:root {
  color-scheme: light;
  --paper: #FFFFFF;
  --muted: #F5F5F5;
  --blue: #007BFF;
  --yellow: #FFD700;
  --green: #2ECC40;
  --orange: #FF8C00;
  --purple: #9370DB;
  --pink: #FF00CC;
  --ink: #162B40;
  --quiet-ink: #405367;
  --link: #0055B4;
  --line: #E3E8EE;
  --shadow: 0 8px 24px rgb(22 43 64 / 6%);
  --section-gap: clamp(4rem, 8vw, 8rem);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 2rem; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: 'Roboto', Arial, sans-serif; font-size: 1rem; font-weight: 400; line-height: 1.6; }
body, button, input, summary { -webkit-text-size-adjust: 100%; }
img { max-width: 100%; }
main, section, aside, article, .wrap, .page-hero > div, .footer-map > div { min-width: 0; }
p, h1, h2, h3, a, summary, li, dt, dd { overflow-wrap: break-word; }
button, a, summary { -webkit-tap-highlight-color: transparent; }
a { color: var(--link); text-underline-offset: .22em; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible, summary:focus-visible { outline: 3px solid var(--blue); outline-offset: 5px; }
h1, h2, h3, p, ul, dl { margin-top: 0; }
h1, h2, h3 { font-weight: 700; letter-spacing: -.025em; line-height: 1.15; }
h1 { font-size: 2.25rem; }
h2 { font-size: 1.5rem; margin-bottom: 1.25rem; }
h3 { font-size: 1.25rem; margin-bottom: 1rem; }
p { margin-bottom: 1.25rem; max-width: 72ch; }
p:last-child { margin-bottom: 0; }
ul { padding-left: 1.4rem; }
li { font-size: 1rem; }
mark { background: var(--yellow); color: var(--ink); padding: 0 .08em; box-decoration-break: clone; -webkit-box-decoration-break: clone; }
.wrap { width: 100%; max-width: 1280px; margin-inline: auto; padding-inline: 1.5rem; }
.mono { font-family: 'JetBrains Mono', ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 1rem; letter-spacing: -.025em; }
.eyebrow { display: block; font-size: 1rem; font-weight: 500; line-height: 1.5; letter-spacing: .02em; margin-bottom: 1rem; }
.topic-yellow, .topic-green, .topic-purple { display: inline-block; color: var(--ink); border-radius: 4px; padding: .25rem .75rem; }
.topic-yellow { background: #FFF4B5; }
.topic-green { background: #DFF8E3; }
.topic-purple { background: #EEE7FA; }
.skip-link { position: absolute; inset: 8px auto auto 8px; transform: translateY(-160%); display: flex; align-items: center; min-height: 48px; background: var(--paper); border: 2px solid var(--blue); padding: .5rem 1rem; z-index: 20; }
.skip-link:focus { transform: translateY(0); }

/* Desktop editorial grid; the smaller layouts simplify at the breakpoints. */
.site-header { display: flex; align-items: center; justify-content: space-between; gap: 2rem; padding-block: 1.5rem; min-height: 104px; }
.wordmark { display: inline-flex; align-items: center; min-height: 48px; gap: .85rem; color: var(--ink); text-decoration: none; font-size: 1.25rem; font-weight: 700; line-height: 1.2; letter-spacing: -.025em; }
.brand-subtitle { display: block; font-size: 1rem; letter-spacing: 0; font-weight: 400; margin-top: .3rem; }
.brand-mark { width: 40px; height: 40px; display: grid; grid-template-columns: 1fr 1fr; gap: 4px; flex: 0 0 40px; }
.brand-mark span { border-radius: 3px; background: var(--blue); }
.brand-mark span:nth-child(2) { background: var(--yellow); }
.brand-mark span:nth-child(3) { background: var(--green); }
.brand-mark span:nth-child(4) { background: var(--purple); }
.header-question { min-height: 48px; display: inline-flex; align-items: center; gap: 1.25rem; font-size: 1rem; font-weight: 500; color: var(--ink); text-decoration: none; border-bottom: 2px solid var(--orange); padding-block: .5rem; }
.question-tabs { border-block: 1px solid var(--line); background: var(--paper); }
.question-tabs ul { display: flex; align-items: stretch; list-style: none; margin-block: 0; gap: .5rem; }
.question-tabs li { flex: 1 1 0; min-width: 0; }
.question-tabs a { position: relative; display: flex; align-items: center; justify-content: center; min-height: 64px; padding: .75rem .7rem; font-weight: 500; font-size: 1rem; text-decoration: none; color: var(--quiet-ink); text-align: center; transition: background-color 160ms ease; }
.question-tabs a:hover { color: var(--ink); background: var(--muted); }
.question-tabs .current-topic { color: var(--ink); background: #EEF6FF; }
.question-tabs .current-topic::after { content: ''; position: absolute; height: 4px; background: var(--blue); left: .7rem; right: .7rem; bottom: -1px; }

.button, .text-button { min-height: 48px; display: inline-flex; align-items: center; justify-content: center; gap: 1rem; padding: .8rem 1.2rem; font-size: 1rem; font-weight: 600; border-radius: 8px; text-decoration: none; line-height: 1.35; }
.button { border: 1px solid transparent; transition: filter 160ms ease, transform 160ms ease; }
.button:hover { filter: brightness(.92); transform: translateY(-1px); }
.button-blue { background: var(--blue); color: #000000; }
.button-orange { background: var(--orange); color: #14293F; }
.text-button { padding-inline: 0; justify-content: flex-start; border-radius: 4px; }
.text-button:hover { color: #003A7B; }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 1.25rem 2rem; margin-top: 2rem; }
.home-hero { display: grid; grid-template-columns: 1.06fr 1fr; gap: 4.5rem; padding-block: 4rem 3rem; align-items: center; }
.guide-tag { display: inline-block; background: #EEF6FF; padding: .4rem .75rem; border-radius: 4px; color: var(--ink); margin-bottom: 1.5rem; }
.home-hero h1 { font-size: clamp(2.5rem, 5vw, 4rem); letter-spacing: -.04em; max-width: 15ch; line-height: 1.07; margin-bottom: 1.75rem; }
.hero-lead { color: var(--quiet-ink); max-width: 54ch; font-size: 1.125rem; line-height: 1.6; }
.hero-visual { position: relative; min-width: 0; min-height: 540px; padding: 24px 0 24px 24px; }
.atmosphere { position: relative; min-width: 0; margin: 0; background: #EDF4FB; border-radius: 8px; overflow: hidden; aspect-ratio: 3 / 2; border: 1px solid var(--line); }
.atmosphere::before { content: ''; position: absolute; width: 46%; height: 76%; top: 0; right: 0; background: #E0EFFF; border-left: 10px solid var(--paper); border-bottom: 10px solid var(--paper); }
.atmosphere::after { content: ''; position: absolute; height: 22%; width: 24%; bottom: 0; right: 18%; background: #DFF1DC; border-radius: 8px 8px 0 0; }
.atmosphere img { display: block; position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; opacity: 0; z-index: 1; }
.atmosphere img[data-ready] { opacity: 1; }
.atmosphere figcaption { position: absolute; bottom: 1rem; left: 1rem; right: 1rem; z-index: 2; background: rgb(255 255 255 / 96%); color: var(--ink); border: 1px solid var(--line); border-radius: 4px; padding: .65rem 1rem; font-size: 1rem; line-height: 1.5; }
.hero-atmosphere { position: absolute; top: 0; left: 24px; right: 0; height: 100%; aspect-ratio: auto; }
.hero-atmosphere figcaption { bottom: 1rem; left: 1rem; right: auto; max-width: calc(100% - 2rem); }
.bill-board { position: relative; z-index: 3; background: var(--paper); border: 1px solid var(--line); border-top: 8px solid var(--yellow); border-radius: 8px; padding: 2rem; box-shadow: var(--shadow); width: calc(100% - 36px); margin-left: -24px; margin-top: 40px; }
.bill-board h2 { font-size: 1.75rem; margin-bottom: 1.5rem; }
.bill-board .eyebrow { margin-bottom: .75rem; color: var(--quiet-ink); }
.bill-board ul { list-style: none; margin: 0; padding: 0; }
.bill-board li { display: grid; grid-template-columns: 40px 1fr auto; gap: 1rem; align-items: center; padding: .85rem 0; border-top: 1px solid var(--line); }
.bill-board li .mono { color: var(--quiet-ink); }
.cost-symbol { width: 40px; height: 40px; display: grid; place-items: center; font-size: 1.5rem; font-weight: 500; color: #06121F; border-radius: 6px; }
.symbol-blue { background: var(--blue); }
.symbol-yellow { background: var(--yellow); }
.symbol-purple { background: #D6C5F3; }
.symbol-green { background: #A1EAA8; }
.visual-spark { position: absolute; right: 0; top: 24px; width: 32px; height: 8px; background: var(--pink); z-index: 3; }

.home-body { padding-top: 3rem; padding-bottom: var(--section-gap); }
.home-body > * + *, .reading-body > * + * { margin-top: var(--section-gap); }
.lesson { max-width: 72ch; }
.lesson > p { max-width: 72ch; }
.home-body > .lesson { max-width: none; }
.home-body > .lesson > p { max-width: 68ch; }
.route-pair { display: grid; grid-template-columns: 1.2fr 1fr; gap: 1.5rem; margin-top: 2rem; }
.route-card { min-height: 144px; display: flex; flex-direction: column; justify-content: space-between; border: 1px solid var(--line); border-left: 6px solid var(--blue); padding: 1.5rem; box-shadow: var(--shadow); border-radius: 8px; color: var(--ink); text-decoration: none; background: var(--paper); transition: background-color 160ms ease; }
.route-card:hover { background: #F7FAFF; }
.route-orange { border-left-color: var(--orange); }
.route-yellow { border-left-color: var(--yellow); }
.route-title { display: flex; justify-content: space-between; gap: 1rem; font-size: 1.25rem; font-weight: 700; line-height: 1.3; margin-bottom: .75rem; }
.route-title > span { color: var(--link); }
.route-copy { color: var(--quiet-ink); font-size: 1rem; line-height: 1.6; }
.feature-row { display: grid; grid-template-columns: 1fr .9fr; align-items: center; gap: 5rem; }
.feature-reverse { grid-template-columns: .9fr 1fr; }
.feature-row > div { min-width: 0; }
.feature-row > div > p { max-width: 62ch; }
.big-question { padding: 3rem; background: #FFF8CD; border-radius: 8px; border: 1px solid #EDE4B4; position: relative; }
.big-question::before { content: ''; width: 56px; height: 8px; position: absolute; top: 0; left: 3rem; background: var(--yellow); }
.big-question h2 { font-size: clamp(1.75rem, 3.5vw, 2.5rem); max-width: 23ch; }
.big-question p { max-width: 65ch; }

.page-hero { display: grid; grid-template-columns: 1.4fr .8fr; gap: 5rem; padding-block: 3rem 4rem; align-items: center; }
.breadcrumb { display: inline-flex; align-items: center; min-height: 44px; gap: 1rem; margin-bottom: 1rem; font-size: 1rem; text-decoration: none; }
.page-hero .eyebrow { color: var(--quiet-ink); }
.page-hero h1 { max-width: 23ch; line-height: 1.15; margin-bottom: 1.5rem; }
.question-note { background: #FFF5BC; border-radius: 8px; border: 1px solid #EBDFAC; padding: 2rem; position: relative; }
.question-note::before { content: ''; position: absolute; top: 0; left: 2rem; width: 56px; height: 6px; background: var(--yellow); }
.question-note .eyebrow { margin-bottom: 1rem; color: var(--ink); }
.question-note p { font-size: 1.5rem; font-weight: 700; line-height: 1.3; max-width: 21ch; margin-bottom: 2rem; letter-spacing: -.025em; }
.note-flourish { display: block; font-size: 2rem; line-height: 1; color: var(--ink); }
.reading-body { padding-bottom: var(--section-gap); }
.reading-body > .lesson { margin-left: 6.5rem; }
.reading-body > .feature-row { margin-inline: 0; }
.question-list { padding-left: 0; list-style: none; margin: 1.5rem 0 0; }
.question-list li { border-bottom: 1px solid var(--line); padding: 1rem 0 1rem 2.5rem; position: relative; min-height: 56px; max-width: 72ch; }
.question-list li:first-child { border-top: 1px solid var(--line); }
.question-list li::before { content: ''; position: absolute; top: 1.35rem; left: 0; width: 16px; height: 16px; border: 2px solid var(--blue); border-radius: 3px; background: var(--paper); }
.evidence-card { border: 1px solid var(--line); border-top: 4px solid var(--purple); border-radius: 8px; box-shadow: var(--shadow); padding: 2rem; margin-top: 1.75rem; background: var(--paper); }
.evidence-label { display: flex; align-items: center; gap: .5rem; font-size: 1rem; font-weight: 500; line-height: 1.5; color: var(--quiet-ink); margin-bottom: .75rem; }
.evidence-dot { width: 8px; height: 8px; background: var(--purple); border-radius: 2px; }
.evidence-card h3 { max-width: 38ch; }
.evidence-limit { padding-left: 1rem; border-left: 3px solid var(--yellow); color: var(--quiet-ink); margin-bottom: 1rem; }
.source-link { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 48px; font-size: 1rem; padding-block: .65rem; line-height: 1.5; text-decoration: none; border-top: 1px solid var(--line); max-width: 72ch; }
.source-link span { flex-shrink: 0; }
.source-link:hover { text-decoration: underline; }
.lesson > .source-link { margin-block: 1.5rem; }
.next-question { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 3rem; border: 1px solid var(--line); background: #F4F8FE; border-radius: 8px; padding: 2.5rem; }
.next-question h2 { max-width: 30ch; }
.next-question .eyebrow { margin-bottom: .75rem; }
.next-question p { margin-bottom: 0; max-width: 57ch; }
.next-question .button { max-width: 240px; }
.comparison-sheet { border: 1px solid var(--line); border-radius: 8px; box-shadow: var(--shadow); margin-top: 2rem; overflow: hidden; }
.sheet-label { background: #EEF6FF; padding: 1rem 1.5rem; font-weight: 500; font-size: 1rem; }
.comparison-sheet dl { margin-bottom: 0; padding-inline: 1.5rem; }
.comparison-sheet dl > div { display: grid; grid-template-columns: 1fr 1.4fr; gap: 1rem; padding-block: 1rem; border-top: 1px solid var(--line); }
.comparison-sheet dt { font-weight: 500; }
.comparison-sheet dd { margin: 0; color: var(--quiet-ink); }
.note-to-keep { max-width: 72ch; margin-left: 6.5rem; border-left: 6px solid var(--green); background: #EFFAF0; border-radius: 8px; padding: 2rem; }

.myth-progress { display: grid; grid-template-columns: 160px 1fr; align-items: center; gap: 1.5rem; margin: 2rem 0 1.5rem; }
.myth-progress p { margin: 0; font-size: 1rem; color: var(--quiet-ink); }
progress { display: block; width: 100%; height: 8px; border: 0; border-radius: 8px; background: var(--muted); accent-color: #17862A; overflow: hidden; }
progress::-webkit-progress-bar { background: var(--muted); border-radius: 8px; }
progress::-webkit-progress-value { background: #17862A; border-radius: 8px; transition: width 180ms ease; }
progress::-moz-progress-bar { background: #17862A; }
.myth-list { display: flex; flex-direction: column; gap: 1rem; }
.myth { border: 1px solid var(--line); box-shadow: var(--shadow); border-radius: 8px; overflow: hidden; }
.myth summary { display: flex; list-style: none; align-items: center; justify-content: space-between; gap: 1.5rem; cursor: pointer; min-height: 80px; padding: 1.25rem 1.5rem; font-size: 1.125rem; font-weight: 600; line-height: 1.5; background: #F8F5FF; }
.myth summary > span:first-child { min-width: 0; }
.myth summary::-webkit-details-marker { display: none; }
.myth summary:hover { background: #F0EAFB; }
.myth[open] summary { background: #EEE7FA; }
.reveal-sign { position: relative; width: 24px; height: 24px; flex: 0 0 24px; }
.reveal-sign::before, .reveal-sign::after { content: ''; position: absolute; width: 16px; height: 2px; top: 11px; left: 4px; background: var(--ink); transition: transform 160ms ease; }
.reveal-sign::after { transform: rotate(90deg); }
.myth[open] .reveal-sign::after { transform: rotate(0); }
.myth-answer { padding: 1.5rem; border-top: 1px solid var(--line); }
.myth[open] .myth-answer { animation: fade-rise 180ms ease-out; }
@keyframes fade-rise { from { opacity: .6; transform: translateY(5px); } to { opacity: 1; transform: translateY(0); } }

.site-footer { border-top: 1px solid var(--line); background: var(--muted); padding-block: 3rem 1rem; }
.footer-top { display: grid; grid-template-columns: .85fr 1.35fr; gap: 6rem; padding-bottom: 2rem; }
.footer-intro p { max-width: 37ch; font-size: 1rem; }
.footer-intro .eyebrow { padding-top: .75rem; border-top: 5px solid var(--yellow); width: fit-content; }
.footer-map { display: grid; grid-template-columns: 1fr 1.2fr; gap: 2rem; }
.footer-map h2 { font-size: 1.125rem; margin-bottom: .75rem; }
.footer-map ul { list-style: none; margin: 0; padding: 0; }
.footer-map a { display: flex; align-items: center; min-height: 44px; font-size: 1rem; padding-block: .5rem; text-decoration: none; line-height: 1.5; }
.footer-map a:hover { text-decoration: underline; }
.footer-end { border-top: 1px solid #D8DFE6; display: flex; justify-content: space-between; align-items: center; gap: 2rem; padding-top: .75rem; font-size: 1rem; color: var(--quiet-ink); }
.footer-end a { display: inline-flex; min-height: 44px; align-items: center; gap: 1rem; padding-block: .5rem; font-size: 1rem; text-decoration: none; }

@media (max-width: 1100px) {
  .home-hero { gap: 2.5rem; }
  .hero-visual { min-height: 500px; }
  .bill-board { padding: 1.5rem; width: calc(100% - 8px); }
  .feature-row, .feature-reverse { gap: 3rem; }
  .page-hero { gap: 3rem; }
  .reading-body > .lesson, .note-to-keep { margin-left: 3rem; }
  .footer-top { gap: 3rem; }
}
@media (max-width: 860px) {
  .site-header { padding-block: 1.25rem; }
  .question-tabs ul { flex-wrap: wrap; gap: 0; }
  .question-tabs li { flex: 1 1 45%; }
  .question-tabs a { min-height: 56px; }
  .home-hero { grid-template-columns: 1fr; padding-block: 3rem 2rem; gap: 2.5rem; }
  .home-hero h1 { max-width: 19ch; }
  .hero-visual { width: 100%; max-width: 580px; min-height: 490px; margin-inline: auto; }
  .home-body { padding-top: 2rem; }
  .feature-row, .feature-reverse { grid-template-columns: 1fr; gap: 2rem; }
  .feature-reverse > .atmosphere { order: 2; }
  .feature-row .atmosphere { width: 100%; max-width: 640px; }
  .page-hero { grid-template-columns: 1fr; gap: 2rem; padding-block: 2rem 3rem; }
  .question-note { max-width: 580px; padding: 1.5rem; }
  .question-note p { max-width: none; margin-bottom: .75rem; font-size: 1.25rem; }
  .question-note .note-flourish { position: absolute; right: 1.5rem; top: 1.4rem; font-size: 1.5rem; }
  .question-note .eyebrow { padding-right: 2rem; }
  .reading-body > .lesson, .note-to-keep { margin-left: 0; }
  .next-question { grid-template-columns: 1fr; gap: 1.5rem; padding: 2rem; }
  .next-question .button { justify-self: start; }
  .footer-top { grid-template-columns: 1fr; gap: 2rem; }
  .footer-intro p { max-width: 62ch; }
}
@media (max-width: 540px) {
  .site-header { gap: 1rem; min-height: 96px; }
  .wordmark { gap: .65rem; font-size: 1.125rem; }
  .brand-mark { width: 32px; height: 32px; flex-basis: 32px; gap: 3px; }
  .brand-subtitle { max-width: 17ch; font-size: 1rem; }
  .header-question { display: none; }
  .question-tabs ul { padding-inline: 1rem; }
  .question-tabs li { flex-basis: 50%; }
  .question-tabs li:last-child { flex-basis: 100%; }
  .question-tabs a { padding: .75rem .5rem; min-height: 52px; }
  .home-hero { padding-top: 2rem; }
  .home-hero h1 { font-size: 2.5rem; max-width: 17ch; }
  .guide-tag { max-width: 27ch; padding: .4rem .6rem; }
  .hero-lead { font-size: 1rem; }
  .hero-actions { gap: .75rem; align-items: stretch; flex-direction: column; }
  .hero-actions .button { justify-content: space-between; align-self: flex-start; }
  .hero-visual { min-height: 475px; padding-left: 16px; }
  .hero-atmosphere { left: 16px; }
  .bill-board { padding: 1.25rem; margin-left: -16px; width: calc(100% - 8px); margin-top: 36px; }
  .bill-board h2 { font-size: 1.5rem; }
  .bill-board li { gap: .75rem; grid-template-columns: 36px 1fr auto; }
  .cost-symbol { width: 36px; height: 36px; }
  .route-pair { grid-template-columns: 1fr; gap: 1rem; }
  .route-card { min-height: 130px; padding: 1.25rem; }
  .feature-row, .feature-reverse { gap: 1.5rem; }
  .big-question { padding: 1.5rem; }
  .big-question::before { left: 1.5rem; }
  .big-question h2 { font-size: 1.75rem; }
  .page-hero h1 { font-size: 2.25rem; max-width: 19ch; }
  .question-note { padding: 1.25rem; }
  .evidence-card { padding: 1.25rem; }
  .next-question { padding: 1.5rem; }
  .comparison-sheet dl { padding-inline: 1rem; }
  .comparison-sheet dl > div { grid-template-columns: 1fr; gap: .25rem; }
  .sheet-label { padding-inline: 1rem; }
  .note-to-keep { padding: 1.5rem; }
  .myth-progress { grid-template-columns: 1fr; gap: .75rem; }
  .myth-progress progress { max-width: 160px; }
  .myth summary { padding: 1rem 1.25rem; font-size: 1rem; }
  .myth-answer { padding: 1.25rem; }
  .footer-map { grid-template-columns: 1fr; gap: 2rem; }
  .footer-end { align-items: flex-start; flex-direction: column; gap: .25rem; }
  .atmosphere figcaption { left: .75rem; right: .75rem; bottom: .75rem; padding: .5rem .75rem; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}
@media print {
  .site-header, .question-tabs, .site-footer, .skip-link, .breadcrumb, .question-note, .next-question, .atmosphere, .text-button, .myth-progress { display: none; }
  .wrap { max-width: none; padding: 0; }
  .page-hero { display: block; padding: 0 0 1.5rem; }
  .reading-body > .lesson, .note-to-keep { margin-left: 0; }
  .reading-body > * + * { margin-top: 2rem; }
  .lesson, .evidence-card, .question-list li { break-inside: avoid; }
  .evidence-card, .note-to-keep { box-shadow: none; }
  body { font-size: 1rem; color: #000000; }
}