:root {
  --paper: #f7f3eb;
  --paper-deep: #eee8dc;
  --white: #fffdf8;
  --ink: #182f37;
  --muted: #586568;
  --navy: #142d36;
  --copper: #96522e;
  --gold: #d7b083;
  --line: #d6d2c7;
  --serif: Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 100px; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: 16px; line-height: 1.65; -webkit-font-smoothing: antialiased; }
[hidden] { display: none !important; }
::selection { background: #dfc398; color: var(--ink); }
a { color: inherit; text-underline-offset: .22em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
button, input, select { font: inherit; }
button { cursor: pointer; }
a, button, input, select, summary { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid var(--copper); outline-offset: 5px; }
.hero :focus-visible, .getting-started :focus-visible, .site-footer :focus-visible { outline-color: var(--gold); }
h1, h2, h3, p, figure, dl { margin: 0; }
h1, h2, h3 { font-weight: 400; }
h2 { font-family: var(--serif); font-size: clamp(2.25rem, 4vw, 3.5rem); line-height: 1.12; letter-spacing: -.035em; }
h3 { font-size: 1.12rem; line-height: 1.4; }
p + p { margin-top: 1.1em; }
svg { display: block; max-width: 100%; }
.container { width: min(1160px, calc(100% - 96px)); margin-inline: auto; }
.section { padding-block: 100px; }
.eyebrow { font-size: .71rem; font-weight: 650; letter-spacing: .16em; text-transform: uppercase; color: var(--copper); line-height: 1.6; margin-bottom: 23px; }
.skip-link { position: fixed; top: 12px; left: 12px; z-index: 100; transform: translateY(-160%); padding: 12px 20px; background: var(--white); color: var(--ink); }
.skip-link:focus { transform: translateY(0); }
.site-header { background: var(--paper); position: sticky; top: 0; z-index: 20; border-bottom: 1px solid var(--line); }
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 91px; gap: 32px; }
.wordmark { display: flex; align-items: center; gap: 13px; text-decoration: none; font-size: .8rem; line-height: 1.3; font-weight: 600; letter-spacing: -.01em; }
.wordmark-symbol { width: 47px; height: 47px; display: grid; align-content: center; position: relative; font-family: var(--serif); font-size: 1.9rem; font-weight: 400; border: 1px solid #aeb5b0; line-height: 1; padding-left: 6px; }
.wordmark-symbol > span { position: absolute; font-size: .95rem; right: 4px; top: 4px; color: var(--copper); }
.site-nav { display: flex; align-items: center; gap: 29px; font-size: .82rem; }
.site-nav a { text-decoration: none; padding-block: 10px; border-bottom: 1px solid transparent; }
.site-nav a:hover { color: var(--copper); border-bottom-color: var(--copper); }
.menu-toggle { background: transparent; border: 1px solid var(--line); color: var(--ink); padding: 8px 12px; border-radius: 2px; font-size: .85rem; }
.menu-toggle > span { margin-left: 15px; }
.hero { background: var(--navy); color: var(--paper); overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.3fr 1fr; gap: 64px; align-items: center; padding-block: 76px 71px; }
.hero .eyebrow { color: var(--gold); display: flex; align-items: center; gap: 12px; margin-bottom: 28px; }
.small-line { width: 25px; height: 1px; background: var(--gold); }
h1 { font-family: var(--serif); font-size: clamp(2.7rem, 5.65vw, 4.9rem); line-height: 1.02; letter-spacing: -.055em; }
.question-mark { color: var(--gold); }
.book-subtitle { font-family: var(--serif); font-size: clamp(1.12rem, 1.8vw, 1.4rem); line-height: 1.45; color: #d9dfd9; max-width: 430px; margin-top: 24px; }
.byline { margin-top: 26px; font-size: .92rem; }
.byline span { display: block; color: #b5c4c5; font-size: .76rem; margin-top: 2px; }
.hero-description { color: #d5deda; font-size: 1.03rem; max-width: 400px; margin-top: 26px; }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 18px 24px; margin-top: 30px; }
.button { display: inline-flex; align-items: center; justify-content: space-between; gap: 18px; min-height: 49px; padding: 13px 21px; border: 1px solid transparent; border-radius: 2px; text-decoration: none; font-size: .8rem; font-weight: 650; line-height: 1.45; transition: background-color .18s, color .18s; }
.button > span { font-size: 1.15rem; font-weight: 400; }
.button-gold { color: var(--navy); background: var(--gold); }
.button-gold:hover { background: #ebc89e; text-decoration: none; }
.button-navy { background: var(--navy); color: var(--paper); }
.button-navy:hover { background: #2c4c56; text-decoration: none; }
.text-link { font-size: .85rem; font-weight: 600; text-decoration: none; border-bottom: 1px solid #b8b4a8; padding-bottom: 4px; }
.text-link > span { margin-left: 12px; }
.light-link { border-color: #6f858a; }
.text-link:hover { border-color: var(--copper); color: var(--copper); }
.light-link:hover { color: var(--gold); border-color: var(--gold); }
.release-label { color: #b5c4c5; font-size: .7rem; letter-spacing: .035em; margin-top: 15px; }
.release-label > span { margin-inline: 7px; }
.publisher-line { border-top: 1px solid #425961; padding-top: 22px; margin-top: 31px; font-size: .76rem; color: #d2dcd8; }
.publisher-line > span { color: #aebfc1; font-size: .71rem; }
.experiment-figure { padding: 22px 0 24px; border-block: 1px solid #47606a; }
.figure-heading { display: flex; justify-content: space-between; gap: 20px; color: #b5c4c5; font-size: .6rem; letter-spacing: .12em; }
.figure-heading > span:last-child { color: var(--gold); white-space: nowrap; }
.experiment-svg { width: 100%; margin-top: 25px; overflow: visible; }
.svg-label { fill: #f4f0e6; font-family: var(--sans); font-size: 14px; }
.svg-small { fill: #b4c5c7; font-family: var(--sans); font-size: 11px; }
.svg-accent { fill: #e3bd92; }
.svg-result { fill: #e3bd92; font-family: var(--serif); font-size: 21px; }
.experiment-figure figcaption { color: #becdcb; font-family: var(--serif); font-style: italic; font-size: .9rem; text-align: center; padding: 12px 14px 0; }
.stats-wrap { border-bottom: 1px solid var(--line); background: var(--paper-deep); }
.stats { display: grid; grid-template-columns: repeat(4, 1fr); padding-block: 29px; }
.stats > div { display: flex; align-items: center; gap: 19px; padding-left: 31px; border-left: 1px solid #c9c8bc; }
.stats > div:first-child { border: 0; padding-left: 0; }
.stats dd { order: -1; font-family: var(--serif); font-size: 2.8rem; letter-spacing: -.05em; line-height: 1; margin: 0; }
.stats dt { font-size: .75rem; line-height: 1.4; max-width: 75px; color: var(--muted); }
.about-section, .errata-section { display: grid; grid-template-columns: 1fr 1.5fr; gap: 100px; }
.section-intro { font-family: var(--serif); font-size: 1.35rem; line-height: 1.45; color: var(--muted); max-width: 275px; margin-top: 30px; }
.about-copy { padding-top: 2px; }
.about-copy > p { color: var(--muted); }
.about-copy > .large-copy { color: var(--ink); font-family: var(--serif); font-size: 1.55rem; line-height: 1.42; margin-bottom: 22px; }
.claim-boundary { display: flex; align-items: flex-start; gap: 22px; border-block: 1px solid var(--line); padding: 24px 0; margin-top: 29px; }
.claim-boundary p { font-family: var(--serif); font-size: 1.22rem; line-height: 1.45; }
.boundary-mark { font-family: var(--serif); color: var(--copper); font-size: 3.5rem; line-height: 1; }
.audience-note { margin-top: 26px; }
.audience-note h3 { font-weight: 650; font-size: .83rem; margin-bottom: 8px; }
.audience-note p { color: var(--muted); font-size: .86rem; }
.chapters-section { background: var(--white); border-block: 1px solid var(--line); }
.section-top { display: flex; align-items: flex-end; justify-content: space-between; gap: 50px; margin-bottom: 42px; }
.section-top > p { font-size: .9rem; color: var(--muted); max-width: 300px; padding-bottom: 4px; }
.chapter-tools { display: flex; gap: 20px; align-items: flex-end; padding: 22px 0; border-block: 1px solid var(--line); margin-bottom: 15px; }
.search-field { flex: 1.2; }
.group-field { flex: 1; }
.chapter-tools label { display: block; font-size: .75rem; color: var(--muted); margin-bottom: 7px; }
.chapter-tools input, .chapter-tools select { display: block; width: 100%; border: 1px solid #b1b6b0; background: var(--white); border-radius: 2px; min-height: 45px; padding: 9px 13px; color: var(--ink); font-size: .85rem; }
.chapter-tools select { padding-right: 27px; }
.chapter-tools input::placeholder { color: #717973; }
.reset-button { background: transparent; color: var(--ink); min-height: 45px; border: 0; text-decoration: underline; text-underline-offset: 4px; font-size: .78rem; padding: 10px 0 10px 8px; }
.chapter-count { color: var(--muted); font-size: .76rem; margin-bottom: 8px; }
.chapter-group { margin-top: 37px; }
.group-heading { display: flex; align-items: baseline; gap: 14px; margin-bottom: 11px; }
.group-index { color: var(--copper); font-size: .63rem; letter-spacing: .06em; }
.group-heading h3 { font-size: .72rem; font-weight: 650; text-transform: uppercase; letter-spacing: .08em; color: var(--copper); }
.chapter { border-top: 1px solid var(--line); }
.chapter:last-child { border-bottom: 1px solid var(--line); }
.chapter summary { display: grid; grid-template-columns: 43px 1fr 26px; align-items: baseline; gap: 14px; padding: 20px 11px 20px 0; cursor: pointer; list-style: none; }
.chapter summary::-webkit-details-marker { display: none; }
.chapter summary:hover .chapter-title { color: var(--copper); }
.chapter-number { font-size: .75rem; color: var(--muted); font-variant-numeric: tabular-nums; }
.chapter-title { font-family: var(--serif); font-size: clamp(1.15rem, 1.8vw, 1.38rem); line-height: 1.4; }
.chapter-toggle { justify-self: end; font-size: 1.2rem; line-height: 1; color: var(--copper); }
.chapter[open] .chapter-toggle { transform: rotate(45deg); }
.chapter[open] .chapter-title { color: var(--copper); }
.chapter-description { padding: 0 55px 23px 57px; color: var(--muted); max-width: 800px; font-size: .9rem; }
.chapter-note { margin-top: 30px; display: flex; justify-content: space-between; gap: 30px; color: var(--muted); font-size: .76rem; }
.chapter-note > p { max-width: 420px; margin: 0; }
.empty-message { padding-block: 40px; font-family: var(--serif); font-size: 1.25rem; }
.download-grid { display: grid; grid-template-columns: 1.1fr 1fr 1fr; gap: 20px; }
.download-card { border: 1px solid var(--line); padding: 28px 26px; display: flex; flex-direction: column; align-items: flex-start; }
.download-featured { background: var(--paper-deep); border-color: #c5b08e; }
.download-kicker { display: flex; justify-content: space-between; width: 100%; gap: 14px; text-transform: uppercase; font-size: .62rem; letter-spacing: .1em; color: var(--copper); font-weight: 650; margin-bottom: 23px; }
.download-kicker > span { font-size: .6rem; color: var(--muted); font-weight: 400; }
.download-card h3 { font-family: var(--serif); font-size: 1.55rem; letter-spacing: -.025em; }
.download-card > p:not(.download-kicker) { color: var(--muted); font-size: .86rem; margin-top: 16px; margin-bottom: 30px; }
.download-card .button { margin-top: auto; width: 100%; padding-inline: 16px; font-size: .75rem; }
.download-link { font-size: .8rem; text-decoration: none; font-weight: 600; width: 100%; margin-top: auto; padding-block: 14px 7px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; align-items: center; gap: 10px; }
.download-link:hover { color: var(--copper); }
.download-link > span { font-size: 1.2rem; font-weight: 400; }
.resource-list { margin-top: 35px; border-top: 1px solid var(--line); }
.resource-list > a { display: flex; justify-content: space-between; align-items: center; gap: 30px; border-bottom: 1px solid var(--line); padding: 19px 0; text-decoration: none; font-size: .88rem; }
.resource-list strong { font-weight: 600; display: inline-block; min-width: 180px; }
.resource-list > a > span:first-child > span { color: var(--muted); font-size: .8rem; }
.resource-list a:hover strong { text-decoration: underline; text-underline-offset: 4px; }
.resource-format { color: var(--copper); font-size: .73rem; white-space: nowrap; }
.resource-format > span { margin-left: 20px; font-size: 1rem; }
.download-footnote { color: var(--muted); font-size: .79rem; max-width: 950px; margin-top: 24px; }
.getting-started { background: var(--navy); color: var(--paper); }
.start-grid { display: grid; grid-template-columns: 1fr 1.35fr; gap: 100px; }
.getting-started .eyebrow { color: var(--gold); }
.start-intro > p:not(.eyebrow) { color: #c1cfce; font-size: .92rem; margin-top: 27px; }
.start-intro > p.start-note { font-size: .77rem; color: #afc2c4; padding-top: 16px; border-top: 1px solid #42616a; }
code { font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace; font-size: .9em; }
.steps { min-width: 0; }
.setup-step + .setup-step { margin-top: 30px; }
.step-heading { display: flex; gap: 16px; align-items: baseline; margin-bottom: 13px; }
.step-heading > span { font-size: .67rem; color: var(--gold); }
.step-heading h3 { font-size: .97rem; font-weight: 500; }
.code-block { border: 1px solid #4d666f; border-radius: 3px; background: #10252c; overflow: hidden; }
.code-label { display: flex; gap: 10px; align-items: center; justify-content: space-between; min-height: 37px; padding: 7px 14px; background: #1c3740; border-bottom: 1px solid #3d5862; color: #bfd0d0; font-size: .63rem; letter-spacing: .015em; }
.copy-button { border: 1px solid #607881; background: transparent; color: #f2eee3; font-size: .65rem; padding: 3px 9px; border-radius: 2px; line-height: 1.4; }
.copy-button:hover { background: #37545e; }
pre { overflow-x: auto; padding: 17px 15px; margin: 0; font-size: .88rem; line-height: 1.8; color: #ead1ad; }
pre code { font-size: 1em; }
.platform-details { margin-top: 10px; }
.platform-details summary { color: #bed0d0; font-size: .73rem; cursor: pointer; padding-block: 5px; }
.platform-details[open] > summary { margin-bottom: 7px; }
.platform-note { color: #afc2c4; font-size: .77rem; margin-top: 13px; }
.notebook-help { border-top: 1px solid #4b646d; margin-top: 30px; padding-top: 18px; }
.notebook-help summary { cursor: pointer; font-size: .87rem; color: #ead1ad; }
.notebook-help p { color: #c1cfce; font-size: .83rem; margin-block: 15px; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; }
.errata-copy { font-size: .9rem; color: var(--muted); }
.errata-status { color: var(--ink); font-size: .82rem; border-bottom: 1px solid var(--line); padding-bottom: 19px; margin-bottom: 20px; }
.errata-status > span { display: inline-block; border: 1px solid var(--copper); width: 7px; height: 7px; border-radius: 50%; margin-right: 9px; vertical-align: 1px; }
.inline-links { display: flex; flex-wrap: wrap; gap: 14px 30px; margin-top: 20px; font-size: .8rem; color: var(--copper); }
.inline-links > a > span { margin-left: 9px; }
.errata-copy h3 { margin-top: 31px; margin-bottom: 10px; font-size: .95rem; color: var(--ink); font-weight: 600; }
.errata-copy .text-link { display: inline-block; color: var(--ink); margin-top: 22px; }
.author-section { background: var(--paper-deep); border-top: 1px solid var(--line); padding-block: 64px; }
.author-grid { display: grid; grid-template-columns: 1fr 1.5fr; gap: 100px; }
.author-grid .eyebrow { margin-bottom: 15px; }
.author-grid h2 { font-size: 2.2rem; }
.author-affiliation { font-size: .82rem; color: var(--muted); margin-top: 9px; }
.author-grid > div:last-child { font-size: .94rem; color: var(--muted); }
.author-grid .text-link { display: inline-block; margin-top: 20px; color: var(--ink); }
.site-footer { background: var(--navy); color: #becdcf; padding-block: 38px; font-size: .71rem; }
.footer-top { display: flex; gap: 30px; align-items: baseline; justify-content: space-between; border-bottom: 1px solid #425d66; padding-bottom: 26px; }
.footer-title { font-family: var(--serif); color: var(--paper); font-size: 1.2rem; text-decoration: none; }
.footer-top > p { margin-left: auto; }
.back-top { text-decoration: none; }
.back-top > span { margin-left: 10px; }
.footer-bottom { display: grid; grid-template-columns: 1.15fr 1fr 1fr; gap: 36px; padding-top: 26px; align-items: start; font-size: .67rem; line-height: 1.7; }
.footer-bottom p { margin: 0; }
.footer-publisher { text-align: right; }
.privacy-note summary { cursor: pointer; text-underline-offset: 3px; }
.privacy-note[open] summary { margin-bottom: 8px; }
.privacy-note p { max-width: 400px; }
@media (min-width: 761px) { .menu-toggle { display: none !important; } }
@media (max-width: 1100px) {
  .container { width: calc(100% - 64px); }
  .hero-grid { gap: 35px; grid-template-columns: 1.2fr 1fr; }
  .hero h1 { font-size: clamp(2.7rem, 5.6vw, 4.5rem); }
  .site-nav { gap: 21px; }
  .about-section, .errata-section, .author-grid, .start-grid { gap: 60px; }
  .stats > div { padding-left: 23px; gap: 13px; }
  .download-card { padding-inline: 21px; }
  .download-card h3 { font-size: 1.37rem; }
  .resource-list strong { min-width: 160px; }
}
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr .9fr; gap: 32px; }
  .hero-actions { gap: 20px; }
  .hero h1 { font-size: 3.25rem; }
  .book-subtitle { font-size: 1.18rem; }
  .stats dd { font-size: 2.35rem; }
  .stats dt { font-size: .69rem; }
  .section { padding-block: 75px; }
  .download-grid { grid-template-columns: 1fr 1fr; }
  .download-featured { grid-column: 1 / -1; display: grid; grid-template-columns: 1fr 1fr; column-gap: 35px; }
  .download-featured .download-kicker { grid-column: 1 / -1; margin-bottom: 15px; }
  .download-featured .button { align-self: end; grid-column: 2; grid-row: 2 / 4; width: auto; }
  .download-featured > p:not(.download-kicker) { margin-bottom: 0; }
  .resource-list strong { display: block; }
  .about-section, .errata-section { grid-template-columns: 1fr 1.4fr; gap: 45px; }
  .start-grid { gap: 40px; grid-template-columns: .9fr 1.2fr; }
  .chapter-tools { flex-wrap: wrap; }
  .reset-button { padding-left: 0; }
}
@media (max-width: 760px) {
  html { scroll-padding-top: 90px; }
  .container { width: calc(100% - 40px); }
  .header-inner { min-height: 76px; flex-wrap: wrap; gap: 0; padding-block: 13px; }
  .wordmark { font-size: .73rem; }
  .wordmark-symbol { width: 41px; height: 41px; font-size: 1.7rem; }
  .site-nav { flex-basis: 100%; justify-content: flex-start; gap: 5px 24px; flex-wrap: wrap; font-size: .77rem; margin-top: 12px; }
  .js-enabled .site-nav { display: none; }
  .js-enabled .site-nav.is-open { display: flex; }
  .hero-grid { grid-template-columns: 1fr; gap: 45px; padding-block: 48px 45px; }
  .hero-copy { max-width: 600px; }
  .hero h1 { font-size: clamp(2.65rem, 9vw, 4.5rem); }
  .hero .eyebrow { font-size: .64rem; margin-bottom: 25px; }
  .book-subtitle { margin-top: 20px; max-width: 390px; font-size: 1.22rem; }
  .hero-description { max-width: 430px; font-size: .98rem; }
  .hero-actions { margin-top: 26px; }
  .publisher-line { max-width: 500px; margin-top: 27px; padding-top: 17px; }
  .experiment-figure { max-width: 450px; width: 100%; margin-inline: auto; padding-top: 18px; }
  .experiment-svg { margin-top: 15px; }
  .experiment-figure figcaption { padding-top: 4px; }
  .stats { grid-template-columns: repeat(4, 1fr); padding-block: 23px; }
  .stats > div, .stats > div:first-child { flex-direction: column; gap: 8px; align-items: flex-start; padding-left: 17px; }
  .stats > div:first-child { padding-left: 0; }
  .stats dd { font-size: 2.5rem; }
  .stats dt { font-size: .64rem; max-width: 70px; }
  .section { padding-block: 61px; }
  .eyebrow { margin-bottom: 18px; font-size: .65rem; }
  h2 { font-size: clamp(2.2rem, 6vw, 3rem); }
  .about-section, .errata-section, .start-grid, .author-grid { grid-template-columns: 1fr; gap: 33px; }
  .section-intro { max-width: 400px; font-size: 1.15rem; margin-top: 22px; }
  .about-copy > .large-copy { font-size: 1.4rem; }
  .about-copy > p { font-size: .94rem; }
  .claim-boundary p { font-size: 1.13rem; }
  .section-top { align-items: flex-start; flex-direction: column; gap: 21px; margin-bottom: 30px; }
  .section-top > p { max-width: 450px; font-size: .85rem; }
  .chapter-tools { gap: 14px; }
  .search-field, .group-field { flex: auto; width: 100%; }
  .reset-button { min-height: 32px; padding-block: 5px; }
  .chapter-tools input, .chapter-tools select { min-height: 47px; font-size: 1rem; }
  .group-heading { gap: 10px; }
  .group-heading h3 { font-size: .64rem; line-height: 1.6; }
  .group-index { font-size: .57rem; }
  .chapter summary { grid-template-columns: 29px 1fr 20px; gap: 11px; padding-block: 17px; padding-right: 4px; }
  .chapter-title { font-size: 1.16rem; }
  .chapter-number { font-size: .67rem; }
  .chapter-description { padding: 0 20px 21px 40px; font-size: .85rem; }
  .chapter-note { flex-direction: column; gap: 13px; }
  .download-grid { gap: 16px; }
  .download-card { padding: 24px; }
  .download-card h3 { font-size: 1.45rem; }
  .download-featured { display: flex; }
  .download-featured > p:not(.download-kicker) { margin-bottom: 25px; }
  .download-featured .button { width: auto; align-self: flex-start; }
  .download-kicker { margin-bottom: 18px; }
  .resource-list > a { gap: 17px; }
  .resource-list > a > span:first-child > span { display: block; margin-top: 3px; font-size: .75rem; }
  .resource-format { font-size: .64rem; }
  .resource-format > span { margin-left: 10px; }
  .start-intro > p:not(.eyebrow) { margin-top: 21px; }
  .start-intro > p.start-note { margin-top: 20px; }
  .start-grid { gap: 37px; }
  pre { font-size: .8rem; }
  .step-heading h3 { font-size: .92rem; }
  .author-section { padding-block: 46px; }
  .author-grid { gap: 25px; }
  .author-grid h2 { font-size: 2rem; }
  .author-grid > div:last-child { font-size: .88rem; }
  .footer-top { flex-wrap: wrap; gap: 15px; }
  .footer-title { flex-basis: 100%; font-size: 1.12rem; }
  .footer-top > p { margin-left: 0; margin-right: auto; font-size: .67rem; }
  .footer-bottom { grid-template-columns: 1fr 1fr; gap: 22px; }
  .footer-publisher { text-align: left; grid-column: 1 / -1; }
}
@media (max-width: 480px) {
  .download-grid { grid-template-columns: 1fr; }
  .download-featured { grid-column: auto; }
  .hero-actions { align-items: flex-start; flex-direction: column; gap: 21px; }
  .hero-actions .button { font-size: .78rem; }
  .book-subtitle { font-size: 1.1rem; }
  .stats dd { font-size: 2.1rem; }
  .stats > div, .stats > div:first-child { padding-left: 10px; }
  .stats > div:first-child { padding-left: 0; }
  .stats dt { font-size: .59rem; }
  .resource-format { display: flex; flex-direction: column; align-items: flex-end; }
  .resource-format > span { margin-left: 0; }
  .claim-boundary { gap: 15px; }
  .footer-bottom { grid-template-columns: 1fr; }
  .footer-publisher { grid-column: auto; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}
@media print {
  body { background: white; color: black; font-size: 11pt; }
  .container { width: 100%; }
  .site-header, .hero-actions, .chapter-tools, .copy-button, .back-top, .site-footer { display: none !important; }
  .section { padding-block: 25px; }
  .hero, .getting-started { background: white; color: black; }
  .hero-grid { padding-block: 20px; }
  .experiment-figure { display: none; }
  .hero-grid, .about-section, .errata-section, .start-grid, .author-grid { display: block; }
  .hero-copy p, .start-intro p, .platform-note { color: black !important; }
  .chapter { break-inside: avoid; }
  .chapter-description { display: block; }
  .download-card, .setup-step { break-inside: avoid; }
}