:root {
  --bg: #ffffff;
  --bg-subtle: #f7f7f7;
  --surface: #ffffff;
  --border: #e2e2e2;
  --border-strong: #cccccc;
  --text: #1a1a1a;
  --muted: #555555;
  --accent: #e65c00;
  --accent-dim: #d35400;
  --accent-soft: rgba(230, 92, 0, 0.1);
  --code-bg: #f6f7f7;
  --link: #c2410c;
  --warn: #996800;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  font-size: 16px;
}

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

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.06);
  padding: 14px 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 20px;
  position: sticky;
  top: 0;
  z-index: 10;
}

.site-header .brand {
  font-weight: 650;
  letter-spacing: -0.02em;
  color: var(--text);
  text-decoration: none;
}

.site-header .brand:hover {
  color: var(--accent-dim);
  text-decoration: none;
}

.site-header nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  font-size: 14px;
}

.site-header nav a {
  color: var(--muted);
  text-decoration: none;
}

.site-header nav a:hover {
  color: var(--text);
  text-decoration: none;
}

.site-header nav a[aria-current="page"] {
  color: var(--accent-dim);
  font-weight: 600;
}

.layout {
  max-width: 920px;
  margin: 0 auto;
  padding: 28px 20px 64px;
}

h1 {
  font-size: 1.75rem;
  font-weight: 650;
  letter-spacing: -0.03em;
  margin: 0 0 12px;
}

h2 {
  font-size: 1.2rem;
  margin: 32px 0 12px;
  color: var(--accent-dim);
  font-weight: 650;
}

h3 { font-size: 1rem; margin: 20px 0 8px; }

.lead { color: var(--muted); font-size: 1.05rem; margin: 0 0 24px; }

.breadcrumb {
  font-size: 13px;
  color: var(--muted);
  margin: 0 0 16px;
}

.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--link); }

.eyebrow {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  margin: 0 0 6px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.section-title {
  font-size: 1rem;
  font-weight: 650;
  margin: 24px 0 10px;
  color: var(--text);
}

.section-intro {
  color: var(--muted);
  font-size: 15px;
  margin: 0 0 14px;
}

.doc-rule {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px;
  margin: 20px 0;
}

.card {
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 18px;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.15s, transform 0.15s;
  display: block;
}

.card:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
  text-decoration: none;
}

.card h3 {
  margin: 0 0 6px;
  font-size: 1rem;
  color: var(--text);
}

.card p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
  line-height: 1.5;
}

.tag {
  display: inline-block;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent-dim);
  margin-bottom: 8px;
  font-weight: 600;
}

.callout {
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  padding: 12px 16px;
  margin: 16px 0;
  border-radius: 0 8px 8px 0;
  font-size: 14px;
}

.callout strong { color: var(--accent-dim); }

pre, code {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
  overflow-x: auto;
  margin: 12px 0;
}

:not(pre) > code {
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--border);
  color: #1d2327;
}

ul, ol { padding-left: 1.25rem; }
li { margin: 6px 0; }

.wax-playground { margin: 14px 0 22px; }

.wax-playground-hint {
  font-size: 14px;
  color: var(--muted);
  margin: 0 0 10px;
}

.wax-playground .demo-panel { margin: 0; }

.demo-panel {
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px;
  margin: 20px 0;
}

.demo-panel button {
  background: var(--accent);
  color: #ffffff;
  border: none;
  border-radius: 6px;
  padding: 8px 14px;
  font-weight: 600;
  cursor: pointer;
  margin: 4px 8px 4px 0;
  font-size: 14px;
}

.demo-panel button:hover { background: var(--accent-dim); }

.demo-panel button.secondary {
  background: #fff;
  color: var(--text);
  border: 1px solid var(--border-strong);
}

.demo-panel label {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin: 12px 0 4px;
  font-weight: 600;
}

.demo-panel input[type="range"] {
  width: 100%;
  max-width: 360px;
  accent-color: var(--accent-dim);
}

.keys {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 12px;
}

.keys button {
  min-width: 40px;
  padding: 14px 8px 8px;
  font-size: 11px;
  font-weight: 600;
  background: #fff;
  color: var(--text);
  border: 1px solid var(--border-strong);
  border-radius: 6px;
  cursor: pointer;
}

.keys button:active,
.keys button.active {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent-dim);
}

.status {
  font-size: 13px;
  color: var(--muted);
  margin-top: 12px;
}

.status.ok { color: #007017; }

.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  font-size: 14px;
}

canvas.scope-canvas {
  width: 100%;
  max-width: 480px;
  height: 80px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 6px;
  display: block;
  margin-top: 12px;
}

.page-source-section {
  margin-top: 48px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}

.page-source-summary {
  cursor: pointer;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--accent-dim);
  list-style: none;
  user-select: none;
}

.page-source-summary:hover { color: var(--accent); }

.page-source-summary::-webkit-details-marker { display: none; }

.page-source-summary::before {
  content: "▸ ";
  color: var(--muted);
  display: inline-block;
  transition: transform 0.15s ease;
}

.page-source-section[open] .page-source-summary::before {
  transform: rotate(90deg);
}

.page-source-section:not([open]) .source-hint,
.page-source-section:not([open]) .page-source-pre {
  display: none;
}

.source-hint {
  font-size: 14px;
  color: var(--muted);
  margin: 0 0 12px;
}

.page-source-pre {
  max-height: min(70vh, 720px);
  overflow: auto;
  margin: 0;
  tab-size: 2;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.page-source-code {
  display: block;
  white-space: pre;
  font-size: 12px;
  line-height: 1.45;
  padding: 14px 16px;
  color: #1d2327;
}

pre {
  color: #1d2327;
}

.footer-links {
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  font-size: 14px;
  color: var(--muted);
}

.link-list {
  list-style: none;
  padding-left: 0;
  margin: 10px 0 16px;
}

.link-list li { margin: 8px 0; }

.quick-ref-block {
  margin: 20px 0;
}