/* JIANSHU Technology — standalone static site styles */
:root {
  --paper: #f7f5f0;
  --ink: #111111;
  --green: #16423c;
  --line: rgba(17, 17, 17, 0.18);
  --muted: #686761;
  --header-height: 80px;
  --page-padding: clamp(24px, 4.2vw, 72px);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

button, a { color: inherit; }
a { text-decoration: none; }
button { font: inherit; }

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 100;
  padding: 10px 14px;
  background: var(--green);
  color: var(--paper);
  transform: translateY(-150%);
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  height: var(--header-height);
  padding: 0 var(--page-padding);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  border-bottom: 1px solid transparent;
  transition: background-color 220ms ease, border-color 220ms ease;
}

.site-header.is-scrolled {
  background: rgba(247, 245, 240, 0.92);
  border-color: var(--line);
  backdrop-filter: blur(14px);
}

.brand { display: inline-flex; align-items: center; gap: 10px; width: max-content; font-size: 12px; font-weight: 700; letter-spacing: 0.16em; }
.brand-mark { display: grid; place-items: center; width: 28px; height: 28px; background: var(--green); color: var(--paper); font-family: Georgia, serif; font-size: 17px; font-weight: 400; letter-spacing: 0; }

.header-nav { display: flex; gap: 32px; font-size: 12px; }
.header-nav a, .language-option { transition: color 180ms ease; }
.header-nav a:hover, .language-option:hover { color: var(--green); }

.language-switcher { justify-self: end; display: flex; align-items: center; gap: 7px; font-size: 11px; letter-spacing: 0.08em; }
.language-label { margin-right: 8px; color: var(--muted); }
.language-option { padding: 2px; border: 0; background: none; color: var(--muted); cursor: pointer; }
.language-option.is-active { color: var(--green); font-weight: 700; }

.hero {
  min-height: 100svh;
  padding: calc(var(--header-height) + 44px) var(--page-padding) 40px;
  display: grid;
  grid-template-rows: auto 1fr auto;
  border-bottom: 1px solid var(--line);
}

.hero-meta { display: flex; justify-content: space-between; color: var(--muted); font-size: 10px; letter-spacing: 0.16em; text-transform: uppercase; }
.hero-content { align-self: center; padding: clamp(48px, 8vh, 100px) 0; }
.eyebrow { margin: 0 0 28px; color: var(--green); font-size: 13px; font-weight: 700; letter-spacing: 0.16em; text-transform: uppercase; }
.hero h1 { max-width: 1160px; margin: 0; font-family: Georgia, "Times New Roman", "Songti SC", serif; font-size: clamp(54px, 7.7vw, 116px); font-weight: 400; line-height: 0.94; letter-spacing: -0.055em; }
.hero-description { max-width: 610px; margin: 36px 0 0 auto; color: #343430; font-size: clamp(17px, 1.45vw, 22px); line-height: 1.55; }
.hero-footer { display: flex; align-items: end; justify-content: space-between; padding-top: 28px; border-top: 1px solid var(--line); }
.hero-footer p { margin: 0; font-size: clamp(11px, 1vw, 14px); font-weight: 600; letter-spacing: 0.06em; }
.hero-footer p span { margin: 0 clamp(5px, 0.7vw, 12px); color: var(--green); }
.text-link { display: inline-flex; align-items: center; gap: 42px; font-size: 12px; }
.arrow { font-size: 19px; transition: transform 180ms ease; }
.text-link:hover .arrow { transform: translateY(4px); }

.section-shell { padding: clamp(84px, 10vw, 150px) var(--page-padding); border-bottom: 1px solid var(--line); }
.section-heading { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; margin-bottom: clamp(52px, 7vw, 96px); }
.section-index { margin: 0 0 12px; color: var(--green); font-size: 11px; font-weight: 700; letter-spacing: 0.12em; }
.section-heading h2 { margin: 0; font-family: Georgia, "Times New Roman", "Songti SC", serif; font-size: clamp(42px, 5vw, 72px); font-weight: 400; line-height: 1; letter-spacing: -0.045em; }
.section-intro { align-self: end; max-width: 420px; margin: 0; color: var(--muted); font-size: 17px; }

.capability-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.capability-card { min-width: 0; border-right: 1px solid var(--line); }
.capability-card:last-child { border-right: 0; }
.card-trigger { width: 100%; min-height: 250px; padding: 24px; display: flex; flex-direction: column; align-items: flex-start; border: 0; background: transparent; text-align: left; cursor: pointer; transition: background-color 220ms ease, color 220ms ease; }
.card-trigger:hover, .capability-card.is-open .card-trigger { background: var(--green); color: var(--paper); }
.card-number { font-size: 10px; letter-spacing: 0.12em; opacity: 0.72; }
.card-name { margin-top: auto; font-family: Georgia, "Times New Roman", serif; font-size: clamp(28px, 2.4vw, 40px); letter-spacing: -0.035em; }
.card-icon { position: relative; width: 22px; height: 22px; margin-top: 18px; }
.card-icon::before, .card-icon::after { content: ""; position: absolute; top: 10px; left: 0; width: 22px; height: 1px; background: currentColor; transition: transform 220ms ease; }
.card-icon::after { transform: rotate(90deg); }
.capability-card.is-open .card-icon::after { transform: rotate(0); }
.card-panel { display: grid; grid-template-rows: 0fr; overflow: hidden; background: rgba(22, 66, 60, 0.045); transition: grid-template-rows 320ms cubic-bezier(.4,0,.2,1); }
.capability-card.is-open .card-panel { grid-template-rows: 1fr; }
.card-panel-inner { min-height: 0; overflow: hidden; padding: 0 24px; opacity: 0; transition: opacity 180ms ease, padding 320ms ease; }
.capability-card.is-open .card-panel-inner { padding-top: 28px; padding-bottom: 32px; opacity: 1; transition-delay: 80ms; }
.card-panel h3 { min-height: 52px; margin: 0; font-size: 16px; line-height: 1.3; }
.cn-title { margin: 8px 0 22px; color: var(--green); font-size: 12px; }
.card-copy { min-height: 66px; margin: 0 0 24px; color: var(--muted); font-size: 13px; line-height: 1.55; }
.card-panel ul { margin: 0; padding: 0; list-style: none; }
.card-panel li { padding: 8px 0; border-top: 1px solid var(--line); font-size: 12px; }
.interaction-hint { margin: 16px 0 0; color: var(--muted); font-size: 10px; letter-spacing: 0.06em; text-align: right; }

.work-list { border-top: 1px solid var(--ink); }
.work-item { display: grid; grid-template-columns: 70px 1fr auto; gap: 24px; align-items: center; min-height: 150px; padding: 26px 0; border-bottom: 1px solid var(--line); }
.work-index { align-self: start; color: var(--green); font-size: 11px; }
.work-item h3 { margin: 0 0 8px; font-family: Georgia, "Times New Roman", serif; font-size: clamp(25px, 3vw, 42px); font-weight: 400; letter-spacing: -0.035em; }
.work-item p { margin: 0; color: var(--muted); font-size: 14px; }
.work-tag { padding: 7px 10px; border: 1px solid var(--line); border-radius: 999px; color: var(--muted); font-size: 9px; letter-spacing: 0.08em; }

.about { background: var(--green); color: var(--paper); }
.about .section-heading { margin-bottom: clamp(64px, 9vw, 130px); }
.about .section-index { color: rgba(247, 245, 240, 0.6); }
.about-grid { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(280px, 0.6fr); gap: clamp(60px, 10vw, 160px); align-items: end; }
.about-statement { max-width: 900px; margin: 0; font-family: Georgia, "Times New Roman", "Songti SC", serif; font-size: clamp(38px, 5.3vw, 78px); line-height: 1.08; letter-spacing: -0.045em; }
.contact-card { padding-top: 20px; border-top: 1px solid rgba(247,245,240,.42); }
.contact-label { margin: 0 0 54px; color: rgba(247,245,240,.6); font-size: 10px; letter-spacing: .15em; text-transform: uppercase; }
.contact-name { margin: 0; font-family: Georgia, serif; font-size: 30px; }
.contact-role { margin: 8px 0 32px; color: rgba(247,245,240,.68); font-size: 13px; }
.contact-link { display: flex; justify-content: space-between; margin: 0; padding: 14px 0; border-top: 1px solid rgba(247,245,240,.25); border-bottom: 1px solid rgba(247,245,240,.25); font-size: 12px; }

.site-footer { padding: 26px var(--page-padding); display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; color: var(--muted); font-size: 10px; letter-spacing: .06em; }
.site-footer p { margin: 0; }
.site-footer p:nth-child(2) { text-align: center; }
.site-footer a { justify-self: end; }

/* Elements appear gently as they enter the viewport. */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity 600ms ease, transform 600ms ease; }
.reveal.is-visible { opacity: 1; transform: translateY(0); }

@media (max-width: 900px) {
  :root { --header-height: 68px; }
  .site-header { grid-template-columns: 1fr auto; }
  .header-nav { display: none; }
  .language-label { display: none; }
  .hero { padding-bottom: 26px; }
  .hero-description { margin-left: 0; }
  .capability-grid { grid-template-columns: 1fr 1fr; }
  .capability-card:nth-child(2) { border-right: 0; }
  .capability-card:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .about-grid { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  :root { --page-padding: 20px; }
  .brand > span:last-child { display: none; }
  .hero { min-height: 100svh; padding-top: calc(var(--header-height) + 28px); }
  .hero-meta span:first-child { max-width: 150px; }
  .hero-content { padding: 54px 0 44px; }
  .eyebrow { margin-bottom: 22px; font-size: 11px; }
  .hero h1 { font-size: clamp(46px, 14vw, 66px); line-height: .97; }
  .hero-description { margin-top: 26px; font-size: 16px; }
  .hero-footer { display: block; }
  .hero-footer p { max-width: 310px; line-height: 2; }
  .text-link { display: none; }
  .section-shell { padding-top: 82px; padding-bottom: 82px; }
  .section-heading { grid-template-columns: 1fr; gap: 24px; margin-bottom: 48px; }
  .section-heading h2 { font-size: 46px; }
  .section-intro { font-size: 15px; }
  .capability-grid { grid-template-columns: 1fr; border-bottom: 0; }
  .capability-card, .capability-card:nth-child(2) { border-right: 0; border-bottom: 1px solid var(--ink); }
  .card-trigger { min-height: 132px; padding: 20px 0; display: grid; grid-template-columns: 40px 1fr 24px; align-items: center; }
  .card-number { align-self: start; padding-top: 4px; }
  .card-name { margin: 0; font-size: 32px; }
  .card-icon { margin: 0; }
  .card-panel-inner { padding-left: 40px; padding-right: 0; }
  .capability-card.is-open .card-panel-inner { padding-top: 6px; padding-bottom: 30px; }
  .card-panel h3, .card-copy { min-height: 0; }
  .interaction-hint { text-align: left; }
  .work-item { grid-template-columns: 38px 1fr; gap: 6px; padding: 28px 0; }
  .work-index { grid-row: 1 / span 2; }
  .work-item h3 { font-size: 27px; line-height: 1.06; }
  .work-item p { margin-top: 12px; line-height: 1.55; }
  .work-tag { display: none; }
  .about-grid { gap: 70px; }
  .about-statement { font-size: 42px; }
  .contact-label { margin-bottom: 36px; }
  .site-footer { grid-template-columns: 1fr auto; gap: 16px; }
  .site-footer p:nth-child(2) { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }
  .reveal { opacity: 1; transform: none; }
}