/* Canonical zero-horizontal-scroll transformations (DF-ZHS-001). */
@media (min-width: 1921px) {
  .hero__title {
    font-size: 8.5rem;
  }
  .hero {
    min-height: 880px;
  }
  .shell {
    max-width: calc(var(--container) + var(--gutter)*2);
  }
}
@media (max-width: 1280px) {
  .desktop-nav {
    gap: 13px;
  }
  .desktop-nav a {
    font-size: .71rem;
  }
  .header-actions .button {
    padding-inline: 13px;
  }
  .hero__title {
    font-size: clamp(3.5rem,8vw,6.9rem);
  }
  .book-callout--lower {
    left: 0;
  }
  .book-callout--upper {
    right: 0;
  }
  .edition-card__info {
    flex-wrap: wrap;
  }
  .edition-card__price {
    margin-left: auto;
  }
}
@media (max-width: 1100px) {
  .desktop-nav {
    display: none;
  }
  .menu-toggle {
    display: flex;
  }
  .hero__layout {
    grid-template-columns: minmax(0,1.02fr) minmax(0,.98fr);
  }
  .hero__title {
    font-size: clamp(3.8rem,8.5vw,6.9rem);
  }
  .hero__lead {
    max-inline-size: 43ch;
  }
  .hero__scanline {
    display: none;
  }
  .hero__book-orbit {
    width: 116%;
  }
  .book-callout {
    display: none;
  }
  .world-pillars {
    margin-top: 38px;
  }
  .pillar {
    padding: 24px;
  }
  .author-visual {
    min-height: 490px;
  }
  .footer-top {
    gap: 30px;
  }
  .footer-links {
    gap: 29px;
  }
}
@media (max-width: 850px) {
  :root {
    --header-height: 72px;
  }
  .section-header--split {
    grid-template-columns: 1fr;
    align-items: start;
    gap: 23px;
  }
  .section-header__aside {
    justify-self: start;
    max-inline-size: 60ch;
  }
  .hero {
    min-height: auto;
  }
  .hero__layout {
    grid-template-columns: 1fr;
    padding-block: calc(var(--header-height) + 68px) 40px;
    gap: 10px;
  }
  .hero__copy {
    order: 1;
  }
  .hero__product {
    order: 2;
    padding-top: 35px;
  }
  .hero__title {
    font-size: clamp(4.5rem,13vw,8rem);
  }
  .hero__lead {
    max-inline-size: 65ch;
  }
  .hero__book-orbit {
    width: min(70vw,640px);
  }
  .book-3d--hero {
    width: min(45vw,385px);
    min-width: 250px;
  }
  .hero__orbit--outer {
    width: 70vw;
    top: 39%;
    right: 10%;
  }
  .hero__orbit--inner {
    width: 56vw;
    top: 41%;
    right: 17%;
  }
  .hero__book-caption {
    bottom: -10px;
  }
  .hero__bottom {
    padding-top: 20px;
  }
  .incident-layout {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .incident-visual {
    min-height: 450px;
  }
  .incident-dossier {
    grid-template-columns: 1fr;
  }
  .terminal-layout {
    grid-template-columns: 1fr;
  }
  .terminal-scene {
    border-right: 0;
    border-bottom: 1px solid var(--c-outline);
  }
  .terminal-scene__radar {
    min-height: 255px;
  }
  .terminal-choice {
    padding: 38px;
  }
  .world-pillars {
    grid-template-columns: 1fr;
  }
  .pillar {
    display: grid;
    grid-template-columns: 50px minmax(0,1fr);
    column-gap: 20px;
  }
  .pillar__index {
    grid-column: 1;
  }
  .pillar__symbol {
    grid-column: 1;
    grid-row: 2 / span 2;
    width: 42px;
    height: 42px;
    margin: 0;
  }
  .pillar h3 {
    grid-column: 2;
    grid-row: 2;
    margin-top: 0;
  }
  .pillar p {
    grid-column: 2;
    grid-row: 3;
  }
  .edition-card__image {
    min-height: 350px;
  }
  .edition-card__book {
    width: min(55%,230px);
  }
  .edition-card__info {
    flex-direction: column;
    align-items: start;
  }
  .edition-card__price {
    margin-left: 0;
  }
  .cover-reveal-layout {
    grid-template-columns: 1fr;
  }
  .cover-reveal-stage {
    min-height: 510px;
  }
  .audio-layout {
    grid-template-columns: 1fr;
  }
  .audio-visual {
    min-height: 420px;
  }
  .audio-visual__disc {
    width: min(63%,360px);
  }
  .author-layout {
    grid-template-columns: 1fr;
  }
  .author-visual {
    min-height: 350px;
  }
  .author-visual__monogram {
    font-size: clamp(6rem,20vw,10rem);
  }
  .faq-layout {
    grid-template-columns: 1fr;
  }
  .faq-intro {
    position: static;
  }
  .footer-top {
    display: grid;
    gap: 55px;
  }
  .footer-links {
    grid-template-columns: repeat(3,minmax(0,1fr));
  }
}
@media (max-width: 640px) {
  :root {
    --gutter: clamp(16px,5vw,26px);
    --section: clamp(74px,12vw,110px);
  }
  .header-buy {
    display: none;
  }
  .header-inner {
    gap: 12px;
  }
  .hero__layout {
    padding-top: calc(var(--header-height) + 54px);
  }
  .hero__pretitle {
    margin-top: 25px;
  }
  .hero__title {
    font-size: clamp(3.3rem,14vw,5.8rem);
  }
  .hero__lead {
    font-size: 1rem;
    margin: 22px 0;
  }
  .hero__actions {
    gap: 20px;
  }
  .hero__actions .button {
    min-height: 56px;
  }
  .hero__product {
    padding-block: 52px 32px;
  }
  .book-3d--hero {
    width: min(57vw,310px);
    min-width: 0;
  }
  .hero__book-caption {
    font-size: .55rem;
    letter-spacing: .14em;
  }
  .hero__orbit {
    display: none;
  }
  .hero__book-orbit {
    width: min(84vw,430px);
  }
  .hero__coordinates {
    display: none;
  }
  .signal-band__track {
    font-size: 1rem;
    gap: 16px;
  }
  .section-title {
    font-size: clamp(2.9rem,11vw,4.7rem);
  }
  .section-header--center p {
    font-size: .97rem;
  }
  .incident-visual {
    min-height: 390px;
  }
  .dossier-row {
    grid-template-columns: 40px minmax(0,1fr);
  }
  .dossier-row__icon {
    display: none;
  }
  .world-portal {
    height: 410px;
  }
  .world-portal__art img {
    object-position: 47% 50%;
  }
  .world-portal__wash {
    background: linear-gradient(0deg,rgba(4,9,24,.95),rgba(4,9,24,.08) 78%);
  }
  .world-portal__message {
    left: 20px;
    right: 20px;
    bottom: 23px;
  }
  .world-portal__message h3 {
    font-size: clamp(2.4rem,9vw,3.6rem);
  }
  .world-portal__message p {
    font-size: .88rem;
  }
  .world-portal__frame {
    left: 15px;
    right: 15px;
    font-size: .53rem;
  }
  .pillar {
    padding: 22px 18px;
  }
  .quote-break__symbol {
    font-size: 5.5rem;
    height: 62px;
  }
  .quote-break blockquote footer {
    font-size: .58rem;
  }
  .reader-shell__toolbar {
    flex-wrap: wrap;
    justify-content: space-between;
  }
  .reader-shell__toolbar > span {
    order: 3;
    flex: 0 0 100%;
    font-size: .58rem;
  }
  .reader-shell__body {
    grid-template-columns: 1fr;
  }
  .reader-shell__margin {
    display: none;
  }
  .reader-shell__page {
    padding: 30px 23px 15px;
  }
  .reader-shell__page p {
    font-size: clamp(1.04rem,4.4vw,1.22rem);
    line-height: 1.87;
  }
  .reader-shell__foot {
    align-items: stretch;
    flex-direction: column;
  }
  .reader-shell__foot .button {
    width: 100%;
  }
  .terminal-scene {
    padding: 28px 23px;
  }
  .terminal-choice {
    padding: 25px 18px;
  }
  .choice-card {
    gap: 10px;
    padding: 16px 12px;
  }
  .edition-grid {
    grid-template-columns: 1fr;
  }
  .edition-card__image {
    min-height: 365px;
  }
  .edition-card__book {
    width: min(48%,225px);
  }
  .edition-card__info {
    flex-direction: row;
  }
  .edition-card__price {
    margin-left: auto;
  }
  .purchase-integrity {
    grid-template-columns: 30px minmax(0,1fr);
    padding: 19px;
  }
  .purchase-integrity__link {
    grid-column: 2;
  }
  .cover-reveal-stage {
    min-height: 445px;
  }
  .cover-reveal-stage__image {
    width: min(57%,235px);
  }
  .audio-visual {
    min-height: 350px;
  }
  .audio-visual__disc {
    width: min(70%,290px);
  }
  .author-visual {
    min-height: 330px;
  }
  .author-copy > p {
    font-size: .97rem;
  }
  .final-cta {
    padding-block: 90px;
    min-height: 500px;
  }
  .final-cta__actions {
    width: 100%;
    flex-direction: column;
  }
  .final-cta__actions .button {
    width: 100%;
  }
  .footer-links {
    grid-template-columns: repeat(2,minmax(0,1fr));
    gap: 32px 23px;
  }
  .footer-top {
    padding-block: 65px 55px;
  }
  .footer-bottom {
    flex-direction: column;
    align-items: start;
  }
}
@media (max-width: 390px) {
  :root {
    --gutter: 16px;
  }
  .brand-lockup__text strong {
    font-size: .99rem;
  }
  .brand-lockup__text small {
    font-size: .51rem;
  }
  .utility-button {
    width: 39px;
  }
  .header-actions {
    gap: 7px;
  }
  .hero__title {
    font-size: clamp(3rem,13.8vw,4rem);
  }
  .eyebrow--tracked {
    gap: 9px;
    font-size: .59rem;
  }
  .eyebrow__rule {
    display: none;
  }
  .hero__assurance {
    gap: 9px;
  }
  .hero__tagline {
    font-size: .8rem;
  }
  .hero__titleplate {
    font-size: .66rem;
  }
  .hero__actions {
    align-items: stretch;
    flex-direction: column;
  }
  .hero__actions .button {
    width: 100%;
  }
  .hero__actions .text-link {
    align-self: start;
  }
  .world-portal {
    height: 450px;
  }
  .edition-card__info {
    flex-direction: column;
  }
  .edition-card__price {
    margin-left: 0;
  }
  .edition-card__image {
    min-height: 335px;
  }
  .edition-card__book {
    width: min(53%,210px);
  }
  .author-visual__side-label {
    font-size: .5rem;
  }
  .footer-links {
    grid-template-columns: 1fr;
  }
  .reader-shell__foot {
    padding: 22px 15px;
  }
}
@media (max-width: 320px) {
  .brand-lockup__text strong {
    font-size: .87rem;
  }
  .brand-lockup__text small {
    font-size: .49rem;
  }
  .hero__title {
    font-size: 2.92rem;
  }
  .hero__book-caption {
    font-size: .49rem;
  }
  .reader-shell__controls button {
    padding: 7px 8px;
  }
  .choice-card {
    grid-template-columns: 23px minmax(0,1fr) 12px;
  }
}