:root {
  color-scheme: light;
  --background: #f4f8f7;
  --ink: #11201f;
  --muted: #667572;
  --quiet: #94a19f;
  --teal: #0fa99a;
  --blue: #4c8fc2;
  --green: #61ad76;
  --lime: #a6b900;
  --line: rgba(17, 32, 31, 0.22);
  font-family:
    Inter, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", system-ui,
    sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-snap-type: y mandatory;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--background);
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

.ambient-field {
  position: fixed;
  z-index: 0;
  top: 50%;
  left: 50%;
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
  transform: translate(-50%, -50%) scale(1.08);
  opacity: 0.44;
  transition: transform 900ms cubic-bezier(0.22, 1, 0.36, 1), opacity 700ms ease;
}

body[data-active="challenge"] .ambient-field {
  transform: translate(-54%, -47%) scale(1.12);
  opacity: 0.48;
}

body[data-active="opportunity"] .ambient-field {
  transform: translate(-46%, -53%) scale(1.1);
  opacity: 0.58;
}

body[data-active="join"] .ambient-field {
  transform: translate(-50%, -48%) scale(1.15);
  opacity: 0.5;
}

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  right: 0;
  left: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 34px 42px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 16px;
  line-height: 1;
}

.brand strong {
  font-weight: 780;
}

.brand > span:last-child {
  color: #273937;
  font-weight: 600;
}

.language-toggle {
  display: inline-flex;
  min-width: 70px;
  min-height: 34px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 0 10px;
  border: 1px solid rgba(17, 32, 31, 0.15);
  border-radius: 6px;
  color: var(--quiet);
  background: rgba(244, 248, 247, 0.72);
  font: inherit;
  font-size: 12px;
  cursor: pointer;
  transition: border-color 180ms ease, color 180ms ease, background 180ms ease;
}

.language-toggle:hover,
.language-toggle:focus-visible {
  border-color: rgba(15, 169, 154, 0.5);
  color: #52625f;
  background: rgba(255, 255, 255, 0.9);
  outline: none;
}

.language-toggle [data-language-option].is-active {
  color: var(--ink);
  font-weight: 700;
}

.language-divider {
  color: rgba(17, 32, 31, 0.25);
}

.chapter-nav {
  position: fixed;
  z-index: 20;
  top: 50%;
  right: 32px;
  display: grid;
  width: 104px;
  transform: translateY(-50%);
}

.chapter-nav a {
  position: relative;
  display: flex;
  min-height: 64px;
  align-items: center;
  justify-content: flex-end;
  padding-right: 30px;
  color: var(--quiet);
  font-size: 13px;
  transition: color 180ms ease;
}

.chapter-nav a::after {
  position: absolute;
  right: 0;
  width: 18px;
  border-top: 1px solid var(--line);
  content: "";
  transition: width 180ms ease, border-color 180ms ease;
}

.chapter-nav a:hover,
.chapter-nav a:focus-visible,
.chapter-nav a[aria-current="true"] {
  color: #52625f;
}

.chapter-nav a[aria-current="true"]::after {
  width: 22px;
  border-color: var(--teal);
  border-width: 2px;
}

.chapter {
  position: relative;
  z-index: 1;
  display: grid;
  min-height: 100svh;
  place-items: center;
  padding: 108px 160px 96px;
  scroll-snap-align: start;
  scroll-snap-stop: always;
}

.chapter-content {
  width: min(860px, 100%);
  text-align: center;
}

.chapter-label {
  margin: 0 0 30px;
  color: #4b817c;
  font-size: 13px;
  font-weight: 600;
}

h1,
h2 {
  margin: 0;
  font-weight: 780;
  letter-spacing: 0;
  text-wrap: balance;
}

body.language-en h1 {
  font-size: 62px;
  line-height: 1.18;
}

body.language-en h2 {
  font-size: 56px;
  line-height: 1.22;
}

body.language-en .chapter-copy {
  max-width: 720px;
  line-height: 1.75;
}

body.language-en .chapter-nav {
  width: 132px;
}

body.language-en .chapter-nav a {
  white-space: nowrap;
}

h1 {
  font-size: 76px;
  line-height: 1.24;
}

h1 > span {
  display: block;
}

h2 {
  font-size: 60px;
  line-height: 1.28;
}

.accent-teal {
  color: var(--teal);
}

.accent-blue {
  color: var(--blue);
}

.accent-green {
  color: var(--green);
}

.accent-lime {
  color: var(--lime);
}

.chapter-copy {
  max-width: 760px;
  margin: 34px auto 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 2;
  text-wrap: pretty;
}

.hero-copy {
  max-width: 820px;
  font-size: 17px;
}

.chapter-note,
.company-name {
  margin: 20px auto 0;
  color: #7b8b88;
  font-size: 13px;
}

.company-name {
  margin-top: 34px;
  color: #435451;
  font-weight: 600;
}

.scroll-cue {
  position: absolute;
  bottom: 24px;
  left: 50%;
  display: grid;
  justify-items: center;
  gap: 14px;
  transform: translateX(-50%);
  color: #8d9a98;
  font-size: 11px;
}

.scroll-cue::after {
  display: block;
  height: 36px;
  border-left: 1px solid rgba(17, 32, 31, 0.3);
  content: "";
}

.scroll-cue-up::after {
  order: -1;
}

.filing-footer {
  position: fixed;
  z-index: 30;
  right: 0;
  bottom: 8px;
  left: 0;
  display: flex;
  justify-content: center;
  gap: 18px;
  padding: 0 18px;
  color: #778582;
  font-size: 11px;
}

.filing-footer[hidden],
.filing-footer a[hidden] {
  display: none;
}

.filing-footer a:hover,
.filing-footer a:focus-visible {
  color: var(--teal);
}

.chapter-content > * {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 560ms ease, transform 700ms cubic-bezier(0.22, 1, 0.36, 1);
}

.chapter.is-visible .chapter-content > * {
  opacity: 1;
  transform: translateY(0);
}

.chapter.is-visible .chapter-content > :nth-child(2) {
  transition-delay: 80ms;
}

.chapter.is-visible .chapter-content > :nth-child(3) {
  transition-delay: 150ms;
}

.chapter.is-visible .chapter-content > :nth-child(4) {
  transition-delay: 210ms;
}

@media (max-width: 900px) {
  .site-header {
    padding: 24px 26px;
  }

  .chapter-nav {
    right: 18px;
    width: 84px;
  }

  .chapter-nav a {
    min-height: 54px;
    padding-right: 24px;
    font-size: 12px;
  }

  .chapter {
    padding: 104px 118px 88px 56px;
  }

  h1 {
    font-size: 60px;
  }

  h2 {
    font-size: 50px;
  }

  body.language-en h1 {
    font-size: 50px;
  }

  body.language-en h2 {
    font-size: 46px;
  }

  body.language-en .chapter-nav {
    width: 116px;
  }
}

@media (max-width: 620px) {
  html {
    scroll-snap-type: y proximity;
  }

  .site-header {
    padding: 20px 18px;
  }

  .brand {
    gap: 7px;
    font-size: 14px;
  }

  .language-toggle {
    min-width: 62px;
    min-height: 32px;
    padding: 0 8px;
    font-size: 11px;
  }

  .chapter-nav {
    top: auto;
    right: 16px;
    bottom: 18px;
    left: 16px;
    display: grid;
    width: auto;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    transform: none;
  }

  .chapter-nav a {
    min-height: 38px;
    justify-content: center;
    padding: 0 0 8px;
    border-bottom: 1px solid rgba(17, 32, 31, 0.15);
    font-size: 11px;
  }

  .chapter-nav a::after {
    right: 50%;
    bottom: -1px;
    width: 0;
    transform: translateX(50%);
  }

  .chapter-nav a[aria-current="true"]::after {
    width: 100%;
  }

  .chapter {
    min-height: 100svh;
    padding: 96px 22px 112px;
  }

  .chapter-label {
    margin-bottom: 22px;
    font-size: 12px;
  }

  h1 {
    font-size: 42px;
    line-height: 1.3;
  }

  h2 {
    font-size: 38px;
    line-height: 1.36;
  }

  body.language-en h1 {
    font-size: 38px;
    line-height: 1.22;
  }

  body.language-en h2 {
    font-size: 34px;
    line-height: 1.28;
  }

  body.language-en .chapter-nav {
    width: auto;
  }

  .chapter-copy,
  .hero-copy {
    margin-top: 24px;
    font-size: 15px;
    line-height: 1.85;
  }

  .chapter-note,
  .company-name {
    font-size: 12px;
  }

  .scroll-cue {
    display: none;
  }

  .filing-footer {
    bottom: 4px;
    gap: 10px;
    font-size: 10px;
  }

  .ambient-field {
    width: 160%;
    height: 100%;
  }
}

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

  .ambient-field,
  .chapter-content > * {
    transition: none;
  }
}

.contact-email {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin: 10px auto 0;
  color: #7b8b88;
  font-size: 13px;
}

.contact-email a {
  color: #435451;
  text-decoration: none;
  transition: color 160ms ease;
}

.contact-email a:hover,
.contact-email a:focus-visible {
  color: var(--teal);
}