:root {
  /* clamp(最小値, 可変値, 最大値): 画面幅に応じて滑らかに変化するフォントサイズ */
  --fs-sm: clamp(0.8rem, 0.74rem + 0.3vw, 0.95rem);
  --fs-base: clamp(0.95rem, 0.88rem + 0.35vw, 1.05rem);
  --fs-lg: clamp(1.15rem, 1rem + 0.75vw, 1.5rem);
  --fs-xl: clamp(1.6rem, 1.25rem + 1.75vw, 2.4rem);

  /* 配色（白基調） */
  --color-bg: #ffffff;
  --color-bg-alt: #f5f6f8;
  --color-text: #1c1c26;
  --color-text-muted: #666672;
  --color-border: #e3e4ea;
  --color-accent: #0284c7;
  --color-viewers: #dc2626;
  --color-likes: #d97706;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  font-size: var(--fs-base);
}
a { color: var(--color-accent); }
h1 { font-size: var(--fs-xl); }
h2 { font-size: var(--fs-lg); }

.site-header {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 16px 24px;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
}
.logo {
  font-weight: 700;
  font-size: var(--fs-lg);
  color: var(--color-text);
  text-decoration: none;
}
.main-nav a {
  margin-right: 16px;
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: var(--fs-sm);
}
.main-nav a:hover { color: var(--color-text); }

.site-main {
  max-width: 900px;
  margin: 0 auto;
  padding: 32px 24px;
}
.lead { color: var(--color-text-muted); }
.empty-state { color: var(--color-text-muted); padding: 40px 0; text-align: center; }

.channel-header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
}
.channel-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  flex-shrink: 0;
}
.channel-header-info {
  flex: 1;
  min-width: 0;
}
.channel-meta {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
}
.broadcast-meta {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  margin-top: 2px;
}

.channel-subscriber-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
}
.channel-subscriber-chart {
  flex: 1 1 320px;
  max-width: 500px;
}
.range-select-form select {
  font-size: var(--fs-sm);
  padding: 4px 8px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  background: var(--color-bg);
  color: var(--color-text);
}

.viewer-chart-box,
.like-chart-box {
  margin-top: 10px;
}

.share-pie-box {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-top: 12px;
  flex-wrap: wrap;
}
.share-pie-legend {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.legend-dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  margin-right: 6px;
}
.legend-dot-top { background: var(--color-accent); }
.legend-dot-rest { background: var(--color-border); }

.marketing-layout {
  display: flex;
  align-items: flex-start;
  gap: 24px;
  flex-wrap: wrap;
}
.heatmap-scroll {
  overflow-x: auto;
  flex: 1 1 auto;
  min-width: 0;
}

.mini-calendar {
  flex: 0 0 auto;
  width: 260px;
}
.mini-calendar-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
  font-weight: 600;
}
.mini-calendar-nav a {
  padding: 2px 10px;
  text-decoration: none;
}
.mini-calendar-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--fs-sm);
  table-layout: fixed;
}
.mini-calendar-table th,
.mini-calendar-table td {
  text-align: center;
  padding: 4px 0;
}
.mini-calendar-table th {
  color: var(--color-text-muted);
  font-weight: normal;
}
.mini-calendar-table td a {
  display: block;
  border-radius: 4px;
  padding: 3px 0;
  text-decoration: none;
  color: var(--color-text);
}
.mini-calendar-table td.out-of-month a {
  color: var(--color-border);
}
.mini-calendar-table tr:hover td a {
  background: var(--color-bg-alt);
}
.mini-calendar-table tr.selected-week td a {
  background: var(--color-accent);
  color: #fff;
}
.mini-calendar-reset {
  display: inline-block;
  margin-top: 8px;
  font-size: var(--fs-sm);
}

.week-breakdown {
  flex: 1 1 320px;
  min-width: 280px;
  padding-left: 24px;
  border-left: 1px solid var(--color-border);
}

.graph-mode-toggle {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}
.graph-mode-toggle a {
  padding: 6px 12px;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  text-decoration: none;
  color: var(--color-text);
  font-size: var(--fs-sm);
}
.graph-mode-toggle a.active {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #fff;
}

.bar-chart-h {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  overflow-x: auto;
  padding: 8px 4px 0;
}
.bar-chart-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex: 0 0 auto;
}
.bar-chart-value {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  margin-bottom: 4px;
  white-space: nowrap;
}
.bar-chart-bar {
  width: 24px;
  background: var(--color-accent);
  border-radius: 3px 3px 0 0;
  min-height: 2px;
}
.bar-chart-label {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  margin-top: 6px;
  white-space: nowrap;
}
.heatmap-table {
  border-collapse: collapse;
  font-size: var(--fs-sm);
  white-space: nowrap;
  table-layout: fixed;
}
.heatmap-table th,
.heatmap-table td {
  border: 1px solid var(--color-border);
  padding: 4px 8px;
  text-align: right;
  width: 64px;
}
.heatmap-table thead th:first-child,
.heatmap-table tbody th {
  width: 48px;
}
.heatmap-table thead th {
  text-align: center;
  color: var(--color-text-muted);
}
.heatmap-table tbody th {
  text-align: left;
  color: var(--color-text-muted);
  font-weight: normal;
}
.heatmap-table td {
  color: var(--color-text);
}
.sparkline-label {
  display: block;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  margin-bottom: 2px;
}
.sparkline-empty {
  color: var(--color-border);
  font-size: var(--fs-sm);
}

.ranking-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.ranking-item {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--color-border);
}
.rank {
  width: 40px;
  font-weight: 700;
  color: var(--color-accent);
  flex-shrink: 0;
}
.thumb-link {
  flex-shrink: 0;
  display: block;
}
.thumb {
  width: 120px;
  height: 68px;
  object-fit: cover;
  border-radius: 6px;
  flex-shrink: 0;
}
.info { flex: 1 1 160px; min-width: 0; }
.ch-name {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  text-decoration: none;
  color: var(--color-text);
}
.ch-name:hover {
  text-decoration: underline;
}
.icon {
  width: 24px;
  height: 24px;
  border-radius: 50%;
}
.tag-groups {
  margin-top: 4px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.tag-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px;
}
.no-tags {
  margin: 2px 0 0;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
}
.tag-row-label {
  flex-shrink: 0;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  width: 3.5em;
}
.tag {
  color: var(--color-accent);
  font-size: var(--fs-sm);
}
.video-title {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.viewers {
  flex-shrink: 0;
  font-weight: 700;
  color: var(--color-viewers);
}

.site-footer {
  text-align: center;
  padding: 24px;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  border-top: 1px solid var(--color-border);
}
.yt-attribution {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}
.yt-logo {
  width: 28px;
  height: auto;
  flex-shrink: 0;
}

.pagination {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 4px;
  padding: 24px 0;
}
.pagination-edge,
.pagination-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 28px;
  height: 28px;
  padding: 0 6px;
  border-radius: 4px;
  text-decoration: none;
  color: var(--color-text);
  font-size: var(--fs-sm);
}
.pagination-edge {
  font-size: 1.8em;
  line-height: 1;
}
.pagination-edge:hover,
.pagination-num:hover {
  background: var(--color-bg-alt);
}
.pagination-edge.disabled {
  color: var(--color-border);
}
.pagination-num.current {
  background: var(--color-accent);
  color: #fff;
  font-weight: 700;
}
.pagination-ellipsis {
  color: var(--color-text-muted);
  padding: 0 4px;
}

/* 狭い画面ではサムネイルを上、情報を下に積む1カラムレイアウトに切り替える */
@media (max-width: 520px) {
  .ranking-item {
    position: relative;
    padding-left: 32px;
  }
  .rank {
    position: absolute;
    left: 0;
    top: 12px;
    width: auto;
  }
  .thumb-link {
    flex: 1 1 100%;
  }
  .thumb {
    width: 100%;
    height: auto;
    aspect-ratio: 16 / 9;
  }
  .info {
    flex: 1 1 100%;
  }
  .video-title {
    white-space: normal;
    overflow: visible;
  }
  .viewers {
    flex: 1 1 100%;
    text-align: right;
  }
}

.thumb-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
}
.gallery-thumb-btn {
  display: block;
  padding: 0;
  border: none;
  background: none;
  cursor: pointer;
  text-align: left;
  font: inherit;
  color: inherit;
}
.gallery-thumb {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 6px;
  display: block;
}
.gallery-thumb-caption {
  display: block;
  margin-top: 4px;
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lightbox {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
}
.lightbox[hidden] {
  display: none;
}
.lightbox-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
}
.lightbox-content {
  position: relative;
  max-width: min(90vw, 900px);
  max-height: 90vh;
  overflow: auto;
  background: var(--color-bg);
  border-radius: 8px;
  padding: 12px;
}
.lightbox-content img {
  display: block;
  max-width: 100%;
  border-radius: 4px;
}
.lightbox-caption {
  margin-top: 8px;
}
.lightbox-caption a {
  display: inline-block;
  margin-top: 4px;
}

.tag-search-form {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 16px 0;
}
.tag-search-form input[type="text"] {
  font-size: var(--fs-base);
  padding: 6px 10px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  background: var(--color-bg);
  color: var(--color-text);
  width: 240px;
  max-width: 100%;
}
.tag-search-form input[type="text"]::placeholder {
  color: #c3c4cd;
}
.tag-search-form button {
  font-size: var(--fs-sm);
  padding: 6px 14px;
  border: 1px solid var(--color-accent);
  border-radius: 4px;
  background: var(--color-accent);
  color: #fff;
  cursor: pointer;
}
.tag-search-clear {
  font-size: var(--fs-sm);
}

.top-tags {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 16px;
}
.top-tags-label {
  flex-shrink: 0;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  margin-right: 4px;
}
.top-tag {
  text-decoration: none;
}
.top-tag.active {
  font-weight: 700;
  text-decoration: underline;
}
#top-tags-more {
  display: contents;
}
#top-tags-more[hidden] {
  display: none;
}
.top-tags-more-btn {
  margin-left: auto;
  font-size: var(--fs-sm);
  padding: 2px 10px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  background: var(--color-bg);
  color: var(--color-text);
  cursor: pointer;
}

.search-result-header {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 1em;
  margin-bottom: 1.6em;
}
.search-result-header h2 {
  margin: 0;
}