:root {
  --bg-main: #0f172a;
  --bg-card: #1e293b;
  --bg-card-hover: #26354d;
  --text-main: #f8fafc;
  --text-sub: #94a3b8;
  --accent: #38bdf8;
  --border: #334155;

  --c-yt-views: #ef4444;
  --c-yt-likes: #f97316;
  --c-yt-comments: #eab308;
  --c-nc-views: #3b82f6;
  --c-nc-mylist: #06b6d4;
  --c-nc-comments: #8b5cf6;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
}

header {
  background: rgba(15, 23, 42, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}
.site-title {
  font-size: 1.45rem;
  font-weight: 800;
  letter-spacing: 0.03em;
  display: flex;
  align-items: center;
  gap: 10px;
}
.site-title span.badge {
  font-size: 0.8rem;
  background: linear-gradient(135deg, var(--c-yt-views), var(--c-nc-views));
  padding: 3px 10px;
  border-radius: 4px;
  font-weight: 700;
}
.update-schedule {
  font-size: 0.85rem;
  color: var(--text-sub);
  background: var(--bg-card);
  padding: 6px 12px;
  border-radius: 6px;
  border: 1px solid var(--border);
}
.update-schedule strong { color: var(--accent); }

.nav-tabs {
  max-width: 1140px;
  margin: 20px auto 0;
  padding: 0 20px;
  display: flex;
  gap: 8px;
  border-bottom: 1px solid var(--border);
  overflow-x: auto;
}
.tab-btn {
  background: transparent;
  color: var(--text-sub);
  border: none;
  padding: 12px 20px;
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  border-bottom: 3px solid transparent;
  transition: all 0.2s;
  white-space: nowrap;
}
.tab-btn:hover { color: var(--text-main); }
.tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

main {
  max-width: 1140px;
  margin: 24px auto 60px;
  padding: 0 20px;
}
.tab-content { display: none; }
.tab-content.active { display: block; }

.chart-meta {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 22px;
  margin-bottom: 22px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px;
}
.meta-note {
  font-size: 0.8rem;
  color: var(--text-sub);
  margin-top: 4px;
}
.archive-control {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
}
.archive-select {
  background: var(--bg-main);
  color: var(--text-main);
  border: 1px solid var(--accent);
  padding: 8px 14px;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
}

.ranking-list { display: flex; flex-direction: column; gap: 16px; }
.rank-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 22px 26px;
  transition: border-color 0.2s;
}
.rank-card.open {
  border-color: var(--accent);
}
.rank-header {
  display: grid;
  grid-template-columns: 72px 1fr auto;
  align-items: center;
  gap: 20px;
}
.rank-num-box { text-align: center; }
.rank-num {
  font-size: 2.2rem;
  font-weight: 900;
  line-height: 1.05;
}
.rank-1 { color: #fbbf24; font-size: 2.5rem; }
.rank-2 { color: #cbd5e1; font-size: 2.35rem; }
.rank-3 { color: #d97706; font-size: 2.35rem; }
.rank-diff {
  font-size: 0.78rem;
  font-weight: 700;
  margin-top: 4px;
}
.diff-up { color: #4ade80; }
.diff-down { color: #f87171; }
.diff-new { color: #38bdf8; }

.song-title-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 6px;
}
.song-title-row h3 {
  font-size: 1.35rem;
  font-weight: 800;
  margin: 0;
}
.detail-toggle-btn {
  background: rgba(56, 189, 248, 0.12);
  color: var(--accent);
  border: 1px solid rgba(56, 189, 248, 0.4);
  padding: 4px 12px;
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}
.detail-toggle-btn:hover {
  background: var(--accent);
  color: var(--bg-main);
  border-color: var(--accent);
}
.rank-card.open .detail-toggle-btn {
  background: var(--accent);
  color: var(--bg-main);
}

.song-meta {
  font-size: 0.92rem;
  color: var(--text-sub);
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}
.point-box { text-align: right; }
.total-pt {
  font-size: 1.75rem;
  font-weight: 900;
  color: var(--accent);
}
.total-pt span {
  font-size: 0.9rem;
  color: var(--text-sub);
  font-weight: 500;
  margin-left: 4px;
}

.share-bar-wrap { margin-top: 16px; }
.share-bar {
  height: 12px;
  border-radius: 6px;
  overflow: hidden;
  display: flex;
  background: #0f172a;
}
.seg-yt-views { background: var(--c-yt-views); }
.seg-yt-likes { background: var(--c-yt-likes); }
.seg-yt-comments { background: var(--c-yt-comments); }
.seg-nc-views { background: var(--c-nc-views); }
.seg-nc-mylist { background: var(--c-nc-mylist); }
.seg-nc-comments { background: var(--c-nc-comments); }

.share-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-sub);
  margin-top: 8px;
}

.chart-visual-box {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  margin-bottom: 24px;
}
.visual-header { margin-bottom: 16px; }
.visual-header h2 { font-size: 1.25rem; color: var(--text-main); }
.visual-sub { font-size: 0.85rem; color: var(--text-sub); margin-top: 4px; }
.canvas-wrap {
  position: relative;
  width: 100%;
  height: 360px;
}

/* 詳細展開パネル（ポイント内訳 -> 視聴ボタン -> YouTubeサムネイル -> 解説） */
.detail-panel {
  display: none;
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px dashed var(--border);
}
.rank-card.open .detail-panel { display: block; }

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 10px;
  margin-bottom: 16px;
}
.metric-box {
  background: rgba(15, 23, 42, 0.6);
  padding: 10px 12px;
  border-radius: 6px;
  border-left: 4px solid var(--border);
}
.metric-name { font-size: 0.75rem; color: var(--text-sub); }
.metric-raw { font-size: 0.95rem; font-weight: 700; margin-top: 2px; }
.metric-pt { font-size: 0.75rem; color: var(--accent); }

.ext-links {
  display: flex;
  gap: 10px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}
.ext-btn {
  text-decoration: none;
  font-size: 0.84rem;
  font-weight: 700;
  padding: 8px 16px;
  border-radius: 6px;
  color: #fff;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: opacity 0.2s;
}
.ext-btn.yt { background: #dc2626; }
.ext-btn.nc { background: #2563eb; }
.ext-btn:hover { opacity: 0.88; }

/* YouTubeサムネイル表示ボックス */
.yt-thumb-wrap {
  margin-bottom: 16px;
}
.yt-thumb-link {
  display: inline-block;
  position: relative;
  width: 100%;
  max-width: 440px;
  aspect-ratio: 16 / 9;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: #0f172a;
}
.yt-thumb-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.25s ease;
}
.yt-thumb-link:hover .yt-thumb-img {
  transform: scale(1.03);
}

.commentary-box {
  background: rgba(56, 189, 248, 0.08);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: 6px;
  padding: 12px 16px;
  font-size: 0.9rem;
}
.commentary-box strong { color: var(--accent); }

.article-box {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
}
.article-box h2 {
  font-size: 1.25rem;
  border-left: 4px solid var(--accent);
  padding-left: 12px;
  margin: 24px 0 12px;
}
.article-box h2:first-child { margin-top: 0; }
.article-box p { margin-bottom: 14px; color: #e2e8f0; }
.rule-table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0 24px;
  font-size: 0.9rem;
}
.rule-table th, .rule-table td {
  border: 1px solid var(--border);
  padding: 10px 14px;
  text-align: left;
}
.rule-table th { background: rgba(15, 23, 42, 0.8); color: var(--accent); }

@media (max-width: 640px) {
  .rank-header { grid-template-columns: 50px 1fr; }
  .point-box { grid-column: 2; text-align: left; }
  .yt-thumb-link { max-width: 100%; }
}