:root {
  color-scheme: dark;
  --page: #07090f;
  --ink: #f7f8fb;
  --muted: #aeb9c9;
  --soft: #758399;
  --line: rgba(179, 202, 232, 0.2);
  --line-strong: rgba(190, 218, 245, 0.38);
  --panel: rgba(15, 21, 31, 0.9);
  --panel-solid: #101722;
  --panel-raised: #151f2e;
  --teal: #8fe7dd;
  --gold: #f4c76b;
  --rose: #ee7895;
  --green: #9be078;
  --blue: #80bfff;
  --shadow: 0 22px 70px rgba(0, 0, 0, 0.34);
  --read-bg: transparent;
  --read-panel: rgba(255, 255, 255, 0.035);
  --read-panel-hover: rgba(143, 231, 221, 0.08);
  --read-ink: var(--ink);
  --read-body: #e1e7f0;
  --read-muted: var(--muted);
  --read-soft: #dfe8f4;
  --read-line: var(--line);
  --read-line-strong: var(--line-strong);
  --read-accent: var(--teal);
  --read-gold: var(--gold);
  --read-callout: #fff2d4;
  --read-callout-bg: transparent;
  --read-shadow: var(--shadow);
  --read-surface-shadow: none;
  --topbar-height: 62px;
  --tabs-height: 64px;
}

* {
  box-sizing: border-box;
  letter-spacing: 0;
}

html {
  min-height: 100%;
  background: var(--page);
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Aptos", "Segoe UI", sans-serif;
  line-height: 1.62;
  background:
    linear-gradient(180deg, rgba(12, 18, 29, 0.9), rgba(7, 9, 15, 0.98) 44%, #04060b),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.018) 0 1px, transparent 1px 84px),
    repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.012) 0 1px, transparent 1px 84px),
    var(--page);
}

button,
input {
  font: inherit;
}

a {
  color: inherit;
}

.site-shell {
  min-height: 100vh;
}

.site-shell[data-reading-theme="light"] {
  --read-bg: #f4f7f8;
  --read-panel: #ffffff;
  --read-panel-hover: #edf6f7;
  --read-ink: #172331;
  --read-body: #243447;
  --read-muted: #566779;
  --read-soft: #314456;
  --read-line: rgba(31, 54, 68, 0.18);
  --read-line-strong: rgba(8, 112, 118, 0.42);
  --read-accent: #087076;
  --read-gold: #8a6217;
  --read-callout: #5e430d;
  --read-callout-bg: rgba(138, 98, 23, 0.08);
  --read-shadow: 0 14px 40px rgba(20, 40, 54, 0.11);
  --read-surface-shadow: 0 24px 76px rgba(5, 12, 20, 0.28);
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 62px;
  padding: 10px clamp(12px, 2vw, 24px);
  border-bottom: 1px solid var(--line);
  background: rgba(7, 10, 17, 0.8);
  backdrop-filter: blur(18px);
}

.site-title {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  color: var(--ink);
  font-weight: 840;
  text-decoration: none;
}

.site-mark {
  width: 24px;
  height: 24px;
  flex: 0 0 auto;
  border: 1px solid rgba(143, 231, 221, 0.72);
  border-radius: 50%;
  background:
    radial-gradient(circle at 50% 50%, var(--gold) 0 3px, transparent 4px),
    linear-gradient(90deg, transparent 47%, rgba(143, 231, 221, 0.62) 48% 52%, transparent 53%),
    linear-gradient(0deg, transparent 47%, rgba(244, 199, 107, 0.72) 48% 52%, transparent 53%),
    #0e1520;
}

.topbar-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  flex-wrap: wrap;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  border: 1px solid rgba(143, 231, 221, 0.34);
  border-radius: 8px;
  color: var(--ink);
  background: rgba(18, 33, 45, 0.94);
  padding: 8px 12px;
  font-weight: 760;
  text-decoration: none;
}

.button:hover,
.button:focus-visible {
  border-color: rgba(143, 231, 221, 0.7);
  background: rgba(24, 43, 58, 0.98);
  outline: none;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(6, 10, 18, 0.86);
  padding: 3px;
}

.theme-toggle span {
  color: var(--muted);
  font-size: 11px;
  line-height: 1;
  padding: 0 5px;
  white-space: nowrap;
}

.theme-option {
  min-height: 30px;
  border: 0;
  border-radius: 6px;
  color: var(--muted);
  background: transparent;
  padding: 5px 9px;
  font-size: 12px;
  font-weight: 790;
  cursor: pointer;
}

.theme-option:hover,
.theme-option:focus-visible,
.theme-option.is-active {
  color: var(--ink);
  background: rgba(143, 231, 221, 0.14);
  outline: none;
}

.search-field {
  display: grid;
  gap: 3px;
}

.search-field span {
  color: var(--muted);
  font-size: 11px;
}

.search-field input {
  width: min(28vw, 260px);
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  background: rgba(6, 10, 18, 0.86);
  padding: 8px 10px;
}

.chapter-tabs {
  position: sticky;
  top: var(--topbar-height);
  z-index: 35;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 10px clamp(12px, 2vw, 24px);
  border-bottom: 1px solid var(--line);
  background: rgba(9, 13, 21, 0.9);
  backdrop-filter: blur(16px);
}

.chapter-tabs a {
  flex: 0 0 auto;
  border: 1px solid transparent;
  border-radius: 8px;
  color: var(--muted);
  padding: 8px 11px;
  font-size: 13px;
  font-weight: 780;
  text-decoration: none;
  white-space: nowrap;
}

.chapter-tabs a:hover,
.chapter-tabs a:focus-visible,
.chapter-tabs a.is-active {
  border-color: rgba(143, 231, 221, 0.34);
  color: var(--ink);
  background: rgba(143, 231, 221, 0.08);
  outline: none;
}

.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(250px, 315px);
  gap: clamp(18px, 3vw, 42px);
  align-items: start;
  width: min(1380px, calc(100vw - 32px));
  margin: 0 auto;
  padding: clamp(22px, 4vw, 54px) 0 80px;
}

.subpage-nav {
  grid-column: 2;
  grid-row: 1;
  position: sticky;
  top: calc(var(--topbar-height) + var(--tabs-height));
  max-height: calc(100vh - var(--topbar-height) - var(--tabs-height) - 18px);
  overflow: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
  padding: 14px;
}

.nav-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.panel-kicker,
.eyebrow {
  margin: 0 0 6px;
  color: var(--teal);
  font-size: 12px;
  font-weight: 840;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

.nav-head h2 {
  margin: 0;
  font-size: 18px;
  line-height: 1.1;
}

.nav-head span {
  color: var(--gold);
  font-size: 12px;
  font-weight: 760;
  white-space: nowrap;
}

.subpage-links {
  display: grid;
  gap: 6px;
}

.subpage-links a {
  display: grid;
  gap: 3px;
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 9px 10px;
  color: var(--muted);
  text-decoration: none;
}

.subpage-links a:hover,
.subpage-links a:focus-visible,
.subpage-links a.is-active {
  border-color: rgba(143, 231, 221, 0.32);
  color: var(--ink);
  background: rgba(143, 231, 221, 0.08);
  outline: none;
}

.subpage-index {
  color: var(--gold);
  font-size: 11px;
  font-weight: 820;
  text-transform: uppercase;
}

.subpage-label {
  font-size: 14px;
  line-height: 1.22;
}

.empty-state {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.page-view {
  grid-column: 1;
  grid-row: 1;
  min-width: 0;
}

.site-shell[data-reading-theme="light"] .page-view {
  border: 1px solid var(--read-line);
  border-radius: 8px;
  color: var(--read-ink);
  background: var(--read-bg);
  box-shadow: var(--read-surface-shadow);
  padding: clamp(16px, 3vw, 38px);
}

.chapter-landing {
  display: grid;
  gap: clamp(22px, 4vw, 44px);
}

.landing-intro {
  max-width: 920px;
  border-bottom: 1px solid var(--read-line);
  padding: clamp(8px, 2vw, 18px) 0 clamp(22px, 4vw, 42px);
}

.landing-intro h1 {
  margin: 0 0 16px;
  font-size: clamp(42px, 7vw, 86px);
  line-height: 0.95;
}

.landing-copy {
  max-width: 760px;
  margin: 0;
  color: var(--read-body);
  font-size: clamp(18px, 1.7vw, 24px);
  line-height: 1.42;
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.topic-card {
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 100%;
  overflow: hidden;
  border: 1px solid var(--read-line);
  border-radius: 8px;
  color: var(--read-ink);
  background: var(--read-panel);
  box-shadow: var(--read-shadow);
  text-decoration: none;
}

.topic-card:hover,
.topic-card:focus-visible {
  border-color: var(--read-line-strong);
  background: var(--read-panel-hover);
  outline: none;
}

.topic-card img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: rgba(255, 255, 255, 0.04);
}

.topic-card-body {
  display: grid;
  align-content: start;
  gap: 9px;
  padding: 14px;
}

.topic-card-kicker {
  color: var(--read-gold);
  font-size: 11px;
  font-weight: 820;
  text-transform: uppercase;
}

.topic-card h2 {
  margin: 0;
  font-size: clamp(18px, 1.7vw, 24px);
  line-height: 1.08;
}

.topic-card p {
  margin: 0;
  color: var(--read-muted);
  font-size: 14px;
  line-height: 1.42;
}

.topic-card strong {
  align-self: end;
  color: var(--read-accent);
  font-size: 13px;
}

.loading-state {
  border: 1px solid var(--read-line);
  border-radius: 8px;
  background: var(--read-panel);
  padding: 30px;
  color: var(--read-muted);
  text-align: center;
}

.page-header {
  padding: clamp(8px, 2vw, 18px) 0 clamp(22px, 4vw, 44px);
  border-bottom: 1px solid var(--read-line);
}

.page-header h1 {
  max-width: 960px;
  margin: 0 0 18px;
  font-size: clamp(38px, 6vw, 76px);
  line-height: 0.96;
  color: var(--read-ink);
}

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

.page-pager.top {
  max-width: 760px;
}

.page-pager.bottom {
  margin-top: clamp(28px, 5vw, 54px);
  padding-top: 18px;
  border-top: 1px solid var(--read-line);
}

.pager-link,
.pager-spacer {
  min-height: 72px;
  border: 1px solid var(--read-line);
  border-radius: 8px;
  background: var(--read-panel);
  padding: 12px;
  text-decoration: none;
}

.pager-link {
  display: grid;
  align-content: center;
  gap: 4px;
}

.pager-link.next {
  text-align: right;
}

.pager-link:hover,
.pager-link:focus-visible {
  border-color: var(--read-line-strong);
  background: var(--read-panel-hover);
  outline: none;
}

.pager-link span {
  color: var(--read-gold);
  font-size: 12px;
  font-weight: 820;
  text-transform: uppercase;
}

.pager-link strong {
  color: var(--read-ink);
  font-size: 15px;
  line-height: 1.22;
}

.pager-spacer {
  visibility: hidden;
}

.page-body {
  display: grid;
  grid-template-columns: minmax(0, 760px) minmax(260px, 37%);
  gap: clamp(22px, 4vw, 48px);
  align-items: start;
  padding-top: clamp(26px, 4vw, 50px);
}

.page-body.no-figures {
  grid-template-columns: minmax(0, 820px);
}

.page-body.no-figures .page-media {
  display: none;
}

.page-text p {
  margin-bottom: 16px;
  color: var(--read-body);
  font-size: clamp(16px, 1.22vw, 19px);
}

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

.page-text .callout {
  margin: 24px 0;
  border-left: 3px solid var(--read-gold);
  border-radius: 0 8px 8px 0;
  background: var(--read-callout-bg);
  padding: 10px 14px 10px 18px;
  color: var(--read-callout);
  font-size: clamp(18px, 1.5vw, 23px);
  line-height: 1.34;
}

.text-list {
  display: grid;
  gap: 9px;
  margin: 18px 0;
  padding: 0;
  list-style: none;
}

.text-list li {
  border-left: 2px solid var(--read-line-strong);
  padding-left: 12px;
  color: var(--read-soft);
  font-size: clamp(15px, 1.15vw, 18px);
}

.page-media {
  display: grid;
  gap: 14px;
}

.page-body.has-many-figures .page-media {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.figure-card {
  overflow: hidden;
  border: 1px solid var(--read-line);
  border-radius: 8px;
  background: var(--read-panel);
  box-shadow: var(--read-shadow);
}

.figure-card.is-wide {
  grid-column: 1 / -1;
}

.figure-card img {
  display: block;
  width: 100%;
  height: auto;
}

.figure-meta {
  margin: 0;
  padding: 8px 10px;
  color: var(--read-muted);
  font-size: 12px;
}

@media (max-width: 1060px) {
  .page-layout {
    grid-template-columns: 1fr;
  }

  .subpage-nav {
    grid-column: 1;
    grid-row: 2;
    position: static;
    max-height: none;
  }

  .page-view {
    grid-column: 1;
    grid-row: 1;
  }

  .subpage-links {
    grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  }

  .page-body,
  .page-body.no-figures {
    grid-template-columns: 1fr;
  }

  .page-media,
  .page-body.has-many-figures .page-media {
    grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  }

  .topic-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .topbar {
    align-items: stretch;
    flex-direction: column;
  }

  .site-title {
    justify-content: flex-start;
  }

  .topbar-actions {
    align-items: stretch;
    justify-content: stretch;
  }

  .search-field,
  .search-field input,
  .theme-toggle,
  .button {
    width: 100%;
  }

  .theme-option {
    flex: 1 1 0;
  }

  .page-layout {
    width: min(100vw - 20px, 1380px);
  }

  .page-pager {
    grid-template-columns: 1fr;
  }

  .pager-link.next {
    text-align: left;
  }

  .page-body.has-many-figures .page-media {
    grid-template-columns: 1fr;
  }

  .topic-grid {
    grid-template-columns: 1fr;
  }
}