:root {
  --ink: #1f2f31;
  --muted: #5f7172;
  --paper: #f8f5ed;
  --panel: #ffffff;
  --soft: #edf6f2;
  --line: rgba(31, 47, 49, 0.14);
  --deep: #17686a;
  --deep-2: #0f4549;
  --mint: #8dc9b7;
  --sun: #f4b64f;
  --rose: #ca5f75;
  --title-main: #0f575c;
  --title-accent: #d38925;
  --title-light: #ffe7a8;
  --shadow: 0 22px 55px rgba(29, 71, 72, 0.16);
  --shadow-strong: 0 28px 70px rgba(20, 69, 70, 0.24);
  --glow: 0 0 0 4px rgba(141, 201, 183, 0.18);
  --radius: 8px;
  --rail: 292px;
  --max: 1120px;
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 82% 12%, rgba(141, 201, 183, 0.22), transparent 30%),
    linear-gradient(180deg, #fbf8ef 0%, var(--paper) 42%, #eef7f1 100%);
  font-size: 16px;
  line-height: 1.75;
}

body.nav-open {
  overflow: hidden;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

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

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  font: inherit;
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  transform: translateY(-150%);
  padding: 10px 14px;
  color: #fff;
  background: var(--deep-2);
  border-radius: var(--radius);
}

.skip-link:focus {
  transform: translateY(0);
}

.page-shell {
  min-height: 100vh;
}

.side-rail {
  position: fixed;
  inset: 0 auto 0 0;
  z-index: 80;
  width: var(--rail);
  display: flex;
  flex-direction: column;
  gap: 22px;
  padding: 24px 22px;
  color: #eaf8f5;
  background:
    radial-gradient(circle at 18% 10%, rgba(244, 182, 79, 0.18), transparent 28%),
    linear-gradient(180deg, rgba(15, 69, 73, 0.98), rgba(23, 104, 106, 0.96)),
    var(--deep-2);
  border-right: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: 18px 0 44px rgba(19, 63, 65, 0.18);
}

.side-rail::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(120deg, rgba(255, 255, 255, 0.1), transparent 36%, rgba(255, 255, 255, 0.06));
  opacity: 0.7;
}

.rail-brand,
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.rail-brand,
.rail-nav,
.rail-meta {
  position: relative;
  z-index: 1;
}

.rail-brand img,
.footer-brand img {
  flex: 0 0 auto;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.72);
  transition: transform 220ms ease, box-shadow 220ms ease;
}

.rail-brand:hover img,
.rail-brand:focus-visible img,
.footer-brand:hover img,
.footer-brand:focus-visible img {
  transform: rotate(-4deg) scale(1.06);
  box-shadow: 0 12px 26px rgba(0, 0, 0, 0.22);
}

.rail-brand strong {
  display: block;
  color: #fff;
  font-size: 18px;
  line-height: 1.2;
  letter-spacing: 0;
}

.rail-brand small {
  display: block;
  margin-top: 2px;
  color: rgba(234, 248, 245, 0.72);
  font-size: 12px;
  line-height: 1.3;
}

.rail-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 42px;
  width: 100%;
  color: #fff;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background 180ms ease, border-color 180ms ease, transform 180ms ease;
}

.rail-toggle:hover,
.rail-toggle:focus-visible {
  background: rgba(255, 255, 255, 0.16);
  border-color: rgba(255, 255, 255, 0.34);
  transform: translateY(-1px);
}

.action svg,
.back-top svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
  flex: 0 0 auto;
}

.menu-bars {
  display: inline-grid;
  gap: 4px;
  width: 20px;
  flex: 0 0 auto;
  place-items: center;
}

.menu-bars span {
  display: block;
  width: 20px;
  height: 2px;
  background: currentColor;
  border-radius: 999px;
  transition: opacity 180ms ease, transform 180ms ease;
}

.rail-nav {
  display: grid;
  gap: 6px;
  padding-top: 10px;
}

.rail-nav a {
  position: relative;
  overflow: hidden;
  display: grid;
  grid-template-columns: 34px 1fr;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 8px 10px;
  color: rgba(234, 248, 245, 0.78);
  border: 1px solid transparent;
  border-radius: var(--radius);
  transition: color 180ms ease, background 180ms ease, border-color 180ms ease, transform 180ms ease, box-shadow 180ms ease;
}

.rail-nav a::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: var(--sun);
  transform: scaleY(0);
  transform-origin: center;
  transition: transform 180ms ease;
}

.rail-nav a:hover,
.rail-nav a:focus-visible,
.rail-nav a.is-active {
  color: #fff;
  background: rgba(255, 255, 255, 0.13);
  border-color: rgba(255, 255, 255, 0.24);
  box-shadow: 0 10px 24px rgba(3, 28, 31, 0.16);
  transform: translateX(4px);
}

.rail-nav a:hover::before,
.rail-nav a:focus-visible::before,
.rail-nav a.is-active::before {
  transform: scaleY(1);
}

.rail-nav span {
  display: inline-grid;
  place-items: center;
  width: 30px;
  height: 30px;
  color: #153f40;
  background: var(--mint);
  border-radius: 50%;
  font-size: 12px;
  font-weight: 900;
}

.rail-nav strong {
  font-size: 15px;
  letter-spacing: 0;
}

.rail-meta {
  margin-top: auto;
  padding: 16px;
  color: rgba(234, 248, 245, 0.82);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: var(--radius);
}

.rail-meta p {
  margin: 0 0 12px;
  font-size: 13px;
}

.rail-meta a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  width: 100%;
  color: #1b292a;
  background: var(--sun);
  border-radius: var(--radius);
  font-weight: 900;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.rail-meta a:hover,
.rail-meta a:focus-visible {
  background: #ffd27c;
  box-shadow: 0 12px 28px rgba(244, 182, 79, 0.28);
  transform: translateY(-2px);
}

.site-main {
  margin-left: var(--rail);
}

.cover-stage {
  position: relative;
  min-height: 100svh;
  display: grid;
  align-items: end;
  overflow: hidden;
  padding: clamp(28px, 4vw, 56px);
  color: #fff;
  background: var(--deep-2);
  isolation: isolate;
}

.cover-stage::after {
  content: "";
  position: absolute;
  inset: auto clamp(18px, 5vw, 70px) clamp(18px, 5vw, 70px) auto;
  z-index: 1;
  width: clamp(180px, 23vw, 360px);
  aspect-ratio: 1;
  pointer-events: none;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 50%;
  background: radial-gradient(circle, rgba(244, 182, 79, 0.18), transparent 62%);
  filter: blur(0.2px);
}

.cover-image,
.cover-tint {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.cover-image {
  object-fit: cover;
  object-position: center;
  transform: scale(1.02);
  animation: coverDrift 18s ease-in-out infinite alternate;
}

.cover-tint {
  background:
    linear-gradient(90deg, rgba(11, 32, 35, 0.88), rgba(11, 32, 35, 0.42) 52%, rgba(11, 32, 35, 0.08)),
    linear-gradient(0deg, rgba(11, 32, 35, 0.76), rgba(11, 32, 35, 0.05) 56%);
}

.cover-copy {
  position: relative;
  z-index: 2;
  width: min(740px, 100%);
  padding-bottom: clamp(130px, 17vw, 178px);
  animation: riseIn 620ms ease both;
}

.label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 12px;
  color: var(--rose);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

.label::before {
  content: "";
  width: 26px;
  height: 2px;
  background: currentColor;
  border-radius: 999px;
}

.cover-copy .label {
  color: #ffcc7d;
}

.cover-copy h1 {
  margin: 0;
  color: var(--title-light);
  background: linear-gradient(92deg, #fff7d6 0%, var(--title-light) 32%, #9fe0cf 72%, #ffffff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  font-size: clamp(36px, 6vw, 70px);
  line-height: 1.05;
  letter-spacing: 0;
  text-wrap: balance;
  text-shadow: 0 6px 22px rgba(0, 0, 0, 0.35);
}

.subhead {
  margin: 18px 0 0;
  color: rgba(255, 255, 255, 0.86);
  font-size: clamp(18px, 2.3vw, 28px);
  line-height: 1.35;
}

.lede {
  max-width: 650px;
  margin: 20px 0 0;
  color: rgba(255, 255, 255, 0.84);
  font-size: 18px;
}

.cover-actions,
.download-band {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.cover-actions {
  margin-top: 30px;
}

.action {
  position: relative;
  overflow: hidden;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 46px;
  padding: 11px 18px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-weight: 900;
  line-height: 1.2;
  transition: transform 170ms ease, box-shadow 170ms ease, background 170ms ease, color 170ms ease, border-color 170ms ease;
}

.action::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(115deg, transparent 0%, rgba(255, 255, 255, 0.44) 46%, transparent 64%);
  transform: translateX(-130%);
  transition: transform 520ms ease;
}

.action > * {
  position: relative;
  z-index: 1;
}

.action:hover,
.action:focus-visible {
  transform: translateY(-3px);
}

.action:hover::before,
.action:focus-visible::before {
  transform: translateX(130%);
}

.action-primary {
  color: #1d2a28;
  background: var(--sun);
  box-shadow: 0 14px 34px rgba(244, 182, 79, 0.3);
}

.action-primary:hover,
.action-primary:focus-visible {
  background: #ffd27c;
  box-shadow: 0 18px 44px rgba(244, 182, 79, 0.38);
}

.action-line {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.34);
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
}

.action-line:hover,
.action-line:focus-visible {
  border-color: rgba(255, 255, 255, 0.58);
  background: rgba(255, 255, 255, 0.17);
}

.action-dark {
  color: #fff;
  background: var(--deep);
}

.action-dark:hover,
.action-dark:focus-visible {
  background: var(--deep-2);
  box-shadow: 0 12px 26px rgba(23, 104, 106, 0.2);
}

.cover-facts {
  position: absolute;
  z-index: 3;
  right: clamp(24px, 4vw, 56px);
  bottom: clamp(24px, 4vw, 56px);
  width: min(640px, calc(100% - 48px));
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: 0;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: var(--radius);
  backdrop-filter: blur(12px);
  box-shadow: 0 20px 48px rgba(4, 27, 31, 0.24);
}

.cover-facts div {
  min-width: 0;
  padding: 14px 15px;
  border-left: 1px solid rgba(255, 255, 255, 0.16);
  transition: background 180ms ease, transform 180ms ease;
}

.cover-facts div:hover {
  background: rgba(255, 255, 255, 0.16);
  transform: translateY(-2px);
}

.cover-facts div:first-child {
  border-left: 0;
}

.cover-facts dt {
  color: rgba(255, 255, 255, 0.68);
  font-size: 12px;
}

.cover-facts dd {
  margin: 4px 0 0;
  color: #fff;
  font-weight: 900;
  line-height: 1.35;
}

.chapter,
.download-band,
.site-footer {
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
}

.chapter {
  padding: clamp(64px, 8vw, 104px) 0;
}

.chapter-band {
  width: 100%;
  padding: clamp(64px, 8vw, 104px) clamp(20px, 4vw, 56px);
  background: var(--soft);
}

.chapter-band > *,
.chapter-band .chapter-heading {
  width: min(var(--max), 100%);
  margin-left: auto;
  margin-right: auto;
}

.chapter-heading {
  display: grid;
  grid-template-columns: 170px minmax(0, 1fr);
  gap: clamp(18px, 4vw, 48px);
  align-items: start;
  margin-bottom: 34px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--line);
}

.chapter-heading h2 {
  position: relative;
}

.chapter-heading h2::after {
  content: "";
  display: block;
  width: 72px;
  height: 3px;
  margin-top: 16px;
  background: linear-gradient(90deg, var(--sun), var(--mint));
  border-radius: 999px;
  transform: scaleX(0.72);
  transform-origin: left;
  transition: transform 220ms ease;
}

.chapter:hover .chapter-heading h2::after,
.chapter-band:hover .chapter-heading h2::after,
.gallery-chapter:hover .chapter-heading h2::after {
  transform: scaleX(1);
}

.chapter h2,
.download-band h2 {
  margin: 0;
  color: var(--title-main);
  background: linear-gradient(92deg, var(--title-main) 0%, var(--deep) 58%, var(--title-accent) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  font-size: clamp(25px, 3.2vw, 38px);
  line-height: 1.18;
  letter-spacing: 0;
  text-wrap: balance;
}

.chapter h3,
.download-band h3 {
  margin: 0;
  color: var(--ink);
  font-size: 20px;
  line-height: 1.35;
  letter-spacing: 0;
}

.chapter p,
.download-band p,
.site-footer p {
  margin: 14px 0 0;
  color: var(--muted);
}

.lead-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
  gap: clamp(28px, 5vw, 68px);
  align-items: center;
}

.text-flow {
  max-width: 660px;
}

.marker-list {
  display: grid;
  gap: 10px;
  padding: 0;
  margin: 24px 0 0;
  list-style: none;
}

.marker-list li {
  position: relative;
  padding-left: 28px;
  color: var(--ink);
  transition: color 160ms ease, transform 160ms ease;
}

.marker-list li:hover {
  color: var(--deep-2);
  transform: translateX(3px);
}

.marker-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--sun);
  box-shadow: 0 0 0 4px rgba(244, 182, 79, 0.18);
}

.scene-frame,
.gallery-main {
  margin: 0;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 220ms ease, box-shadow 220ms ease, border-color 220ms ease;
}

.scene-frame:hover,
.scene-frame:focus-within,
.gallery-main:hover,
.gallery-main:focus-within {
  transform: translateY(-5px);
  border-color: rgba(23, 104, 106, 0.28);
  box-shadow: var(--shadow-strong);
}

.scene-frame img,
.gallery-main img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  transition: transform 520ms ease, filter 220ms ease;
}

.scene-frame:hover img,
.gallery-main:hover img {
  transform: scale(1.035);
  filter: saturate(1.08) contrast(1.03);
}

figcaption {
  padding: 14px 16px;
  color: var(--muted);
  background: #fff;
  font-size: 14px;
}

.loop-board {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #fff;
  box-shadow: 0 18px 42px rgba(29, 71, 72, 0.08);
}

.loop-board article {
  position: relative;
  min-width: 0;
  padding: 24px;
  border-left: 1px solid var(--line);
  transition: background 180ms ease, transform 180ms ease, box-shadow 180ms ease;
}

.loop-board article::after {
  content: "";
  position: absolute;
  left: 24px;
  right: 24px;
  bottom: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--sun), var(--mint));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 200ms ease;
}

.loop-board article:hover {
  z-index: 1;
  background: #fbfffd;
  box-shadow: 0 18px 36px rgba(29, 71, 72, 0.12);
  transform: translateY(-3px);
}

.loop-board article:hover::after {
  transform: scaleX(1);
}

.loop-board article:first-child {
  border-left: 0;
}

.loop-board span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  margin-bottom: 20px;
  color: #1f2f31;
  background: var(--sun);
  border-radius: 50%;
  font-size: 13px;
  font-weight: 900;
  transition: transform 180ms ease, background 180ms ease;
}

.loop-board article:hover span {
  background: #ffd27c;
  transform: rotate(-5deg) scale(1.08);
}

.systems-grid {
  display: grid;
  grid-template-columns: 340px minmax(0, 1fr);
  gap: clamp(28px, 5vw, 58px);
  align-items: start;
}

.systems-intro {
  position: sticky;
  top: 28px;
  padding: 24px;
  color: #fff;
  background:
    radial-gradient(circle at 86% 10%, rgba(244, 182, 79, 0.22), transparent 34%),
    var(--deep-2);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.systems-intro .label,
.systems-intro p {
  color: rgba(255, 255, 255, 0.78);
}

.systems-intro h2 {
  color: var(--title-light);
  background: linear-gradient(92deg, #fff7d6 0%, var(--title-light) 48%, #9fe0cf 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.systems-intro .action {
  margin-top: 22px;
  background: var(--sun);
  color: #1f2f31;
}

.system-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.system-list article,
.update-ledger article,
.faq-list details {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 12px 32px rgba(29, 71, 72, 0.06);
}

.system-list article {
  position: relative;
  overflow: hidden;
  min-height: 190px;
  padding: 22px;
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.system-list article::before {
  content: "";
  position: absolute;
  inset: 0;
  width: 4px;
  background: linear-gradient(180deg, var(--sun), var(--mint));
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 200ms ease;
}

.system-list article:hover {
  transform: translateY(-5px);
  border-color: rgba(23, 104, 106, 0.3);
  box-shadow: var(--shadow);
}

.system-list article:hover::before {
  transform: scaleY(1);
}

.gallery-chapter {
  width: 100%;
  padding-left: clamp(20px, 4vw, 56px);
  padding-right: clamp(20px, 4vw, 56px);
}

.gallery-chapter .chapter-heading,
.gallery-board {
  width: min(var(--max), 100%);
  margin-left: auto;
  margin-right: auto;
}

.gallery-board {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 18px;
  align-items: stretch;
}

.gallery-main {
  min-width: 0;
}

.gallery-main img {
  height: 100%;
  min-height: 410px;
}

.gallery-choices {
  display: grid;
  gap: 12px;
}

.gallery-choices button {
  position: relative;
  overflow: hidden;
  display: grid;
  grid-template-columns: 82px 1fr;
  align-items: center;
  gap: 12px;
  min-height: 84px;
  padding: 8px;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  cursor: pointer;
  text-align: left;
  transition: border-color 180ms ease, transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.gallery-choices button::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(110deg, transparent, rgba(141, 201, 183, 0.18), transparent);
  transform: translateX(-120%);
  transition: transform 420ms ease;
}

.gallery-choices button:hover,
.gallery-choices button:focus-visible,
.gallery-choices button.is-active {
  border-color: rgba(23, 104, 106, 0.42);
  box-shadow: 0 12px 28px rgba(29, 71, 72, 0.1);
  transform: translateY(-2px);
  background: #fbfffd;
}

.gallery-choices button:hover::after,
.gallery-choices button:focus-visible::after,
.gallery-choices button.is-active::after {
  transform: translateX(120%);
}

.gallery-choices img {
  width: 82px;
  height: 58px;
  object-fit: cover;
  border-radius: 6px;
  transition: transform 220ms ease;
}

.gallery-choices button:hover img,
.gallery-choices button:focus-visible img,
.gallery-choices button.is-active img {
  transform: scale(1.05);
}

.gallery-choices span {
  font-weight: 900;
}

.guide-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.88fr) minmax(0, 1.12fr);
  gap: clamp(28px, 5vw, 64px);
  align-items: start;
}

.route-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: route;
}

.route-list li {
  position: relative;
  padding: 20px 20px 20px 72px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease, background 180ms ease;
}

.route-list li:hover {
  background: #fbfffd;
  border-color: rgba(23, 104, 106, 0.28);
  box-shadow: 0 14px 34px rgba(29, 71, 72, 0.1);
  transform: translateX(4px);
}

.route-list li::before {
  counter-increment: route;
  content: counter(route, decimal-leading-zero);
  position: absolute;
  left: 20px;
  top: 20px;
  display: inline-grid;
  place-items: center;
  width: 34px;
  height: 34px;
  color: #153f40;
  background: var(--mint);
  border-radius: 50%;
  font-size: 12px;
  font-weight: 900;
  transition: transform 180ms ease, background 180ms ease;
}

.route-list li:hover::before {
  background: var(--sun);
  transform: scale(1.08);
}

.route-list strong {
  display: block;
  color: var(--ink);
  font-size: 18px;
}

.route-list p {
  margin-top: 6px;
}

.update-ledger {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.update-ledger article {
  position: relative;
  overflow: hidden;
  padding: 22px;
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.update-ledger article::after {
  content: "";
  position: absolute;
  inset: auto 22px 0 22px;
  height: 3px;
  background: linear-gradient(90deg, var(--rose), var(--sun), var(--mint));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 220ms ease;
}

.update-ledger article:hover {
  border-color: rgba(23, 104, 106, 0.25);
  box-shadow: var(--shadow);
  transform: translateY(-4px);
}

.update-ledger article:hover::after {
  transform: scaleX(1);
}

.update-ledger time {
  display: inline-block;
  color: var(--rose);
  font-size: 13px;
  font-weight: 900;
}

.update-ledger h3 {
  margin-top: 8px;
}

.faq-chapter {
  width: 100%;
  padding-left: clamp(20px, 4vw, 56px);
  padding-right: clamp(20px, 4vw, 56px);
  background: #fff;
}

.faq-layout {
  width: min(var(--max), 100%);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 0.86fr) minmax(0, 1.14fr);
  gap: clamp(28px, 5vw, 64px);
  align-items: start;
}

.faq-list {
  display: grid;
  gap: 10px;
}

.faq-list details {
  overflow: hidden;
  transition: border-color 180ms ease, box-shadow 180ms ease, transform 180ms ease, background 180ms ease;
}

.faq-list details:hover,
.faq-list details[open] {
  border-color: rgba(23, 104, 106, 0.26);
  box-shadow: 0 16px 36px rgba(29, 71, 72, 0.09);
  transform: translateY(-2px);
  background: #fbfffd;
}

.faq-list summary {
  cursor: pointer;
  padding: 18px 48px 18px 18px;
  color: var(--ink);
  font-weight: 900;
  list-style: none;
  position: relative;
  transition: color 160ms ease, background 160ms ease;
}

.faq-list summary:hover,
.faq-list summary:focus-visible {
  color: var(--deep);
  background: rgba(141, 201, 183, 0.1);
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--deep);
  font-size: 22px;
  line-height: 1;
  transition: transform 180ms ease, color 180ms ease;
}

.faq-list details[open] summary::after {
  content: "-";
  color: var(--rose);
  transform: translateY(-50%) rotate(180deg);
}

.faq-list details p {
  margin: 0;
  padding: 0 18px 18px;
}

.download-band {
  justify-content: space-between;
  gap: 24px;
  margin-top: clamp(56px, 7vw, 88px);
  margin-bottom: clamp(56px, 7vw, 88px);
  padding: clamp(24px, 4vw, 36px);
  color: #fff;
  background:
    radial-gradient(circle at 86% 12%, rgba(244, 182, 79, 0.24), transparent 30%),
    linear-gradient(135deg, var(--deep-2), var(--deep));
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 200ms ease, box-shadow 200ms ease;
}

.download-band:hover {
  box-shadow: var(--shadow-strong);
  transform: translateY(-3px);
}

.download-band h2,
.download-band p {
  color: #fff;
}

.download-band h2 {
  background: linear-gradient(92deg, #fff7d6 0%, var(--title-light) 48%, #9fe0cf 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.download-band p {
  max-width: 690px;
  color: rgba(255, 255, 255, 0.78);
}

.site-footer {
  padding: 34px 0 42px;
  border-top: 1px solid var(--line);
}

.footer-main {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(180px, 0.7fr) minmax(220px, 0.9fr);
  gap: clamp(22px, 4vw, 52px);
}

.footer-brand {
  color: var(--deep-2);
  font-size: 18px;
  font-weight: 900;
}

.site-footer h2 {
  margin: 0 0 12px;
  color: var(--ink);
  font-size: 16px;
  line-height: 1.3;
}

.site-footer a:not(.footer-brand) {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  transition: color 160ms ease, transform 160ms ease;
}

.site-footer a:hover,
.site-footer a:focus-visible {
  color: var(--deep);
  transform: translateX(3px);
}

.friend-links {
  margin-top: clamp(34px, 5vw, 56px);
  padding-top: clamp(28px, 4vw, 42px);
  text-align: center;
  border-top: 1px solid var(--line);
}

.friend-links h2 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(22px, 2.6vw, 30px);
  line-height: 1.2;
}

.friend-link-list {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 22px;
}

.friend-link-list a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 96px;
  min-height: 42px;
  margin-top: 0;
  padding: 9px 22px;
  color: var(--ink);
  background: #fff;
  border: 1px solid rgba(31, 47, 49, 0.09);
  border-radius: 999px;
  box-shadow: 0 8px 22px rgba(31, 47, 49, 0.08);
  font-weight: 800;
  transition: transform 180ms ease, box-shadow 180ms ease, color 180ms ease, border-color 180ms ease;
}

.friend-link-list a:hover,
.friend-link-list a:focus-visible {
  color: var(--deep);
  border-color: rgba(23, 104, 106, 0.22);
  box-shadow: 0 12px 28px rgba(31, 47, 49, 0.12);
  transform: translateY(-2px);
}

.legal {
  margin-top: 22px;
  font-size: 13px;
}

.back-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 90;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  color: #fff;
  background: var(--deep);
  border: 0;
  border-radius: 50%;
  box-shadow: 0 12px 28px rgba(15, 69, 73, 0.28);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity 170ms ease, transform 170ms ease, background 170ms ease;
}

.back-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.back-top:hover,
.back-top:focus-visible {
  background: var(--deep-2);
  box-shadow: 0 16px 34px rgba(15, 69, 73, 0.36);
  transform: translateY(-2px);
}

@keyframes coverDrift {
  from {
    transform: scale(1.02) translate3d(0, 0, 0);
  }

  to {
    transform: scale(1.075) translate3d(-1.2%, -1%, 0);
  }
}

@keyframes riseIn {
  from {
    opacity: 0;
    transform: translateY(18px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

@media (max-width: 1180px) {
  :root {
    --rail: 264px;
  }

  .side-rail {
    padding: 20px 18px;
  }

  .cover-facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .cover-facts div:nth-child(3) {
    border-left: 0;
    border-top: 1px solid rgba(255, 255, 255, 0.16);
  }

  .cover-facts div:nth-child(4) {
    border-top: 1px solid rgba(255, 255, 255, 0.16);
  }

  .loop-board {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .loop-board article:nth-child(3) {
    border-left: 0;
  }

  .loop-board article:nth-child(n+3) {
    border-top: 1px solid var(--line);
  }
}

@media (max-width: 920px) {
  .side-rail {
    inset: 0 0 auto 0;
    width: 100%;
    min-height: 70px;
    padding: 12px 18px;
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 12px;
    align-items: center;
  }

  .rail-brand img {
    width: 42px;
    height: 42px;
  }

  .rail-toggle {
    display: inline-flex;
    width: auto;
    min-width: 104px;
    padding: 0 13px;
  }

  .rail-nav {
    position: fixed;
    inset: 70px 0 auto 0;
    display: none;
    grid-column: 1 / -1;
    padding: 14px 18px 20px;
    background: var(--deep-2);
    border-top: 1px solid rgba(255, 255, 255, 0.12);
    box-shadow: 0 18px 36px rgba(15, 69, 73, 0.26);
  }

  body.nav-open .rail-nav {
    display: grid;
  }

  .rail-meta {
    display: none;
  }

  .site-main {
    margin-left: 0;
    padding-top: 70px;
  }

  .cover-stage {
    min-height: calc(100svh - 70px);
  }

  .chapter-heading,
  .lead-layout,
  .systems-grid,
  .gallery-board,
  .guide-layout,
  .faq-layout,
  .footer-main {
    grid-template-columns: 1fr;
  }

  .systems-intro {
    position: static;
  }

  .gallery-main img {
    min-height: 0;
  }

  .gallery-choices {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .gallery-choices button {
    grid-template-columns: 1fr;
    min-height: 0;
  }

  .gallery-choices img {
    width: 100%;
    height: auto;
    aspect-ratio: 16 / 10;
  }

}

@media (max-width: 720px) {
  body {
    font-size: 15px;
  }

  .rail-brand strong {
    font-size: 16px;
  }

  .rail-brand small {
    font-size: 11px;
  }

  .cover-stage {
    padding: 24px 18px;
  }

  .cover-copy {
    padding-bottom: 232px;
  }

  .cover-facts {
    right: 18px;
    bottom: 18px;
    width: calc(100% - 36px);
  }

  .cover-facts div {
    padding: 12px;
  }

  .chapter,
  .download-band,
  .site-footer {
    width: min(var(--max), calc(100% - 32px));
  }

  .chapter-band,
  .gallery-chapter,
  .faq-chapter {
    padding-left: 16px;
    padding-right: 16px;
  }

  .system-list,
  .update-ledger,
  .loop-board {
    grid-template-columns: 1fr;
  }

  .loop-board article,
  .loop-board article:nth-child(3) {
    border-left: 0;
  }

  .loop-board article + article {
    border-top: 1px solid var(--line);
  }

  .gallery-choices {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .download-band {
    align-items: stretch;
  }

  .download-band .action {
    width: 100%;
  }
}

@media (max-width: 460px) {
  .rail-toggle [data-toggle-label] {
    display: none;
  }

  .rail-toggle {
    min-width: 44px;
    width: 44px;
    padding: 0;
  }

  .cover-copy h1 {
    font-size: 34px;
  }

  .cover-actions .action {
    width: 100%;
  }

  .cover-facts {
    grid-template-columns: 1fr;
  }

  .cover-facts div,
  .cover-facts div:nth-child(3),
  .cover-facts div:nth-child(4) {
    border-left: 0;
    border-top: 1px solid rgba(255, 255, 255, 0.16);
  }

  .cover-facts div:first-child {
    border-top: 0;
  }

  .cover-copy {
    padding-bottom: 360px;
  }

  .route-list li {
    padding-left: 62px;
  }
}

.rail-toggle.is-open .menu-bars,
.rail-toggle[aria-expanded="true"] .menu-bars,
body.nav-open .rail-toggle .menu-bars {
  display: inline-grid;
  gap: 0;
}

.rail-toggle.is-open .menu-bars span,
.rail-toggle[aria-expanded="true"] .menu-bars span,
body.nav-open .rail-toggle .menu-bars span {
  grid-area: 1 / 1;
}

.rail-toggle.is-open .menu-bars span:nth-child(1),
.rail-toggle[aria-expanded="true"] .menu-bars span:nth-child(1),
body.nav-open .rail-toggle .menu-bars span:nth-child(1) {
  transform: rotate(45deg);
}

.rail-toggle.is-open .menu-bars span:nth-child(2),
.rail-toggle[aria-expanded="true"] .menu-bars span:nth-child(2),
body.nav-open .rail-toggle .menu-bars span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.rail-toggle.is-open .menu-bars span:nth-child(3),
.rail-toggle[aria-expanded="true"] .menu-bars span:nth-child(3),
body.nav-open .rail-toggle .menu-bars span:nth-child(3) {
  transform: rotate(-45deg);
}