:root {
  --bg: #f9fafb;
  --bg-card: #ffffff;
  --fg: #111827;
  --fg-muted: #6b7280;
  --accent: #2563eb;
  --radius: 10px;
  --shadow: 0 8px 20px rgba(15,23,42,0.06);
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

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

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--fg);
  background: var(--bg);
  line-height: 1.7;
}

/* ヘッダー */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(249,250,251,0.96);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid #e5e7eb;
}

.header-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 10px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand a {
  font-weight: 700;
  font-size: 18px;
  text-decoration: none;
  color: var(--fg);
}

.brand span {
  color: var(--accent);
}

.nav a {
  margin-left: 12px;
  font-size: 14px;
  text-decoration: none;
  color: var(--fg-muted);
}

.nav a:hover {
  color: var(--accent);
}

/* ページ共通 */
.page {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px;
}

/* ヒーロー */
.hero {
  margin: 16px 0 24px;
  padding: 16px 18px;
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero h1 {
  margin: 0 0 8px;
  font-size: 20px;
}

.hero p {
  margin: 0;
  font-size: 14px;
  color: var(--fg-muted);
}

/* セクション */
.section h2,
.section h1 {
  font-size: 18px;
  margin: 8px 0 12px;
}

/* 投稿リスト */
.post-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.post-item {
  margin: 0 0 16px;
  padding: 12px 14px;
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.post-link {
  text-decoration: none;
  color: inherit;
}

.post-title {
  margin: 0 0 6px;
  font-size: 16px;
}

.post-meta {
  font-size: 12px;
  color: var(--fg-muted);
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 6px;
}

.post-excerpt {
  margin: 4px 0 0;
  font-size: 13px;
  color: var(--fg-muted);
}

/* 個別記事 */
.post-detail-header h1 {
  margin: 12px 0 4px;
  font-size: 20px;
}

.post-body p {
  margin: 0 0 10px;
  font-size: 14px;
}

.source-link {
  margin-top: 16px;
  font-size: 13px;
}

/* フッター */
.site-footer {
  margin-top: 32px;
  padding: 16px;
  text-align: center;
  font-size: 12px;
  color: var(--fg-muted);
}

.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  margin-top: 24px;
}

.pagination .page-btn {
  padding: 6px 12px;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  font-size: 14px;
}

.pagination .page-btn:hover {
  opacity: 0.85;
}

.pagination .page-status {
  font-size: 13px;
  color: var(--fg-muted);
}

/* ===== パンくず ===== */
.breadcrumb {
  font-size: 12px;
  color: var(--fg-muted);
  margin: 8px 0 12px;
}

.breadcrumb a {
  color: var(--fg-muted);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.breadcrumb-sep {
  margin: 0 4px;
}

.breadcrumb-current {
  color: var(--fg);
}