:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --bg-soft: #f5f5f7;
  --bg-deep: #fbfbfd;
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --line: rgba(0, 0, 0, 0.08);
  --link: #0066cc;
  --link-hover: #0077ed;
  --teal: #0f766e;
  --teal-deep: #0b5a54;
  --btn: #0f766e;
  --btn-hover: #0b5a54;
  --btn-active: #084843;
  --shadow: 0 2px 24px rgba(0, 0, 0, 0.08);
  --nav-bg: rgba(255, 255, 255, 0.72);
  --nav-bg-scrolled: rgba(255, 255, 255, 0.82);
  --card: #ffffff;
  --card-soft: rgba(255, 255, 255, 0.88);
  --card-soft-end: rgba(255, 255, 255, 0.72);
  --radius: 28px;
  /* Latin → SF Pro; CJK → PingFang (browser picks by glyph) */
  --font-sf: "SF Pro Display", "SF Pro Text", "SF Pro", -apple-system, BlinkMacSystemFont;
  --font-cjk: "PingFang SC", "PingFang HK";
  --font-display: var(--font-sf), var(--font-cjk), sans-serif;
  --font-sans: var(--font-sf), var(--font-cjk), sans-serif;
  --max: 1120px;
  --pad: clamp(1.25rem, 4vw, 2.5rem);
  --page-pad-inline-start: max(var(--pad), env(safe-area-inset-left, 0px));
  --page-pad-inline-end: max(var(--pad), env(safe-area-inset-right, 0px));
  --focus: #005eb8;
  --belief-shimmer: #8a9199;
}

html[data-locale="zh-Hans"] {
  --font-cjk: "PingFang SC", "PingFang HK";
  --font-display: var(--font-sf), var(--font-cjk), sans-serif;
  --font-sans: var(--font-sf), var(--font-cjk), sans-serif;
}

html[data-locale="zh-Hant"] {
  --font-cjk: "PingFang HK", "PingFang SC";
  --font-display: var(--font-sf), var(--font-cjk), sans-serif;
  --font-sans: var(--font-sf), var(--font-cjk), sans-serif;
}

html[data-locale="en"] {
  --font-cjk: "PingFang SC", "PingFang HK";
  --font-display: var(--font-sf), var(--font-cjk), sans-serif;
  --font-sans: var(--font-sf), var(--font-cjk), sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --bg-soft: #161617;
    --bg-deep: #0b0b0c;
    --ink: #f5f5f7;
    --muted: #a1a1a6;
    --line: rgba(255, 255, 255, 0.12);
    --link: #2997ff;
    --link-hover: #6cb6ff;
    --teal: #2dd4bf;
    --teal-deep: #5eead4;
    --btn: #0f766e;
    --btn-hover: #14b8a6;
    --btn-active: #0d9488;
    --shadow: 0 2px 24px rgba(0, 0, 0, 0.45);
    --nav-bg: rgba(22, 22, 23, 0.72);
    --nav-bg-scrolled: rgba(22, 22, 23, 0.88);
    --card: #1c1c1e;
    --card-soft: rgba(28, 28, 30, 0.92);
    --card-soft-end: rgba(28, 28, 30, 0.78);
    --focus: #7cc4ff;
    --belief-shimmer: #c7c7cc;
  }

  .nav-brand:hover,
  .nav-links a:hover,
  .nav-toggle:hover {
    background: rgba(255, 255, 255, 0.08);
  }

  .btn.ghost {
    border-color: rgba(255, 255, 255, 0.18);
  }

  .btn.ghost:hover {
    background: rgba(45, 212, 191, 0.12);
  }

  .pillar-card:hover {
    background: #222224;
  }

  .dot-field .dot.is-hot {
    background: #f5f5f7;
  }

  .footer {
    color: #a1a1a6;
  }

  .footer-col a {
    color: #a1a1a6;
  }

  .footer-col a:hover,
  .footer-col h3,
  .footer-col-toggle {
    color: var(--ink);
  }

  .footer-col-toggle::after {
    color: #a1a1a6;
  }

  .footer-legal p {
    color: #86868b;
  }

  img {
    opacity: 0.96;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  font-family: var(--font-sans);
  background: var(--bg);
  line-height: 1.6;
  font-weight: 400;
  letter-spacing: -0.01em;
  overflow-x: hidden;
  overflow-wrap: break-word;
  -webkit-font-smoothing: antialiased;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}
body.is-nav-open {
  overflow: hidden;
}

main[id],
section[id] {
  scroll-margin-top: calc(3.5rem + env(safe-area-inset-top, 0px));
}

img { display: block; max-width: 100%; height: auto; }
picture { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  border-radius: 8px;
}

/* —— Nav: thin glass bar —— */
.nav {
  position: sticky;
  top: 0;
  z-index: 40;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 1rem;
  min-height: calc(52px + env(safe-area-inset-top, 0px));
  padding:
    env(safe-area-inset-top, 0px)
    var(--page-pad-inline-end)
    0
    var(--page-pad-inline-start);
  backdrop-filter: saturate(180%) blur(20px);
  background: var(--nav-bg);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background 0.3s ease;
}
.nav.is-scrolled,
.nav.is-menu-open {
  border-bottom-color: var(--line);
  background: var(--nav-bg-scrolled);
}
.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  min-height: 2.5rem;
  max-width: 100%;
  justify-self: start;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: -0.015em;
  border-radius: 10px;
  padding: 0.3rem 0.45rem 0.3rem 0.28rem;
  margin-left: -0.2rem;
  white-space: nowrap;
  transition: background 0.25s ease, transform 0.25s ease;
}
.nav-brand:hover {
  background: rgba(0, 0, 0, 0.04);
  transform: translateY(-1px);
}
.brand-logo {
  width: 1.85rem;
  height: auto;
  flex-shrink: 0;
  display: block;
}
.nav-links {
  display: flex;
  gap: 0.15rem;
  justify-self: center;
  color: var(--ink);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: -0.01em;
}
.nav-links a {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 2.5rem;
  padding: 0.4rem 0.75rem;
  border-radius: 6px;
  opacity: 0.72;
  transition: opacity 0.2s ease, background 0.2s ease, color 0.2s ease;
}
.nav-links a:hover {
  opacity: 1;
  background: rgba(0, 0, 0, 0.05);
}
.nav-end {
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  justify-self: end;
  gap: 0.65rem;
  flex-shrink: 0;
}

.lang-switch {
  display: inline-flex;
  align-items: stretch;
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow: hidden;
  background: color-mix(in srgb, var(--bg) 80%, transparent);
}
.nav-lang-panel {
  display: none;
}
.lang-opt {
  appearance: none;
  border: 0;
  margin: 0;
  padding: 0.55rem 0.7rem;
  min-width: 2.75rem;
  min-height: 2.75rem;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
  line-height: 1.2;
  transition: background 0.2s ease, color 0.2s ease;
}
.lang-opt + .lang-opt {
  border-left: 1px solid var(--line);
}
.lang-opt:hover {
  color: var(--ink);
  background: color-mix(in srgb, var(--ink) 5%, transparent);
}
.lang-opt.is-active {
  color: #fff;
  background: var(--btn);
}
.lang-opt:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: -2px;
  z-index: 1;
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.28rem;
  min-height: 2.75rem;
  padding: 0.5rem 1.05rem;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: #fff;
  background: var(--btn);
  transition: background 0.2s ease, color 0.2s ease;
}
.nav-cta span {
  font-size: 1.15em;
  line-height: 1;
  transition: transform 0.2s ease;
}
.nav-cta:hover {
  background: var(--btn-hover);
}
.nav-cta:hover span { transform: translateX(2px); }
.nav-cta:active { background: var(--btn-active); }

.nav-toggle {
  display: none;
  appearance: none;
  border: 1px solid var(--line);
  margin: 0;
  padding: 0;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 4px;
  background: color-mix(in srgb, var(--bg) 80%, transparent);
  color: var(--ink);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  transition:
    background 0.25s ease,
    border-color 0.25s ease,
    transform 0.35s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.nav-toggle:hover {
  background: color-mix(in srgb, var(--ink) 5%, transparent);
}
.nav-toggle:active {
  transform: scale(0.92);
}
.nav-toggle-box {
  position: relative;
  display: block;
  width: 1.15rem;
  height: 0.9rem;
}
.nav-toggle-box span {
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  border-radius: 1px;
  background: currentColor;
  transform-origin: center;
  transition:
    top 0.45s cubic-bezier(0.2, 0.8, 0.2, 1),
    transform 0.45s cubic-bezier(0.2, 0.8, 0.2, 1),
    opacity 0.25s ease,
    width 0.35s ease,
    left 0.35s ease,
    right 0.35s ease;
}
.nav-toggle-box span:nth-child(1) { top: 0; }
.nav-toggle-box span:nth-child(2) { top: calc(50% - 0.75px); }
.nav-toggle-box span:nth-child(3) { top: calc(100% - 1.5px); }
.nav.is-menu-open .nav-toggle {
  border-color: color-mix(in srgb, var(--ink) 18%, transparent);
  background: color-mix(in srgb, var(--ink) 6%, transparent);
}
.nav.is-menu-open .nav-toggle-box span:nth-child(1) {
  top: calc(50% - 0.75px);
  transform: rotate(45deg);
}
.nav.is-menu-open .nav-toggle-box span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0.35);
}
.nav.is-menu-open .nav-toggle-box span:nth-child(3) {
  top: calc(50% - 0.75px);
  transform: rotate(-45deg);
}

/* —— Hero: Apple product block —— */
.hero {
  position: relative;
  isolation: isolate;
  display: grid;
  justify-items: center;
  min-height: min(50rem, calc(100svh - 3.25rem));
  padding: 3.75rem var(--page-pad-inline-end) 4.5rem var(--page-pad-inline-start);
  overflow: hidden;
  text-align: center;
  background: var(--bg-deep);
}
.hero-background {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}
.hero-background picture,
.hero-background img {
  display: block;
  width: 100%;
  height: 100%;
}
.hero-background img {
  object-fit: cover;
  object-position: center 57%;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.94) 0%, rgba(255, 255, 255, 0.84) 41%, rgba(250, 252, 253, 0.22) 70%, rgba(248, 251, 252, 0.48) 100%);
}
@media (prefers-color-scheme: dark) {
  .hero::before {
    background: linear-gradient(180deg, rgba(8, 12, 18, 0.90) 0%, rgba(8, 12, 18, 0.76) 46%, rgba(8, 12, 18, 0.36) 72%, rgba(8, 12, 18, 0.58) 100%);
  }
}
.hero-copy {
  position: relative;
  z-index: 2;
  max-width: 740px;
  margin: 0 auto 2.15rem;
}
.eyebrow {
  margin: 0 0 0.55rem;
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--teal-deep);
}
.hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2.75rem, 7vw, 4.6rem);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.03em;
  color: var(--ink);
  text-wrap: balance;
}
.lede {
  margin: 0.95rem auto 0;
  max-width: 34rem;
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  font-weight: 400;
  line-height: 1.55;
  color: var(--muted);
  letter-spacing: -0.01em;
  text-wrap: pretty;
}
.lede-rest {
  display: inline;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 0.75rem;
  margin-top: 1.65rem;
}

.text-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  min-height: 2.5rem;
  color: var(--link);
  font-size: 1.02rem;
  font-weight: 500;
  padding: 0.4rem 0.15rem;
  border-radius: 6px;
  line-height: 1.35;
  transition: color 0.22s ease, background 0.22s ease, transform 0.22s ease;
}
.text-link::after {
  content: "";
  position: absolute;
  left: 0.15rem;
  right: 0.15rem;
  bottom: 0.15rem;
  height: 1px;
  background: currentColor;
  transform: scaleX(0.35);
  transform-origin: left center;
  opacity: 0.35;
  transition: transform 0.3s cubic-bezier(0.2, 0.8, 0.2, 1), opacity 0.3s ease;
}
.text-link span {
  font-size: 1.25em;
  line-height: 1;
  transition: transform 0.28s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.text-link:hover {
  color: var(--link-hover);
  transform: translateY(-1px);
}
.text-link:hover::after {
  transform: scaleX(1);
  opacity: 0.85;
}
.text-link:hover span { transform: translateX(4px); }
.text-link:active { transform: translateY(0); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: 2.85rem;
  padding: 0.75rem 1.45rem;
  border-radius: 6px;
  border: 1px solid transparent;
  font-family: var(--font-sans);
  font-size: 1.02rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}
.hero-actions .btn {
  min-height: 3.05rem;
  padding: 0.82rem 1.6rem;
  font-size: 1.05rem;
}
.btn span[aria-hidden="true"] {
  font-size: 1.15em;
  line-height: 1;
  transition: transform 0.2s ease;
}
.btn.primary {
  color: #fff;
  background: var(--btn);
}
.btn.primary:hover { background: var(--btn-hover); }
.btn.primary:active { background: var(--btn-active); }
.btn.ghost {
  color: var(--ink);
  background: transparent;
  border-color: rgba(0, 0, 0, 0.16);
}
.btn.ghost:hover {
  color: var(--btn);
  border-color: var(--btn);
  background: rgba(15, 118, 110, 0.06);
}
.btn.ghost:hover span[aria-hidden="true"] { transform: translateX(3px); }
.btn.ghost:active { background: rgba(15, 118, 110, 0.1); }

.strip {
  padding: 3rem var(--page-pad-inline-end) 1.25rem var(--page-pad-inline-start);
  text-align: center;
  background: var(--bg);
}
.flow {
  display: inline-flex;
  align-items: center;
  flex-wrap: nowrap;
  white-space: nowrap;
  justify-content: center;
  max-width: 100%;
  gap: clamp(0.35rem, 2.2vw, 0.85rem);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(0.95rem, 3.4vw, 1.55rem);
  letter-spacing: -0.02em;
  line-height: 1.2;
}
.flow i {
  flex: 0 0 auto;
  width: clamp(0.65rem, 3.8vw, 2rem);
  height: 1px;
  background: rgba(0, 0, 0, 0.18);
  position: relative;
  overflow: hidden;
}
.flow i::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--ink);
  transform: translateX(-100%);
  animation: shimmer 2.8s ease-in-out infinite;
}
.flow span {
  flex: 0 0 auto;
  opacity: 0.62;
  transition: opacity 0.4s ease, color 0.4s ease;
}
.flow span.is-active {
  opacity: 1;
  color: var(--ink);
}
html[data-locale="en"] .flow {
  font-size: clamp(0.78rem, 3.2vw, 1.55rem);
  letter-spacing: -0.03em;
  gap: clamp(0.28rem, 1.8vw, 0.85rem);
}
.strip-note {
  margin: 1.05rem auto 0;
  max-width: 38rem;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.65;
  text-wrap: pretty;
}

.section {
  padding: 5.5rem var(--page-pad-inline-end) 5.5rem var(--page-pad-inline-start);
}
.section-head {
  max-width: 640px;
  margin: 0 auto 3rem;
  text-align: center;
}
.section-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4.2vw, 2.85rem);
  font-weight: 700;
  letter-spacing: -0.028em;
  line-height: 1.2;
  text-wrap: balance;
}
.section-head p:last-child {
  margin: 0.9rem 0 0;
  color: var(--muted);
  font-size: 1.05rem;
  line-height: 1.65;
  text-wrap: pretty;
}

#products { background: var(--bg); }
.product {
  display: grid;
  grid-template-columns: 0.95fr 1.15fr;
  gap: clamp(1.5rem, 4vw, 3.25rem);
  align-items: center;
  max-width: var(--max);
  margin: 0 auto;
  padding: 3.15rem 0;
}
.product + .product {
  border-top: 1px solid var(--line);
}
.product.reverse { direction: rtl; }
.product.reverse > * { direction: ltr; }
.product-kicker {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
  color: var(--teal-deep);
  font-weight: 600;
  letter-spacing: -0.01em;
  font-size: 0.9rem;
}
.product h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 2.6vw, 2rem);
  font-weight: 600;
  line-height: 1.32;
  letter-spacing: -0.022em;
  text-wrap: balance;
  max-width: 22em;
}
.product-copy > p {
  color: var(--muted);
  margin: 0.8rem 0 0;
  font-size: 1.02rem;
  line-height: 1.7;
  text-wrap: pretty;
}
.product ul {
  margin: 1.1rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.5rem;
}
.product li {
  position: relative;
  padding-left: 1rem;
  color: var(--ink);
  font-size: 0.98rem;
  line-height: 1.55;
}
.product li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 0.35rem;
  height: 0.35rem;
  border-radius: 50%;
  background: var(--teal);
}
.product-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem 1.35rem;
  margin-top: 1.25rem;
}
.product-links .text-link { font-size: 0.98rem; }

.product-media {
  margin: 0;
  position: relative;
  overflow: visible;
  /* keep float from covering the main shot */
  padding-bottom: 3.25rem;
}
.product-media > picture:first-of-type,
.product-media > img:first-of-type {
  display: block;
  width: 100%;
}
.product-media > picture:first-of-type img,
.product-media > img:first-of-type {
  width: 100%;
  height: auto;
  max-height: none;
  object-fit: contain;
  object-position: center center;
  border-radius: 22px;
  box-shadow: var(--shadow);
  background: var(--bg-soft);
  transition: transform 0.7s cubic-bezier(0.2, 0.8, 0.2, 1);
}
@media (hover: hover) and (pointer: fine) {
  .product:hover .product-media > picture:first-of-type img,
  .product:hover .product-media > img:first-of-type {
    transform: translateY(-4px);
  }
}
.product-media .float {
  position: absolute;
  width: min(34%, 180px);
  right: 3%;
  /* sit mostly in the padding zone so the main UI stays fully visible */
  bottom: 0.15rem;
  border-radius: 16px;
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.14);
  animation: float-y 6s ease-in-out infinite;
  overflow: visible;
  z-index: 2;
}
.product-media .float img {
  width: 100%;
  height: auto;
  object-fit: contain;
  border-radius: 16px;
  display: block;
}
.product-media .float.secondary {
  right: auto;
  left: 3%;
  bottom: 0.35rem;
  width: min(40%, 210px);
  animation-delay: -1.5s;
}

.method {
  background: var(--bg-soft);
}
.method .pillars {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  max-width: var(--max);
  margin: 0 auto;
}
.pillar-card {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--card);
  isolation: isolate;
  transition: border-color 0.25s ease, background 0.25s ease;
}
.pillar-card:hover {
  border-color: color-mix(in srgb, var(--teal) 45%, transparent);
  background: var(--card);
}
.pillar-card:hover .dot-field { opacity: 0.9; }

.dot-field {
  position: absolute;
  inset: 0;
  z-index: 0;
  display: grid;
  grid-template-columns: repeat(16, 1fr);
  grid-template-rows: repeat(10, 1fr);
  pointer-events: none;
  opacity: 0.7;
  transition: opacity 0.3s ease;
}
.dot-field .dot {
  width: 2px;
  height: 2px;
  margin: auto;
  border-radius: 50%;
  background: var(--teal);
  opacity: 0.12;
  transition: opacity 0.35s linear, transform 0.35s linear;
}
.dot-field .dot.is-lit {
  opacity: 0.75;
  transform: scale(1.25);
}
.dot-field .dot.is-near {
  opacity: 0.55;
  transform: scale(1.2);
}
.dot-field .dot.is-hot {
  opacity: 1;
  background: var(--ink);
  transform: scale(1.55);
}

.pillar-body {
  position: relative;
  z-index: 1;
  padding: 1.45rem 1.3rem;
  background: linear-gradient(
    180deg,
    var(--card-soft) 0%,
    var(--card-soft-end) 100%
  );
}
.pillar-body span {
  font-family: var(--font-display);
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
}
.pillar-body h3 {
  margin: 0.5rem 0 0.4rem;
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.25;
}
.pillar-body p {
  margin: 0;
  color: var(--muted);
  font-size: 0.94rem;
  line-height: 1.55;
}

.beliefs { background: var(--bg); }
.beliefs-split {
  display: grid;
  grid-template-columns: 1.2fr 0.9fr;
  gap: clamp(1.75rem, 4vw, 3.5rem);
  align-items: center;
  max-width: var(--max);
  margin: 0 auto;
}
.beliefs-visual {
  margin: 0;
  min-width: 0;
  overflow: visible;
}
.beliefs-visual img {
  width: 100%;
  height: auto;
  object-fit: contain;
  object-position: center top;
  border-radius: 22px;
  background: var(--bg-soft);
  box-shadow: var(--shadow);
}
.belief-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1.35rem;
  min-width: 0;
}
.belief-list li {
  position: relative;
  display: grid;
  grid-template-columns: 2px 1fr;
  gap: 0.9rem;
  align-items: start;
  margin: 0;
  padding: 0.1rem 0;
  font-family: var(--font-display);
  font-size: clamp(1.08rem, 1.9vw, 1.35rem);
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: -0.02em;
  color: var(--ink);
  opacity: 0.62;
  transition: opacity 0.55s ease;
  text-wrap: pretty;
}
.belief-list li.is-in { opacity: 1; }
.belief-list.is-cycling li { opacity: 0.62; }
.belief-list.is-cycling li.is-active { opacity: 1; }

.belief-rail {
  display: block;
  width: 2px;
  min-height: 1.2em;
  height: 100%;
  margin-top: 0.28em;
  background: var(--teal);
  transform: scaleY(0);
  transform-origin: top center;
  transition: transform 0.7s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.belief-list li.is-in .belief-rail { transform: scaleY(1); }
.belief-list.is-cycling li.is-active .belief-rail {
  animation: belief-rail-flow 2.4s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}

.belief-text {
  display: block;
  clip-path: inset(0 100% 0 0);
  transform: translateX(-0.4rem);
  transition:
    clip-path 0.95s cubic-bezier(0.2, 0.8, 0.2, 1),
    transform 0.95s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.belief-list li.is-in .belief-text {
  clip-path: inset(0 0 0 0);
  transform: none;
}
.belief-list.is-cycling li.is-active .belief-text {
  background-image: linear-gradient(
    100deg,
    var(--ink) 0%,
    var(--ink) 38%,
    var(--belief-shimmer) 50%,
    var(--ink) 62%,
    var(--ink) 100%
  );
  background-size: 220% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: belief-data-flow 2.4s linear;
}
.belief-list strong { font-weight: 700; }

@keyframes belief-rail-flow {
  0% { transform: scaleY(0); transform-origin: top center; opacity: 1; }
  35% { transform: scaleY(1); opacity: 1; }
  70% { transform: scaleY(1); transform-origin: bottom center; opacity: 1; }
  100% { transform: scaleY(0); transform-origin: bottom center; opacity: 0.35; }
}
@keyframes belief-data-flow {
  from { background-position: 100% 0; }
  to { background-position: -100% 0; }
}

.academy {
  background: var(--bg);
}

.academy-panel {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: center;
  padding: clamp(1.5rem, 3.5vw, 2.5rem);
  border-radius: calc(var(--radius) + 4px);
  background: var(--bg-soft);
  border: 1px solid var(--line);
}

.academy-copy .eyebrow {
  margin-bottom: 0.75rem;
}

.academy-copy h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4vw, 2.85rem);
  line-height: 1.12;
  letter-spacing: -0.03em;
}

.academy-lede {
  margin: 0.9rem 0 0;
  max-width: 34rem;
  font-size: 1.08rem;
  color: var(--muted);
}

.academy-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 1.5rem;
  margin: 1.35rem 0 0;
  padding: 0;
  list-style: none;
}

.academy-stats li {
  min-width: 4.5rem;
}

.academy-stats strong {
  display: block;
  font-size: 1.75rem;
  letter-spacing: -0.03em;
  line-height: 1.1;
}

.academy-stats span {
  color: var(--muted);
  font-size: 0.9rem;
}

.academy-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.85rem 1.25rem;
  margin-top: 1.5rem;
}

.academy-visual {
  margin: 0;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg);
}

.academy-visual img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.open { background: var(--bg-soft); }
.repo-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  max-width: var(--max);
  margin: 0 auto;
}
.repo {
  position: relative;
  display: grid;
  gap: 0.3rem;
  padding: 1.6rem 2.6rem 1.6rem 1.5rem;
  border-radius: 22px;
  background: var(--card);
  border: 1px solid transparent;
  box-shadow: 0 1px 0 color-mix(in srgb, var(--ink) 4%, transparent);
  transition:
    transform 0.35s cubic-bezier(0.2, 0.8, 0.2, 1),
    border-color 0.3s ease,
    box-shadow 0.35s ease,
    background 0.3s ease;
}
.repo:hover {
  transform: translateY(-5px);
  border-color: color-mix(in srgb, var(--link) 28%, transparent);
  box-shadow: var(--shadow);
  background: var(--card);
}
.repo span {
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  font-family: var(--font-display);
  font-weight: 600;
  transition: color 0.25s ease;
}
.repo:hover span { color: var(--link); }
.repo strong {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}
.repo em {
  font-style: normal;
  color: var(--muted);
  font-size: 0.95rem;
}
.repo-arrow {
  position: absolute;
  right: 1.15rem;
  top: 50%;
  margin: 0;
  font-style: normal;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 500;
  color: var(--link);
  opacity: 0.55;
  transform: translate(0, -50%);
  transition: opacity 0.28s ease, transform 0.28s cubic-bezier(0.2, 0.8, 0.2, 1);
}
@media (hover: hover) and (pointer: fine) {
  .repo-arrow {
    opacity: 0;
    transform: translate(4px, -50%);
  }
  .repo:hover .repo-arrow {
    opacity: 1;
    transform: translate(0, -50%);
  }
}

.contact {
  background: var(--bg);
  text-align: center;
  padding: 6.25rem var(--page-pad-inline-end) 5.75rem var(--page-pad-inline-start);
}
.contact-plane {
  max-width: 560px;
  margin: 0 auto;
}
.contact-plane h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4vw, 2.6rem);
  font-weight: 600;
  letter-spacing: -0.028em;
  line-height: 1.22;
  color: var(--ink);
  text-wrap: balance;
}
.contact-lede {
  margin: 0.9rem auto 0;
  max-width: 28rem;
  color: var(--muted);
  font-size: 1.1rem;
  line-height: 1.6;
  text-wrap: pretty;
}
.contact-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 1.25rem 1.75rem;
  margin-top: 1.65rem;
}
.contact-actions .text-link {
  font-size: 1.12rem;
  font-weight: 500;
}

.wechat-float { display: none; }

@media (min-width: 1025px) and (hover: hover) and (pointer: fine) {
  .wechat-float {
    position: fixed;
    right: max(1.5rem, env(safe-area-inset-right, 0px));
    bottom: max(1.5rem, env(safe-area-inset-bottom, 0px));
    z-index: 30;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    min-height: 2.85rem;
    padding: 0.65rem 0.85rem 0.65rem 0.75rem;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: color-mix(in srgb, var(--bg) 84%, transparent);
    color: var(--ink);
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    text-decoration: none;
    opacity: 0;
    pointer-events: none;
    transform: translateY(0.65rem);
    transition: opacity 0.24s ease, transform 0.24s cubic-bezier(0.2, 0.8, 0.2, 1), border-color 0.2s ease, background 0.2s ease;
    backdrop-filter: saturate(160%) blur(16px);
  }
  .is-wechat-float-visible .wechat-float {
    opacity: 1;
    pointer-events: auto;
    transform: none;
  }
  .wechat-float:hover {
    border-color: color-mix(in srgb, var(--btn) 42%, var(--line));
    background: color-mix(in srgb, var(--bg) 94%, transparent);
  }
  .wechat-float > span:last-child {
    font-size: 1.18em;
    line-height: 1;
    transition: transform 0.2s ease;
  }
  .wechat-float:hover > span:last-child { transform: translateX(2px); }
  .wechat-float-dot {
    width: 0.5rem;
    height: 0.5rem;
    border-radius: 50%;
    background: #4caf72;
    box-shadow: 0 0 0 3px color-mix(in srgb, #4caf72 13%, transparent);
  }
}

.footer {
  padding: 0;
  background: var(--bg-soft);
  border-top: 1px solid var(--line);
  color: #6e6e73;
  font-size: 0.75rem;
  line-height: 1.33337;
}
.footer-inner {
  max-width: 980px;
  margin: 0 auto;
  padding:
    1.25rem
    var(--page-pad-inline-end)
    max(1.75rem, calc(1rem + env(safe-area-inset-bottom, 0px)))
    var(--page-pad-inline-start);
}
.footer-dir {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.25rem 2rem;
  padding: 0.35rem 0 1.25rem;
  border-bottom: 1px solid var(--line);
}
.footer-col {
  display: grid;
  gap: 0.15rem;
  align-content: start;
}
.footer-col-title {
  margin: 0 0 0.2rem;
}
.footer-col h3 {
  margin: 0 0 0.2rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.footer-col-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  margin: 0;
  padding: 0;
  border: 0;
  background: none;
  font: inherit;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.01em;
  line-height: 1.33337;
  text-align: left;
  cursor: default;
  -webkit-tap-highlight-color: transparent;
}
.footer-col-toggle::after {
  content: none;
}
.footer-col-panel {
  display: grid;
  gap: 0.15rem;
}
.footer-col a {
  color: #6e6e73;
  font-size: 0.75rem;
  font-weight: 400;
  width: fit-content;
  min-height: 0;
  padding: 0.2rem 0;
  line-height: 1.35;
  display: inline-flex;
  align-items: center;
  transition: color 0.2s ease, text-decoration-color 0.2s ease;
  text-decoration: none;
}
.footer-col a:hover {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.footer-legal {
  padding-top: 0.85rem;
  display: grid;
  gap: 0.18rem;
}
.footer-lang {
  margin-bottom: 0.4rem;
}
.footer-lang .lang-opt {
  min-width: 2.25rem;
  min-height: 2rem;
  padding: 0.32rem 0.55rem;
}
.footer-legal p {
  margin: 0;
  color: #6e6e73;
  font-size: 0.75rem;
  max-width: 52rem;
  line-height: 1.35;
}
.footer-beian {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease;
}
.footer-beian:hover {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.reveal {
  opacity: 1;
  transform: none;
}
.js .reveal {
  opacity: 0;
  transform: translateY(18px);
  transition:
    opacity 0.9s cubic-bezier(0.2, 0.8, 0.2, 1),
    transform 0.9s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.js .reveal.is-in {
  opacity: 1;
  transform: none;
}
.delay-1 { transition-delay: 0.08s; }
.delay-2 { transition-delay: 0.16s; }
.delay-3 { transition-delay: 0.24s; }

@keyframes float-y {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}
@keyframes shimmer {
  0%, 30% { transform: translateX(-100%); }
  70%, 100% { transform: translateX(100%); }
}
@keyframes rise-in {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: none; }
}

@media (max-width: 1024px) {
  .nav {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
  }
  .js .nav-toggle { display: inline-flex; }
  .js .nav-cta { display: none; }
  .js .nav-links {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    width: 100%;
    justify-self: stretch;
    flex-direction: column;
    align-items: center;
    gap: 0.15rem;
    max-height: 0;
    padding:
      0
      max(var(--pad), env(safe-area-inset-right, 0px))
      0
      max(var(--pad), env(safe-area-inset-left, 0px));
    overflow: hidden;
    visibility: hidden;
    pointer-events: none;
    opacity: 0;
    transform: translateY(-10px);
    background: var(--bg);
    backdrop-filter: none;
    border-bottom: 1px solid transparent;
    box-shadow: none;
    font-size: 1rem;
    text-align: center;
    transition:
      max-height 0.5s cubic-bezier(0.2, 0.8, 0.2, 1),
      opacity 0.32s ease,
      transform 0.42s cubic-bezier(0.2, 0.8, 0.2, 1),
      padding 0.4s cubic-bezier(0.2, 0.8, 0.2, 1),
      border-color 0.3s ease,
      box-shadow 0.35s ease,
      visibility 0s linear 0.4s;
  }
  .js .nav.is-menu-open .nav-links {
    max-height: calc(100dvh - 3.5rem - env(safe-area-inset-top, 0px));
    visibility: visible;
    pointer-events: auto;
    opacity: 1;
    transform: none;
    padding-top: 0.65rem;
    padding-bottom: calc(1rem + env(safe-area-inset-bottom, 0px));
    border-bottom-color: var(--line);
    box-shadow: var(--shadow);
    overflow-y: auto;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
    transition:
      max-height 0.55s cubic-bezier(0.2, 0.8, 0.2, 1),
      opacity 0.35s ease,
      transform 0.45s cubic-bezier(0.2, 0.8, 0.2, 1),
      padding 0.4s cubic-bezier(0.2, 0.8, 0.2, 1),
      border-color 0.3s ease,
      box-shadow 0.35s ease,
      visibility 0s;
  }
  .js .nav.is-menu-open {
    background: var(--bg);
    backdrop-filter: none;
  }
  .js .nav-links a {
    width: 100%;
    justify-content: center;
    opacity: 0;
    padding: 0.7rem 0.85rem;
    transform: translateY(12px);
    transition:
      opacity 0.4s cubic-bezier(0.2, 0.8, 0.2, 1),
      transform 0.45s cubic-bezier(0.2, 0.8, 0.2, 1),
      background 0.2s ease,
      color 0.2s ease;
  }
  .js .nav-lang-panel {
    display: inline-flex;
    align-self: center;
    margin: 0.65rem 0 0.2rem;
    opacity: 0;
    transform: translateY(12px) scale(0.96);
    transition:
      opacity 0.4s cubic-bezier(0.2, 0.8, 0.2, 1),
      transform 0.45s cubic-bezier(0.2, 0.8, 0.2, 1);
  }
  .js .nav.is-menu-open .nav-links a,
  .js .nav.is-menu-open .nav-lang-panel {
    opacity: 1;
    transform: none;
  }
  .js .nav.is-menu-open .nav-links a:nth-child(1) { transition-delay: 0.05s; }
  .js .nav.is-menu-open .nav-links a:nth-child(2) { transition-delay: 0.09s; }
  .js .nav.is-menu-open .nav-links a:nth-child(3) { transition-delay: 0.13s; }
  .js .nav.is-menu-open .nav-links a:nth-child(4) { transition-delay: 0.17s; }
  .js .nav.is-menu-open .nav-links a:nth-child(5) { transition-delay: 0.21s; }
  .js .nav.is-menu-open .nav-links a:nth-child(6) { transition-delay: 0.25s; }
  .js .nav.is-menu-open .nav-lang-panel { transition-delay: 0.32s; }

  html:not(.js) .nav-links {
    order: 3;
    width: 100%;
    justify-content: center;
    flex-wrap: wrap;
  }
  .product,
  .product.reverse {
    grid-template-columns: 1fr;
    direction: ltr;
    text-align: center;
  }
  .product-copy ul { text-align: left; max-width: 28rem; margin-left: auto; margin-right: auto; }
  .product-copy h3 { max-width: none; margin-left: auto; margin-right: auto; }
  .product-links { justify-content: center; }
  .product-media {
    width: 100%;
    max-width: 42rem;
    margin-left: auto;
    margin-right: auto;
    padding-bottom: 0;
  }
  .product-media .float {
    display: none;
  }
  .method .pillars,
  .repo-grid {
    grid-template-columns: 1fr 1fr;
  }
  .beliefs-split {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .belief-list { text-align: left; }
  .belief-list li { font-size: 1.15rem; }
  .academy-panel {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .hero { min-height: calc(100svh - 3.25rem); padding-top: 2.75rem; padding-bottom: 2rem; }
  .hero-background img { object-position: 50% 64%; }
  .hero h1 { font-size: clamp(2.35rem, 11vw, 2.9rem); line-height: 1.1; }
  .lede { font-size: 1.08rem; line-height: 1.55; max-width: 22rem; }
  .lede-rest { display: block; }
  .hero-actions { gap: 0.65rem; margin-top: 1.35rem; }
  .hero-actions .btn {
    min-height: 2.85rem;
    padding: 0.7rem 1.25rem;
    font-size: 1rem;
    width: min(100%, 16rem);
  }
  .nav-brand { font-size: 1rem; }
  .brand-logo { width: 1.7rem; }
  .method .pillars,
  .repo-grid { grid-template-columns: 1fr; }
  .product-media > picture:first-of-type {
    aspect-ratio: 3 / 2;
    overflow: hidden;
    border-radius: 18px;
    background: var(--bg-soft);
    box-shadow: var(--shadow);
  }
  .product-media > picture:first-of-type img {
    height: 100%;
    object-fit: contain;
    border-radius: inherit;
    box-shadow: none;
  }
  .product { padding: 2.5rem 0; }
  .product h3 { font-size: 1.4rem; line-height: 1.35; }
  .section { padding: 3.75rem var(--page-pad-inline-end) 3.75rem var(--page-pad-inline-start); }
  .section-head { margin-bottom: 2.35rem; }
  .beliefs-visual { display: none; }
  .beliefs-split { gap: 0; }
  .belief-list { gap: 1rem; }
  .contact { padding: 4.25rem var(--page-pad-inline-end) 3.75rem var(--page-pad-inline-start); }
  .contact-actions { gap: 0.75rem 1.25rem; }
  .text-link {
    font-size: 0.9375rem;
    min-height: 2.25rem;
    padding: 0.28rem 0.1rem;
  }
  .text-link span {
    font-size: 1.12em;
  }
  .product-links .text-link,
  .contact-actions .text-link {
    font-size: 0.9375rem;
  }
  .footer-dir {
    grid-template-columns: 1fr;
    gap: 0;
    padding: 0;
  }
  .footer-col {
    gap: 0;
    border-bottom: 1px solid var(--line);
  }
  .footer-col:last-child {
    grid-column: auto;
  }
  .footer-col-title {
    margin: 0;
  }
  .footer-col-toggle {
    min-height: 2.75rem;
    padding: 0.65rem 0;
    font-size: 0.75rem;
    cursor: pointer;
  }
  .footer-col-toggle::after {
    content: "+";
    flex: 0 0 auto;
    margin-inline-start: 0.75rem;
    font-size: 1.35rem;
    font-weight: 300;
    line-height: 1;
    color: #6e6e73;
  }
  .footer-col.is-open .footer-col-toggle::after {
    content: "−";
  }
  .footer-col-panel {
    display: none;
    gap: 0;
    padding: 0 0 0.75rem;
  }
  .footer-col.is-open .footer-col-panel {
    display: grid;
  }
  .footer-col a {
    min-height: 1.75rem;
    padding: 0.18rem 0;
    font-size: 0.8125rem;
    line-height: 1.25;
  }
  .footer-inner {
    padding-top: 0.85rem;
    padding-bottom: max(1.15rem, calc(0.65rem + env(safe-area-inset-bottom, 0px)));
  }
  .footer-legal {
    padding-top: 0.55rem;
    gap: 0.08rem;
  }
  .footer-lang { margin-bottom: 0.28rem; }
  .footer-lang .lang-opt { min-width: 2.5rem; min-height: 2.25rem; }
  .footer-legal p { font-size: 0.75rem; line-height: 1.3; }
  .nav-end { gap: 0.4rem; }
}

@media (max-width: 380px) {
  .flow {
    display: grid;
    grid-template-columns: repeat(2, max-content);
    justify-content: center;
    gap: 0.65rem 1.1rem;
    white-space: normal;
  }
  .flow i { display: none; }
}

/* When a real vertical hinge is exposed, keep a text block or visual inside a
   single pane instead of allowing key content to sit under the fold. */
@media (horizontal-viewport-segments: 2), (spanning: single-fold-vertical) {
  :root {
    --fold-gap: max(
      1rem,
      calc(env(viewport-segment-left 1 0) - env(viewport-segment-right 0 0))
    );
  }

  .hero {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    column-gap: var(--fold-gap);
    align-items: center;
    padding-top: 3rem;
    padding-bottom: 3rem;
    text-align: left;
  }
  .hero-copy {
    width: 100%;
    margin: 0;
  }
  .hero-actions { justify-content: flex-start; }

  .product,
  .product.reverse,
  .beliefs-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    column-gap: var(--fold-gap);
    align-items: center;
  }
  .product.reverse { direction: rtl; }
  .product.reverse > * { direction: ltr; }

  /* The <picture> source switches these panes back to desktop evidence.
     Keep the real hinge layout wide and never crop it as a phone card. */
  .product-media > picture:first-of-type { aspect-ratio: 3 / 2; }
  .product-media > picture:first-of-type img { object-fit: contain; }

  .method .pillars,
  .repo-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: var(--fold-gap);
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .product-media .float, .flow i::after,
  .belief-list.is-cycling li.is-active .belief-rail,
  .belief-list.is-cycling li.is-active .belief-text { animation: none; }
  .dot-field .dot { transition: none; }
  .belief-list li,
  .belief-list.is-cycling li,
  .belief-list.is-cycling li.is-active { opacity: 1; }
  .belief-rail { transform: none; }
  .belief-text {
    clip-path: none;
    transform: none;
    color: var(--ink);
    background: none;
    -webkit-background-clip: unset;
    background-clip: unset;
  }
  .nav-toggle,
  .nav-toggle-box span,
  .nav-links,
  .nav-links a,
  .nav-lang-panel,
  .wechat-float,
  .wechat-float > span:last-child {
    transition: none !important;
    animation: none !important;
  }
  .nav-links a,
  .nav-lang-panel {
    opacity: 1;
    transform: none;
  }
}