/* ==========================================================================
   Photon Academy book template 2026 (the "Mix" book product pages).
   /books/ (the shelf) and /books/<book>/ (cover, what's inside, contents, sample pages, buy, FAQ).
   Tokens, buttons (.s26-btn), text links (.s26-tl) and the whole shell live in site-2026.css; this file only
   styles <main> on body.bkp. It replaces css/books.css on these pages (tools/site2026_books.py swaps the link).
   The buy flow is untouched: js/books-buy.js and the page's own script wire #bkOffers, [data-programme],
   #bkWho, the sample lightbox and the "already yours" panel (.bk-included, created by script), so every class
   they use is styled here. The regions generated by tools/build_books.py keep their markup.
   ========================================================================== */

[hidden] {
  display: none !important;
}
body.bkp {
  margin: 0;
  background: #fff;
  color: var(--ink);
  font: 400 17px/1.62 var(--fu);
  font-kerning: normal;
}
@media (max-width: 599px) {
  body.bkp {
    font-size: 16.5px;
  }
}
body.bkp main {
  display: block;
}
/* resets for the page body: low specificity, so every class rule below overrides them (but they beat css/global.css) */
main :where(h1, h2, h3, h4, ul, ol, figure, dl) {
  margin: 0;
}
main p {
  font: inherit;
  color: inherit;
  margin: 0 0 1em;
}
main :where(ul, ol) {
  list-style: none;
  padding: 0;
}
main :where(a) {
  color: inherit;
}
main :where(img) {
  max-width: 100%;
  height: auto;
}
main :focus-visible,
.bk-lightbox :focus-visible {
  outline: 3px solid var(--navy);
  outline-offset: 3px;
  border-radius: 2px;
}
main :where(b, strong) {
  font-weight: 600;
}
.bk-sec--dark :focus-visible {
  outline-color: var(--gold);
}
body.bkp {
  --bkp-sticky: 0px;
}

/* container (was .bk in books.css) */
.bk {
  width: 100%;
  max-width: calc(var(--s26-max) + var(--s26-gut) * 2);
  margin-inline: auto;
  padding-inline: var(--s26-gut);
}

/* ---------- Masthead ---------- */
.bk-hero {
  background: #fff;
  padding: clamp(24px, 3.4vw, 48px) 0 clamp(32px, 4vw, 60px);
}
.bk-crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 2px 8px;
  margin: 0 0 clamp(18px, 2.4vw, 30px) !important;
  font: 500 13.5px/1.5 var(--fu);
  color: var(--ink2);
}
.bk-crumbs a {
  color: var(--ink2);
  text-decoration: underline;
  text-decoration-color: var(--line);
  text-decoration-thickness: 1.5px;
  text-underline-offset: 3px;
}
.bk-crumbs a:hover {
  color: var(--ink);
  text-decoration-color: var(--gold);
}
.bk-crumbs span[aria-hidden] {
  color: #8f9bb0;
}
.bk-crumbs [aria-current] {
  color: var(--ink);
}
.bk-eyebrow,
.bk-kicker {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 8px;
  font: 600 12px/1.2 var(--fu);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink2);
}
.bk-eyebrow::before,
.bk-kicker::before {
  content: "";
  flex: none;
  width: 28px;
  height: 2px;
  background: var(--gold);
}
.bk-kicker {
  margin-bottom: 14px;
}
.bk-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
  gap: clamp(32px, 5vw, 88px);
  align-items: center;
}
/* the masthead text column: the call to action sits right after the lead, ahead of the facts and the offer */
.bk-hero-grid > div:first-child {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  min-width: 0;
}
.bk-hero-grid > div:first-child > * {
  max-width: 100%;
}
.bk-hero-grid .bk-eyebrow {
  order: 1;
}
.bk-hero-grid h1 {
  order: 2;
}
.bk-hero-grid .bk-by {
  order: 3;
}
.bk-hero-grid .bk-lead {
  order: 4;
}
.bk-hero-grid .bk-ctas {
  order: 5;
  margin: 0 0 clamp(22px, 2.6vw, 32px);
}
.bk-hero-grid .bk-facts {
  order: 6;
  width: 100%;
}
.bk-hero-grid .bk-launch {
  order: 7;
}
.bk-hero h1 {
  margin: 10px 0 clamp(16px, 2vw, 26px);
  max-width: 18em;
  font-family: var(--fd);
  font-weight: 380;
  font-optical-sizing: auto;
  font-size: clamp(30px, 3.3vw, 47px);
  line-height: 1.07;
  letter-spacing: -0.02em;
  text-wrap: balance;
  color: var(--ink);
}
.bk-by {
  margin: 0 0 16px !important;
  font-size: 16.5px !important;
  color: var(--ink2) !important;
}
.bk-lead {
  max-width: 36em;
  margin: 0 0 clamp(18px, 2vw, 26px) !important;
  font-size: clamp(17px, 1.45vw, 19.5px) !important;
  line-height: 1.55 !important;
  color: var(--ink2) !important;
}
.bk-lead b {
  color: var(--ink);
  font-weight: 600;
}
/* facts: a spec sheet, three columns of hairline-topped cells */
.bk-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0 20px;
  max-width: 40em;
  margin: 0 0 clamp(20px, 2.4vw, 28px) !important;
}
.bk-facts li {
  padding: 10px 0 12px;
  border-top: 1px solid var(--line);
  font: 500 14.5px/1.35 var(--fu);
  color: var(--ink);
  font-variant-numeric: lining-nums tabular-nums;
}
@media (max-width: 599px) {
  .bk-facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 16px;
  }
}
.bk-ctas {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 26px;
}
/* buttons: gold is the page's primary action (the first call to action in the masthead); ink for the rest */
.bk-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 26px;
  border: 1.5px solid var(--gold);
  border-radius: var(--s26-r);
  background: var(--gold);
  color: var(--ink);
  font: 600 15.5px/1.1 var(--fu);
  letter-spacing: 0.005em;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color 0.18s,
    color 0.18s,
    border-color 0.18s;
}
.bk-cta:hover {
  background: #ffba2e;
  border-color: #ffba2e;
  color: var(--ink);
}
.bk-cta.navy {
  border-color: var(--ink);
  background: var(--ink);
  color: #fff;
}
.bk-cta.navy:hover {
  border-color: var(--navy);
  background: var(--navy);
  color: #fff;
}
.bk-cta.line {
  border-color: var(--ink);
  background: transparent;
  color: var(--ink);
}
.bk-cta.line:hover {
  background: var(--ink);
  color: #fff;
}
.bk-cta.alt {
  min-height: 0;
  padding: 14px 0;
  border: 0;
  background: none;
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--gold);
  text-decoration-thickness: 2px;
  text-underline-offset: 5px;
  transition: text-decoration-thickness 0.15s;
}
.bk-cta.alt::after {
  content: "\2192";
  margin-left: 0.2em;
  text-decoration: none;
  display: inline-block;
  transition: transform 0.2s;
}
.bk-cta.alt:hover {
  background: none;
  color: var(--ink);
  text-decoration-thickness: 4px;
}
.bk-cta.alt:hover::after {
  transform: translateX(3px);
}
.bk-cta[disabled],
.bk-cta.is-disabled {
  border-color: var(--line);
  background: var(--chalk);
  color: var(--ink2);
  cursor: not-allowed;
}

/* covers */
.bk-covers {
  position: relative;
  width: 100%;
  max-width: 470px;
  justify-self: center;
  aspect-ratio: 1 / 0.98;
}
.bk-covers img {
  position: absolute;
  display: block;
  width: 62%;
  height: auto;
  border-radius: 2px;
  box-shadow: 0 18px 40px rgba(13, 31, 60, 0.22), 0 2px 6px rgba(13, 31, 60, 0.18);
}
.bk-covers img:first-child {
  left: 0;
  top: 0;
  z-index: 2;
}
.bk-covers img:last-child:not(:first-child) {
  right: 0;
  top: 9%;
  z-index: 1;
}
.bk-covers img:only-child {
  position: relative;
  left: auto;
  top: auto;
  width: min(72%, 340px);
  margin: 0 auto;
}
@media (max-width: 899px) {
  .bk-hero-grid {
    display: flex;
    flex-direction: column;
    gap: 28px;
    align-items: stretch;
  }
  /* phones and tablets: cover first, then the call to action right under the title, then the lead */
  .bk-hero-grid .bk-ctas {
    order: 4;
    margin-bottom: 22px;
  }
  .bk-hero-grid .bk-lead {
    order: 5;
  }
  .bk-hero-grid .bk-facts {
    order: 6;
  }
  .bk-covers {
    order: -1;
    max-width: 290px;
    justify-self: auto;
    align-self: flex-start;
    aspect-ratio: 1 / 0.9;
  }
  .bk-covers img:only-child {
    width: 62%;
    margin: 0;
  }
}

/* launch offer banners (generated by tools/build_books.py; they remove themselves after the end date) */
.bk-launch {
  position: relative;
  max-width: 40em;
  margin: 0 0 clamp(18px, 2vw, 26px);
  padding: 14px 18px 14px 20px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold);
  border-radius: var(--s26-r);
  background: var(--chalk);
}
.bk-launch p {
  margin: 0;
}
.bk-launch__h {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 12px;
  font: 600 16px/1.4 var(--fu);
  color: var(--ink);
}
.bk-launch__tag {
  padding: 3px 8px;
  border-radius: var(--s26-r);
  background: var(--gold);
  color: var(--ink);
  font: 700 10.5px/1.5 var(--fu);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  white-space: nowrap;
}
.bk-launch__p {
  margin-top: 6px !important;
  font-size: 15px !important;
  line-height: 1.55 !important;
  color: var(--ink2) !important;
}
.bk-launch a {
  color: var(--ink);
  font-weight: 600;
  text-decoration: underline;
  text-decoration-color: var(--gold);
  text-decoration-thickness: 1.5px;
  text-underline-offset: 3px;
}
.bk-launch--buy {
  max-width: none;
  margin: 0 0 22px;
}

/* ---------- Bands ---------- */
.bk-sec {
  padding: clamp(44px, 6vw, 92px) 0;
  background: #fff;
  scroll-margin-top: var(--bkp-sticky);
}
.bk-sec--off {
  background: var(--chalk);
}
.bk-sec--dark {
  background: var(--navy);
  color: #fff;
}
.bk-sec--dark .bk-kicker {
  color: var(--onnavy);
}
.bk-sec-head {
  margin: 0 0 clamp(26px, 3.4vw, 42px);
}
.bk-sec-head h2 {
  max-width: 26em;
}
.bk-sec-head p {
  max-width: 46em;
  margin: 14px 0 0 !important;
  font-size: clamp(17px, 1.4vw, 19px) !important;
  line-height: 1.55 !important;
  color: var(--ink2) !important;
}
.bk-sec h2,
.bk-prose h2 {
  margin: 0 0 6px;
  font-family: var(--fd);
  font-weight: 380;
  font-optical-sizing: auto;
  font-size: clamp(28px, 3vw, 42px);
  line-height: 1.1;
  letter-spacing: -0.015em;
  text-wrap: balance;
  color: var(--ink);
}
.bk-sec--dark h2 {
  color: #fff;
}
.bk-sec h3 {
  font-family: var(--fd);
  font-weight: 420;
  font-size: 22px;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.bk-prose > * {
  max-width: 44em;
}
.bk-prose h2 {
  margin-bottom: 20px;
}
.bk-prose p {
  font-size: 17.5px;
  line-height: 1.65;
  color: var(--ink);
}
.bk-sec p a,
.bk-sec li a,
.bk-sec td a,
.bk-faq a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--gold);
  text-decoration-thickness: 1.5px;
  text-underline-offset: 3px;
}
.bk-sec p a:hover,
.bk-sec li a:hover,
.bk-sec td a:hover {
  text-decoration-thickness: 3px;
}
.bk-sec--dark p a {
  color: #fff;
}
.bk-sec p.bk-cta-p a.bk-cta {
  text-decoration: none;
}

/* features: four hairline-topped columns, no icons */
.bk-feats {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 270px), 1fr));
  gap: clamp(28px, 3vw, 40px) clamp(28px, 3.4vw, 48px);
}
.bk-feat {
  padding-top: 16px;
  border-top: 2px solid var(--ink);
}
.bk-feat h3 {
  margin: 0 0 8px;
}
.bk-feat p {
  margin: 0;
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink2);
}

/* contents (generated region) */
.bk-toc {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 380px), 1fr));
  gap: clamp(32px, 4vw, 48px) clamp(32px, 6vw, 96px);
}
.bk-toc__vol {
  min-width: 0;
  padding-top: 18px;
  border-top: 2px solid var(--ink);
}
.bk-toc__vol h3 {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
  margin: 0 0 8px;
  font-weight: 400;
  font-size: clamp(24px, 2.3vw, 30px);
}
.bk-toc__vol h3 small {
  font: 500 13.5px/1.35 var(--fu);
  letter-spacing: 0;
  color: var(--goldt);
}
.bk-toc__vol:only-child {
  grid-column: 1 / -1;
}
.bk-toc__vol:only-child ol {
  columns: 2 360px;
  column-gap: clamp(32px, 6vw, 96px);
}
.bk-toc ol {
  margin: 0;
}
.bk-toc li {
  display: flex;
  gap: 16px;
  align-items: baseline;
  padding: 10px 0;
  border-top: 1px solid #cbd4e0;
  font: 400 17px/1.35 var(--fu);
  color: var(--ink);
  break-inside: avoid;
}
.bk-toc li span {
  flex: 0 0 2.6em;
  text-align: right;
  font-family: var(--fd);
  font-size: 18px;
  color: var(--goldt);
  font-variant-numeric: lining-nums tabular-nums;
}

/* samples (generated region) and the free chapter panel */
.bk-free {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px 28px;
  flex-wrap: wrap;
  margin: 0 0 clamp(28px, 3.4vw, 40px);
  padding: 20px 24px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--ink);
  border-radius: var(--s26-r);
  background: #fff;
}
.bk-free h3 {
  margin: 0 0 4px;
}
.bk-free p {
  margin: 0;
  max-width: 40em;
  font-size: 16px;
  color: var(--ink2);
}
.bk-sample-vol {
  margin: 26px 0 14px !important;
  font: 600 12px/1.3 var(--fu) !important;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink2) !important;
}
.bk-samples {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 28px);
  margin: 0 0 8px;
}
@media (max-width: 899px) {
  .bk-samples {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}
.bk-samples li {
  list-style: none;
}
.bk-samples figure {
  max-width: none;
}
.bk-samples button {
  display: block;
  width: 100%;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--s26-r);
  overflow: hidden;
  background: #fff;
  cursor: zoom-in;
  transition:
    border-color 0.18s,
    box-shadow 0.18s;
}
.bk-samples button:hover {
  border-color: var(--ink);
  box-shadow: 0 10px 26px rgba(13, 31, 60, 0.16);
}
.bk-samples button:focus-visible {
  outline: 3px solid var(--navy);
  outline-offset: 3px;
}
.bk-samples img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 480 / 625;
}
.bk-samples figcaption {
  margin-top: 10px;
  font: italic 400 14px/1.45 var(--fd);
  color: var(--ink2);
}
.bk-lightbox {
  width: 100%;
  max-width: min(96vw, 760px);
  max-height: 96vh;
  margin: auto; /* css/global.css zeroes every margin, which pinned the dialog to the top left */
  padding: 0;
  border: 0;
  background: transparent;
  overflow: visible;
}
.bk-lightbox::backdrop {
  background: rgba(5, 12, 26, 0.86);
}
.bk-lightbox img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 86vh;
  object-fit: contain;
  border-radius: var(--s26-r);
  background: #fff;
}
.bk-lightbox p {
  margin: 10px 0 0;
  font: 400 14px/1.45 var(--fu);
  color: #fff;
  text-align: center;
}
.bk-lightbox__x {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 50%;
  background: rgba(13, 31, 60, 0.9);
  color: #fff;
  font-size: 24px;
  line-height: 42px;
  text-align: center;
  cursor: pointer;
}

/* buy: offers (generated region), the "who is signed in" line, print note */
.bk-who {
  max-width: 44em;
  margin: 0 0 22px !important;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--ink);
  border-radius: var(--s26-r);
  background: var(--chalk);
  font-size: 15.5px !important;
  color: var(--ink) !important;
}
.bk-who:empty {
  display: none;
}
.bk-buy {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 28px);
}
.bk-buy--2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  max-width: 900px;
}
.bk-buy--1 {
  grid-template-columns: minmax(0, 440px);
}
@media (max-width: 799px) {
  .bk-buy,
  .bk-buy--2 {
    grid-template-columns: minmax(0, 1fr);
  }
}
.bk-offer {
  display: flex;
  flex-direction: column;
  min-width: 0;
  padding: 24px;
  border: 1px solid var(--line);
  border-top: 3px solid var(--ink);
  border-radius: var(--s26-r);
  background: #fff;
}
.bk-sec--off .bk-offer {
  background: #fff;
}
.bk-offer__top {
  display: flex;
  gap: 18px;
  align-items: flex-start;
  margin: 0 0 16px;
}
.bk-offer__top img {
  flex: none;
  width: 78px;
  height: auto;
  border-radius: 2px;
  box-shadow: 0 8px 18px rgba(13, 31, 60, 0.2), 0 1px 3px rgba(13, 31, 60, 0.16);
}
.bk-offer h3 {
  margin: 2px 0 4px;
  font-size: 24px;
  font-weight: 400;
}
.bk-offer__scope {
  margin: 0 !important;
  font-size: 14.5px !important;
  line-height: 1.5 !important;
  color: var(--ink2) !important;
}
.bk-offer ul {
  flex: 1;
  margin: 0 0 18px;
}
.bk-offer li {
  position: relative;
  padding: 7px 0 7px 22px;
  border-top: 1px solid var(--line);
  font-size: 15.5px;
  line-height: 1.5;
  color: var(--ink);
}
.bk-offer li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 14px;
  width: 10px;
  height: 6px;
  border-left: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
  transform: rotate(-45deg);
}
.bk-price {
  margin: 0 0 6px !important;
  font-family: var(--fd) !important;
  font-weight: 380 !important;
  font-size: 36px !important;
  line-height: 1.1 !important;
  letter-spacing: -0.015em;
  color: var(--ink) !important;
  font-variant-numeric: lining-nums;
}
.bk-price small {
  display: block;
  margin-top: 4px;
  font: 500 13.5px/1.4 var(--fu);
  letter-spacing: 0;
  color: var(--ink2);
}
.bk-isbn {
  margin: 0 0 14px !important;
  font-size: 12.5px !important;
  line-height: 1.5 !important;
  color: var(--ink2) !important;
  font-variant-numeric: lining-nums tabular-nums;
}
.bk-isbn span {
  display: block;
}
.bk-offer .bk-cta {
  width: 100%;
}
.bk-owned {
  display: block;
  margin: 0 0 12px;
  padding: 6px 10px;
  border: 1px solid var(--ink);
  border-radius: var(--s26-r);
  font: 600 12px/1.3 var(--fu);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-align: center;
  color: var(--ink);
}
.bk-note {
  margin: 14px 0 0 !important;
  font-size: 14px !important;
  line-height: 1.6 !important;
  color: var(--ink2) !important;
}
.bk-err {
  display: none;
  margin: 10px 0 0 !important;
  padding: 8px 12px;
  border: 1px solid #b42318;
  border-radius: var(--s26-r);
  background: #fff4f2;
  font-size: 14px !important;
  line-height: 1.5 !important;
  color: #8a1a10 !important;
}
.bk-print {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 18px;
  margin-top: 24px;
  padding: 14px 18px;
  border: 1px dashed #aab6c8;
  border-radius: var(--s26-r);
}
.bk-print p {
  margin: 0;
  font-size: 15.5px;
  color: var(--ink2);
}
/* "already yours" panels, created by the page script */
.bk-included {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px 24px;
  padding: 20px 24px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--ink);
  border-radius: var(--s26-r);
  background: var(--chalk);
}
#bkOwned,
#bkIncluded {
  margin-bottom: 22px;
}
.bk-included h3 {
  margin: 0 0 4px;
}
.bk-included p {
  margin: 0;
  font-size: 15.5px;
  color: var(--ink2);
}
.bk-included__go {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* chips (pills) */
.bk-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0 0 14px;
}
.bk-pill {
  display: inline-block;
  padding: 3px 9px;
  border: 1px solid var(--line);
  border-radius: var(--s26-r);
  background: #fff;
  font: 600 11.5px/1.5 var(--fu);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
  color: var(--ink2);
}
.bk-pill--navy {
  border-color: var(--ink);
  color: var(--ink);
}
.bk-pill--soon {
  border-style: dashed;
  border-color: #b8a266;
  color: var(--goldt);
}

/* e-book and print table */
.bk-compare {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  font-size: 16px;
}
.bk-compare th,
.bk-compare td {
  padding: 14px 18px 14px 0;
  border-top: 1px solid #cbd4e0;
  text-align: left;
  vertical-align: top;
  line-height: 1.5;
  color: var(--ink2);
  font-weight: 400;
}
.bk-compare thead th {
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--ink);
  font: 600 12px/1.3 var(--fu);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink2);
}
.bk-compare tbody th {
  width: 24%;
  font-weight: 600;
  color: var(--ink);
}
.bk-compare tbody tr:last-child th,
.bk-compare tbody tr:last-child td {
  border-bottom: 1px solid #cbd4e0;
}
@media (max-width: 599px) {
  .bk-compare th,
  .bk-compare td {
    padding: 11px 12px 11px 0;
    font-size: 15px;
  }
}

/* author */
.bk-author {
  display: grid;
  grid-template-columns: minmax(180px, 260px) minmax(0, 1fr);
  gap: clamp(24px, 4vw, 64px);
  align-items: start;
}
.bk-author img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--s26-r);
  filter: grayscale(1) contrast(1.03);
}
@media (max-width: 699px) {
  .bk-author {
    grid-template-columns: minmax(0, 1fr);
  }
  .bk-author img {
    max-width: 220px;
  }
}

/* FAQ */
.bk-faq {
  max-width: 52em;
}
.bk-faq details {
  border-top: 1px solid #cbd4e0;
}
.bk-faq details:last-of-type {
  border-bottom: 1px solid #cbd4e0;
}
.bk-faq summary {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 20px;
  min-height: 44px;
  padding: 18px 0;
  font: 500 18px/1.35 var(--fu);
  list-style: none;
  cursor: pointer;
  color: var(--ink);
}
.bk-faq summary::-webkit-details-marker {
  display: none;
}
.bk-faq summary::after {
  content: "";
  flex: none;
  width: 14px;
  height: 14px;
  margin-top: 6px;
  background:
    linear-gradient(var(--goldt), var(--goldt)) center / 100% 2px no-repeat,
    linear-gradient(var(--goldt), var(--goldt)) center / 2px 100% no-repeat;
  transition: transform 0.2s;
}
.bk-faq details[open] summary::after {
  background: linear-gradient(var(--goldt), var(--goldt)) center / 100% 2px no-repeat;
}
.bk-faq details p {
  max-width: 40em;
  margin: 0 0 20px;
  font-size: 16.5px;
  color: var(--ink2);
}
@media (max-width: 599px) {
  .bk-faq summary {
    font-size: 17px;
  }
}
.bk-disclaimer {
  max-width: 52em !important;
  margin: 28px 0 0 !important;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: 13.5px !important;
  line-height: 1.6 !important;
  color: var(--ink2) !important;
}

/* ---------- The shelf (/books/) ---------- */
.bk-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(32px, 4vw, 52px) clamp(32px, 6vw, 96px);
}
@media (max-width: 899px) {
  .bk-grid {
    grid-template-columns: minmax(0, 1fr);
  }
}
.bk-card {
  display: grid;
  grid-template-columns: 124px minmax(0, 1fr);
  gap: 22px;
  align-items: start;
  padding-top: 20px;
  border-top: 2px solid var(--ink);
}
.bk-card img {
  display: block;
  width: 124px;
  height: auto;
  border-radius: 2px;
  box-shadow: 0 12px 26px rgba(13, 31, 60, 0.2), 0 1px 4px rgba(13, 31, 60, 0.16);
}
.bk-card__series {
  margin: 0 0 8px !important;
  font: 600 12px/1.3 var(--fu) !important;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink2) !important;
}
.bk-card h3 {
  margin: 0 0 8px;
  font-size: clamp(21px, 1.9vw, 25px);
  line-height: 1.18;
}
.bk-card h3 a {
  color: inherit;
  text-decoration: none;
}
.bk-card h3 a:hover {
  text-decoration: underline;
  text-decoration-color: var(--gold);
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
}
.bk-card p {
  font-size: 15.5px;
  line-height: 1.55;
  color: var(--ink2);
}
.bk-card__price {
  margin: 0 0 8px !important;
  font: 600 15.5px/1.4 var(--fu) !important;
  color: var(--ink) !important;
  font-variant-numeric: lining-nums tabular-nums;
}
.bk-card__go,
.bk-card__sample {
  display: block;
  width: fit-content;
  padding: 11px 0;
  font: 600 15px/1.4 var(--fu);
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--gold);
  text-decoration-thickness: 2px;
  text-underline-offset: 5px;
}
.bk-card__go:hover,
.bk-card__sample:hover {
  text-decoration-thickness: 4px;
}
.bk-card__sample {
  margin-top: -6px;
  font-weight: 500;
  color: var(--ink2);
}
@media (max-width: 479px) {
  .bk-card {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: 16px;
  }
  .bk-card img {
    width: 96px;
  }
}
.bk-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(24px, 4vw, 56px);
  counter-reset: s;
}
@media (max-width: 799px) {
  .bk-steps {
    grid-template-columns: minmax(0, 1fr);
  }
}
.bk-steps li {
  padding-top: 18px;
  border-top: 1px solid var(--navyline);
  counter-increment: s;
}
.bk-steps li::before {
  content: counter(s, decimal-leading-zero);
  display: block;
  margin-bottom: 12px;
  font: 400 30px/1 var(--fd);
  color: var(--gold);
  font-variant-numeric: lining-nums;
}
.bk-steps h3 {
  margin: 0 0 8px;
  color: #fff;
}
.bk-steps p {
  margin: 0;
  font-size: 16.5px;
  line-height: 1.6;
  color: var(--onnavy);
}
.bk-steps a {
  color: #fff;
}

/* shelf of covers in the /books/ masthead (decorative: the cards below carry the real links) */
.bkp-shelf {
  display: flex;
  align-items: flex-end;
  justify-content: center;
}
.bkp-shelf img {
  display: block;
  width: 29%;
  height: auto;
  border-radius: 2px;
  box-shadow: 0 14px 30px rgba(13, 31, 60, 0.22), 0 1px 4px rgba(13, 31, 60, 0.16);
}
.bkp-shelf img + img {
  margin-left: -7%;
}
.bkp-shelf img:nth-child(1) {
  transform: translateY(0);
}
.bkp-shelf img:nth-child(2) {
  transform: translateY(-4%);
}
.bkp-shelf img:nth-child(3) {
  transform: translateY(2%);
}
.bkp-shelf img:nth-child(4) {
  transform: translateY(-3%);
}
.bkp-hero--shelf > .bk {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 0.8fr);
  column-gap: clamp(32px, 6vw, 96px);
  align-items: center;
}
.bkp-hero--shelf > .bk > * {
  grid-column: 1;
}
.bkp-hero--shelf > .bk > .bkp-shelf {
  grid-column: 2;
  grid-row: 1 / span 8;
}
@media (max-width: 899px) {
  .bkp-hero--shelf > .bk {
    display: flex;
    flex-direction: column;
    align-items: stretch;
  }
  .bkp-hero--shelf .bk-crumbs {
    order: -2;
  }
  .bkp-hero--shelf .bkp-shelf {
    order: -1;
    width: 100%;
    max-width: 360px;
    margin: 0 0 22px;
    justify-content: flex-start;
  }
}

/* ---------- In-page nav (product pages) ---------- */
.bkp-nav {
  position: sticky;
  top: var(--s26-hdr);
  z-index: 30;
  background: #fff;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.bkp-nav ul {
  display: flex;
  gap: clamp(18px, 2.6vw, 36px);
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}
.bkp-nav ul::-webkit-scrollbar {
  display: none;
}
.bkp-nav li {
  flex: none;
}
.bkp-nav a {
  display: block;
  padding: 15px 0 13px;
  border-bottom: 2px solid transparent;
  font: 500 15px/1.3 var(--fu);
  color: var(--ink2);
  text-decoration: none;
  white-space: nowrap;
}
.bkp-nav a:hover {
  color: var(--ink);
}
.bkp-nav a[aria-current] {
  border-bottom-color: var(--gold);
  color: var(--ink);
  font-weight: 600;
}
body.bkp.has-nav {
  --bkp-sticky: 50px;
}
@media (max-width: 599px) {
  .bkp-nav a {
    padding: 15px 0 13px;
    font-size: 14.5px;
  }
}

@media (prefers-reduced-motion: reduce) {
  body.bkp *,
  body.bkp *::before,
  body.bkp *::after {
    transition: none !important;
  }
}