:root {
  --ink: #0a1628;
  --ink-soft: #1a2b42;
  --fog: #e8eef5;
  --paper: #f7f9fc;
  --muted: #5d6f86;
  --line: rgba(10, 22, 40, 0.12);
  --accent: #2f6f8f;
  --accent-deep: #1e4f68;
  --glow: rgba(47, 111, 143, 0.35);
  --radius: 2px;
  --font-sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", sans-serif;
  --font-serif: "Noto Serif SC", "Songti SC", serif;
  --shell: min(1120px, calc(100% - 2.5rem));
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}

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

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

a:hover {
  color: var(--accent-deep);
}

.shell {
  width: var(--shell);
  margin-inline: auto;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--ink);
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 100;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

/* Header */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  transition: background 0.35s ease, border-color 0.35s ease, backdrop-filter 0.35s ease;
  border-bottom: 1px solid transparent;
}

.site-header.is-scrolled {
  background: rgba(247, 249, 252, 0.88);
  border-bottom-color: var(--line);
  backdrop-filter: blur(12px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 4.25rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
}

.brand-mark {
  width: 1.25rem;
  height: 1.25rem;
  box-shadow: 0 0 0 1px rgba(10, 22, 40, 0.12);
  background: url('/corp-assets/favicon.svg?v=2') center / contain no-repeat;
}

.brand-text {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.08em;
  color: #fff;
  transition: color 0.25s ease;
}

.site-header.is-scrolled .brand-text {
  color: var(--ink);
}

.nav {
  display: none;
  gap: 1.75rem;
}

.nav a {
  font-size: 0.92rem;
  color: rgba(255, 255, 255, 0.86);
  transition: color 0.2s ease;
}

.site-header.is-scrolled .nav a {
  color: var(--ink-soft);
}

.nav a:hover {
  color: #fff;
}

.site-header.is-scrolled .nav a:hover {
  color: var(--accent);
}

.nav-toggle {
  width: 2.5rem;
  height: 2.5rem;
  border: 0;
  background: transparent;
  display: grid;
  place-content: center;
  gap: 6px;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 1.25rem;
  height: 1.5px;
  background: #fff;
  transition: background 0.2s ease;
}

.site-header.is-scrolled .nav-toggle span {
  background: var(--ink);
}

.mobile-nav {
  display: grid;
  gap: 0.25rem;
  padding: 0.5rem 1.25rem 1.25rem;
  background: rgba(10, 22, 40, 0.96);
}

.mobile-nav a {
  color: #fff;
  padding: 0.75rem 0.25rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.mobile-nav[hidden] {
  display: none;
}

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  color: #f4f7fb;
}

.hero-plane {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(115deg, rgba(10, 22, 40, 0.55) 12%, rgba(10, 22, 40, 0.25) 48%, rgba(10, 22, 40, 0.72) 100%),
    radial-gradient(ellipse 80% 60% at 75% 35%, rgba(74, 160, 196, 0.35), transparent 55%),
    linear-gradient(160deg, #0a1628 0%, #14304a 42%, #0d2136 100%);
  transform: scale(1.02);
  animation: plane-drift 18s ease-in-out infinite alternate;
}

.hero-plane::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55), transparent 85%);
  opacity: 0.5;
}

@keyframes plane-drift {
  from { transform: scale(1.02) translate3d(0, 0, 0); }
  to { transform: scale(1.06) translate3d(-1.5%, 1%, 0); }
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 7.5rem 0 5.5rem;
}

.hero-brand {
  margin: 0 0 1.25rem;
  font-family: var(--font-serif);
  font-size: clamp(2.4rem, 7vw, 4.6rem);
  font-weight: 700;
  letter-spacing: 0.14em;
  line-height: 1.1;
}

.hero-title {
  margin: 0;
  max-width: 16ch;
  font-family: var(--font-serif);
  font-size: clamp(1.55rem, 3.6vw, 2.35rem);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: 0.04em;
}

.hero-lead {
  margin: 1.25rem 0 0;
  max-width: 36rem;
  color: rgba(244, 247, 251, 0.82);
  font-size: 1.02rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 2rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.85rem;
  padding: 0 1.25rem;
  border: 1px solid transparent;
  font-size: 0.95rem;
  font-weight: 500;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: #f4f7fb;
  color: var(--ink);
}

.btn-primary:hover {
  background: #fff;
  color: var(--ink);
}

.btn-ghost {
  border-color: rgba(244, 247, 251, 0.4);
  color: #f4f7fb;
}

.btn-ghost:hover {
  border-color: #fff;
  color: #fff;
}

/* Sections */
.section {
  padding: 5.5rem 0;
}

.section-alt {
  background: linear-gradient(180deg, #eef3f8 0%, #f7f9fc 100%);
}

.eyebrow {
  margin: 0 0 0.75rem;
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.16em;
}

.section-title {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(1.7rem, 3vw, 2.2rem);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.3;
}

.section-lead {
  margin: 1rem 0 0;
  max-width: 42rem;
  color: var(--muted);
}

.about-grid {
  display: grid;
  gap: 1.5rem;
  margin-top: 2.75rem;
}

.about-item {
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
}

.about-item h3,
.biz-row h3,
.career-panel h3,
.contact-grid h3 {
  margin: 0 0 0.55rem;
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 600;
}

.about-item p,
.biz-row p,
.career-panel p,
.contact-grid p {
  margin: 0;
  color: var(--muted);
}

.biz-list {
  margin-top: 2.5rem;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.biz-row {
  display: grid;
  gap: 1rem;
  padding: 1.6rem 0;
  border-bottom: 1px solid var(--line);
  transition: background 0.2s ease;
}

a.biz-row:hover {
  background: rgba(47, 111, 143, 0.05);
}

.biz-link {
  color: var(--accent-deep);
  font-size: 0.9rem;
  font-weight: 600;
}

.biz-meta {
  color: var(--muted);
  font-size: 0.9rem;
}

.career-panel {
  margin-top: 2.5rem;
  display: grid;
  gap: 2rem;
  padding: 1.75rem 0 0;
  border-top: 1px solid var(--line);
}

.career-panel ul {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--muted);
}

.career-panel li + li {
  margin-top: 0.35rem;
}

.career-cta .btn-primary {
  margin-top: 1rem;
  background: var(--ink);
  color: #fff;
}

.career-cta .btn-primary:hover {
  background: var(--ink-soft);
  color: #fff;
}

.contact-grid {
  margin-top: 2.5rem;
  display: grid;
  gap: 1.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
}

.contact-grid a {
  color: var(--accent-deep);
}

/* Footer */
.site-footer {
  background: var(--ink);
  color: rgba(244, 247, 251, 0.82);
  padding: 3.5rem 0 1.75rem;
}

.footer-top {
  display: grid;
  gap: 2.5rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand-row .brand-text {
  color: #fff;
}

.footer-brand p {
  margin: 0.9rem 0 0;
  color: rgba(244, 247, 251, 0.62);
  font-size: 0.92rem;
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.25rem;
}

.footer-heading {
  margin: 0 0 0.75rem;
  color: #fff;
  font-size: 0.85rem;
  font-weight: 600;
}

.footer-cols a {
  display: block;
  margin-top: 0.45rem;
  color: rgba(244, 247, 251, 0.68);
  font-size: 0.9rem;
}

.footer-cols a:hover {
  color: #fff;
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  padding-top: 1.35rem;
  font-size: 0.78rem;
  color: rgba(244, 247, 251, 0.55);
}

.footer-bottom p {
  margin: 0;
}

.beian a {
  color: rgba(244, 247, 251, 0.72);
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.beian a:hover {
  color: #fff;
  border-bottom-color: rgba(255, 255, 255, 0.45);
}

/* Reveal motion */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.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; }

@media (min-width: 720px) {
  .nav {
    display: flex;
  }

  .nav-toggle {
    display: none;
  }

  .about-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 2rem;
  }

  .biz-row {
    grid-template-columns: 1fr auto;
    align-items: end;
  }

  .career-panel {
    grid-template-columns: 1.2fr 1fr;
    align-items: end;
  }

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

  .footer-top {
    grid-template-columns: 1.2fr 1.5fr;
  }

  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

@media (min-width: 980px) {
  .contact-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .hero-content {
    padding-bottom: 6.5rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .hero-plane { animation: none; }
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}