/* Seeds of Times — minimal vessel stylesheet
 * 2026-07-30 Σ-Edita 制定・骨組みのみ・中身は空
 */

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

:root {
  --bg: #fafaf8;
  --fg: #1a1a1a;
  --muted: #6b6b6b;
  --accent: #2b5c8a;
  --border: #e5e5e0;
  --panel-bg: #ffffff;
  --hover: #f0efeb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16171a;
    --fg: #e9e9e6;
    --muted: #9a9a95;
    --accent: #78b1e0;
    --border: #2a2c31;
    --panel-bg: #1c1e22;
    --hover: #23262b;
  }
}

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic UI", sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.55;
}

.site-header {
  padding: 1.2rem 1.6rem 0.6rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.site-title {
  margin: 0;
  font-size: 1.4rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.site-meta {
  font-size: 0.85rem;
  color: var(--muted);
}

.tab-nav {
  display: flex;
  gap: 0.2rem;
  padding: 0.4rem 1.2rem 0;
  border-bottom: 1px solid var(--border);
  overflow-x: auto;
}

.tab-btn {
  appearance: none;
  border: none;
  background: transparent;
  color: var(--muted);
  padding: 0.55rem 1rem;
  font-size: 0.9rem;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: color .15s, border-color .15s, background .15s;
  white-space: nowrap;
}

.tab-btn:hover {
  color: var(--fg);
  background: var(--hover);
}

.tab-btn.is-active {
  color: var(--fg);
  border-bottom-color: var(--accent);
  font-weight: 500;
}

.tab-panels {
  padding: 1.4rem 1.6rem;
  max-width: 1080px;
  margin: 0 auto;
}

.tab-panel {
  display: none;
}

.tab-panel.is-active {
  display: block;
}

.empty-note {
  color: var(--muted);
  font-size: 0.95rem;
  padding: 2rem 1rem;
  background: var(--panel-bg);
  border: 1px dashed var(--border);
  border-radius: 6px;
  text-align: center;
  margin: 0;
}

.site-footer {
  padding: 1.2rem 1.6rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.8rem;
  text-align: center;
  margin-top: 2rem;
}