:root {
  color-scheme: dark;
  --ink: #f5f0e6;
  --muted: #aaa49a;
  --line: rgba(245, 240, 230, 0.14);
  --cyan: #68d8e8;
  --amber: #f2b24d;
  --rose: #ff6474;
  --green: #71d68f;
  --panel: rgba(13, 15, 16, 0.82);
  --panel-soft: rgba(255, 255, 255, 0.035);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  background:
    radial-gradient(circle at 12% 0%, rgba(104, 216, 232, 0.12), transparent 30%),
    radial-gradient(circle at 88% 18%, rgba(242, 178, 77, 0.1), transparent 30%),
    #090a0a;
  color: var(--ink);
  overflow-x: hidden;
}

a {
  color: var(--cyan);
  text-decoration: none;
}

a:hover {
  color: var(--ink);
}

.book-shell {
  display: grid;
  grid-template-columns: minmax(210px, 250px) minmax(0, 820px) minmax(190px, 250px);
  gap: 24px;
  width: min(1340px, 100%);
  margin: 0 auto;
  padding: 18px;
}

.book-shell > * {
  min-width: 0;
}

.book-nav,
.page-toc {
  position: sticky;
  top: 18px;
  align-self: start;
  max-height: calc(100vh - 36px);
  overflow: auto;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.book-nav strong,
.page-toc strong {
  display: block;
  margin-bottom: 12px;
  color: var(--amber);
  font-size: 0.76rem;
  text-transform: uppercase;
}

.book-nav a,
.page-toc a {
  display: block;
  padding: 8px 9px;
  border-radius: 6px;
  color: rgba(245, 240, 230, 0.76);
  font-size: 0.9rem;
  line-height: 1.3;
  overflow-wrap: anywhere;
}

.book-nav .nav-section-label {
  display: block;
  margin: 14px 0 6px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  color: var(--amber);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.book-nav a[aria-current="page"],
.book-nav a:hover,
.page-toc a:hover {
  color: var(--ink);
  background: rgba(104, 216, 232, 0.1);
}

.book-main {
  min-width: 0;
  padding: clamp(14px, 3vw, 28px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    linear-gradient(180deg, rgba(13, 15, 16, 0.88), rgba(13, 15, 16, 0.72)),
    var(--panel-soft);
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--amber);
  font-size: 0.74rem;
  font-weight: 800;
  text-transform: uppercase;
}

h1,
h2,
h3,
p,
li {
  letter-spacing: 0;
  overflow-wrap: break-word;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 5vw, 4rem);
  line-height: 0.98;
  overflow-wrap: anywhere;
}

.subtitle {
  margin: 8px 0 16px;
  color: var(--cyan);
  font-size: 1.08rem;
  font-weight: 700;
}

h2 {
  margin: 40px 0 12px;
  padding-top: 8px;
  border-top: 1px solid rgba(245, 240, 230, 0.1);
  font-size: clamp(1.45rem, 3vw, 2.2rem);
  line-height: 1.1;
  scroll-margin-top: 22px;
}

h3 {
  margin: 26px 0 8px;
  color: var(--ink);
  font-size: 1.08rem;
  line-height: 1.2;
  scroll-margin-top: 22px;
}

p,
li {
  color: rgba(245, 240, 230, 0.8);
  font-size: 1rem;
  line-height: 1.68;
}

p {
  margin: 0 0 16px;
}

ul,
ol {
  display: grid;
  gap: 8px;
  margin: 0 0 18px;
  padding-left: 1.2rem;
}

.lede {
  margin-top: 18px;
  color: rgba(245, 240, 230, 0.86);
  font-size: clamp(1.08rem, 1.7vw, 1.24rem);
}

.callout,
.claim-lock {
  margin: 22px 0;
  padding: 16px;
  border: 1px solid rgba(242, 178, 77, 0.24);
  border-radius: 8px;
  background: rgba(242, 178, 77, 0.065);
}

.claim-lock {
  border-color: rgba(255, 100, 116, 0.26);
  background: rgba(255, 100, 116, 0.06);
}

.callout strong,
.claim-lock strong {
  color: var(--ink);
}

.formula {
  position: relative;
  margin: 18px 0;
  border: 1px solid rgba(104, 216, 232, 0.2);
  border-radius: 8px;
  background: rgba(104, 216, 232, 0.055);
  overflow: hidden;
}

.formula pre {
  margin: 0;
  padding: 18px 54px 18px 18px;
  overflow: auto;
}

.formula code {
  color: var(--cyan);
  font-family: "Cascadia Mono", "SFMono-Regular", Consolas, monospace;
  font-size: 0.96rem;
  line-height: 1.55;
  white-space: pre;
}

.copy-formula {
  position: absolute;
  top: 9px;
  right: 9px;
  min-height: 30px;
  border: 1px solid rgba(245, 240, 230, 0.16);
  border-radius: 6px;
  color: rgba(245, 240, 230, 0.78);
  background: rgba(8, 10, 10, 0.72);
  cursor: pointer;
}

.copy-formula:hover {
  color: var(--ink);
  border-color: rgba(104, 216, 232, 0.52);
}

.mini-grid,
.result-grid,
.pdf-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 20px 0;
}

.mini-grid article,
.result-grid article,
.pdf-list article {
  min-width: 0;
  padding: 14px;
  border: 1px solid rgba(245, 240, 230, 0.11);
  border-radius: 8px;
  background: var(--panel-soft);
}

.mini-grid h3,
.result-grid h3,
.pdf-list h3 {
  margin-top: 0;
}

.pdf-list {
  grid-template-columns: 1fr;
}

.detailed-pdf-list article {
  scroll-margin-top: 22px;
}

.compact-meta {
  margin-top: 10px;
}

.compact-meta span {
  min-height: 28px;
  padding: 6px 8px;
  font-size: 0.78rem;
}

.glossary-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 18px 0;
}

.glossary-list div {
  min-width: 0;
  padding: 14px;
  border: 1px solid rgba(245, 240, 230, 0.11);
  border-radius: 8px;
  background: var(--panel-soft);
}

.glossary-list dt {
  margin-bottom: 7px;
  color: var(--amber);
  font-weight: 800;
}

.glossary-list dd {
  margin: 0;
  color: rgba(245, 240, 230, 0.78);
  font-size: 0.94rem;
  line-height: 1.58;
}

.pdf-index-toc .toc-break {
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid rgba(245, 240, 230, 0.12);
}

.pdf-index-toc a span {
  display: inline-flex;
  min-width: 2.1em;
  color: var(--amber);
  font-weight: 800;
}

.source-status {
  display: inline-flex;
  align-items: center;
  min-height: 22px;
  padding: 0 8px;
  border: 1px solid rgba(242, 178, 77, 0.28);
  border-radius: 999px;
  color: var(--amber);
  background: rgba(242, 178, 77, 0.06);
  font-size: 0.68rem;
  font-weight: 800;
  text-transform: uppercase;
}

.pdf-actions,
.summary-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.pdf-actions a,
.summary-meta a,
.summary-meta span {
  max-width: 100%;
  min-width: 0;
  min-height: 34px;
  display: inline-flex;
  align-items: center;
  padding: 8px 10px;
  border: 1px solid rgba(104, 216, 232, 0.2);
  border-radius: 7px;
  color: rgba(245, 240, 230, 0.82);
  background: rgba(104, 216, 232, 0.06);
  overflow-wrap: anywhere;
  white-space: normal;
}

.summary-meta span {
  border-color: rgba(245, 240, 230, 0.12);
  background: rgba(255, 255, 255, 0.035);
}

.pdf-actions a:hover,
.summary-meta a:hover {
  border-color: rgba(104, 216, 232, 0.52);
  color: var(--ink);
  background: rgba(104, 216, 232, 0.12);
}

.chapter-pager {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 44px;
  padding-top: 20px;
  border-top: 1px solid rgba(245, 240, 230, 0.12);
}

.chapter-pager a {
  min-width: 0;
  padding: 10px 12px;
  border: 1px solid rgba(104, 216, 232, 0.22);
  border-radius: 7px;
  color: rgba(245, 240, 230, 0.84);
  background: rgba(104, 216, 232, 0.06);
}

.chapter-pager a:hover {
  color: var(--ink);
  border-color: rgba(104, 216, 232, 0.52);
  background: rgba(104, 216, 232, 0.12);
}

@media (max-width: 1080px) {
  .book-shell {
    grid-template-columns: minmax(180px, 230px) minmax(0, 1fr);
  }

  .page-toc {
    display: none;
  }
}

@media (max-width: 760px) {
  .book-shell {
    display: block;
    grid-template-columns: 1fr;
    width: 100%;
    max-width: 100%;
    padding: 10px;
    overflow-x: hidden;
  }

  h1 {
    font-size: clamp(1.35rem, 5.5vw, 1.75rem);
    line-height: 1.08;
  }

  .book-nav {
    display: flex;
    flex-wrap: wrap;
    overflow-x: hidden;
    position: static;
    width: 100%;
    max-width: 370px;
    max-height: none;
    margin-bottom: 24px;
  }

  .book-main {
    width: 100%;
    max-width: 370px;
    overflow-x: hidden;
  }

  .book-main > *,
  .book-main section > *,
  .book-main .summary-meta,
  .book-main .pdf-actions,
  .book-main .formula {
    max-width: calc(100vw - 52px);
  }

  .book-nav strong,
  .book-nav .nav-section-label {
    flex: 0 0 100%;
  }

  .book-nav a {
    display: inline-flex;
    max-width: 100%;
    margin: 0 4px 6px 0;
    white-space: normal;
  }

  .formula pre {
    max-width: 100%;
    padding: 14px;
  }

  .formula code {
    overflow-wrap: anywhere;
    white-space: pre-wrap;
  }

  .mini-grid,
  .result-grid,
  .glossary-list {
    grid-template-columns: 1fr;
  }

  .chapter-pager {
    flex-direction: column;
  }
}