:root {
  --bg: #0b0e17;
  --bg-card: #141a29;
  --text: #e6e9f0;
  --text-dim: #9aa4b8;
  --accent: #6ea8fe;
  --border: #232b3d;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

header.site-header {
  padding: 24px 20px;
  border-bottom: 1px solid var(--border);
  text-align: center;
}

header.site-header h1 {
  margin: 0 0 4px 0;
  font-size: 1.6rem;
}

header.site-header p {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.9rem;
}

nav.section-nav {
  margin-top: 10px;
  font-size: 0.85rem;
}

nav.breadcrumb {
  padding: 12px 20px;
  font-size: 0.85rem;
  color: var(--text-dim);
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 20px;
}

main.full-width {
  max-width: none;
  margin: 0;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px;
  display: block;
}

.card h3 {
  margin: 0 0 6px 0;
  font-size: 1.1rem;
}

.card p {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.85rem;
}

.session-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 18px;
  margin-bottom: 16px;
}

.session-block h3 {
  margin-top: 0;
}

.photo-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 8px;
}

.photo-grid img {
  max-width: 260px;
  max-height: 220px;
  border-radius: 6px;
  border: 1px solid var(--border);
  display: block;
}

.file-list {
  list-style: none;
  padding: 0;
  margin: 8px 0 0 0;
}

.file-list li {
  padding: 8px 0;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.file-list li:first-child { border-top: none; }

.file-icon {
  vertical-align: middle;
  margin-right: 6px;
}

.file-actions a {
  margin-left: 14px;
  font-size: 0.85rem;
}

table.xls-table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.85rem;
  margin-top: 16px;
}

table.xls-table th, table.xls-table td {
  border: 1px solid var(--border);
  padding: 6px 10px;
  text-align: left;
}

table.xls-table th {
  background: var(--bg-card);
  position: sticky;
  top: 0;
}

.sheet-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 16px;
}

.sheet-tabs button {
  background: var(--bg-card);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 12px;
  cursor: pointer;
  font-size: 0.85rem;
}

.sheet-tabs button.active {
  border-color: var(--accent);
  color: var(--accent);
}

.empty-hint {
  color: var(--text-dim);
  font-style: italic;
}