:root {
  --bg: #f7f4ee;
  --ink: #1f1b16;
  --muted: #5a534b;
  --card: #ffffff;
  --accent: #2f5d50;
  --border: #d6d0c6;
  --danger: #7a1b1b;
  --danger-bg: #f3e5e5;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: "IBM Plex Serif", "Georgia", "Times New Roman", serif;
  background: var(--bg);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.55;
}

header {
  padding: 24px 20px 12px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(120deg, #e8dfd1, #f7f4ee);
}

header h1 {
  margin: 0 0 6px 0;
  font-size: 24px;
}

header p {
  margin: 0;
  color: var(--muted);
}

.site-header-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 18px;
  margin-top: 14px;
}

.page-diagram-wrap {
  display: flex;
  justify-content: center;
  margin: 12px 0 18px;
}

.page-diagram {
  width: min(720px, 100%);
  height: auto;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #ffffff;
  padding: 6px 8px;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  font-size: 14px;
}

.site-nav a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

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

.site-nav a.active {
  border-bottom-color: var(--accent);
  font-weight: 700;
}

main {
  max-width: 980px;
  margin: 24px auto 64px;
  padding: 0 20px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px 24px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  font-size: 14px;
  margin: 0 0 16px 0;
}

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

a:hover {
  border-bottom-color: var(--accent);
}

h1, h2, h3, h4, h5, h6 {
  font-family: "IBM Plex Sans", "Helvetica Neue", Arial, sans-serif;
}

.draft {
  border: 1px dashed var(--danger);
  background: var(--danger-bg);
  color: var(--danger);
  padding: 10px 12px;
  border-radius: 10px;
  font-weight: 700;
  margin: 0 0 16px 0;
}

pre {
  background: #111110;
  color: #f5f3ed;
  padding: 14px 16px;
  border-radius: 8px;
  overflow-x: auto;
}

code {
  font-family: "IBM Plex Mono", "Courier New", monospace;
  background: #eee6da;
  padding: 2px 4px;
  border-radius: 4px;
}

pre code {
  background: transparent;
  padding: 0;
}

blockquote {
  border-left: 4px solid var(--accent);
  padding-left: 12px;
  color: var(--muted);
  margin-left: 0;
}

ul, ol {
  padding-left: 22px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
  font-size: 15px;
}

th, td {
  border: 1px solid var(--border);
  padding: 8px 10px;
  vertical-align: top;
}

th {
  background: #efe7da;
  text-align: left;
}

tbody tr:nth-child(even) td {
  background: #fbfaf7;
}

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 18px 0;
}

.table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.grid {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.mini-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #fbfaf7;
  padding: 12px 14px;
}

.mini-card h3 {
  margin: 0 0 8px 0;
  font-size: 16px;
}

.toc {
  border: 1px solid var(--border);
  background: #fbfaf7;
  border-radius: 12px;
  padding: 12px 14px;
  margin: 16px 0;
}

.toc h2, .toc h3 {
  margin-top: 0;
}

.muted {
  color: var(--muted);
}

.site-footer {
  margin-top: 40px;
  font-size: 14px;
  color: var(--muted);
}

.site-footer a {
  color: var(--accent);
}

@media (max-width: 680px) {
  header { padding: 18px 14px 10px; }
  header h1 { font-size: 20px; }
  main { margin: 16px auto 48px; padding: 0 14px; }
  .card { padding: 16px 16px; }
  .nav { gap: 8px 12px; }
  table { font-size: 14px; }
  pre { padding: 12px 12px; }
}