:root {
  --bg: #f4efe4;
  --bg-soft: rgba(255, 251, 242, 0.8);
  --surface: rgba(255, 248, 237, 0.92);
  --surface-strong: #fffaf0;
  --border: rgba(61, 47, 34, 0.14);
  --text: #201813;
  --muted: #665547;
  --accent: #ad3f2d;
  --accent-strong: #8f2d1e;
  --accent-soft: rgba(173, 63, 45, 0.12);
  --olive: #596449;
  --shadow: 0 18px 48px rgba(34, 24, 17, 0.08);
  --radius-xl: 28px;
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 10px;
  --transition: 180ms ease;
  --serif: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Georgia, serif;
  --sans: "Avenir Next", "Segoe UI", "Helvetica Neue", Helvetica, sans-serif;
  --mono: "SFMono-Regular", "Menlo", "Monaco", monospace;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: var(--sans);
  background:
    radial-gradient(circle at top left, rgba(173, 63, 45, 0.16), transparent 26%),
    radial-gradient(circle at bottom right, rgba(89, 100, 73, 0.14), transparent 28%),
    linear-gradient(180deg, #faf4e8 0%, #f2ebde 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.16) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.16) 1px, transparent 1px);
  background-size: 32px 32px;
  mask-image: radial-gradient(circle at center, black, transparent 80%);
  opacity: 0.25;
}

.page-shell {
  position: relative;
  max-width: 1440px;
  margin: 0 auto;
  padding: 14px 14px 12px;
}

.panel {
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.eyebrow,
.panel-label,
.meta-label,
.source-heading {
  margin: 0 0 8px;
  color: var(--accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-size: 0.72rem;
  font-weight: 700;
}

.detail-note,
.empty-copy,
.subtech-list,
.section-copy,
.source-summary,
.sidebar-header p,
.detail-body p,
.detail-list li {
  color: var(--muted);
}

.app-layout {
  display: grid;
  grid-template-columns: minmax(300px, 420px) minmax(0, 1fr);
  gap: 14px;
  min-height: calc(100vh - 28px);
}

.panel {
  overflow: hidden;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.sidebar {
  display: flex;
  flex-direction: column;
  min-height: calc(100vh - 28px);
}

.level-switcher {
  display: flex;
  gap: 8px;
  padding: 12px 12px 0;
  flex-wrap: wrap;
}

.level-tab {
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 10px 16px;
  background: rgba(32, 24, 19, 0.06);
  color: var(--text);
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  transition:
    transform var(--transition),
    background var(--transition),
    border-color var(--transition),
    color var(--transition);
}

.level-tab:hover,
.level-tab:focus-visible {
  transform: translateY(-1px);
  background: rgba(32, 24, 19, 0.1);
  outline: none;
}

.level-tab.is-active {
  background: var(--accent);
  color: white;
  border-color: rgba(255, 255, 255, 0.3);
}

.sidebar-header {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  align-items: flex-start;
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
}

.sidebar-header h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: 1.35rem;
}

.source-link,
.detail-sources a,
.inline-link {
  color: var(--accent-strong);
  text-decoration: none;
}

.source-link:hover,
.detail-sources a:hover,
.inline-link:hover {
  text-decoration: underline;
}

.curriculum-list {
  padding: 2px 8px 8px;
  overflow: auto;
}

.curriculum-item {
  display: grid;
  gap: 0;
  margin-top: 0;
}

.curriculum-item.is-family[data-depth="0"] {
  margin-top: 4px;
}

.curriculum-item.is-family[data-depth="0"]:first-child {
  margin-top: 0;
}

.curriculum-item.is-family:not([data-depth="0"]) {
  margin-top: 1px;
}

.curriculum-button {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  width: 100%;
  text-align: left;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  padding: 6px 10px;
  color: inherit;
  cursor: pointer;
  transition:
    transform var(--transition),
    background var(--transition),
    border-color var(--transition);
}

.curriculum-button:hover,
.curriculum-button:focus-visible {
  background: rgba(32, 24, 19, 0.05);
  border-color: rgba(32, 24, 19, 0.08);
  transform: translateX(2px);
  outline: none;
}

.curriculum-button.is-active {
  background: linear-gradient(135deg, rgba(173, 63, 45, 0.14), rgba(173, 63, 45, 0.04));
  border-color: rgba(173, 63, 45, 0.18);
}

.curriculum-button.is-root {
  padding-top: 7px;
  padding-bottom: 7px;
}

.curriculum-button.is-child {
  padding-top: 3px;
  padding-bottom: 3px;
}

.curriculum-code {
  min-width: 54px;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--accent);
  padding-top: 1px;
}

.curriculum-title {
  line-height: 1.2;
  font-size: 0.94rem;
}

.curriculum-item.is-family > .curriculum-button .curriculum-title {
  font-weight: 700;
}

.curriculum-button.is-child .curriculum-title {
  font-size: 0.92rem;
}

.curriculum-children {
  display: grid;
  gap: 0;
}

.detail {
  display: block;
  padding: 14px 16px 16px;
}

.detail-header {
  margin-bottom: 14px;
}

.detail-title-row {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 10px;
}

.detail-title-wrap {
  min-width: 0;
}

.detail-title-wrap h2 {
  margin: 0 0 6px;
  font-family: var(--serif);
  font-size: clamp(1.8rem, 2.7vw, 2.9rem);
  line-height: 0.95;
}

.detail-title-wrap h2.long-title {
  font-size: clamp(1.45rem, 2vw, 2.15rem);
  line-height: 1.05;
}

.detail-code {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 11px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-family: var(--mono);
  font-size: 0.8rem;
  flex: 0 0 auto;
}

.detail-meta {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.detail-meta-inline {
  flex: 1 1 auto;
}

.meta-chip {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  min-width: 0;
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.52);
  border: 1px solid var(--border);
}

.meta-chip-focus {
  max-width: min(42ch, 100%);
}

.meta-value {
  font-weight: 700;
  line-height: 1.3;
}

.meta-chip .meta-label,
.meta-chip .meta-value {
  margin: 0;
}

.meta-chip .meta-label {
  margin-bottom: 0;
  font-size: 0.65rem;
  letter-spacing: 0.11em;
}

.meta-chip .meta-value {
  font-size: 0.92rem;
}

.detail-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.detail-strip {
  margin-bottom: 12px;
  padding: 14px 16px;
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, rgba(173, 63, 45, 0.14), rgba(173, 63, 45, 0.05)),
    rgba(255, 255, 255, 0.68);
  border: 1px solid rgba(173, 63, 45, 0.22);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.6),
    0 10px 24px rgba(173, 63, 45, 0.08);
}

.detail-strip-copy {
  margin: 0;
  color: #4f3a2f;
  line-height: 1.55;
}

.detail-strip .panel-label {
  color: var(--accent-strong);
}

.detail-card {
  padding: 14px;
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.52);
  border: 1px solid var(--border);
}

.detail-card h3 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-size: 1.2rem;
}

.detail-body p {
  margin-top: 0;
  margin-bottom: 0;
  line-height: 1.55;
}

.detail-title-wrap > .detail-body {
  margin-top: 12px;
}

.detail-list,
.detail-sources {
  margin: 0;
  padding-left: 18px;
}

.detail-list li,
.detail-sources li {
  margin-bottom: 10px;
  line-height: 1.55;
}

.detail-footer {
  margin-top: 12px;
  padding: 12px 14px;
  border-radius: var(--radius-lg);
  background: rgba(89, 100, 73, 0.08);
  border: 1px solid rgba(89, 100, 73, 0.16);
}

.empty-state {
  height: 100%;
  min-height: 360px;
  display: grid;
  place-items: center;
  text-align: center;
}

.empty-state h2 {
  margin: 0 0 10px;
  font-family: var(--serif);
  font-size: 2rem;
}

.subtech-list {
  margin: 10px 0 0;
  padding-left: 18px;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.detail > * {
  animation: fadeUp 240ms ease;
}

@media (max-width: 1080px) {
  .app-layout,
  .detail-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .page-shell {
    padding: 10px;
  }

  .detail,
  .sidebar-header {
    padding: 12px;
  }

  .curriculum-code {
    min-width: 48px;
  }

  .detail-title-row {
    flex-direction: column;
    align-items: stretch;
  }

  .detail-meta {
    justify-content: flex-start;
  }
}