:root {
  /* Slate & copper palette */
  --spruce: oklch(0.37 0.035 250);     /* Slate primary background */
  --bone: oklch(0.94 0.01 250);        /* Slate light ink */
  --soft: oklch(0.79 0.035 55);        /* Copper soft accent */
  --line: oklch(0.52 0.025 250);
  --page-bg: var(--spruce);
  --page-ink: var(--bone);
  --reading-bg: oklch(0.89 0.015 250);
  --reading-ink: oklch(0.3 0.035 250);
  --doc-bg: oklch(0.96 0.01 250);
  --rule: oklch(0.6 0.02 250);
  --caption-bg: var(--spruce);
  --frame-max: 1440px;                  /* content frame cap; backgrounds stay full-bleed */

  /* Fonts for Slate & copper */
  --sans: 'Public Sans', sans-serif;
  --serif: 'Chakra Petch', sans-serif;
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: auto;
}

body {
  margin: 0;
  background: var(--page-bg);
  color: var(--page-ink);
  font: 18px/1.6 var(--sans);
}

a {
  color: inherit;
  text-underline-offset: 5px;
}

button, select {
  font: inherit;
}

a, button, select, summary {
  touch-action: manipulation;
}

a:focus-visible, button:focus-visible, select:focus-visible, summary:focus-visible {
  outline: 3px solid currentColor;
  outline-offset: 5px;
}

button, a {
  transition: background-color 150ms, color 150ms;
}

p {
  max-width: 65ch;
  text-wrap: pretty;
}

h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 500;
  line-height: 1.15;
  text-wrap: balance;
  margin: 0;
}

h1 {
  font-size: clamp(3.6rem, 6vw, 5.5rem);
  letter-spacing: -0.03em;
}

h2 {
  font-size: clamp(1.8rem, 3.2vw, 3.2rem);
  letter-spacing: -0.02em;
}

h3 {
  font-size: 1.5rem;
}

.skip {
  position: absolute;
  top: -100px;
  left: 20px;
  z-index: 5;
  background: var(--bone);
  color: var(--spruce);
  padding: 12px;
  text-decoration: none;
  font-weight: 600;
}

.skip:focus {
  top: 12px;
}

.masthead {
  position: absolute;
  max-width: var(--frame-max);
  margin-inline: auto;
  inset: 0 0 auto;
  z-index: 3;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 4vw;
  gap: 24px;
}

.brand {
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
}

.brand-logo {
  display: block;
  height: 34px;
  width: auto;
  max-width: 100%;
  object-fit: contain;
}

.masthead nav {
  display: flex;
  gap: 28px;
}

.masthead nav a {
  font-size: 15px;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
}

.journey {
  position: relative;
  isolation: isolate;
  max-width: var(--frame-max);
  margin-inline: auto;
}

.scene {
  position: sticky;
  top: 0;
  height: 100svh;
  min-height: 600px;
  z-index: 0;
}

.scene #server {
  position: absolute;
  left: 0;
  width: 100%;
  height: 100%;
  top: 0;
  --xs-ink: var(--page-ink);
  --xs-accent: var(--soft);
  --xs-font: var(--sans);
  --xs-font-mono: var(--serif);
  touch-action: pan-y;
  box-sizing: border-box;
  border: 16px solid transparent;
}

.scene-caption {
  position: absolute;
  left: 43%;
  right: 4vw;
  bottom: 90px;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  font-size: 13px;
  color: var(--bone);
}

.scene-caption > span {
  background: var(--caption-bg);
  padding: 4px 8px;
  border-radius: 2px;
}

.chapters {
  position: relative;
  margin-top: -100svh;
  pointer-events: none;
}

.chapter {
  min-height: 100svh;
  display: flex;
  align-items: center;
  padding: 130px 4vw 120px;
  position: relative;
}

.chapter-copy {
  width: 36%;
  max-width: 480px;
  pointer-events: auto;
}

.chapter h2 {
  font-size: clamp(1.8rem, 2.8vw, 2.8rem);
  line-height: 1.25;
}

.part-reference {
  display: block;
  font-size: 15px;
  color: var(--soft);
  margin-bottom: 24px;
}

.intro {
  margin: 0 0 24px;
  font-size: 16px;
  color: var(--soft);
  letter-spacing: 0.02em;
}

.hero-copy {
  font-size: 18px;
  line-height: 1.6;
  margin: 28px 0;
}

.hint {
  font-size: 14px;
  line-height: 1.7;
  color: var(--bone);
  background: var(--caption-bg);
  padding: 6px 10px;
  display: inline-block;
  margin: 24px 0 14px;
  border-radius: 2px;
}

.tour-link {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 30px;
  font-size: 15px;
  text-decoration: none;
  border-bottom: 1px solid var(--line);
}

.reading {
  position: relative;
  z-index: 2;
  background: var(--reading-bg);
  color: var(--reading-ink);
  color-scheme: light;
  padding: 0 6vw 100px;
}

.content-section {
  max-width: var(--frame-max);
  margin: auto;
  padding: 120px 0;
}

.demo {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 8vw;
}

.section-intro p {
  max-width: 34ch;
}

.small {
  font-size: 14px;
  line-height: 1.65;
}

.document-demo {
  padding: 32px;
  background: var(--doc-bg);
  border: 1px solid var(--rule);
}

fieldset {
  border: 0;
  padding: 0;
  margin: 0 0 24px;
}

legend {
  margin-bottom: 10px;
  font-size: 15px;
  font-weight: 600;
}

.role-options {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

button {
  min-height: 44px;
  padding: 9px 14px;
  border: 1px solid var(--reading-ink);
  background: transparent;
  color: var(--reading-ink);
  cursor: pointer;
  border-radius: 2px;
}

button[aria-pressed=true], button:hover {
  background: var(--reading-ink);
  color: var(--reading-bg);
}

label {
  display: block;
  font-size: 15px;
  margin-bottom: 10px;
  font-weight: 600;
}

select {
  width: 100%;
  max-width: 100%;
  min-height: 48px;
  border: 1px solid var(--reading-ink);
  background: transparent;
  color: var(--reading-ink);
  padding: 8px;
  font-size: 15px;
  border-radius: 2px;
}

.answer {
  margin-top: 28px;
  padding-top: 16px;
  border-top: 1px solid var(--rule);
}

.answer-status {
  font-size: 13px;
  font-weight: 600;
  text-transform: none;
}

.answer > p:nth-child(2) {
  font: 21px/1.55 var(--serif);
}

.answer footer {
  margin-top: 26px;
  font-size: 14px;
}

.answer blockquote {
  margin: 12px 0;
  font-family: var(--serif);
  font-size: 16px;
}

.questions {
  padding-top: 50px;
}

.questions dl {
  margin-top: 50px;
  max-width: 950px;
  margin-left: auto;
}

.questions dl div {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5vw;
  padding: 30px 0;
  border-top: 1px solid var(--rule);
}

dt {
  font: 22px/1.45 var(--serif);
}

dd {
  margin: 0;
  font-size: 16px;
}

.process {
  padding-top: 80px;
}

.process ol {
  display: flex;
  list-style: none;
  padding: 0;
  margin: 55px 0 0;
  counter-reset: steps;
  gap: 35px;
}

.process li {
  flex: 1;
  counter-increment: steps;
  border-top: 1px solid var(--reading-ink);
  padding-top: 20px;
}

.process li:before {
  content: counter(steps);
  display: block;
  font: 18px var(--serif);
  margin-bottom: 25px;
}

.process li p {
  font-size: 16px;
  line-height: 1.65;
}

.boundaries {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 8vw;
}

.boundaries > div > p {
  max-width: 32ch;
}

.faq details {
  border-top: 1px solid var(--rule);
  padding: 8px 0;
}

.faq summary {
  min-height: 52px;
  padding: 12px 0;
  font-size: 17px;
  cursor: pointer;
}

.faq p {
  font-size: 16px;
  margin: 8px 0 24px;
}

.assessment {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8vw;
  padding-top: 60px;
}

.booking {
  font-weight: 600;
  padding-top: 20px;
  border-top: 1px solid var(--reading-ink);
}

.site-footer {
  max-width: var(--frame-max);
  margin: 40px auto 0;
  padding: 30px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  border-top: 1px solid var(--reading-ink);
  font-size: 14px;
}

.site-footer > a:last-child {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
}

/* Footer-only: darken the brand logo to ~#1a1a1a; header logo untouched */
.site-footer .brand-logo {
  filter: brightness(0) invert(0.1);
}

.xs-overlay {
  z-index: 1;
}

.xs-callout {
  position: absolute;
  top: 0;
  left: 0;
  display: flex;
  align-items: baseline;
  gap: 6px;
  font: 12px/18px var(--sans);
  color: var(--xs-ink);
  white-space: nowrap;
}

.xs-callout.xs-right {
  flex-direction: row-reverse;
  text-align: right;
}

.xs-callout-num {
  border: 1px solid currentColor;
  border-radius: 50%;
  width: 18px;
  height: 18px;
  display: inline-flex;
  justify-content: center;
  align-items: center;
  font-size: 11px;
  flex: none;
  background: var(--caption-bg);
}

.xs-callout.xs-hi {
  font-weight: 700;
}

.xs-leader {
  stroke: var(--xs-ink);
  stroke-width: 1;
  opacity: 0.55;
}

.xs-leader-dot {
  fill: var(--xs-ink);
}

.xs-leader.xs-hi {
  opacity: 1;
  stroke-width: 2;
}

.xs-tag {
  position: absolute;
  top: 0;
  left: 0;
  translate: -50% -50%;
  font: 12px var(--sans);
  color: var(--xs-ink);
  white-space: nowrap;
  padding: 3px 6px;
  background: var(--caption-bg);
  border-radius: 2px;
}

/* Let the last sentence leave the viewport before releasing the object. */
.journey::after {
  content: "";
  display: block;
  height: 100svh;
}

@media (max-width: 760px) {
  body {
    font-size: 16px;
  }
  .masthead {
    padding: 16px 20px;
    align-items: flex-start;
  }
  .brand-logo {
    height: 30px;
  }
  .masthead nav {
    gap: 0;
    flex-direction: column;
    align-items: flex-end;
  }
  .masthead nav a {
    font-size: 12px;
    min-height: 44px;
  }
  .masthead nav a:last-child {
    display: none;
  }
  .scene {
    min-height: 0;
  }
  .scene #server {
    left: 0;
    top: 46%;
    width: 100%;
    height: 43%;
    border-width: 12px;
  }
  .scene.hero-state #server {
    top: 41%;
    height: 43%;
  }
  .scene-caption {
    left: 20px;
    right: 20px;
    bottom: 90px;
    font-size: 11px;
  }
  .scene.hero-state .scene-caption {
    display: none;
  }
  .scene-caption > span {
    max-width: 48%;
    min-width: 0;
  }
  .scene-caption > span:last-child {
    text-align: right;
  }
  .chapters {
    margin-top: -100svh;
  }
  .chapter {
    padding: 100px 20px 95px;
    align-items: flex-start;
    min-height: 100svh;
  }
  .chapter-copy {
    width: 100%;
    max-width: none;
  }
  .chapter h2 {
    font-size: 25px;
    line-height: 1.25;
    max-width: 24ch;
  }
  .part-reference {
    font-size: 12px;
    margin-bottom: 12px;
  }
  .hero h1 {
    font-size: 52px;
    line-height: 1.05;
  }
  .hero .intro {
    font-size: 13px;
    margin: 0 0 16px;
  }
  .hero-copy {
    font-size: 14px;
    line-height: 1.55;
    max-width: 32ch;
    margin: 18px 0;
  }
  .hero .hint {
    position: absolute;
    bottom: 120px;
    margin: 0;
    font-size: 12px;
    padding: 6px 10px;
  }
  .hero .tour-link {
    position: absolute;
    bottom: 68px;
    font-size: 12px;
    min-height: 44px;
  }
  .hero .chapter-copy {
    max-width: 350px;
  }
  .reading {
    padding: 0 20px 100px;
  }
  .content-section {
    padding: 75px 0;
  }
  .demo, .boundaries, .assessment {
    display: block;
  }
  .section-intro {
    margin-bottom: 35px;
  }
  .document-demo {
    padding: 20px;
  }
  .answer > p:nth-child(2) {
    font-size: 20px;
  }
  .questions dl {
    margin-top: 30px;
  }
  .questions dl div {
    display: block;
    padding: 25px 0;
  }
  dt {
    font-size: 21px;
  }
  dd {
    margin-top: 15px;
  }
  .process ol {
    display: block;
    margin-top: 35px;
  }
  .process li {
    padding: 20px 0;
  }
  .process li:before {
    float: left;
    margin: 3px 18px 0 0;
  }
  .process li p {
    padding-left: 28px;
  }
  .faq {
    margin-top: 35px;
  }
  .assessment > div {
    margin-top: 30px;
  }
  .site-footer {
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 18px;
  }
  .site-footer p {
    width: 100%;
    order: 2;
    margin: 0;
  }
  .xs-tag {
    font-size: 10px;
  }
  .xs-callout {
    font-size: 10px;
  }
}

@media (max-width: 480px) {
  .brand-logo {
    height: 26px;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto !important;
    transition: none !important;
  }
  .hint {
    display: none;
  }
  .chapter {
    min-height: 100svh;
  }
}