#about-modal .modal-card.about-book-modal {
  width: min(1540px, calc(100vw - 2rem));
  max-width: min(1540px, calc(100vw - 2rem)) !important;
  height: min(94vh, 1040px);
  max-height: 94vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background:
    radial-gradient(circle at 85% 8%, rgba(91, 81, 204, 0.10), transparent 30rem),
    radial-gradient(circle at 12% 22%, rgba(14, 125, 168, 0.10), transparent 28rem),
    var(--bg-card, #fff);
}

#about-modal .about-book-modal > .modal-header {
  flex: 0 0 auto;
  z-index: 5;
}

#about-modal .about-book-modal > .modal-header .badge {
  display: inline-flex;
  align-items: center;
  gap: 0.42rem;
}

#about-modal .about-book-modal-body {
  flex: 1 1 auto;
  min-height: 0;
  padding: 0;
  overflow: auto;
  overscroll-behavior: contain;
  scroll-behavior: smooth;
  scrollbar-gutter: stable;
}

.about-book {
  --book-ink: var(--text-primary, #182339);
  --book-muted: var(--text-secondary, #45526e);
  --book-blue: var(--accent-cyan, #0e7da8);
  --book-indigo: var(--accent-indigo, #5b51cc);
  --book-line: var(--border-subtle, rgba(30, 52, 96, 0.12));
  color: var(--book-ink);
  font-size: clamp(0.92rem, 0.25vw + 0.86rem, 1.02rem);
  line-height: 1.7;
}

.about-book button {
  font: inherit;
}

.about-book__cover {
  min-height: min(64vh, 660px);
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(250px, 0.65fr);
  align-items: end;
  gap: clamp(2rem, 6vw, 7rem);
  padding: clamp(3rem, 8vw, 8.5rem) clamp(1.5rem, 7vw, 7.5rem) clamp(2.5rem, 5vw, 5.5rem);
  color: #f8fbff;
  background:
    linear-gradient(115deg, rgba(7, 23, 48, 0.97), rgba(9, 66, 99, 0.91) 55%, rgba(55, 48, 141, 0.88)),
    radial-gradient(circle at 74% 32%, rgba(61, 213, 255, 0.30), transparent 23rem);
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
  scroll-margin-top: 1rem;
}

.about-book__eyebrow {
  margin: 0 0 1rem;
  color: #8ee6ff;
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.16em;
}

.about-book__title {
  max-width: 18ch;
  margin: 0;
  color: #fff;
  font-size: clamp(2.4rem, 5vw, 5.4rem);
  line-height: 0.98;
  letter-spacing: -0.055em;
  text-wrap: balance;
}

.about-book__subtitle {
  max-width: 68ch;
  margin: 1.6rem 0 0;
  color: rgba(244, 249, 255, 0.82);
  font-size: clamp(1rem, 0.55vw + 0.9rem, 1.3rem);
  line-height: 1.58;
}

.about-book__edition {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem;
  margin: 1rem 0 0;
  color: rgba(244, 249, 255, 0.58);
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.about-book__version {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding-inline-start: 0.65rem;
  border-inline-start: 1px solid rgba(244, 249, 255, 0.32);
  color: #fff;
  letter-spacing: 0.035em;
}

.about-book__version-label {
  color: rgba(244, 249, 255, 0.62);
}

.about-book__version b {
  font-weight: 850;
}

.about-book__start,
.about-book__founder-link,
.about-book__next {
  min-height: 44px;
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.about-book__start {
  padding: 0.75rem 1.2rem;
  color: #092239;
  background: #f4fbff;
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.2);
  font-weight: 800;
}

.about-book__cover-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.7rem;
  margin-block-start: 2rem;
}

.about-book__founder-link {
  padding: 0.7rem 1rem;
  border-color: rgba(255, 255, 255, 0.25);
  color: #f4fbff;
  background: rgba(255, 255, 255, 0.09);
  font-size: 0.84rem;
  font-weight: 760;
  backdrop-filter: blur(8px);
}

.about-book__start:hover,
.about-book__start:focus-visible,
.about-book__founder-link:hover,
.about-book__founder-link:focus-visible,
.about-book__next:hover,
.about-book__next:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 12px 24px rgba(14, 125, 168, 0.18);
  outline: 3px solid rgba(22, 152, 201, 0.24);
  outline-offset: 2px;
}

.about-book__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.about-book__fact {
  min-height: 122px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(10px);
}

.about-book__fact strong {
  color: #7bdff9;
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 0.72rem;
}

.about-book__fact span {
  color: #fff;
  font-weight: 700;
  line-height: 1.3;
}

.about-book__status {
  margin: clamp(1.2rem, 3vw, 2.5rem) clamp(1rem, 4vw, 4.5rem) 0;
  padding: 1rem 1.15rem;
  border: 1px solid rgba(14, 125, 168, 0.22);
  border-inline-start: 4px solid var(--book-blue);
  border-radius: 14px;
  color: var(--book-muted);
  background: rgba(14, 125, 168, 0.07);
  font-size: 0.88rem;
}

.about-book__layout {
  width: min(1320px, calc(100% - 2rem));
  display: grid;
  grid-template-columns: minmax(230px, 285px) minmax(0, 1fr);
  align-items: start;
  gap: clamp(2rem, 5vw, 6rem);
  margin: 0 auto;
  padding: clamp(2rem, 5vw, 5rem) 0 7rem;
}

.about-book__toc {
  position: sticky;
  top: 1.25rem;
  max-height: calc(94vh - 9rem);
  overflow: auto;
  padding: 1.15rem;
  border: 1px solid var(--book-line);
  border-radius: 18px;
  background: color-mix(in srgb, var(--bg-card, #fff) 92%, transparent);
  box-shadow: 0 18px 44px rgba(23, 35, 57, 0.08);
  backdrop-filter: blur(14px);
}

.about-book__toc-title {
  margin: 0 0 0.65rem;
  color: var(--text-bright, #0b1220);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.about-book__progress {
  width: 100%;
  height: 4px;
  display: block;
  margin: 0 0 0.85rem;
  border: 0;
  border-radius: 999px;
  overflow: hidden;
  appearance: none;
  background: var(--bg-tertiary, #e3e9f4);
}

.about-book__progress::-webkit-progress-bar { background: var(--bg-tertiary, #e3e9f4); }
.about-book__progress::-webkit-progress-value { background: linear-gradient(90deg, var(--book-blue), var(--book-indigo)); }
.about-book__progress::-moz-progress-bar { background: linear-gradient(90deg, var(--book-blue), var(--book-indigo)); }

.about-book__toc-list {
  display: grid;
  gap: 0.2rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.about-book__toc-button {
  width: 100%;
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  gap: 0.55rem;
  align-items: start;
  padding: 0.55rem 0.6rem;
  border: 0;
  border-radius: 10px;
  color: var(--book-muted);
  background: transparent;
  cursor: pointer;
  text-align: start;
}

.about-book__toc-button:hover,
.about-book__toc-button:focus-visible,
.about-book__toc-button.is-active {
  color: var(--book-blue);
  background: rgba(14, 125, 168, 0.08);
  outline: none;
}

.about-book__toc-button:focus-visible {
  box-shadow: inset 0 0 0 2px rgba(14, 125, 168, 0.42);
}

.about-book__toc-number {
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 0.68rem;
  font-weight: 800;
}

.about-book__toc-text {
  font-size: 0.79rem;
  font-weight: 650;
  line-height: 1.35;
}

.about-book__pages {
  min-width: 0;
}

.about-book__chapter {
  position: relative;
  min-height: 70vh;
  padding: clamp(1.4rem, 4vw, 3.8rem);
  border: 1px solid var(--book-line);
  border-radius: 24px;
  background:
    linear-gradient(90deg, transparent 0, transparent 35px, rgba(14, 125, 168, 0.055) 36px, transparent 37px),
    var(--bg-card, #fff);
  box-shadow: 0 22px 55px rgba(23, 35, 57, 0.08);
  scroll-margin-top: 1rem;
}

.about-book__chapter + .about-book__chapter {
  margin-block-start: clamp(2rem, 5vw, 5rem);
}

.about-book__chapter-number {
  margin: 0 0 0.85rem;
  color: var(--book-blue);
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.about-book__chapter-title {
  max-width: 24ch;
  margin: 0;
  color: var(--text-bright, #0b1220);
  font-size: clamp(1.65rem, 2.4vw, 2.8rem);
  line-height: 1.08;
  letter-spacing: -0.035em;
  text-wrap: balance;
}

.about-book__lead {
  max-width: 72ch;
  margin: 1.15rem 0 2rem;
  color: var(--book-blue);
  font-size: clamp(1.02rem, 0.4vw + 0.95rem, 1.22rem);
  font-weight: 650;
  line-height: 1.55;
}

.about-book__paragraph {
  max-width: 78ch;
  margin: 0 0 1.15rem;
  color: var(--book-muted);
}

.about-book__founder-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 0.85fr);
  align-items: stretch;
  gap: 1rem;
  margin: 0 0 2rem;
  padding: clamp(1rem, 3vw, 1.6rem);
  border: 1px solid rgba(14, 125, 168, 0.23);
  border-radius: 18px;
  background:
    linear-gradient(125deg, rgba(14, 125, 168, 0.10), rgba(91, 81, 204, 0.07)),
    var(--bg-card, #fff);
}

.about-book__founder-identity {
  min-width: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 0.4rem;
}

.about-book__founder-kicker {
  margin: 0 0 0.35rem;
  color: var(--book-blue);
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 0.7rem;
  font-weight: 850;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.about-book__founder-name {
  margin: 0;
  color: var(--text-bright, #0b1220);
  font-size: clamp(1.35rem, 2vw, 2rem);
  line-height: 1.15;
  letter-spacing: -0.025em;
}

.about-book__founder-details {
  display: grid;
  gap: 0.55rem;
  margin: 0;
}

.about-book__founder-detail {
  display: grid;
  grid-template-columns: minmax(3.75rem, auto) minmax(0, 1fr);
  gap: 0.65rem;
  align-items: baseline;
  padding: 0.7rem 0.8rem;
  border: 1px solid var(--book-line);
  border-radius: 11px;
  background: rgba(255, 255, 255, 0.52);
}

.about-book__founder-detail dt {
  color: var(--book-muted);
  font-size: 0.72rem;
  font-weight: 760;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.about-book__founder-detail dd {
  min-width: 0;
  margin: 0;
  color: var(--book-ink);
  font-weight: 700;
  overflow-wrap: anywhere;
}

.about-book__founder-email {
  color: var(--book-blue);
  font-size: 0.88rem;
  white-space: nowrap;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
}

.about-book__founder-email:hover,
.about-book__founder-email:focus-visible {
  color: var(--book-indigo);
  outline: 3px solid rgba(14, 125, 168, 0.18);
  outline-offset: 3px;
  border-radius: 3px;
}

.about-book__chapter--founder .about-book__point {
  border-color: rgba(14, 125, 168, 0.18);
  background: rgba(14, 125, 168, 0.045);
}

.about-book__points {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.7rem;
  margin: 1.8rem 0;
  padding: 0;
  list-style: none;
}

.about-book__point {
  display: grid;
  grid-template-columns: 1.65rem minmax(0, 1fr);
  gap: 0.55rem;
  align-items: start;
  padding: 0.85rem;
  border: 1px solid var(--book-line);
  border-radius: 13px;
  color: var(--book-ink);
  background: rgba(23, 35, 57, 0.025);
  line-height: 1.48;
}

.about-book__point-mark {
  width: 1.5rem;
  height: 1.5rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: var(--book-blue);
  background: rgba(14, 125, 168, 0.11);
  font-size: 0.72rem;
  font-weight: 900;
}

.about-book__note {
  display: grid;
  grid-template-columns: 2.25rem minmax(0, 1fr);
  gap: 0.85rem;
  margin-block-start: 1.8rem;
  padding: 1rem 1.1rem;
  border: 1px solid rgba(91, 81, 204, 0.20);
  border-radius: 15px;
  color: var(--book-muted);
  background: rgba(91, 81, 204, 0.07);
}

.about-book__note-mark {
  width: 2.1rem;
  height: 2.1rem;
  display: grid;
  place-items: center;
  border-radius: 10px;
  color: var(--book-indigo);
  background: rgba(91, 81, 204, 0.13);
  font-family: Georgia, serif;
  font-weight: 800;
}

.about-book__note p { margin: 0; }

.about-book__chapter-footer {
  display: flex;
  justify-content: flex-end;
  margin-block-start: 2.4rem;
  padding-block-start: 1.2rem;
  border-top: 1px solid var(--book-line);
}

.about-book__next {
  padding: 0.65rem 1rem;
  border-color: rgba(14, 125, 168, 0.20);
  color: var(--book-blue);
  background: rgba(14, 125, 168, 0.08);
  font-weight: 750;
}

[dir='rtl'] .about-book__cover,
[dir='rtl'] .about-book__chapter,
[dir='rtl'] .about-book__toc-button {
  text-align: right;
}

[dir='rtl'] .about-book__chapter {
  background:
    linear-gradient(270deg, transparent 0, transparent 35px, rgba(14, 125, 168, 0.055) 36px, transparent 37px),
    var(--bg-card, #fff);
}

@media (max-width: 960px) {
  #about-modal .modal-card.about-book-modal {
    width: calc(100vw - 1rem);
    max-width: calc(100vw - 1rem) !important;
    height: calc(100dvh - 1rem);
    max-height: calc(100dvh - 1rem);
    border-radius: 16px;
  }

  .about-book__cover {
    min-height: auto;
    grid-template-columns: 1fr;
    align-items: start;
    padding-block: 3.5rem 2.5rem;
  }

  .about-book__facts { max-width: 620px; }
  .about-book__layout { grid-template-columns: 1fr; }

  .about-book__toc {
    position: sticky;
    top: 0.5rem;
    z-index: 3;
    max-height: none;
    overflow: hidden;
    padding: 0.75rem;
  }

  .about-book__toc-title { margin-block-end: 0.35rem; }
  .about-book__toc-list { display: flex; overflow-x: auto; scroll-snap-type: x proximity; padding-block-end: 0.25rem; }
  .about-book__toc-item { flex: 0 0 min(78vw, 300px); scroll-snap-align: start; }
  .about-book__toc-button { height: 100%; }
  .about-book__chapter { min-height: auto; }
  .about-book__founder-card { grid-template-columns: 1fr; }
}

@media (max-width: 620px) {
  #about-modal { padding: 0.25rem; }
  #about-modal .modal-card.about-book-modal {
    width: calc(100vw - 0.5rem);
    max-width: calc(100vw - 0.5rem) !important;
    height: calc(100dvh - 0.5rem);
    max-height: calc(100dvh - 0.5rem);
    border-radius: 12px;
  }

  #about-modal .about-book-modal > .modal-header { padding: 0.75rem; }
  .about-book__cover { padding: 2.5rem 1.1rem 2rem; }
  .about-book__title { font-size: clamp(2.15rem, 12vw, 3.3rem); }
  .about-book__facts { grid-template-columns: 1fr 1fr; gap: 0.5rem; }
  .about-book__fact { min-height: 98px; padding: 0.75rem; }
  .about-book__cover-actions { align-items: stretch; }
  .about-book__start,
  .about-book__founder-link { width: 100%; }
  .about-book__status { margin-inline: 0.65rem; }
  .about-book__layout { width: calc(100% - 1.25rem); gap: 1.25rem; padding-block-start: 1.25rem; }
  .about-book__chapter { padding: 1.25rem 1rem; border-radius: 17px; background: var(--bg-card, #fff); }
  [dir='rtl'] .about-book__chapter { background: var(--bg-card, #fff); }
  .about-book__points { grid-template-columns: 1fr; }
  .about-book__point { padding: 0.75rem; }
  .about-book__founder-detail { grid-template-columns: 1fr; gap: 0.2rem; }
  .about-book__founder-email { white-space: normal; }
}

@media (prefers-reduced-motion: reduce) {
  #about-modal .about-book-modal-body { scroll-behavior: auto; }
  .about-book__start,
  .about-book__founder-link,
  .about-book__next { transition: none; }
}

@media print {
  #about-modal .modal-card.about-book-modal,
  #about-modal .about-book-modal-body { height: auto; max-height: none; overflow: visible; }
  .about-book__cover { min-height: 70vh; break-after: page; }
  .about-book__toc { display: none; }
  .about-book__layout { display: block; width: 100%; }
  .about-book__chapter { min-height: auto; break-before: page; box-shadow: none; }
  .about-book__chapter-footer { display: none; }
}