:root {
  color-scheme: light;
  --bg: #f4f1ea;
  --bg-raised: #fbf9f4;
  --bg-inset: #ebe6da;
  --rule: #d6cfc0;
  --ink: #1c1f24;
  --ink-muted: #545a63;
  --ink-faint: #8a8f97;
  --accent: #1f5f8b;
  --accent-dark: #164666;
  --accent-soft: #e1ecf4;
  --amber: #a5640f;
  --amber-soft: #f6e9d2;
  --green: #2e6b45;
  --green-soft: #dfeee4;
  --rose: #9b2f3f;
  --rose-soft: #f4e1e4;
  --violet: #5d3f8c;
  --violet-soft: #ebe3f5;
  --teal: #1f6f6a;
  --teal-soft: #dcefed;
  --highlight: #fff3b0;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --measure: 44rem;
  --wide: 72rem;
  --reader-max: 96rem;
  --radius: 6px;
  --shadow: 0 1px 0 rgba(28, 31, 36, 0.05), 0 10px 28px rgba(28, 31, 36, 0.06);
}

:root[data-theme="light"] {
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #14171c;
    --bg-raised: #1c2027;
    --bg-inset: #0f1216;
    --rule: #333a44;
    --ink: #e7e4dc;
    --ink-muted: #aeb3bb;
    --ink-faint: #7f858e;
    --accent: #7fb3dc;
    --accent-dark: #a9cde8;
    --accent-soft: #1d2d3b;
    --amber: #e0a955;
    --amber-soft: #33291a;
    --green: #86c39d;
    --green-soft: #1a2c22;
    --rose: #e08a97;
    --rose-soft: #35202a;
    --violet: #b59ddb;
    --violet-soft: #2a2238;
    --teal: #7fc7c1;
    --teal-soft: #1a2f2e;
    --highlight: #4a4520;
    --shadow: 0 1px 0 rgba(0, 0, 0, 0.4), 0 10px 28px rgba(0, 0, 0, 0.3);
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #14171c;
  --bg-raised: #1c2027;
  --bg-inset: #0f1216;
  --rule: #333a44;
  --ink: #e7e4dc;
  --ink-muted: #aeb3bb;
  --ink-faint: #7f858e;
  --accent: #7fb3dc;
  --accent-dark: #a9cde8;
  --accent-soft: #1d2d3b;
  --amber: #e0a955;
  --amber-soft: #33291a;
  --green: #86c39d;
  --green-soft: #1a2c22;
  --rose: #e08a97;
  --rose-soft: #35202a;
  --violet: #b59ddb;
  --violet-soft: #2a2238;
  --teal: #7fc7c1;
  --teal-soft: #1a2f2e;
  --highlight: #4a4520;
  --shadow: 0 1px 0 rgba(0, 0, 0, 0.4), 0 10px 28px rgba(0, 0, 0, 0.3);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5.5rem;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1.02rem;
  line-height: 1.55;
  text-rendering: optimizeLegibility;
  transition: background-color 0.2s ease, color 0.2s ease;
}

img {
  max-width: 100%;
}

a {
  color: var(--accent);
  text-underline-offset: 0.18em;
}

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

code,
kbd {
  font-family: var(--mono);
  font-size: 0.88em;
}

kbd {
  border: 1px solid var(--rule);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 0 0.35em;
  background: var(--bg-raised);
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: 0.75rem;
  top: -3rem;
  z-index: 20;
  background: var(--ink);
  color: var(--bg);
  padding: 0.4rem 0.7rem;
  text-decoration: none;
}

.skip-link:focus {
  top: 0.75rem;
}

/* ---------------- header ---------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
}

.header-inner {
  max-width: var(--reader-max);
  margin: 0 auto;
  padding: 0.7rem 1.25rem 0.6rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1rem;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  text-decoration: none;
  color: inherit;
  min-width: 0;
}

.brand:hover {
  color: inherit;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border: 1px solid var(--rule);
  border-radius: 4px;
  color: var(--accent);
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.25rem;
  flex-shrink: 0;
}

.brand-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.brand-name {
  font-family: var(--serif);
  font-size: 1rem;
  font-weight: 600;
  white-space: nowrap;
}

.brand-sub {
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.site-nav {
  display: flex;
  gap: 0.25rem;
  flex-wrap: wrap;
}

.site-nav a {
  text-decoration: none;
  color: var(--ink-muted);
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  font-size: 0.95rem;
}

.site-nav a:hover {
  color: var(--ink);
  background: var(--bg-inset);
}

.site-nav a[aria-current="page"] {
  color: var(--bg-raised);
  background: var(--ink);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.icon-button,
.btn,
.toggle-btn,
.tool-btn {
  font: inherit;
  cursor: pointer;
}

.icon-button {
  width: 2.1rem;
  height: 2.1rem;
  border-radius: 999px;
  border: 1px solid var(--rule);
  background: var(--bg-raised);
  color: var(--ink);
  display: grid;
  place-items: center;
  padding: 0;
}

.theme-icon-sun {
  display: none;
}

:root[data-theme="dark"] .theme-icon-sun {
  display: inline;
}

:root[data-theme="dark"] .theme-icon-moon {
  display: none;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-icon-sun {
    display: inline;
  }
  :root:not([data-theme="light"]) .theme-icon-moon {
    display: none;
  }
}

.export-menu {
  position: relative;
}

.export-menu summary {
  list-style: none;
  cursor: pointer;
  border: 1px solid var(--rule);
  border-radius: 999px;
  padding: 0.35rem 0.8rem;
  font-size: 0.9rem;
  background: var(--bg-raised);
}

.export-menu summary::-webkit-details-marker {
  display: none;
}

.export-menu-panel {
  position: absolute;
  right: 0;
  top: calc(100% + 0.35rem);
  background: var(--bg-raised);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  min-width: 9rem;
  z-index: 15;
}

.export-menu-panel button {
  font: inherit;
  text-align: left;
  background: none;
  border: 0;
  padding: 0.55rem 0.9rem;
  cursor: pointer;
  color: var(--ink);
}

.export-menu-panel button:hover {
  background: var(--bg-inset);
}

.progress-rail {
  height: 3px;
  background: var(--bg-inset);
}

.progress-rail-fill {
  display: block;
  height: 100%;
  width: 0;
  background: var(--accent);
  transition: width 0.3s ease;
}

/* ---------------- banners ---------------- */

.banner {
  padding: 0.6rem 1.25rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.5rem 1rem;
  font-size: 0.92rem;
  border-bottom: 1px solid var(--rule);
}

.banner[hidden] {
  display: none;
}

.banner p {
  margin: 0;
}

.banner-warn {
  background: var(--rose-soft);
}

.banner-info {
  background: var(--amber-soft);
}

.banner-actions {
  display: flex;
  gap: 0.4rem;
}

/* ---------------- layout ---------------- */

main#app {
  flex: 1;
  width: 100%;
  max-width: var(--wide);
  margin: 0 auto;
  padding: 1.5rem 1.25rem 4rem;
}

main#app:has(.reader) {
  max-width: var(--reader-max);
}

.site-footer {
  border-top: 1px solid var(--rule);
  color: var(--ink-faint);
  font-size: 0.85rem;
  text-align: center;
  padding: 1.25rem;
}

.site-footer p {
  margin: 0 auto;
  max-width: var(--measure);
}

.loading-line {
  color: var(--ink-faint);
  font-style: italic;
}

.eyebrow {
  margin: 0 0 0.35rem;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.eyebrow a {
  color: inherit;
}

h1,
h2,
h3 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.2;
  margin: 0 0 0.5rem;
}

h1 {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
}

.lede {
  font-size: 1.12rem;
  color: var(--ink-muted);
  max-width: var(--measure);
  margin: 0 0 1rem;
}

.muted {
  color: var(--ink-faint);
  font-size: 0.9em;
}

.section {
  margin-top: 2.5rem;
}

.section-title {
  font-size: 1.35rem;
  margin-bottom: 1rem;
}

.prose {
  max-width: var(--measure);
}

.prose p,
.prose ul {
  margin: 0 0 0.9rem;
}

.prose h2 {
  font-size: 1.3rem;
  margin-top: 1.75rem;
}

.hero {
  padding: 1rem 0 0.5rem;
}

.stat-row {
  display: flex;
  gap: 1.5rem 2.5rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.stat {
  display: flex;
  flex-direction: column;
}

.stat-num {
  font-family: var(--serif);
  font-size: 1.9rem;
  font-weight: 600;
  line-height: 1;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--ink-faint);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.continue-box {
  margin-top: 2rem;
  padding: 1.25rem 1.5rem;
  border: 1px solid var(--rule);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  background: var(--bg-raised);
  box-shadow: var(--shadow);
}

.continue-box h2 {
  font-size: 1.4rem;
}

.continue-box h2 a {
  color: inherit;
  text-decoration: none;
}

.continue-box p {
  color: var(--ink-muted);
  margin: 0 0 0.75rem;
}

.btn {
  display: inline-block;
  padding: 0.55rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  font-weight: 500;
}

.btn:hover {
  background: var(--accent-dark);
  border-color: var(--accent-dark);
  color: #fff;
}

.btn-small {
  padding: 0.3rem 0.7rem;
  font-size: 0.85rem;
}

.btn-ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--rule);
}

.btn-ghost:hover {
  background: var(--bg-inset);
  color: var(--ink);
  border-color: var(--rule);
}

/* ---------------- cards ---------------- */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(17rem, 1fr));
  gap: 1rem;
}

.card {
  background: var(--bg-raised);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  box-shadow: var(--shadow);
}

.card-stub {
  opacity: 0.85;
}

.card-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
}

.card-step {
  display: grid;
  place-items: center;
  width: 1.6rem;
  height: 1.6rem;
  border-radius: 999px;
  background: var(--ink);
  color: var(--bg-raised);
  font-size: 0.8rem;
  font-weight: 600;
}

.card-badges {
  display: flex;
  gap: 0.3rem;
  flex-wrap: wrap;
  margin-left: auto;
}

.card-title {
  font-size: 1.15rem;
  margin: 0;
}

.card-title a {
  color: inherit;
  text-decoration: none;
}

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

.card-meta,
.card-sub {
  margin: 0;
  color: var(--ink-muted);
  font-size: 0.9rem;
}

.card-overview {
  margin: 0;
  font-size: 0.93rem;
  color: var(--ink-muted);
  flex: 1;
}

.card-foot {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-top: 0.4rem;
}

.card-pct {
  font-size: 0.8rem;
  color: var(--ink-faint);
  min-width: 2.5rem;
  text-align: right;
}

.mini-bar {
  flex: 1 1 auto;
  height: 5px;
  min-height: 5px;
  max-height: 5px;
  align-self: center;
  border-radius: 999px;
  background: var(--bg-inset);
  overflow: hidden;
}

.mini-bar span {
  display: block;
  height: 100%;
  background: var(--green);
  transition: width 0.3s ease;
}

.path-preview {
  margin: 0.25rem 0 0;
  padding-left: 1.2rem;
  font-size: 0.88rem;
  color: var(--ink-muted);
  columns: 2;
  column-gap: 1rem;
}

.badge {
  display: inline-block;
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.12rem 0.5rem;
  border-radius: 999px;
  border: 1px solid var(--rule);
  color: var(--ink-muted);
  background: var(--bg);
  white-space: nowrap;
}

.badge-complete {
  color: var(--green);
  border-color: color-mix(in srgb, var(--green) 40%, var(--rule));
  background: var(--green-soft);
}

.badge-partial {
  color: var(--amber);
  border-color: color-mix(in srgb, var(--amber) 40%, var(--rule));
  background: var(--amber-soft);
}

.badge-stub {
  color: var(--ink-faint);
}

.badge-hosted {
  color: var(--accent);
  background: var(--accent-soft);
  border-color: color-mix(in srgb, var(--accent) 40%, var(--rule));
}

.badge-working-translation {
  color: var(--violet);
  background: var(--violet-soft);
  border-color: color-mix(in srgb, var(--violet) 40%, var(--rule));
}

.badge-paraphrase {
  color: var(--rose);
  background: var(--rose-soft);
  border-color: color-mix(in srgb, var(--rose) 40%, var(--rule));
}

.badge-tag {
  text-transform: none;
  letter-spacing: 0;
}

/* ---------------- about table ---------------- */

.table-wrap {
  overflow-x: auto;
  max-width: none;
}

.license-table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.9rem;
}

.license-table th,
.license-table td {
  text-align: left;
  vertical-align: top;
  padding: 0.5rem 0.6rem;
  border-bottom: 1px solid var(--rule);
}

.license-table th {
  font-weight: 600;
  color: var(--ink-muted);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* ---------------- paper header ---------------- */

.paper-head {
  max-width: var(--wide);
  margin: 0 auto 1.5rem;
}

.paper-title {
  margin-bottom: 0.25rem;
}

.paper-original-title {
  font-family: var(--serif);
  font-style: italic;
  color: var(--ink-muted);
  margin: 0 0 0.3rem;
  font-size: 1.1rem;
}

.paper-citation {
  margin: 0 0 0.75rem;
  color: var(--ink-muted);
  font-size: 0.95rem;
}

.paper-badges {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.paper-overview {
  font-size: 1.05rem;
}

.paper-prereqs {
  font-size: 0.95rem;
  color: var(--ink-muted);
}

.paper-missing {
  font-size: 0.95rem;
  padding: 0.6rem 0.9rem;
  background: var(--amber-soft);
  border-radius: var(--radius);
}

.paper-nav {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  font-size: 0.92rem;
  color: var(--ink-muted);
  padding: 0.6rem 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  margin: 1rem 0;
}

.paper-nav-links {
  display: flex;
  gap: 1rem;
}

.license-box {
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--bg-raised);
  padding: 0.6rem 1rem;
  font-size: 0.92rem;
}

.license-box summary {
  cursor: pointer;
  font-weight: 600;
}

.lic-list {
  margin: 0.75rem 0 0.5rem;
  display: grid;
  gap: 0.25rem;
}

.lic-row {
  display: grid;
  grid-template-columns: 8rem 1fr;
  gap: 0.5rem;
}

.lic-row dt {
  color: var(--ink-faint);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 0.75rem;
  padding-top: 0.15rem;
}

.lic-row dd {
  margin: 0;
  text-transform: none;
}

.lic-row dd::first-letter {
  text-transform: uppercase;
}

.lic-notes {
  margin: 0.5rem 0;
}

.lic-attr {
  margin: 0.25rem 0 0;
  color: var(--ink-faint);
  font-size: 0.88rem;
}

.reader-note {
  max-width: var(--wide);
  margin: 0 auto 1.25rem;
  padding: 0.8rem 1.1rem;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
  background: var(--bg-raised);
  font-size: 0.95rem;
}

.reader-note p:last-child {
  margin-bottom: 0;
}

.reader-note p:first-child {
  margin-top: 0;
}

.reader-note-paraphrase {
  border-color: color-mix(in srgb, var(--rose) 45%, var(--rule));
  background: var(--rose-soft);
}

.reader-note-working-translation {
  border-color: color-mix(in srgb, var(--violet) 45%, var(--rule));
  background: var(--violet-soft);
}

.stub-body {
  max-width: var(--measure);
  margin: 2rem auto;
  padding: 1.25rem 1.5rem;
  border: 1px dashed var(--rule);
  border-radius: var(--radius);
}

/* ---------------- reader toolbar ---------------- */

.reader-toolbar {
  position: sticky;
  top: 3.6rem;
  z-index: 5;
  max-width: var(--reader-max);
  margin: 0 auto 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem 1.5rem;
  flex-wrap: wrap;
  padding: 0.5rem 0.9rem;
  background: color-mix(in srgb, var(--bg-raised) 94%, transparent);
  backdrop-filter: blur(8px);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  font-size: 0.9rem;
}

.toolbar-progress {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  min-width: 14rem;
  flex: 1;
}

.toolbar-count {
  white-space: nowrap;
  color: var(--ink-muted);
}

.toolbar-toggles {
  display: flex;
  gap: 0.4rem;
}

.toggle-btn {
  border: 1px solid var(--rule);
  background: var(--bg);
  color: var(--ink);
  border-radius: 999px;
  padding: 0.3rem 0.8rem;
  font-size: 0.88rem;
}

.toggle-btn.is-on {
  background: var(--ink);
  color: var(--bg-raised);
  border-color: var(--ink);
}

.toolbar-keys {
  margin: 0;
  color: var(--ink-faint);
  font-size: 0.8rem;
}

/* ---------------- two-column reader ---------------- */

.reader {
  max-width: var(--reader-max);
  margin: 0 auto;
}

.column-heads {
  display: grid;
  grid-template-columns: 3rem minmax(0, 1fr) minmax(0, 1fr) 2.5rem;
  gap: 0 1.5rem;
  padding: 0 0 0.35rem;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 0.5rem;
}

.column-head {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-faint);
}

.section-heading {
  font-size: 1.3rem;
  margin: 2rem 0 0.75rem;
  padding-left: 3rem;
  padding-left: calc(3rem + 1.5rem);
}

.section-intro {
  padding-left: calc(3rem + 1.5rem);
  color: var(--ink-muted);
  max-width: var(--measure);
  font-size: 0.95rem;
}

/* One block = one grid row: gutter | original | commentary | tools. */
.block {
  display: grid;
  grid-template-columns: 3rem minmax(0, 1fr) minmax(0, 1fr) 2.5rem;
  grid-template-areas:
    "gutter left right tools"
    "gutter note note tools";
  gap: 0.4rem 1.5rem;
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--rule);
  position: relative;
  scroll-margin-top: 7.5rem;
}

.block:focus {
  outline: none;
}

.block:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
  border-radius: var(--radius);
}

.block.is-highlighted .source-text {
  background: linear-gradient(transparent 55%, var(--highlight) 55%, var(--highlight) 92%, transparent 92%);
  background-size: 100% 1.55em;
}

.block.is-understood {
  background: linear-gradient(90deg, var(--green-soft), transparent 8%);
}

.block.is-bookmark {
  box-shadow: inset 4px 0 0 var(--accent);
}

.block-gutter {
  grid-area: gutter;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.2rem;
  padding-right: 0.25rem;
  padding-top: 0.2rem;
}

.block-label {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-faint);
  white-space: nowrap;
}

.block-bookmark {
  color: var(--accent);
  font-family: var(--serif);
  font-size: 1rem;
}

.block-left {
  grid-area: left;
  min-width: 0;
}

.source-text {
  font-family: var(--serif);
  font-size: 1.08rem;
  line-height: 1.6;
}

.source-text p {
  margin: 0 0 0.75rem;
}

.source-text p:last-child {
  margin-bottom: 0;
}

.block-figure {
  margin: 0.75rem 0 0;
}

.block-figure img {
  display: block;
  background: #fff;
  border-radius: var(--radius);
  padding: 0.5rem;
  border: 1px solid var(--rule);
}

.block-figure figcaption {
  font-size: 0.85rem;
  color: var(--ink-muted);
  margin-top: 0.35rem;
}

.block-right {
  grid-area: right;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.block-tools {
  grid-area: tools;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
  padding-top: 0.15rem;
}

.block-note {
  grid-area: note;
}

.block-note[hidden] {
  display: none;
}

.note-input {
  width: 100%;
  font: inherit;
  font-size: 0.93rem;
  padding: 0.5rem 0.7rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--bg-raised);
  color: var(--ink);
  resize: vertical;
}

.understood-toggle {
  display: flex;
  flex-direction: column;
  align-items: center;
  font-size: 0.65rem;
  color: var(--ink-faint);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  cursor: pointer;
  gap: 0.1rem;
}

.understood-toggle input {
  width: 1.1rem;
  height: 1.1rem;
  accent-color: var(--green);
  cursor: pointer;
  margin: 0;
}

.tool-btn {
  width: 1.8rem;
  height: 1.8rem;
  border-radius: 999px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--ink-faint);
  font-family: var(--serif);
  font-size: 1rem;
  line-height: 1;
  padding: 0;
}

.tool-btn:hover {
  border-color: var(--rule);
  color: var(--ink);
  background: var(--bg-raised);
}

.tool-btn.is-on {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-soft);
}

.ann-empty {
  margin: 0;
  color: var(--ink-faint);
  font-style: italic;
  font-size: 0.9rem;
}

/* ---------------- annotations ---------------- */

.ann {
  border-left: 3px solid var(--rule);
  padding: 0.35rem 0 0.35rem 0.85rem;
  font-size: 0.95rem;
  line-height: 1.55;
}

.ann-head {
  display: flex;
  gap: 0.6rem;
  align-items: baseline;
  flex-wrap: wrap;
  margin-bottom: 0.25rem;
}

.ann-kind {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 600;
}

.ann-title {
  font-weight: 600;
  font-size: 0.95rem;
}

.ann-body p {
  margin: 0 0 0.6rem;
}

.ann-body p:last-child,
.ann-body ul:last-child {
  margin-bottom: 0;
}

.ann-body ul {
  margin: 0 0 0.6rem;
  padding-left: 1.2rem;
}

.ann-notation {
  border-color: var(--accent);
}
.ann-notation .ann-kind {
  color: var(--accent);
}

.ann-derivation {
  border-color: var(--teal);
}
.ann-derivation .ann-kind {
  color: var(--teal);
}

.ann-why {
  border-color: var(--amber);
}
.ann-why .ann-kind {
  color: var(--amber);
}

.ann-context {
  border-color: var(--ink-faint);
}
.ann-context .ann-kind {
  color: var(--ink-muted);
}

.ann-forward {
  border-color: var(--violet);
}
.ann-forward .ann-kind {
  color: var(--violet);
}

.ann-check {
  border-color: var(--green);
  background: color-mix(in srgb, var(--green-soft) 60%, transparent);
  border-radius: 0 var(--radius) var(--radius) 0;
}
.ann-check .ann-kind {
  color: var(--green);
}

.math-block {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.25rem 0;
  margin: 0.4rem 0;
}

.katex-display {
  margin: 0.5rem 0;
  overflow-x: auto;
  overflow-y: hidden;
}

.katex {
  font-size: 1.05em;
}

.source-text .katex {
  font-size: 1em;
}

/* ---------------- column hiding ---------------- */

.reader.hide-right .block {
  grid-template-columns: 3rem minmax(0, 1fr) 2.5rem;
  grid-template-areas:
    "gutter left tools"
    "gutter note tools";
}

.reader.hide-right .block-right,
.reader.hide-right .column-head-right {
  display: none;
}

.reader.hide-right .column-heads {
  grid-template-columns: 3rem minmax(0, 1fr) 2.5rem;
}

.reader.hide-right .block-left {
  max-width: var(--measure);
}

.reader.hide-left .block {
  grid-template-columns: 3rem minmax(0, 1fr) 2.5rem;
  grid-template-areas:
    "gutter right tools"
    "gutter note tools";
}

.reader.hide-left .block-left,
.reader.hide-left .column-head:not(.column-head-right) {
  display: none;
}

.reader.hide-left .column-heads {
  grid-template-columns: 3rem minmax(0, 1fr) 2.5rem;
}

.reader.hide-left .block-right {
  max-width: var(--measure);
}

.paper-foot {
  max-width: var(--wide);
  margin: 2rem auto 0;
}

/* ---------------- narrow screens: stack left then right ---------------- */

@media (max-width: 56rem) {
  .column-heads {
    display: none;
  }

  .section-heading,
  .section-intro {
    padding-left: 0;
  }

  .block,
  .reader.hide-right .block,
  .reader.hide-left .block {
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas:
      "gutter tools"
      "left left"
      "right right"
      "note note";
    gap: 0.5rem 0.75rem;
  }

  .block-gutter {
    flex-direction: row;
    align-items: center;
    gap: 0.5rem;
    padding: 0;
  }

  .block-tools {
    flex-direction: row;
    padding: 0;
  }

  .block-right {
    padding-left: 0.75rem;
    border-left: 1px dashed var(--rule);
  }

  .reader.hide-right .block-left,
  .reader.hide-left .block-right {
    max-width: none;
  }

  .toolbar-keys {
    display: none;
  }

  .reader-toolbar {
    top: auto;
    position: static;
  }

  .lic-row {
    grid-template-columns: 1fr;
    gap: 0.1rem;
  }
}

@media (max-width: 40rem) {
  .header-inner {
    padding: 0.6rem 0.9rem;
  }

  main#app {
    padding: 1rem 0.9rem 3rem;
  }

  .path-preview {
    columns: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  * {
    transition: none !important;
  }
}



/* ---------------- catalog ---------------- */

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.section-head .section-title {
  margin-bottom: 0;
}

.section-link {
  font-size: 0.92rem;
}

.catalog-filters {
  margin: 0 0 1.25rem;
  padding: 1rem 1.1rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--bg-raised);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.catalog-search-row {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  align-items: center;
}

.catalog-search-row input[type="search"] {
  flex: 1;
  min-width: 12rem;
  font: inherit;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--ink);
}

.catalog-filter-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem 0.85rem;
}

.catalog-filter-row label {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.catalog-filter-row select {
  font: inherit;
  font-size: 0.9rem;
  text-transform: none;
  letter-spacing: 0;
  color: var(--ink);
  padding: 0.35rem 0.5rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--bg);
  min-width: 7.5rem;
}

.catalog-count {
  margin: 0;
  color: var(--ink-muted);
  font-size: 0.92rem;
}

.catalog-list {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.catalog-row:not(:has(.catalog-side)) {
  grid-template-columns: minmax(0, 1fr);
}

.catalog-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 6.5rem;
  gap: 0.75rem 1.25rem;
  padding: 0.9rem 1rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--bg-raised);
  border-left-width: 4px;
  border-left-color: var(--rule);
}

.catalog-complete {
  border-left-color: var(--green);
}

.catalog-partial {
  border-left-color: var(--amber);
}

.catalog-stub {
  border-left-color: var(--ink-faint);
  opacity: 0.92;
  background: color-mix(in srgb, var(--bg-inset) 35%, var(--bg-raised));
}

.catalog-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-bottom: 0.35rem;
}

.catalog-title {
  font-size: 1.12rem;
  margin: 0 0 0.2rem;
}

.catalog-title a {
  color: inherit;
  text-decoration: none;
}

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

.catalog-original {
  margin: 0 0 0.25rem;
  font-family: var(--serif);
  font-style: italic;
  color: var(--ink-muted);
  font-size: 0.95rem;
}

.catalog-meta,
.catalog-overview {
  margin: 0 0 0.35rem;
  color: var(--ink-muted);
  font-size: 0.92rem;
}

.catalog-paths {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-top: 0.25rem;
}

.path-chip {
  display: inline-block;
  font-size: 0.72rem;
  padding: 0.1rem 0.45rem;
  border-radius: 999px;
  background: var(--chip-bg, var(--bg-inset));
  color: var(--chip-fg, var(--ink-muted));
}

.catalog-side {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  align-self: center;
  flex-shrink: 0;
}

.progress-ring {
  --p: 0;
  --size: 2.5rem;
  box-sizing: border-box;
  width: var(--size);
  height: var(--size);
  min-width: var(--size);
  min-height: var(--size);
  max-width: var(--size);
  max-height: var(--size);
  aspect-ratio: 1 / 1;
  flex: 0 0 var(--size);
  border-radius: 50%;
  background:
    radial-gradient(closest-side, var(--bg-raised) 72%, transparent 73% 100%),
    conic-gradient(var(--green) calc(var(--p) * 1%), var(--bg-inset) 0);
  display: grid;
  place-items: center;
  color: var(--ink-muted);
  font-size: 0.62rem;
  font-weight: 600;
  line-height: 1;
}

.progress-ring-value {
  position: relative;
  z-index: 1;
}

.empty-state {
  color: var(--ink-faint);
  font-style: italic;
  padding: 1.5rem 0;
}

.compendium-counts {
  margin-top: 1.25rem;
}

.start-here-box {
  border-left-color: var(--amber);
}

/* ---------------- timeline ---------------- */

.tl-legend {
  list-style: none;
  margin: 0.75rem 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  font-size: 0.88rem;
  color: var(--ink-muted);
}

.tl-legend li {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.tl-swatch {
  display: inline-block;
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 999px;
  flex-shrink: 0;
}

.timeline-axis-wrap {
  margin: 1.25rem 0 1.75rem;
  padding: 0 0.25rem;
}

.tl-axis-rail {
  position: relative;
  height: 3.2rem;
}

.tl-axis-track {
  position: absolute;
  left: 0;
  right: 0;
  top: 1.6rem;
  height: 3px;
  background: var(--rule);
  border-radius: 999px;
}

.tl-axis-label {
  position: absolute;
  top: 0;
  transform: translateX(-50%);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--ink-faint);
}

.tl-axis-label:first-child {
  transform: translateX(0);
}

.tl-axis-label:last-of-type {
  transform: translateX(-100%);
}

.tl-axis-dot {
  position: absolute;
  top: 50%;
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 999px;
  transform: translate(-50%, -50%);
  border: 2px solid var(--bg);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--ink) 15%, transparent);
}

.tl-axis-dot:hover {
  transform: translate(-50%, -50%) scale(1.25);
  z-index: 2;
}

.timeline-bands {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.tl-band {
  display: grid;
  grid-template-columns: 5.5rem minmax(0, 1fr);
  gap: 0.75rem 1rem;
  align-items: start;
}

.tl-band-label {
  margin: 0.35rem 0 0;
  font-size: 0.95rem;
  color: var(--ink-muted);
}

.tl-band-items {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tl-chip {
  display: grid;
  grid-template-columns: auto auto;
  grid-template-areas:
    "dots year"
    "title title"
    "authors authors";
  gap: 0.1rem 0.45rem;
  max-width: 16rem;
  padding: 0.45rem 0.65rem;
  border: 1px solid var(--rule);
  border-left-width: 3px;
  border-radius: var(--radius);
  background: var(--bg-raised);
  text-decoration: none;
  color: inherit;
}

.tl-chip.catalog-complete { border-left-color: var(--green); }
.tl-chip.catalog-partial { border-left-color: var(--amber); }
.tl-chip.catalog-stub { border-left-color: var(--ink-faint); }

.tl-chip:hover {
  border-color: var(--accent);
}

.tl-chip-dots { grid-area: dots; display: flex; gap: 0.12rem; align-items: center; }
.tl-chip-year { grid-area: year; font-family: var(--mono); font-size: 0.75rem; color: var(--ink-muted); }
.tl-chip-title { grid-area: title; font-family: var(--serif); font-size: 0.92rem; font-weight: 600; line-height: 1.25; }
.tl-chip-authors { grid-area: authors; font-size: 0.78rem; color: var(--ink-faint); }

.tl-dot {
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 999px;
  display: inline-block;
}

.tl-empty {
  margin: 0.4rem 0;
  font-size: 0.9rem;
}

.paper-nav {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.paper-nav-row {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.4rem 1rem;
  align-items: center;
}

.paper-nav-path {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

@media (max-width: 48rem) {
  .timeline-axis-wrap {
    display: none;
  }

  .tl-band {
    grid-template-columns: 1fr;
    gap: 0.35rem;
  }

  .catalog-row:not(:has(.catalog-side)) {
  grid-template-columns: minmax(0, 1fr);
}

.catalog-row {
    grid-template-columns: 1fr;
  }

  .catalog-side {
    justify-content: flex-start;
  }
}

@media print {
  .site-header,
  .site-footer,
  .reader-toolbar,
  .block-tools,
  .block-note {
    display: none;
  }

  .block {
    break-inside: avoid;
  }
}