:root {
  --paper: #f3f1ea;
  --paper-deep: #e9e6dd;
  --surface: #fffefa;
  --ink: #153447;
  --ink-deep: #0e2939;
  --ink-muted: #50646f;
  --teal: #0d6c68;
  --teal-deep: #07514f;
  --teal-pale: #dceee9;
  --copper: #a65f35;
  --line: #ccd4d2;
  --line-dark: #aebbb9;
  --white: #ffffff;
  --serif: Georgia, "Times New Roman", serif;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --page-width: 72rem;
  --page-gutter: clamp(1.25rem, 4vw, 3.5rem);
  --section-space: clamp(4.5rem, 9vw, 8rem);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 1.5rem;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image: radial-gradient(rgb(21 52 71 / 8%) 0.6px, transparent 0.6px);
  background-size: 7px 7px;
  content: "";
  pointer-events: none;
}

a {
  color: inherit;
}

img,
svg {
  display: block;
  max-width: 100%;
}

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

h1,
h2,
h3 {
  color: var(--ink-deep);
  font-family: var(--serif);
  font-weight: 400;
  line-height: 1.12;
  text-wrap: balance;
}

h1 {
  margin-bottom: 1.5rem;
  font-size: clamp(2.9rem, 6.6vw, 5.75rem);
  letter-spacing: -0.045em;
}

h1 em {
  color: var(--teal-deep);
  font-style: italic;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(2.25rem, 4.5vw, 3.8rem);
  letter-spacing: -0.035em;
}

h3 {
  font-size: clamp(1.55rem, 2.7vw, 2.25rem);
  letter-spacing: -0.025em;
}

.page-width {
  width: min(var(--page-width), calc(100% - (2 * var(--page-gutter))));
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 20;
  padding: 0.7rem 1rem;
  border: 2px solid var(--white);
  border-radius: 0.25rem;
  background: var(--ink-deep);
  color: var(--white);
  font-weight: 700;
  transform: translateY(-150%);
  transition: transform 120ms ease-out;
}

.skip-link:focus {
  transform: translateY(0);
}

:focus-visible {
  outline: 3px solid var(--copper);
  outline-offset: 4px;
}

#main-content:focus {
  outline: none;
}

.eyebrow {
  margin-bottom: 1rem;
  color: var(--teal-deep);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.15em;
  line-height: 1.3;
  text-transform: uppercase;
}

.site-header {
  border-bottom: 1px solid var(--line);
  background: rgb(243 241 234 / 92%);
}

.site-header__inner {
  display: flex;
  min-height: 5.5rem;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.site-brand {
  display: inline-flex;
  min-width: 0;
  align-items: center;
  gap: 0.7rem;
  color: var(--ink-deep);
  font-size: clamp(0.92rem, 2vw, 1.05rem);
  font-weight: 750;
  letter-spacing: -0.02em;
  line-height: 1.1;
  text-decoration: none;
}

.site-brand__mark {
  width: 2.35rem;
  flex: 0 0 auto;
  fill: none;
  stroke: currentcolor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.7;
}

.site-brand__mark path:last-child {
  stroke: var(--teal);
}

.site-brand__name {
  overflow-wrap: anywhere;
}

.site-brand__name span {
  color: var(--teal-deep);
  font-weight: 600;
}

.primary-nav ul {
  display: flex;
  margin: 0;
  padding: 0;
  align-items: center;
  gap: clamp(1.1rem, 3vw, 2.25rem);
  list-style: none;
}

.primary-nav a {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  border-bottom: 2px solid transparent;
  color: var(--ink-muted);
  font-size: 0.91rem;
  font-weight: 700;
  text-decoration: none;
}

.primary-nav a:hover {
  border-bottom-color: var(--teal);
  color: var(--ink-deep);
}

.hero {
  position: relative;
  overflow: clip;
  border-bottom: 1px solid var(--line);
}

.hero::before {
  position: absolute;
  top: -12rem;
  left: -9rem;
  width: 31rem;
  height: 31rem;
  border: 1px solid rgb(13 108 104 / 16%);
  border-radius: 50%;
  box-shadow: 0 0 0 4rem rgb(13 108 104 / 3%), 0 0 0 8rem rgb(13 108 104 / 2%);
  content: "";
  pointer-events: none;
}

.hero__inner {
  position: relative;
  display: grid;
  min-height: clamp(39rem, 72vh, 50rem);
  padding-block: clamp(4.5rem, 9vw, 8rem);
  align-items: center;
  grid-template-columns: minmax(0, 1.18fr) minmax(18rem, 0.82fr);
  gap: clamp(3rem, 7vw, 7rem);
}

.hero__content {
  position: relative;
  z-index: 1;
}

.hero__lead {
  max-width: 39rem;
  margin-bottom: 2.25rem;
  color: var(--ink-muted);
  font-size: clamp(1.1rem, 2vw, 1.3rem);
  line-height: 1.7;
}

.hero__actions {
  display: flex;
  align-items: center;
  gap: 1.25rem 1.5rem;
  flex-wrap: wrap;
}

.button {
  display: inline-flex;
  min-height: 3.25rem;
  padding: 0.75rem 1.2rem;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  border: 1px solid transparent;
  border-radius: 0.25rem;
  font-size: 0.9rem;
  font-weight: 800;
  line-height: 1.35;
  text-decoration: none;
  transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease, transform 150ms ease;
}

.button svg {
  width: 1.15rem;
  flex: 0 0 auto;
  fill: none;
  stroke: currentcolor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.7;
}

.button:hover {
  transform: translateY(-2px);
}

.button--primary {
  background: var(--teal-deep);
  color: var(--white);
}

.button--primary:hover {
  background: var(--ink-deep);
}

.button--secondary {
  align-self: flex-start;
  border-color: var(--ink-deep);
  background: var(--ink-deep);
  color: var(--white);
}

.button--secondary:hover {
  border-color: var(--teal-deep);
  background: var(--teal-deep);
}

.availability {
  display: inline-flex;
  margin: 0;
  align-items: center;
  gap: 0.6rem;
  color: var(--ink-muted);
  font-size: 0.84rem;
  font-weight: 700;
}

.availability span,
.status-label span {
  width: 0.55rem;
  height: 0.55rem;
  border: 2px solid var(--surface);
  border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 0 0 1px var(--teal);
}

.hero-illustration {
  position: relative;
  border: 1px solid var(--line-dark);
  background: rgb(255 254 250 / 58%);
  box-shadow: 1.1rem 1.1rem 0 rgb(21 52 71 / 5%);
}

.hero-illustration::before,
.hero-illustration::after {
  position: absolute;
  z-index: 2;
  width: 0.65rem;
  height: 0.65rem;
  border-radius: 50%;
  background: var(--copper);
  content: "";
}

.hero-illustration::before {
  top: -0.35rem;
  left: -0.35rem;
}

.hero-illustration::after {
  right: -0.35rem;
  bottom: -0.35rem;
}

.hero-illustration__label,
.hero-illustration__caption {
  display: flex;
  color: var(--ink-muted);
  font-size: 0.63rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  line-height: 1.4;
  text-transform: uppercase;
}

.hero-illustration__label {
  position: absolute;
  top: 1rem;
  left: 1.15rem;
  z-index: 2;
}

.hero-illustration__caption {
  position: absolute;
  right: 1.15rem;
  bottom: 1rem;
  left: 1.15rem;
  justify-content: space-between;
  gap: 1rem;
}

.hero-illustration svg {
  width: 100%;
}

.illustration-grid {
  fill: none;
  stroke: rgb(21 52 71 / 8%);
  stroke-width: 0.8;
}

.illustration-rule,
.illustration-dash,
.illustration-book,
.illustration-spine,
.illustration-detail,
.illustration-accent,
.illustration-accent-ring {
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.illustration-rule {
  stroke: var(--ink);
  stroke-width: 1.5;
}

.illustration-dash {
  stroke: rgb(21 52 71 / 28%);
  stroke-dasharray: 3 8;
  stroke-width: 1;
}

.illustration-node {
  fill: var(--copper);
}

.illustration-book {
  fill: rgb(255 254 250 / 72%);
  stroke: var(--ink);
  stroke-width: 2;
}

.illustration-spine {
  fill: var(--teal-pale);
  stroke: var(--teal-deep);
  stroke-width: 2;
}

.illustration-detail {
  stroke: rgb(21 52 71 / 42%);
  stroke-width: 1.5;
}

.illustration-accent {
  stroke: var(--teal-deep);
  stroke-width: 2;
}

.illustration-accent-ring {
  stroke: var(--copper);
  stroke-width: 1.5;
}

.section {
  padding-block: var(--section-space);
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 2rem;
}

.section-intro {
  max-width: 42rem;
  margin: 1.5rem 0 3rem;
  color: var(--ink-muted);
  font-size: 1.08rem;
}

.title-count {
  display: flex;
  margin: 0 0 0.4rem;
  padding-left: 1.5rem;
  align-items: baseline;
  gap: 0.6rem;
  border-left: 1px solid var(--line-dark);
  color: var(--ink-muted);
  font-size: 0.78rem;
  font-weight: 750;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
}

.title-count strong {
  color: var(--teal-deep);
  font-family: var(--serif);
  font-size: 2.4rem;
  font-weight: 400;
  letter-spacing: -0.04em;
}

.catalog {
  display: grid;
  gap: 1.5rem;
}

.book-card {
  display: grid;
  overflow: hidden;
  border: 1px solid var(--line-dark);
  border-radius: 0.4rem;
  background: var(--surface);
  box-shadow: 0 1.5rem 4rem rgb(21 52 71 / 7%);
  grid-template-columns: minmax(17.5rem, 0.78fr) minmax(0, 1.45fr);
}

.book-card__visual {
  display: grid;
  min-height: 34rem;
  padding: clamp(2rem, 5vw, 4rem);
  place-items: center;
  border-right: 1px solid var(--line);
  background-color: var(--paper-deep);
  background-image: linear-gradient(rgb(21 52 71 / 6%) 1px, transparent 1px), linear-gradient(90deg, rgb(21 52 71 / 6%) 1px, transparent 1px);
  background-size: 1.5rem 1.5rem;
}

.book-cover {
  position: relative;
  display: flex;
  width: min(100%, 17rem);
  aspect-ratio: 4 / 5.25;
  padding: 1.25rem 1.15rem 1rem;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid rgb(255 255 255 / 25%);
  background: var(--ink-deep);
  box-shadow: -0.6rem 0.8rem 0 var(--teal), 0 1.6rem 2.4rem rgb(14 41 57 / 24%);
  color: var(--white);
}

.book-cover::before {
  position: absolute;
  top: -25%;
  right: -45%;
  width: 95%;
  aspect-ratio: 1;
  border: 1px solid rgb(85 183 170 / 55%);
  border-radius: 50%;
  box-shadow: 0 0 0 1.7rem rgb(85 183 170 / 5%), 0 0 0 3.4rem rgb(85 183 170 / 4%);
  content: "";
}

.book-cover__header,
.book-cover__footer {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  font-size: 0.48rem;
  font-weight: 750;
  letter-spacing: 0.11em;
  line-height: 1.35;
  text-transform: uppercase;
}

.book-cover__header {
  padding-bottom: 0.8rem;
  border-bottom: 1px solid rgb(255 255 255 / 35%);
}

.book-cover__body {
  position: relative;
  z-index: 1;
  display: flex;
  flex: 1;
  padding-top: 1.15rem;
  align-items: flex-start;
  flex-direction: column;
}

.book-cover__series {
  margin: 0 0 0.3rem;
  color: #8bd3c8;
  font-size: 0.48rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.book-cover__number {
  margin: 0.14rem 0 0 0.32rem;
  color: var(--white);
  font-family: var(--serif);
  font-size: clamp(4.1rem, 8vw, 5.3rem);
  letter-spacing: -0.075em;
  line-height: 0.88;
}

.book-cover__title {
  max-width: 10.75rem;
  padding-left: 0.02rem;
  color: var(--white);
  font-family: var(--serif);
  font-size: 0.89rem;
  line-height: 1.18;
}

.book-cover__title--epa {
  margin: 0.72rem 0 0.08rem;
}

.book-cover__diagram {
  position: absolute;
  right: auto;
  bottom: 2.55rem;
  left: 50%;
  width: 62%;
  overflow: visible;
  transform: translateX(-50%);
}

.book-cover__ac-body {
  fill: rgb(255 254 250 / 92%);
  stroke: rgb(139 211 200 / 88%);
  stroke-width: 1.5;
}

.book-cover__ac-top,
.book-cover__ac-divider,
.book-cover__ac-fan-ring,
.book-cover__ac-fan-spoke,
.book-cover__ac-vent,
.book-cover__ac-base {
  fill: none;
  stroke: var(--ink-deep);
  stroke-linecap: round;
  stroke-linejoin: round;
}

.book-cover__ac-top,
.book-cover__ac-divider {
  stroke-width: 1.15;
  opacity: 0.6;
}

.book-cover__ac-fan-ring {
  stroke-width: 1.25;
}

.book-cover__ac-fan-spoke {
  stroke-width: 1;
  opacity: 0.78;
}

.book-cover__ac-fan-hub {
  fill: var(--copper);
  stroke: rgb(139 211 200 / 95%);
  stroke-width: 1.2;
}

.book-cover__ac-vent {
  stroke-width: 2.3;
}

.book-cover__ac-base {
  stroke: rgb(139 211 200 / 88%);
  stroke-width: 1.4;
}

.book-cover__footer {
  padding-top: 0.75rem;
  border-top: 1px solid rgb(255 255 255 / 35%);
}

.book-card__content {
  display: flex;
  min-width: 0;
  padding: clamp(2rem, 5vw, 4.5rem);
  flex-direction: column;
}

.book-card__labels {
  display: flex;
  margin-bottom: 1.35rem;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.subject-label,
.status-label {
  margin: 0;
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  line-height: 1.4;
  text-transform: uppercase;
}

.subject-label {
  color: var(--teal-deep);
}

.status-label {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--ink-muted);
}

.book-card h3 {
  max-width: 40rem;
  margin-bottom: 1.25rem;
  overflow-wrap: anywhere;
}

.book-card__description {
  max-width: 42rem;
  margin-bottom: 1.7rem;
  color: var(--ink-muted);
  font-size: 1.06rem;
  line-height: 1.72;
}

.book-metadata {
  display: grid;
  margin: 0 0 2.25rem;
  border-top: 1px solid var(--line);
}

.book-metadata div {
  display: grid;
  padding-block: 0.8rem;
  border-bottom: 1px solid var(--line);
  grid-template-columns: 7.25rem minmax(0, 1fr);
  gap: 1rem;
}

.book-metadata dt {
  color: var(--ink-muted);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.book-metadata dd {
  margin: 0;
  color: var(--ink);
  font-size: 0.9rem;
  font-weight: 650;
  line-height: 1.5;
}

.about {
  border-top: 1px solid var(--line);
  background: var(--ink-deep);
  color: #d5dfe2;
}

.about__inner {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(24rem, 1.18fr);
  gap: clamp(3.5rem, 8vw, 8rem);
}

.about .eyebrow {
  color: #8bd3c8;
}

.about h2,
.about h3 {
  color: var(--white);
}

.about__statement > p:last-child {
  max-width: 37rem;
  margin: 1.5rem 0 0;
  color: #b9c8cd;
  font-size: 1.08rem;
}

.principles {
  margin: 0;
  padding: 0;
  border-top: 1px solid rgb(255 255 255 / 22%);
  list-style: none;
}

.principles li {
  display: grid;
  padding-block: 1.35rem;
  border-bottom: 1px solid rgb(255 255 255 / 22%);
  grid-template-columns: 3.25rem minmax(0, 1fr);
  gap: 1.25rem;
}

.principles__number {
  color: #8bd3c8;
  font-family: var(--serif);
  font-size: 1.3rem;
}

.principles h3 {
  margin-bottom: 0.35rem;
  font-family: var(--sans);
  font-size: 1rem;
  font-weight: 750;
  letter-spacing: 0;
}

.principles p {
  max-width: 33rem;
  margin: 0;
  color: #aebfc5;
  font-size: 0.91rem;
}

.site-footer {
  border-top: 1px solid rgb(255 255 255 / 12%);
  background: #0a202d;
  color: #aebfc5;
}

.site-footer__inner {
  display: flex;
  min-height: 8.5rem;
  padding-block: 1.5rem;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem 3rem;
}

.site-brand--footer {
  color: var(--white);
}

.site-brand--footer .site-brand__mark path:last-child {
  stroke: currentcolor;
}

.site-brand--footer .site-brand__name span {
  color: #8bd3c8;
}

.site-footer p {
  max-width: 30rem;
  margin: 0;
  font-size: 0.78rem;
  text-align: right;
}

@media (max-width: 56rem) {
  .hero__inner {
    min-height: auto;
    grid-template-columns: 1fr;
  }

  .hero__content {
    max-width: 47rem;
  }

  .hero-illustration {
    width: min(100%, 35rem);
    justify-self: end;
  }

  .book-card {
    grid-template-columns: minmax(15rem, 0.72fr) minmax(0, 1.28fr);
  }

  .book-card__visual {
    min-height: 31rem;
    padding-inline: 2rem;
  }

  .book-card__content {
    padding-inline: clamp(1.75rem, 4vw, 3rem);
  }

  .book-metadata div {
    grid-template-columns: 1fr;
    gap: 0.25rem;
  }

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

@media (max-width: 43rem) {
  :root {
    --page-gutter: clamp(1rem, 5vw, 1.5rem);
  }

  .site-header__inner {
    min-height: 4.75rem;
    gap: 1rem;
  }

  .site-brand__mark {
    width: 2rem;
  }

  .site-brand__name {
    max-width: none;
    font-size: 0.78rem;
    overflow-wrap: normal;
    white-space: nowrap;
  }

  .primary-nav ul {
    gap: 0.8rem;
  }

  .primary-nav a {
    padding-inline: 0.2rem;
    font-size: 0.82rem;
  }

  .hero__inner {
    padding-block: 4.5rem;
    gap: 3.25rem;
  }

  .hero__actions {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero-illustration__caption span:last-child {
    display: none;
  }

  .section-heading {
    align-items: flex-start;
    flex-direction: column;
    gap: 1.25rem;
  }

  .title-count {
    padding-left: 0;
    border-left: 0;
  }

  .section-intro {
    margin-top: 1.25rem;
  }

  .book-card {
    grid-template-columns: 1fr;
  }

  .book-card__visual {
    min-height: auto;
    padding-block: 3rem;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .book-cover {
    width: min(75vw, 15.5rem);
  }

  .book-card__content {
    padding: 2rem 1.4rem 2.25rem;
  }

  .button--secondary {
    width: 100%;
  }

  .about__inner {
    gap: 3rem;
  }

  .principles li {
    grid-template-columns: 2.3rem minmax(0, 1fr);
    gap: 0.8rem;
  }

  .site-footer__inner {
    padding-block: 2rem;
    align-items: flex-start;
    flex-direction: column;
  }

  .site-footer p {
    text-align: left;
  }
}

@media (max-width: 24rem) {
  .site-header .site-brand__name {
    font-size: 0.72rem;
  }

  .site-header .site-brand__name span {
    display: none;
  }

  .primary-nav ul {
    gap: 0.35rem;
  }

  .primary-nav a {
    font-size: 0.76rem;
  }

  .hero-illustration__label {
    font-size: 0.53rem;
  }

  .book-card__labels {
    align-items: flex-start;
    flex-direction: column;
  }
}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

@media (forced-colors: active) {
  .button,
  .book-card,
  .hero-illustration {
    border: 1px solid CanvasText;
  }

  .availability span,
  .status-label span {
    border: 2px solid CanvasText;
    background: CanvasText;
    box-shadow: none;
  }

  .book-cover {
    border: 2px solid CanvasText;
  }
}