/* ================================================
   SnowDeBGM - フリー音楽素材サイト
   雪をイメージした青/白系デザイン
   ================================================ */

:root {
  --primary-color: #4a9eff;
  --primary-dark: #2d7ad6;
  --primary-light: #7ab8ff;
  --accent-color: #6ee7ff;
  --bg-main: #0a1929;
  --bg-card: #0d2137;
  --bg-card-hover: #132d4a;
  --bg-header: rgba(10, 25, 41, 0.95);
  --text-primary: #ffffff;
  --text-secondary: #b0c4de;
  --text-muted: #7a8fa3;
  --border-color: rgba(74, 158, 255, 0.2);
  --border-light: rgba(255, 255, 255, 0.1);
  --shadow-glow: 0 0 20px rgba(74, 158, 255, 0.3);
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.3);
  --transition: 0.3s ease;
}

*, *::before, *::after { box-sizing: border-box; }

body {
  font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
  background: var(--bg-main);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

a { color: var(--primary-light); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent-color); }

.container { max-width: 1200px; margin: 0 auto; padding: 0 1rem; }

/* ヘッダー */
.site-header {
  background: var(--bg-header);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-light);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-content { display: flex; align-items: center; justify-content: space-between; padding: 0.75rem 0; }

.logo { display: flex; align-items: center; gap: 0.5rem; font-size: 1.5rem; font-weight: 700; color: var(--text-primary); }
.logo:hover { color: var(--primary-light); }
.logo-icon { color: var(--accent-color); animation: spin 10s linear infinite; }

@keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }

.main-nav { display: flex; gap: 1.5rem; }
.nav-link { color: var(--text-secondary); padding: 0.5rem 0; position: relative; }
.nav-link:hover, .nav-link.active { color: var(--text-primary); }
.nav-link.active::after { content: ''; position: absolute; bottom: 0; left: 0; right: 0; height: 2px; background: var(--primary-color); }

.mobile-menu-toggle { display: none; background: none; border: none; color: var(--text-primary); font-size: 1.5rem; cursor: pointer; }
.mobile-nav { display: none; flex-direction: column; padding: 1rem 0; border-top: 1px solid var(--border-light); }
.mobile-nav.active { display: flex; }

@media (max-width: 768px) {
  .main-nav { display: none; }
  .mobile-menu-toggle { display: block; }
}

/* ヒーロー */
.hero {
  background: linear-gradient(135deg, #1a365d 0%, #0a1929 50%, #0d2137 100%);
  padding: 2rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero-small { padding: 2rem 0; }
.hero h1 { font-size: 3rem; font-weight: 700; margin-bottom: 0.5rem; text-shadow: 0 0 30px rgba(74, 158, 255, 0.5); }
.hero h1 i { color: var(--accent-color); animation: spin 10s linear infinite; }
.hero-subtitle { font-size: 1.5rem; color: var(--text-secondary); margin-bottom: 0.5rem; }
.hero-description { color: var(--text-muted); font-size: 1rem; }

/* 雪エフェクト */
.snowfall { position: absolute; top: 0; left: 0; right: 0; bottom: 0; pointer-events: none; overflow: hidden; }
.snowflake { position: absolute; color: rgba(255, 255, 255, 0.8); font-size: 10px; animation: fall linear infinite; text-shadow: 0 0 5px rgba(255, 255, 255, 0.5); }
@keyframes fall { 0% { transform: translateY(-10px) rotate(0deg); opacity: 1; } 100% { transform: translateY(100vh) rotate(360deg); opacity: 0.3; } }

/* 広告 */
.ad-container { max-width: 1200px; margin: 1.5rem auto; padding: 0 1rem; }
.ad-inline { margin: 2rem auto; }

/* フィルター */
.filter-section { background: var(--bg-card); border-bottom: 1px solid var(--border-light); padding: 1rem 0; }
.filter-wrapper { display: flex; flex-wrap: wrap; gap: 1rem; align-items: flex-end; }
.search-box { display: flex; flex: 1; min-width: 200px; max-width: 400px; }
.search-input { flex: 1; background: var(--bg-main); border: 1px solid var(--border-color); border-right: none; border-radius: 8px 0 0 8px; padding: 0.75rem 1rem; color: var(--text-primary); font-size: 1rem; }
.search-input::placeholder { color: var(--text-muted); }
.search-input:focus { outline: none; border-color: var(--primary-color); }
.search-btn { background: var(--primary-color); border: none; border-radius: 0 8px 8px 0; padding: 0.75rem 1.25rem; color: white; cursor: pointer; transition: background var(--transition); }
.search-btn:hover { background: var(--primary-dark); }
.filter-group { display: flex; flex-direction: column; gap: 0.25rem; }
.filter-group label { font-size: 0.8rem; color: var(--text-muted); }
.filter-select { background: var(--bg-main); border: 1px solid var(--border-color); border-radius: 8px; padding: 0.75rem 2rem 0.75rem 1rem; color: var(--text-primary); font-size: 0.9rem; cursor: pointer; appearance: none; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%237a8fa3' d='M6 8L1 3h10z'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 0.75rem center; }
.filter-select:focus { outline: none; border-color: var(--primary-color); }
.clear-filter-btn { background: transparent; border: 1px solid var(--border-color); border-radius: 8px; padding: 0.75rem 1rem; color: var(--text-secondary); cursor: pointer; transition: all var(--transition); }
.clear-filter-btn:hover { background: rgba(255, 255, 255, 0.1); color: var(--text-primary); }

/* 楽曲セクション */
.tracks-section { padding: 2rem 0; }
.section-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 1.5rem; }
.section-header h2 { font-size: 1.5rem; font-weight: 600; }
.section-header h2 i { color: var(--primary-color); margin-right: 0.5rem; }
.track-count { color: var(--text-muted); font-size: 0.9rem; }

.tracks-list { display: flex; flex-direction: column; gap: 0.75rem; }
.loading { text-align: center; padding: 3rem; color: var(--text-muted); }
.loading i { margin-right: 0.5rem; }
.no-tracks { text-align: center; padding: 3rem; color: var(--text-muted); }

/* 楽曲カード */
.track-card { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: 12px; padding: 1rem 1.25rem; display: flex; align-items: center; gap: 1rem; transition: all var(--transition); }
.track-card:hover { background: var(--bg-card-hover); border-color: var(--primary-color); box-shadow: var(--shadow-glow); }
.track-play-btn { width: 48px; height: 48px; border-radius: 50%; background: var(--primary-color); border: none; color: white; font-size: 1.2rem; cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all var(--transition); flex-shrink: 0; }
.track-play-btn:hover { background: var(--primary-dark); transform: scale(1.1); }
.track-play-btn.playing { background: var(--accent-color); animation: pulse 1.5s ease-in-out infinite; }
@keyframes pulse { 0%, 100% { box-shadow: 0 0 0 0 rgba(110, 231, 255, 0.4); } 50% { box-shadow: 0 0 0 10px rgba(110, 231, 255, 0); } }

.track-info { flex: 1; min-width: 0; }
.track-title { font-size: 1rem; font-weight: 600; color: var(--text-primary); margin-bottom: 0.25rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.track-series { font-size: 0.75rem; color: var(--primary-light); margin-bottom: 0.25rem; display: flex; align-items: center; gap: 0.3rem; }
.track-series i { color: var(--accent-color); }
.track-meta { display: flex; flex-wrap: wrap; gap: 0.75rem; font-size: 0.8rem; color: var(--text-muted); }
.track-meta span { display: flex; align-items: center; gap: 0.25rem; }
.track-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.5rem; }
.track-tag { background: rgba(74, 158, 255, 0.2); color: var(--primary-light); padding: 0.2rem 0.6rem; border-radius: 999px; font-size: 0.7rem; }
.track-actions { display: flex; gap: 0.5rem; flex-shrink: 0; }
.track-action-btn { width: 40px; height: 40px; border-radius: 8px; background: rgba(255, 255, 255, 0.1); border: 1px solid var(--border-color); color: var(--text-primary); cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all var(--transition); }
.track-action-btn:hover { background: var(--primary-color); border-color: var(--primary-color); color: white; }
.track-action-btn.download-btn { color: #5dd879; }
.track-action-btn.download-btn:hover { background: #28a745; border-color: #28a745; color: white; }

/* ページネーション */
.pagination { display: flex; justify-content: center; gap: 0.5rem; margin-top: 2rem; }
.page-btn { width: 40px; height: 40px; border-radius: 8px; background: var(--bg-card); border: 1px solid var(--border-color); color: var(--text-secondary); cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all var(--transition); }
.page-btn:hover:not(:disabled) { background: var(--primary-color); border-color: var(--primary-color); color: white; }
.page-btn.active { background: var(--primary-color); border-color: var(--primary-color); color: white; }
.page-btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* オーディオプレイヤー */
.audio-player { position: fixed; bottom: 0; left: 0; right: 0; background: var(--bg-header); backdrop-filter: blur(10px); border-top: 1px solid var(--border-light); padding: 0.75rem 1rem; display: none; align-items: center; gap: 1rem; z-index: 1001; }
.audio-player.active { display: flex; }
.player-info { flex: 0 0 150px; min-width: 0; }
.player-title { font-size: 0.9rem; font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; display: block; }
.player-controls { display: flex; align-items: center; gap: 0.5rem; }
.player-btn { width: 36px; height: 36px; border-radius: 50%; background: transparent; border: none; color: var(--text-secondary); cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all var(--transition); }
.player-btn:hover { color: var(--text-primary); background: rgba(255, 255, 255, 0.1); }
.player-btn-main { width: 44px; height: 44px; background: var(--primary-color); color: white; }
.player-btn-main:hover { background: var(--primary-dark); color: white; }
.player-progress { flex: 1; display: flex; align-items: center; gap: 0.75rem; }
.player-time { font-size: 0.8rem; color: var(--text-muted); min-width: 40px; text-align: center; }
.player-seek { flex: 1; height: 4px; -webkit-appearance: none; appearance: none; background: rgba(255, 255, 255, 0.2); border-radius: 2px; cursor: pointer; }
.player-seek::-webkit-slider-thumb { -webkit-appearance: none; width: 12px; height: 12px; border-radius: 50%; background: var(--primary-color); cursor: pointer; }
.player-volume { display: flex; align-items: center; gap: 0.5rem; }
.player-volume-slider { width: 80px; height: 4px; -webkit-appearance: none; appearance: none; background: rgba(255, 255, 255, 0.2); border-radius: 2px; cursor: pointer; }
.player-volume-slider::-webkit-slider-thumb { -webkit-appearance: none; width: 12px; height: 12px; border-radius: 50%; background: var(--primary-color); cursor: pointer; }
.player-close { color: var(--text-muted); }
.player-close:hover { color: #dc3545; background: rgba(220, 53, 69, 0.2); }

@media (max-width: 768px) {
  .audio-player { flex-wrap: wrap; padding: 0.5rem; gap: 0.5rem; }
  .player-info { order: 1; flex: 1; }
  .player-close { order: 2; }
  .player-controls { order: 3; }
  .player-progress { order: 4; flex-basis: 100%; }
  .player-volume { display: none; }
}

/* フッター */
.site-footer { background: var(--bg-card); border-top: 1px solid var(--border-light); padding: 2rem 0; margin-top: 2rem; }
.footer-content { text-align: center; }
.footer-brand { font-size: 1.5rem; font-weight: 700; margin-bottom: 0.5rem; color: var(--text-primary); }
.footer-brand i { color: var(--accent-color); margin-right: 0.5rem; }
.footer-description { color: var(--text-muted); font-size: 0.9rem; margin-bottom: 0.5rem; }
.footer-ai-notice { color: var(--accent-color); font-size: 0.8rem; margin-bottom: 1rem; }
.footer-ai-notice i { margin-right: 0.3rem; }
.footer-links { margin-bottom: 1rem; }
.footer-links a { color: var(--text-secondary); }
.footer-links .separator { color: var(--text-muted); margin: 0 0.5rem; }
.copyright { color: var(--text-muted); font-size: 0.8rem; }

/* 利用規約 */
.terms-section { padding: 2rem 0; }
.terms-content { max-width: 800px; margin: 0 auto; background: var(--bg-card); border-radius: 16px; padding: 2rem; border: 1px solid var(--border-color); }
.terms-content h2 { font-size: 1.75rem; margin-bottom: 2rem; padding-bottom: 1rem; border-bottom: 1px solid var(--border-light); }
.terms-content h3 { font-size: 1.2rem; margin: 2rem 0 1rem; color: var(--primary-light); }
.terms-content h3 i { margin-right: 0.5rem; }
.terms-content ul { list-style: none; padding: 0; }
.terms-content ul li { padding: 0.5rem 0 0.5rem 1.5rem; position: relative; }
.terms-content ul li::before { content: '○'; position: absolute; left: 0; color: var(--primary-color); }
.terms-content ul.prohibited li::before { content: '×'; color: #dc3545; }
.credit-example { background: var(--bg-main); padding: 1rem; border-radius: 8px; border-left: 3px solid var(--primary-color); margin: 1rem 0; }
.credit-example code { color: var(--accent-color); }
.terms-content .updated { margin-top: 2rem; color: var(--text-muted); font-size: 0.9rem; text-align: right; }

@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; }
  .hero-subtitle { font-size: 1.1rem; }
  .filter-wrapper { flex-direction: column; align-items: stretch; }
  .search-box { max-width: none; }
  .track-card { flex-wrap: wrap; }
  .track-info { order: 2; flex-basis: calc(100% - 60px); }
  .track-actions { order: 3; flex-basis: 100%; justify-content: flex-end; margin-top: 0.5rem; }
  .terms-content { padding: 1.5rem; }
}

/* 利用規約ページ追加スタイル */
.terms-intro { font-size: 1rem; color: var(--text-secondary); margin-bottom: 2rem; line-height: 1.8; }

.terms-summary { background: linear-gradient(135deg, rgba(74, 158, 255, 0.1), rgba(110, 231, 255, 0.1)); border-radius: 16px; padding: 2rem; margin-bottom: 2rem; border: 1px solid var(--border-color); }
.terms-summary h2 { font-size: 1.3rem; margin-bottom: 1.5rem; color: var(--accent-color); }
.terms-summary h2 i { margin-right: 0.5rem; }

.summary-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 1rem; }
.summary-item { display: flex; align-items: center; gap: 0.5rem; padding: 0.75rem 1rem; border-radius: 8px; font-weight: 500; }
.summary-item.ok { background: rgba(40, 167, 69, 0.2); color: #5dd879; }
.summary-item.ng { background: rgba(220, 53, 69, 0.2); color: #ff6b7a; }
.summary-item i { font-size: 1.2rem; }
.summary-note { margin-top: 5px; }

.faq-list { margin-top: 1rem; }
.faq-item { background: var(--bg-main); border-radius: 8px; padding: 1rem; margin-bottom: 1rem; border-left: 3px solid var(--primary-color); }
.faq-q { color: var(--text-primary); margin-bottom: 0.5rem; }
.faq-a { color: var(--text-secondary); margin: 0; padding-left: 1rem; }

/* ダウンロードドロップダウン */
.download-dropdown { position: relative; display: inline-block; }
.download-menu { position: absolute; top: 100%; right: 0; background: var(--bg-card); border: 1px solid var(--border-color); border-radius: 8px; padding: 0.5rem 0; min-width: 120px; display: none; z-index: 100; box-shadow: var(--shadow-card); }
.download-menu.active { display: block; }
.download-menu a { display: flex; align-items: center; gap: 0.5rem; padding: 0.5rem 1rem; color: var(--text-secondary); font-size: 0.85rem; transition: all var(--transition); }
.download-menu a:hover { background: var(--primary-color); color: white; }
.download-menu a i { width: 16px; text-align: center; }

/* 広告エリア追加 */
.ad-sidebar { margin-top: 1.5rem; }
.ad-between { margin: 1.5rem 0; }

/* 利用案内バナー */
.info-banner { background: var(--bg-card); padding: 1rem 0; border-bottom: 1px solid var(--border-light); }
.info-grid { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 1.5rem; }
.info-item { display: flex; align-items: center; gap: 0.5rem; color: #5dd879; font-weight: 500; }
.info-item i { font-size: 1.1rem; }
.info-link { display: flex; align-items: center; gap: 0.5rem; padding: 0.5rem 1rem; background: var(--primary-color); color: white; border-radius: 8px; font-size: 0.9rem; transition: all var(--transition); }
.info-link:hover { background: var(--primary-dark); color: white; }
.info-disclaimer { text-align: center; color: var(--text-muted); font-size: 0.8rem; margin-top: 1rem; }
.info-disclaimer i { color: #ffc107; margin-right: 0.3rem; }

/* サイドバー */
.sidebar { position: sticky; top: 80px; }
.sidebar-box { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: 12px; padding: 1.25rem; margin-top: 1.5rem; }
.sidebar-box h3 { font-size: 1rem; font-weight: 600; margin-bottom: 1rem; color: var(--text-primary); }
.sidebar-box h3 i { color: var(--primary-color); margin-right: 0.5rem; }
.sidebar-box ul { list-style: none; padding: 0; margin: 0 0 1rem 0; }
.sidebar-box ul li { padding: 0.4rem 0; color: var(--text-secondary); font-size: 0.9rem; }
.sidebar-box ul li i { color: #5dd879; margin-right: 0.5rem; width: 16px; }
.sidebar-link { display: flex; align-items: center; justify-content: space-between; padding: 0.75rem 1rem; background: rgba(74, 158, 255, 0.1); border-radius: 8px; color: var(--primary-light); font-size: 0.9rem; transition: all var(--transition); }
.sidebar-link:hover { background: var(--primary-color); color: white; }

/* フォーマット説明 */
.format-info { display: flex; flex-direction: column; gap: 0.75rem; }
.format-item { padding: 0.75rem; background: var(--bg-main); border-radius: 8px; }
.format-item strong { display: block; color: var(--primary-light); font-size: 0.9rem; margin-bottom: 0.25rem; }
.format-item span { color: var(--text-muted); font-size: 0.8rem; }

@media (max-width: 992px) {
  .sidebar { position: static; margin-top: 2rem; }
  .info-grid { gap: 1rem; }
  .info-item { font-size: 0.85rem; }
}

/* ヒーローのAI表示 */
.hero-notice { color: var(--text-muted); font-size: 0.9rem; margin-top: 0.5rem; }
.hero-notice i { margin-right: 0.3rem; color: var(--accent-color); }

/* AI/著作権バッジ */
.info-item.info-ai { color: var(--accent-color); }
.summary-item.ai { background: rgba(110, 231, 255, 0.2); color: var(--accent-color); }
.summary-item.copyright { background: rgba(255, 193, 7, 0.2); color: #ffc107; }

/* AI説明ボックス */
.ai-notice { background: linear-gradient(135deg, rgba(110, 231, 255, 0.1), rgba(74, 158, 255, 0.1)); border: 1px solid var(--accent-color); border-radius: 12px; padding: 1.5rem; margin-bottom: 2rem; }
.ai-notice h3 { font-size: 1.1rem; color: var(--accent-color); margin-bottom: 1rem; }
.ai-notice h3 i { margin-right: 0.5rem; }
.ai-notice p { margin-bottom: 1rem; }
.ai-notice ul { margin: 0; padding-left: 1.5rem; }
.ai-notice ul li { padding: 0.3rem 0; color: var(--text-secondary); }
.ai-notice ul li::before { content: none; }

/* 歌詞ボタン */
.lyrics-btn { color: #ff9ff3 !important; }
.lyrics-btn:hover { color: #f368e0 !important; }

/* 歌詞モーダル */
.lyrics-modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  z-index: 2000;
  justify-content: center;
  align-items: center;
  backdrop-filter: blur(5px);
}
.lyrics-modal.active { display: flex; }
.lyrics-modal-content {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  max-width: 500px;
  width: 90%;
  max-height: 80vh;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
}
.lyrics-modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--glass-border);
  background: rgba(110, 231, 255, 0.1);
}
.lyrics-modal-header h3 {
  margin: 0;
  font-size: 1.1rem;
  color: var(--accent-color);
}
.lyrics-close {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 1.2rem;
  cursor: pointer;
  padding: 0.5rem;
  transition: color 0.2s;
}
.lyrics-close:hover { color: var(--text-color); }
.lyrics-modal-body {
  padding: 1.5rem;
  overflow-y: auto;
  max-height: 60vh;
  white-space: pre-wrap;
  line-height: 1.8;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* 歌詞付きトラック */
.track-card.has-lyrics {
  background: linear-gradient(135deg, rgba(155, 89, 182, 0.15), rgba(142, 68, 173, 0.1));
  border-color: rgba(155, 89, 182, 0.3);
}
.track-card.has-lyrics .track-play-btn {
  background: rgba(155, 89, 182, 0.3);
  color: #9b59b6;
}
.track-card.has-lyrics .track-play-btn:hover {
  background: #9b59b6;
  color: #fff;
}

/* ランキング */
.ranking-list { display: flex; flex-direction: column; gap: 0.5rem; }
.ranking-item { display: flex; align-items: center; gap: 0.5rem; padding: 0.5rem; background: var(--bg-main); border-radius: 8px; cursor: pointer; transition: all var(--transition); }
.ranking-item:hover { background: var(--bg-card-hover); }
.ranking-num { width: 24px; height: 24px; border-radius: 50%; background: var(--primary-color); color: white; font-size: 0.75rem; font-weight: 700; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.ranking-item:nth-child(1) .ranking-num { background: #FFD700; color: #333; }
.ranking-item:nth-child(2) .ranking-num { background: #C0C0C0; color: #333; }
.ranking-item:nth-child(3) .ranking-num { background: #CD7F32; color: #fff; }
.ranking-title { flex: 1; font-size: 0.85rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.ranking-dl { font-size: 0.7rem; color: var(--text-muted); flex-shrink: 0; }
.loading-small { font-size: 0.85rem; color: var(--text-muted); padding: 0.5rem 0; }