/* ============================
   HIMAWARI SYMPHONY UNIT
   再起 × 成長 × やさしい光
============================ */

/* 全体背景 */
body {
  background: linear-gradient(135deg, #fff3b0,  /* 淡いひまわりイエロー */
    #ffe066,  /* 明るい黄色 */
    #fff7cc );
  font-family: "Noto Sans JP", sans-serif;
  color: #333;
  margin: 0;
  padding: 0;
}

/* ----------------------------
   ヒーローカード
---------------------------- */
.hero-card {
  width: 90%;
  max-width: 1200px;
  margin: 40px auto;
  display: flex;
  align-items: center;

  background: linear-gradient(
    135deg,
    rgba(255, 224, 102, 0.95), /* Yellow */
    rgba(247, 183, 200, 0.92), /* Pink */
    rgba(110, 199, 224, 0.90), /* Blue */
    rgba(123, 207, 155, 0.88)  /* Green */
  );

  border-radius: 22px;
  padding: 30px;
  box-shadow: 0 0 30px rgba(255, 224, 102, 0.45);
  overflow: hidden;
}

/* テキスト */
.hero-text {
  flex: 1;
  padding-right: 20px;
  font-size: 20px;
  color: #ffffff;
  font-weight: bold;
  text-shadow: 0 0 10px rgba(0,0,0,0.4);
  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;
}

/* フェードインアニメーション */
@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); }
}

/* ----------------------------
   セクション共通
---------------------------- */
section {
  max-width: 1000px;
  margin: 55px auto;
  padding: 26px 22px;
  background: #ffffff;
  border-radius: 18px;
  box-shadow: 0 5px 25px rgba(180, 220, 200, 0.35);
}

/* 見出し */
h2 {
  color: #fff;
  padding: 12px 20px;
  border-radius: 14px;
  margin-bottom: 25px;

  background: linear-gradient(
    135deg,
    #ffe066,
    #f7b7c8,
    #6ec7e0
  );

  text-shadow: 0 0 8px rgba(0,0,0,0.3);
}

/* ----------------------------
   楽曲一覧
---------------------------- */
.song-list {
  display: flex;
  justify-content: center;
  gap: 25px;
}

.song-item {
  width: 220px;
  transition: 0.3s ease;
}

.song-img {
  width: 100%;
  border-radius: 16px;
  box-shadow: 0 0 18px rgba(255, 224, 102, 0.45);
}

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

/* ----------------------------
   戻るボタン
---------------------------- */
.back-btn {
  display: block;
  width: fit-content;
  margin: 40px auto;

  padding: 10px 18px;
  border-radius: 12px;

  background: linear-gradient(
    45deg,
    #ffe066,
    #f7b7c8,
    #6ec7e0
  );

  color: #fff;
  text-decoration: none;
  box-shadow: 0 0 18px rgba(255, 224, 102, 0.6);
}

.back-btn:hover {
  transform: scale(1.05);
}

/* ----------------------------
   レスポンシブ
---------------------------- */
@media (max-width: 768px) {
  .hero-card {
    flex-direction: column;
    text-align: center;
  }

  .hero-img {
    margin-top: 20px;
  }

  .song-item {
    width: 80%;
  }
}