/* ============================
      ゆらゆらシスターズ CSS
      - ユニット紹介＆楽曲詳細
      - カラー: White / Light Blue
============================ */

/* ----------------------------
        ヒーローカード
---------------------------- */
.hero-card {
  width: 90%;
  max-width: 1200px;
  margin: 40px auto;
  display: flex;
  flex-direction: row;
  align-items: center;
  background: linear-gradient(
    135deg,
    rgba(173, 216, 230, 0.95), /* LightBlue */
    rgba(255, 255, 255, 0.95)   /* White */
  );
  border-radius: 20px;
  padding: 30px;
  box-shadow: 0 0 25px rgba(173, 216, 230, 0.25);
  overflow: hidden;
}

.hero-text {
  flex: 1;
  padding-right: 20px;
  font-size: 20px;
  color: #ffffff;
  font-weight: bold;
  text-shadow: 0 0 8px rgba(0,0,0,0.25);
  opacity: 0;
  animation: textFade 2.5s ease forwards 0.5s;
}

.hero-img {
  flex: 1;
  width: 100%;
  max-width: 500px;
  border-radius: 15px;
  opacity: 0;
  animation: logoFade 2.5s ease forwards 1s;
}

@keyframes textFade {
  from { opacity: 0; transform: translateX(-20px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes logoFade {
  from { opacity: 0; transform: translateX(20px); }
  to { opacity: 1; transform: translateX(0); }
}

@media (max-width: 768px) {
  .hero-card {
    flex-direction: column;
    padding: 20px;
  }
  .hero-text {
    padding-right: 0;
    margin-bottom: 20px;
  }
  .hero-img {
    max-width: 100%;
  }
}

/* ----------------------------
        ページ全体
---------------------------- */
body {
  background: linear-gradient(135deg, #f0f8ff, #ffffff); /* 柔らかホワイト＋ライトブルー */
  font-family: "Noto Sans JP", sans-serif;
  color: #333;
  margin: 0;
  padding: 0;
}

/* セクション */
section {
  max-width: 1000px;
  margin: 50px auto;
  padding: 25px 20px;
  background: #ffffff;
  border-radius: 16px;
  box-shadow: 0 5px 25px rgba(173, 216, 230, 0.25);
}

/* 見出し */
h1, h2 {
  color: #ffffff;
  padding: 12px 18px;
  border-radius: 12px;
  font-size: 1.8rem;
  text-shadow: 0 0 8px rgba(173, 216, 230, 0.5);
  margin-bottom: 25px;
  background: linear-gradient(
    135deg,
    rgba(173, 216, 230, 0.95),
    rgba(255, 255, 255, 0.92)
  );
}

/* ----------------------------
       曲サムネイル一覧
---------------------------- */
.song-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 25px;
}

.song-item {
  width: 210px;
  text-align: center;
  transition: 0.3s ease;
}

.song-img {
  width: 100%;
  border-radius: 14px;
  box-shadow: 0 5px 18px rgba(173,216,230,0.3);
  transition: 0.3s ease;
}

.song-item:hover {
  transform: translateY(-6px) scale(1.04);
}

.song-item:hover .song-img {
  box-shadow: 0 0 25px rgba(173,216,230,0.55);
}

.song-title {
  margin-top: 12px;
  font-weight: bold;
}

/* 戻るボタン */
.back-btn {
  display: block;              /* ← ここ重要 */
  width: fit-content;          /* 中身サイズに合わせる */
  margin: 30px auto 0;         /* autoで中央寄せ */

  padding: 8px 15px;
  border-radius: 8px;
  background: linear-gradient(45deg, #ffffff, #add8e6, #e0ffff);
  color: #333;
  text-decoration: none;
  box-shadow: 0 0 12px rgba(173,216,230,0.55);
  transition: 0.25s;
}

.back-btn:hover {
  transform: scale(1.06);
  box-shadow: 0 0 22px rgba(173,216,230,0.8);
}

@media (max-width: 768px) {
  .song-item {
    width: 45%;
  }
}

/* ----------------------------
      曲詳細カード（song-detail）
---------------------------- */
.song-detail-card {
  width: 80%;
  margin: 40px auto;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.95),
    rgba(173, 216, 230, 0.85),
    rgba(224, 255, 255, 0.88)
  );
  border-radius: 20px;
  padding: 25px;
  box-shadow: 0 0 18px rgba(173,216,230,0.45), 0 0 35px rgba(255,255,255,0.25);
  border: 2px solid rgba(173,216,230,0.65);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.song-detail-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 0 25px rgba(173,216,230,0.65), 0 0 45px rgba(255,255,255,0.35);
}

.song-left {
  float: left;
  width: 30%;
}

.song-album {
  width: 65%;
  border-radius: 14px;
  display: block;
  margin: 0 auto;
  box-shadow: 0 0 18px rgba(173,216,230,0.45), 0 0 30px rgba(255,255,255,0.25);
}

.song-right {
  float: right;
  width: 65%;
  padding-left: 25px;
  border-left: 4px solid rgba(173,216,230,0.85);
}

.song-title {
  color: #333;
  font-size: 28px;
  text-shadow: 0 0 6px rgba(255,255,255,0.5);
  margin-bottom: 10px;
  border-bottom: 3px solid;
  border-image: linear-gradient(90deg, #ffffff, #add8e6) 1;
}

.song-description {
  color: #333;
  font-size: 1.15rem;
  line-height: 1.7;
}

.song-footer {
  clear: both;
  margin-top: 25px;
  padding-top: 15px;
  border-top: 2px solid rgba(173,216,230,0.8);
  display: flex;
  gap: 25px;
  font-size: 14px;
  color: #333;
}

@media (max-width: 768px) {
  .song-left,
  .song-right {
    float: none;
    width: 100%;
    padding-left: 0;
    border-left: none;
    margin-bottom: 20px;
  }
  .song-detail-card {
    width: 95%;
    padding: 20px;
  }
}