:root {
  color-scheme: dark;
  --bg: oklch(0.16 0.045 285);
  --bg-deep: oklch(0.105 0.03 282);
  --surface: oklch(0.22 0.045 282);
  --ink: oklch(0.985 0 0);
  --muted: oklch(0.79 0.025 280);
  --yellow: oklch(0.91 0.19 105);
  --lime: oklch(0.9 0.22 122);
  --cyan: oklch(0.82 0.145 205);
  --cyan-deep: oklch(0.67 0.14 211);
  --line: oklch(0.4 0.05 282 / 0.7);
  --bg-light: oklch(0.965 0.008 266);
  --ink-dark: oklch(0.19 0.035 280);
  --ink-dark-muted: oklch(0.4 0.035 280);
  --yellow-ink: oklch(0.3 0.055 285);
  --cyan-ink: oklch(0.3 0.055 282);
  --line-light: oklch(0.19 0.035 280 / 0.18);
  --line-dark: oklch(1 0 0 / 0.16);
  --max-width: 1200px;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --z-sticky: 20;
  --z-dropdown: 30;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  overflow-x: hidden;
  background: var(--bg-deep);
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}

::selection {
  background: var(--yellow);
  color: var(--bg-deep);
}

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

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

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

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  text-wrap: balance;
}

p {
  text-wrap: pretty;
}

section[id] {
  scroll-margin-top: 84px;
}

.skip-link {
  position: fixed;
  left: 1rem;
  top: 1rem;
  z-index: 100;
  padding: 0.65rem 1rem;
  background: var(--yellow);
  color: var(--bg-deep);
  transform: translateY(-160%);
  transition: transform 180ms ease;
}

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

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: var(--z-sticky);
  transition:
    background-color 240ms ease,
    border-color 240ms ease;
}

.site-header.is-scrolled {
  border-bottom: 1px solid oklch(1 0 0 / 0.08);
  background: oklch(0.12 0.035 282 / 0.94);
  backdrop-filter: blur(18px) saturate(130%);
}

.header-inner,
.section-shell,
.footer-inner {
  width: min(calc(100% - 3rem), var(--max-width));
  margin-inline: auto;
}

.header-inner {
  min-height: 84px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.brand {
  width: clamp(184px, 18vw, 238px);
}

.primary-nav {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2vw, 2rem);
  font-size: 0.9rem;
  color: var(--muted);
}

.primary-nav a {
  position: relative;
  padding-block: 0.55rem;
  transition: color 180ms ease;
}

.primary-nav a:not(.nav-cta)::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 260ms var(--ease-out);
}

.primary-nav a:hover,
.primary-nav a:focus-visible,
.primary-nav a[aria-current="true"] {
  color: var(--ink);
}

.primary-nav a:not(.nav-cta):hover::after,
.primary-nav a:not(.nav-cta):focus-visible::after,
.primary-nav a[aria-current="true"]::after {
  transform: scaleX(1);
  transform-origin: left;
}

.primary-nav .nav-cta {
  padding: 0.6rem 1.1rem;
  border: 1px solid var(--yellow);
  color: var(--yellow);
  transition:
    background-color 180ms ease,
    color 180ms ease,
    transform 220ms var(--ease-out);
}

.primary-nav .nav-cta:hover,
.primary-nav .nav-cta:focus-visible {
  background: var(--yellow);
  color: var(--bg-deep);
  transform: translateY(-1px);
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 0;
  background: transparent;
  color: var(--ink);
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  margin: 6px auto;
  background: currentColor;
  transition: transform 220ms var(--ease-out);
}

.menu-toggle[aria-expanded="true"] span:first-child {
  transform: translateY(4px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] span:last-child {
  transform: translateY(-4px) rotate(-45deg);
}

.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: hidden;
  background:
    linear-gradient(90deg, oklch(0.105 0.03 282 / 0.99) 0%, oklch(0.105 0.03 282 / 0.94) 38%, oklch(0.105 0.03 282 / 0.36) 66%, oklch(0.105 0.03 282 / 0.1) 100%),
    linear-gradient(180deg, oklch(0.105 0.03 282 / 0.2), oklch(0.105 0.03 282 / 0.54)),
    url("./assets/hero-pineapple-v4.png") center / cover no-repeat,
    var(--bg-deep);
}

.hero-inner {
  position: relative;
  width: min(calc(100% - 3rem), var(--max-width));
  margin: 8rem auto 5rem;
}

.hero-copy {
  width: min(60%, 720px);
}

.hero-kicker {
  margin-bottom: 1.2rem;
  color: var(--cyan);
  font-size: 0.95rem;
  font-weight: 800;
  letter-spacing: 0.035em;
}

.section-index {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.35rem;
  color: var(--cyan);
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 0;
}

.section-index::before {
  content: "";
  width: 18px;
  height: 2px;
  background: currentColor;
}

.hero h1 {
  max-width: 12ch;
  margin-bottom: 1.8rem;
  font-size: clamp(3.2rem, 7.5vw, 6rem);
  line-height: 1.02;
  letter-spacing: -0.03em;
}

.hero h1::after {
  content: "";
  display: block;
  width: 2.6ch;
  height: 8px;
  margin-top: 1.5rem;
  background: var(--yellow);
}

.hero-lead {
  max-width: 62ch;
  margin-bottom: 2.2rem;
  color: var(--muted);
  font-size: clamp(1rem, 1.4vw, 1.2rem);
  line-height: 1.82;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
}

.button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1.35rem;
  border: 1px solid transparent;
  font-weight: 700;
  transition:
    transform 220ms var(--ease-out),
    background-color 180ms ease,
    border-color 180ms ease;
}

.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
}

.button:active {
  transform: translateY(0);
}

.button-primary {
  background: var(--yellow);
  color: var(--bg-deep);
}

.button-quiet {
  border-color: oklch(1 0 0 / 0.28);
  color: var(--ink);
}

.button-quiet:hover,
.button-quiet:focus-visible {
  border-color: var(--cyan);
}

.signal-strip {
  position: relative;
  width: min(calc(100% - 3rem), var(--max-width));
  margin: auto auto 2rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line-dark);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  color: var(--muted);
  font-size: 0.85rem;
}

.signal-strip span::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-right: 0.55rem;
  border-radius: 50%;
  background: var(--lime);
  box-shadow: 0 0 18px var(--lime);
}

.section {
  position: relative;
  padding-block: clamp(5rem, 10vw, 9rem);
}

.section h2 {
  margin-bottom: 1.4rem;
  font-size: clamp(2.35rem, 5vw, 4.75rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
}

.about {
  background: var(--bg-light);
  border-top: 1px solid var(--line-light);
  color: var(--ink-dark);
}

.about .section-index,
.business .section-index,
.responsibility .section-index {
  color: oklch(0.5 0.13 215);
}

.about-layout {
  display: grid;
  grid-template-columns: 0.75fr 1.25fr;
  gap: clamp(3rem, 8vw, 8rem);
  align-items: start;
}

.section-heading {
  position: sticky;
  top: 120px;
}

.about-lead {
  max-width: 34ch;
  margin-bottom: 1.5rem;
  font-size: clamp(1.45rem, 2.6vw, 2.25rem);
  line-height: 1.42;
  font-weight: 700;
}

.about-copy > p:not(.about-lead) {
  max-width: 68ch;
  color: var(--ink-dark-muted);
}

.principles {
  margin-top: 3rem;
  border-top: 1px solid var(--line-light);
}

.principles article {
  display: grid;
  grid-template-columns: minmax(100px, 0.35fr) 1fr;
  gap: 1rem;
  padding-block: 1.2rem;
  border-bottom: 1px solid var(--line-light);
}

.principles strong {
  color: oklch(0.42 0.15 215);
}

.business {
  background: var(--yellow);
  color: oklch(0.16 0.045 285);
}

.business-heading {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3rem;
  align-items: end;
  margin-bottom: clamp(3rem, 6vw, 5rem);
}

.business-heading > p {
  max-width: 52ch;
  margin-bottom: 1.3rem;
  color: var(--yellow-ink);
}

.business-list {
  border-top: 2px solid currentColor;
}

.business-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: clamp(1.5rem, 5vw, 5rem);
  align-items: center;
  padding-block: clamp(2.1rem, 4vw, 3.2rem);
  border-bottom: 1px solid oklch(0.16 0.045 285 / 0.38);
}

.business-item > div {
  display: grid;
  grid-template-columns: minmax(220px, 0.72fr) minmax(0, 1.28fr);
  align-items: baseline;
  gap: clamp(1.5rem, 4vw, 4rem);
}

.business-item h3 {
  margin-bottom: 0;
  font-size: clamp(1.4rem, 2.2vw, 2rem);
}

.business-item p {
  max-width: 64ch;
  margin-bottom: 0;
  color: var(--yellow-ink);
}

.business-tag {
  padding: 0.35rem 0.8rem;
  border: 1px solid currentColor;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
  white-space: nowrap;
}

.capabilities {
  overflow: hidden;
  background:
    radial-gradient(circle at 8% 110%, oklch(0.35 0.13 215 / 0.35), transparent 35%),
    var(--bg);
}

.capabilities-layout {
  display: grid;
  grid-template-columns: 0.72fr 1.28fr;
  gap: clamp(3rem, 8vw, 8rem);
  align-items: start;
}

.capabilities-intro {
  position: sticky;
  top: 120px;
}

.capabilities-intro p:last-child {
  max-width: 52ch;
  color: var(--muted);
}

.capability-list {
  display: grid;
  grid-template-columns: 1fr;
  border-top: 1px solid var(--line-dark);
}

.capability-list article {
  min-height: 0;
  padding-block: clamp(1.8rem, 3vw, 2.5rem);
  border-bottom: 1px solid var(--line-dark);
  display: grid;
  grid-template-columns: minmax(220px, 0.8fr) minmax(0, 1.2fr);
  align-items: baseline;
  gap: clamp(1.5rem, 4vw, 4rem);
}

.capability-list h3 {
  margin-bottom: 0;
  color: var(--ink);
  font-size: clamp(1.15rem, 1.65vw, 1.45rem);
}

.capability-list p {
  margin-bottom: 0;
  color: var(--muted);
}

.opc {
  background: var(--bg-light);
  color: var(--ink-dark);
}

.opc-layout {
  display: grid;
  grid-template-columns: 0.7fr 1.3fr;
  gap: clamp(3rem, 8vw, 8rem);
  align-items: center;
}

.opc-monogram {
  position: relative;
  min-height: 410px;
  display: grid;
  place-items: center;
  background: oklch(0.19 0.035 280);
  color: var(--yellow);
  overflow: hidden;
}

.opc-monogram::before,
.opc-monogram::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  border: 1px solid oklch(0.82 0.145 205 / 0.36);
}

.opc-monogram::before {
  width: 75%;
  aspect-ratio: 1;
}

.opc-monogram::after {
  width: 112%;
  aspect-ratio: 1;
}

.opc-monogram span {
  position: relative;
  z-index: 1;
  font-size: clamp(4rem, 9vw, 8rem);
  font-weight: 900;
  letter-spacing: -0.04em;
}

.opc-monogram i {
  position: absolute;
  width: 42%;
  height: 7px;
  bottom: 25%;
  background: var(--cyan);
}

.opc-copy .section-index {
  color: oklch(0.5 0.13 215);
}

.opc-lead {
  max-width: 60ch;
  color: var(--ink-dark-muted);
  font-size: 1.12rem;
}

.opc-path {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 2.3rem;
}

.opc-path span {
  padding: 0.55rem 0.9rem;
  border: 1px solid oklch(0.19 0.035 280 / 0.3);
  border-radius: 999px;
  font-size: 0.86rem;
}

.responsibility {
  background: var(--cyan);
  color: oklch(0.145 0.04 282);
}

.responsibility-heading {
  max-width: 850px;
  margin-bottom: clamp(3rem, 7vw, 5rem);
}

.responsibility-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 2px solid currentColor;
}

.responsibility-grid article {
  padding: 2rem clamp(1.3rem, 3vw, 2.5rem) 1rem 0;
}

.responsibility-grid article + article {
  padding-left: clamp(1.3rem, 3vw, 2.5rem);
  border-left: 1px solid oklch(0.145 0.04 282 / 0.3);
}

.responsibility-icon {
  display: block;
  margin-bottom: 2.5rem;
  color: oklch(0.36 0.12 285);
  font-size: 2rem;
}

.responsibility-grid h3 {
  font-size: 1.35rem;
}

.responsibility-grid p {
  margin-bottom: 0;
  color: var(--cyan-ink);
}

.contact {
  overflow: hidden;
  background: var(--bg-deep);
  text-align: left;
}

.contact-grid {
  position: absolute;
  inset: 0;
  opacity: 0.22;
  background-image:
    linear-gradient(to right, var(--cyan) 1px, transparent 1px),
    linear-gradient(to bottom, var(--cyan) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: radial-gradient(circle at center, black, transparent 68%);
}

.contact-inner {
  position: relative;
  max-width: var(--max-width);
}

.contact h2 {
  max-width: 12ch;
}

.contact-inner > p:not(.section-index) {
  max-width: 60ch;
  margin: 0 0 clamp(3rem, 6vw, 5rem);
  color: var(--muted);
  font-size: 1.08rem;
}

.contact-line {
  width: 100%;
  padding: 1.4rem 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  text-align: left;
}

.contact-line span {
  color: var(--cyan);
  font-size: 0.86rem;
  font-weight: 700;
}

.contact-line strong {
  color: var(--yellow);
  font-size: 1.1rem;
}

.site-footer {
  padding-block: 2.4rem;
  border-top: 1px solid var(--line);
  background: var(--bg-deep);
}

.footer-inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 1.5rem;
}

.footer-inner img {
  width: 190px;
}

.footer-inner p {
  margin: 0;
  color: var(--muted);
  font-size: 0.85rem;
}

.candidate-note {
  text-align: right;
}

:focus-visible {
  outline: 3px solid var(--yellow);
  outline-offset: 4px;
}

@media (max-width: 900px) {
  body.menu-open {
    overflow: hidden;
  }

  .hero {
    background:
      linear-gradient(90deg, oklch(0.105 0.03 282 / 0.98), oklch(0.105 0.03 282 / 0.88) 58%, oklch(0.105 0.03 282 / 0.34)),
      linear-gradient(180deg, oklch(0.105 0.03 282 / 0.18), oklch(0.105 0.03 282 / 0.58)),
      url("./assets/hero-pineapple-v4.png") 68% center / cover no-repeat,
      var(--bg-deep);
  }

  .header-inner,
  .section-shell,
  .footer-inner,
  .hero-inner,
  .signal-strip {
    width: min(calc(100% - 2rem), var(--max-width));
  }

  .menu-toggle {
    display: block;
  }

  .primary-nav {
    position: fixed;
    z-index: var(--z-dropdown);
    inset: 76px 1rem auto;
    padding: 1rem;
    border: 1px solid oklch(1 0 0 / 0.12);
    background: var(--surface);
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    opacity: 0;
    transform: translateY(-12px);
    pointer-events: none;
    transition:
      opacity 180ms ease,
      transform 220ms var(--ease-out);
  }

  .primary-nav.is-open {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
  }

  .primary-nav a {
    min-height: 48px;
    display: flex;
    align-items: center;
    padding: 0.75rem 0.85rem;
  }

  .primary-nav .nav-cta {
    margin-top: 0.5rem;
    text-align: center;
  }

  .hero-inner,
  .about-layout,
  .business-heading,
  .capabilities-layout,
  .opc-layout {
    grid-template-columns: 1fr;
  }

  .hero-inner {
    margin-top: 8.5rem;
  }

  .hero-copy {
    width: 100%;
    max-width: 760px;
  }

  .section-heading,
  .capabilities-intro {
    position: static;
  }

  .business-item > div,
  .capability-list article {
    grid-template-columns: 1fr;
    gap: 0.65rem;
  }

  .responsibility-grid {
    grid-template-columns: 1fr;
  }

  .responsibility-grid article,
  .responsibility-grid article + article {
    padding: 1.75rem 0;
    border-left: 0;
    border-bottom: 1px solid oklch(0.145 0.04 282 / 0.3);
  }

  .responsibility-icon {
    margin-bottom: 1.3rem;
  }
}

@media (max-width: 640px) {
  .header-inner {
    min-height: 72px;
  }

  .brand {
    width: 164px;
  }

  .primary-nav {
    inset-block-start: 68px;
  }

  .hero {
    min-height: auto;
    background:
      linear-gradient(180deg, oklch(0.105 0.03 282 / 0.97) 0%, oklch(0.105 0.03 282 / 0.91) 58%, oklch(0.105 0.03 282 / 0.54) 100%),
      linear-gradient(90deg, oklch(0.105 0.03 282 / 0.88), oklch(0.105 0.03 282 / 0.3)),
      url("./assets/hero-pineapple-v4.png") 72% center / cover no-repeat,
      var(--bg-deep);
  }

  .hero-inner {
    margin-top: 7.6rem;
    margin-bottom: 3.5rem;
    gap: 3.5rem;
  }

  .hero h1 {
    font-size: clamp(3rem, 15vw, 4.4rem);
  }

  .hero h1::after {
    height: 6px;
  }

  .hero-actions,
  .hero-actions .button {
    width: 100%;
  }

  .signal-strip {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
  }

  .section {
    padding-block: 4.75rem;
  }

  .section h2 {
    font-size: clamp(2.4rem, 11vw, 3.4rem);
  }

  .principles article {
    grid-template-columns: 1fr;
    gap: 0.15rem;
  }

  .business-item {
    grid-template-columns: 1fr;
    align-items: start;
    gap: 1rem;
  }

  .business-tag {
    justify-self: start;
  }

  .capability-list {
    grid-template-columns: 1fr;
  }

  .opc-monogram {
    min-height: 300px;
  }

  .contact-line,
  .footer-inner {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
  }

  .candidate-note {
    text-align: left;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

}