 2px, #111 4px);
    background-size: 4px 4px;
    background-attachment: scroll;

    padding: 160px 0px 100px 0px;
    font-size: 110%;
  }
}

/* =========================
   PC/SP 切り替え
========================= */
.show-pc { display: block !important; }
.show-sp { display: none !important; }

@media only screen and (max-width: 720px) {
  .show-pc { display: none !important; }
  .show-sp { display: block !important; }
}

/* =========================
   ヘッダー
========================= */
.site-header {
  z-index: 9998;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 90px;

  display: flex;
  justify-content: space-between;
  align-items: center;

  background-color: rgba(32, 32, 32, 0.9);
  padding: 0;
}

/* =========================
   現在ページバッジ（中央寄せ）
========================= */
.current-page-badge {
  position: sticky;
  top: 90px;

  display: block;
  margin: 0 auto;
  width: fit-content;

  height: 40px;
  padding: 0 20px;

  background-color: #0000ff;
  border: 2px solid #ffffff;
  border-radius: 6px;
  color: #ffffff;
  font-weight: bold;
  text-decoration: none;
}

/* =========================
   セクション背景
========================= */
.section-box {
  background-color: rgba(154, 154, 154, 0.7);
  padding: 10px;
  margin: 15px 0;
}

/* =========================
   8bit ボタンデザイン
========================= */

/* ナビボタン */
.btn-nav {
  display: inline-block;
  padding: 6px 14px;
  color: #fff;
  text-align: center;
  background-color: #962e0e;
  border-radius: 4px;
  cursor: pointer;
  border: 3px solid #ffffff;
  image-rendering: pixelated;
  box-shadow: 0 4px #5a1a0a;
  font-size: 95%;
  font-family: "MS PGothic", monospace;
}

.btn-nav:active {
  box-shadow: 0 1px #5a1a0a;
  transform: translateY(3px);
}

/* MENU ボタン */
.btn-menu {
  color: #ffffff;
  font-weight: bold;
  background: #962e0e;
  width: 140px;
  font-size: 120%;
  padding: 12px 0;
  border-radius: 4px;
  cursor: pointer;
  border: 4px solid #ffffff;
  box-shadow: 0 4px #5a1a0a;
  image-rendering: pixelated;
  font-family: "MS PGothic", monospace;
}

.btn-menu:active {
  box-shadow: 0 1px #5a1a0a;
  transform: translateY(3px);
}

/* ダウンロードボタン */
.btn-download {
  width: 90%;
  margin: 10px auto;
  padding: 8px 0;
  font-size: 14px;
  font-weight: bold;
  font-family: "MS PGothic", monospace;
  background: #d00000;
  color: #fff;
  border: 3px solid #ffffff;
  border-radius: 4px;
  box-shadow: 0 3px #5a1a0a;
  cursor: pointer;
  image-rendering: pixelated;
  text-align: center;
}

.btn-download:active {
  box-shadow: 0 1px #5a1a0a;
  transform: translateY(2px);
}

/* =========================
   アイテムグリッド
========================= */
.item-grid {
  display: grid;
  gap: 24px;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  max-width: 1800px;
  margin: 0 auto;
}

/* bgcolor カード */
.bgcolor {
  width: 100%;
  background-color: #000000;
  margin: 10px 5px;
  padding: 5px;
  border: 4px solid #ffffff;
  border-radius: 8px;
  display: flex;
  flex-direction: column;
  text-align: center;
}

/* audio プレイヤー（上下余裕＋中央） */
.bgcolor audio {
  display: inline-block;
  margin: 10px auto;
}

/* タイトル（統合版） */
.title {
  margin-top: 8px;
  margin-bottom: 4px;
  font-weight: bold;
  color: #ffffff;
}

/* YouTube プレイヤー（CLS対策） */
.yt-player {
  width: 100%;
  aspect-ratio: 16 / 9;
  height: auto;
  overflow: hidden;
}

/* =========================
   footer
========================= */
footer {
  margin: 15px 0px;
}

.footer-license {
  text-align: center;
  background-color: rgba(32, 32, 32, 0.9);
  color: #ffffff;
}

/* アクセシビリティ */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}