:root {
  --ink: #1b2420;
  --ink-soft: #47544d;
  --ink-faint: #7c877f;
  --paper: #f5f3ec;
  --paper-2: #ece7db;
  --line: #d8d3c6;
  --green: #1f4b3f;
  --green-2: #163a30;
  --green-3: #0f2b23;
  --green-line: #34675a;
  --mint: #d7e5df;
  --copper: #b76a34;
  --copper-2: #9a5729;
  --copper-tint: #ecd6c1;
  --sans: "Segoe UI", "Helvetica Neue", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  --display: Georgia, "Times New Roman", "Microsoft YaHei", serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
/* The fixed header overlays the page, but every section already carries a
   generous padding-top; landing on the section box itself lets that padding
   supply the clearance instead of stacking a second gap on top of it. */
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
body {
  font-family: var(--sans);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

/* ---------- bilingual ---------- */
.lang-en { display: none; }
html[data-lang="en"] .lang-zh { display: none; }
html[data-lang="en"] .lang-en { display: inline; }
html[data-lang="en"] .lang-en-block { display: block; }

/* ---------- header ---------- */
.header {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 11px 48px;
  background: rgba(15, 43, 35, 0.86);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(236, 214, 193, 0.14);
}
.logo { display: flex; align-items: center; gap: 14px; color: #fff; }
.logo__mark {
  width: 42px; height: 42px; border: 2px solid var(--copper);
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 800; font-size: 16px; letter-spacing: 2px;
  /* letter-spacing leaves a trailing gap after the last glyph — indent the
     same amount so the two characters sit optically centred in the box. */
  padding-left: 2px; white-space: nowrap; line-height: 1;
  background: var(--green-2);
}
.logo__name { display: flex; flex-direction: column; line-height: 1.25; }
.logo__name b { font-size: 17px; font-weight: 700; letter-spacing: 0.06em; }
.logo__name span { font-size: 11px; letter-spacing: 0.22em; color: var(--copper-tint); }

.nav { display: flex; align-items: center; gap: 26px; }
.nav a { color: rgba(245, 243, 236, 0.85); font-size: 15px; letter-spacing: 0.04em; transition: color 0.2s; position: relative; }
.nav a:hover { color: #fff; }
.nav a::after { content: ""; position: absolute; left: 0; bottom: -6px; width: 0; height: 2px; background: var(--copper); transition: width 0.25s; }
.nav a:hover::after { width: 100%; }
.lang-toggle {
  display: flex; border: 1px solid var(--copper); overflow: hidden;
  font-size: 13px; font-weight: 700; letter-spacing: 0.05em;
}
.lang-toggle button {
  all: unset; cursor: pointer; padding: 7px 14px; color: var(--copper-tint);
  transition: background 0.2s, color 0.2s;
}
.lang-toggle button.on { background: var(--copper); color: #fff; }

/* ---------- hero ---------- */
.hero { position: relative; min-height: 100vh; display: flex; align-items: center; color: #fff; overflow: hidden; }
.hero__img { position: absolute; inset: 0; }
.hero__img img { width: 100%; height: 100%; object-fit: cover; }
.hero__img::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(105deg, rgba(15, 43, 35, 0.92) 0%, rgba(15, 43, 35, 0.72) 42%, rgba(15, 43, 35, 0.25) 100%);
}
.hero__inner { position: relative; z-index: 2; padding: 160px 48px 120px; max-width: 1200px; margin: 0 auto; width: 100%; }
.hero__eyebrow {
  display: inline-flex; align-items: center; gap: 14px;
  font-size: 14px; font-weight: 700; letter-spacing: 0.2em; color: var(--copper-tint);
  text-transform: uppercase; margin-bottom: 28px;
}
.hero__eyebrow::before { content: ""; width: 48px; height: 3px; background: var(--copper); }
.hero h1 { font-size: clamp(38px, 5vw, 64px); font-weight: 800; line-height: 1.28; letter-spacing: 0.01em; max-width: 800px; }
.hero h1 .accent { color: var(--copper); }
.hero__sub { margin-top: 26px; font-size: 18px; color: rgba(245, 243, 236, 0.85); max-width: 640px; line-height: 1.9; }
.hero__cta { display: flex; gap: 18px; margin-top: 44px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 15px 34px; font-size: 15px; font-weight: 700; letter-spacing: 0.06em;
  transition: transform 0.2s, background 0.2s, color 0.2s;
}
.btn--solid { background: var(--copper); color: #fff; }
.btn--solid:hover { background: var(--copper-2); transform: translateY(-2px); }
.btn--ghost { border: 1.5px solid rgba(245, 243, 236, 0.55); color: #fff; }
.btn--ghost:hover { border-color: #fff; background: rgba(255, 255, 255, 0.08); transform: translateY(-2px); }
.hero__badges { display: flex; gap: 14px; margin-top: 56px; flex-wrap: wrap; }
.hero__badge {
  padding: 10px 18px; border: 1px solid rgba(236, 214, 193, 0.35);
  font-size: 13px; letter-spacing: 0.08em; color: rgba(245, 243, 236, 0.9);
  background: rgba(15, 43, 35, 0.5);
}
.hero__scroll { position: absolute; bottom: 34px; left: 50%; transform: translateX(-50%); z-index: 2; color: rgba(245,243,236,0.6); font-size: 12px; letter-spacing: 0.3em; writing-mode: vertical-rl; }

/* ---------- section base ---------- */
.section { padding: 92px 48px 100px; position: relative; overflow: hidden; }
.section--paper2 { background: var(--paper-2); }
.section--dark { background: var(--green); color: var(--paper); }
.section--deep { background: var(--green-3); color: var(--paper); }
.wrap { max-width: 1200px; margin: 0 auto; position: relative; z-index: 2; }

.sec-head { margin-bottom: 46px; max-width: 900px; }
.kicker {
  display: inline-flex; align-items: center; gap: 14px;
  font-size: 14px; font-weight: 700; letter-spacing: 0.16em; color: var(--copper-2);
  text-transform: uppercase; margin-bottom: 18px;
}
.kicker::before { content: ""; width: 42px; height: 3px; background: var(--copper); }
.section--dark .kicker, .section--deep .kicker { color: var(--copper-tint); }
.sec-head h2 { font-size: clamp(30px, 3.4vw, 44px); font-weight: 800; line-height: 1.3; letter-spacing: 0.01em; }
.sec-head .lead { margin-top: 20px; font-size: 17px; color: var(--ink-soft); line-height: 1.9; }
.section--dark .sec-head .lead, .section--deep .sec-head .lead { color: rgba(245, 243, 236, 0.82); }

/* ---------- deco ---------- */
.deco-dots {
  position: absolute; width: 240px; height: 180px; pointer-events: none;
  background-image: radial-gradient(currentColor 2.2px, transparent 2.5px);
  background-size: 28px 28px; color: var(--copper); opacity: 0.16;
}
.deco-ring { position: absolute; border: 2px solid var(--copper); border-radius: 50%; opacity: 0.22; pointer-events: none; }
.ghost {
  position: absolute; font-family: var(--display); font-weight: 700; line-height: 0.8;
  color: var(--green); opacity: 0.05; letter-spacing: -0.03em; user-select: none; pointer-events: none;
}
.section--dark .ghost, .section--deep .ghost { color: #fff; opacity: 0.04; }

/* ---------- about ---------- */
.about-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 72px; align-items: center; }
.about-text p { font-size: 16.5px; color: var(--ink-soft); line-height: 2; margin-bottom: 20px; }
.about-text p b { color: var(--green); }
.about-points { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.about-point {
  background: #fff; border: 1px solid var(--line); border-top: 4px solid var(--green);
  padding: 28px 26px; display: flex; flex-direction: column; gap: 12px;
  transition: transform 0.25s, box-shadow 0.25s;
}
.about-point:hover { transform: translateY(-5px); box-shadow: 0 18px 40px rgba(20, 30, 25, 0.12); }
.about-point--c { border-top-color: var(--copper); }
.icon-badge {
  width: 60px; height: 60px; border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  background: var(--mint); color: var(--green);
}
.icon-badge--c { background: var(--copper-tint); color: var(--copper-2); }
.icon-badge svg, .ico { fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.about-point h3 { font-size: 18px; font-weight: 700; }
.about-point p { font-size: 14px; color: var(--ink-soft); line-height: 1.75; }

/* ---------- tech ---------- */
.tech-grid { display: grid; grid-template-columns: 0.95fr 1.05fr; gap: 72px; align-items: center; }
.tech-img { position: relative; border: 2px solid var(--copper); }
.tech-img img { width: 100%; aspect-ratio: 4 / 3.4; object-fit: cover; }
.tech-img .tag {
  position: absolute; bottom: 22px; left: 22px; z-index: 2;
  background: rgba(15, 43, 35, 0.9); color: var(--copper-tint);
  font-size: 13px; letter-spacing: 0.1em; padding: 9px 16px;
}
.mechs { display: flex; flex-direction: column; gap: 20px; }
.mech {
  display: flex; gap: 24px; background: #fff; border: 1px solid var(--line);
  padding: 24px 28px; border-left: 5px solid var(--green);
  transition: transform 0.25s, box-shadow 0.25s;
}
.mech:hover { transform: translateX(6px); box-shadow: 0 14px 34px rgba(20, 30, 25, 0.1); }
.mech--c { border-left-color: var(--copper); }
.mech__n { font-family: var(--display); font-size: 30px; font-weight: 700; color: var(--copper-2); line-height: 1; padding-top: 4px; }
.mech h3 { font-size: 19px; font-weight: 700; margin-bottom: 8px; }
.mech p { font-size: 14.5px; color: var(--ink-soft); line-height: 1.8; }

/* ---------- solutions ---------- */
.sol-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.sol-card {
  background: #fff; border: 1px solid var(--line); overflow: hidden;
  display: flex; flex-direction: column;
  transition: transform 0.25s, box-shadow 0.25s;
}
.sol-card:hover { transform: translateY(-6px); box-shadow: 0 22px 48px rgba(20, 30, 25, 0.14); }
.sol-card__img { position: relative; height: 200px; overflow: hidden; }
.sol-card__img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.sol-card:hover .sol-card__img img { transform: scale(1.06); }
/* Direct child only — the badge wraps bilingual <span>s, which would
   otherwise inherit the absolute positioning and collapse the label. */
.sol-card__img > span {
  position: absolute; top: 18px; left: 18px; background: var(--green-3);
  color: var(--copper-tint); font-size: 12px; font-weight: 700; letter-spacing: 0.12em;
  padding: 7px 14px; white-space: nowrap;
}
.sol-card__body { padding: 30px 28px 32px; display: flex; flex-direction: column; gap: 14px; flex: 1; }
.sol-card__body h3 { font-size: 20px; font-weight: 800; }
.sol-card__body p { font-size: 14.5px; color: var(--ink-soft); line-height: 1.8; }
.sol-card__body ul { display: flex; flex-direction: column; gap: 8px; margin-top: auto; padding-top: 8px; }
.sol-card__body li { font-size: 13.5px; color: var(--ink-soft); display: flex; gap: 10px; align-items: flex-start; line-height: 1.6; }
.sol-card__body li::before { content: ""; flex: 0 0 auto; width: 7px; height: 7px; margin-top: 8px; background: var(--copper); transform: rotate(45deg); }

/* ---------- value band ---------- */
/* Short band: fill the viewport and vertically centre the copy so a nav
   jump does not park the section flush to the top with the next block peeking. */
#value {
  /* Match html scroll-padding-top so a nav jump fills the viewport flush. */
  min-height: calc(100vh - 24px);
  min-height: calc(100dvh - 24px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  box-sizing: border-box;
}
#value .sec-head { margin-bottom: 36px; }
.value-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 72px; align-items: center; }
.value-statement { font-size: clamp(26px, 2.8vw, 36px); font-weight: 800; line-height: 1.55; }
.value-statement .accent { color: var(--copper-tint); }
.value-statement + p { margin-top: 24px; font-size: 15.5px; color: rgba(245, 243, 236, 0.8); line-height: 1.9; }
.stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.stat {
  background: rgba(255, 255, 255, 0.05); border: 1px solid var(--green-line);
  border-top: 4px solid var(--copper); padding: 30px 28px;
}
.stat__n { font-family: var(--display); font-size: 46px; font-weight: 700; color: var(--copper-tint); line-height: 1.1; font-variant-numeric: tabular-nums; }
.stat__n small { font-size: 22px; }
.stat__l { margin-top: 10px; font-size: 14px; color: rgba(245, 243, 236, 0.82); line-height: 1.6; }

/* ---------- case ---------- */
.case-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; margin-bottom: 34px; }
.case-photo { position: relative; overflow: hidden; height: 250px; }
.case-photo img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.case-photo:hover img { transform: scale(1.05); }
.case-photo > span {
  position: absolute; top: 20px; left: 20px; background: var(--copper);
  color: #fff; font-size: 13px; font-weight: 700; letter-spacing: 0.06em;
  padding: 8px 16px; white-space: nowrap;
}
.case-photo .cap {
  position: absolute; left: 0; right: 0; bottom: 0;
  background: linear-gradient(to top, rgba(12, 20, 16, 0.88), rgba(12, 20, 16, 0));
  color: #fff; padding: 40px 26px 20px; font-size: 14px;
}
.case-data { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.case-kpi { background: #fff; border: 1px solid var(--line); padding: 22px 24px; border-bottom: 4px solid var(--green); }
.case-kpi--c { border-bottom-color: var(--copper); }
.case-kpi .k { font-size: 13px; color: var(--ink-faint); letter-spacing: 0.04em; }
.case-kpi .v { font-family: var(--display); font-size: 36px; font-weight: 700; color: var(--green); margin-top: 6px; font-variant-numeric: tabular-nums; }
.case-kpi--c .v { color: var(--copper-2); }
.case-kpi .d { font-size: 13px; color: var(--ink-soft); margin-top: 8px; line-height: 1.6; }
.road { display: flex; align-items: stretch; margin-top: 34px; background: var(--paper-2); border: 1px solid var(--line); }
.road__step { flex: 1; padding: 26px 24px; position: relative; }
.road__step + .road__step::before { content: ""; position: absolute; left: 0; top: 22px; bottom: 22px; width: 1px; background: var(--line); }
.road__step .t { font-size: 12px; font-weight: 700; letter-spacing: 0.1em; color: var(--copper-2); }
.road__step h4 { font-size: 17px; font-weight: 700; margin: 8px 0 6px; }
.road__step p { font-size: 13px; color: var(--ink-soft); line-height: 1.65; }
.road__step--done { background: var(--green); }
.road__step--done .t { color: var(--copper-tint); }
.road__step--done h4 { color: #fff; }
.road__step--done p { color: rgba(245, 243, 236, 0.8); }

/* ---------- capabilities ---------- */
.cap-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 26px; }
.cap-card {
  background: #fff; border: 1px solid var(--line); padding: 34px 28px;
  display: flex; flex-direction: column; gap: 16px; border-top: 4px solid var(--green);
  transition: transform 0.25s, box-shadow 0.25s;
}
.cap-card:hover { transform: translateY(-5px); box-shadow: 0 18px 40px rgba(20, 30, 25, 0.12); }
.cap-card--c { border-top-color: var(--copper); }
.cap-card h3 { font-size: 18px; font-weight: 700; }
.cap-card p { font-size: 14px; color: var(--ink-soft); line-height: 1.8; }

/* ---------- cooperation ---------- */
.coop-list { display: grid; grid-template-columns: 1fr 1fr; gap: 0; }
.coop-item {
  display: flex; gap: 26px; padding: 26px 32px; border-bottom: 1px solid var(--green-line);
  align-items: flex-start;
}
.coop-item:nth-child(odd) { border-right: 1px solid var(--green-line); }
.coop-item__n { font-family: var(--display); font-size: 26px; font-weight: 700; color: var(--copper); line-height: 1.2; }
.coop-item h3 { font-size: 18px; font-weight: 700; color: #fff; margin-bottom: 6px; }
.coop-item p { font-size: 14px; color: rgba(245, 243, 236, 0.75); line-height: 1.75; }

/* ---------- contact ---------- */
.contact-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 72px; align-items: center; }
.contact-text h2 { font-size: clamp(30px, 3.2vw, 42px); font-weight: 800; line-height: 1.35; color: #fff; }
.contact-text h2 .accent { color: var(--copper); }
.contact-text p { margin-top: 22px; font-size: 15.5px; color: rgba(245, 243, 236, 0.82); line-height: 1.9; max-width: 560px; }
.contact-card {
  background: #fff; padding: 44px 42px; color: var(--ink);
  border-top: 5px solid var(--copper); box-shadow: 0 24px 60px rgba(0, 0, 0, 0.25);
}
.contact-card__row { display: flex; gap: 20px; padding: 18px 0; border-bottom: 1px solid var(--line); align-items: flex-start; }
.contact-card__row:last-child { border-bottom: none; }
.contact-card__row .lbl { flex: 0 0 96px; font-size: 13px; font-weight: 700; letter-spacing: 0.06em; color: var(--copper-2); padding-top: 4px; }
.contact-card__row .val { font-size: 15.5px; font-weight: 600; line-height: 1.7; }
.contact-card__row .val small { display: block; font-size: 13px; color: var(--ink-faint); font-weight: 400; }
.contact-card__row .val a { color: inherit; border-bottom: 1px solid rgba(183, 106, 52, 0.35); transition: color 0.2s, border-color 0.2s; }
.contact-card__row .val a:hover { color: var(--copper-2); border-bottom-color: var(--copper); }

/* ---------- footer ---------- */
.footer { background: #0a1f19; color: rgba(245, 243, 236, 0.6); padding: 36px 48px; }
.footer .wrap { display: flex; justify-content: space-between; align-items: center; gap: 20px; flex-wrap: wrap; font-size: 13px; }
.footer .slogan { color: var(--copper-tint); letter-spacing: 0.1em; }

/* ---------- reveal ---------- */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }

/* ---------- responsive ---------- */
@media (max-width: 1080px) {
  .section { padding: 74px 40px 82px; }
  .sec-head { margin-bottom: 38px; }
  .about-grid, .tech-grid, .value-grid, .contact-grid { grid-template-columns: 1fr; gap: 40px; }
  /* Stacked full-width, the portrait ratio would run ~600px tall and push the
     rest of the section off screen. */
  .tech-img img { aspect-ratio: 16 / 9; max-height: 320px; }
  .sol-grid { grid-template-columns: 1fr 1fr; }
  .cap-grid { grid-template-columns: 1fr 1fr; }
  .case-data { grid-template-columns: 1fr 1fr; }
  .coop-item:nth-child(odd) { border-right: none; }
  .coop-list { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
  .header { padding: 12px 20px; }
  .nav { display: none; }
  .section { padding: 72px 22px; }
  .hero__inner { padding: 130px 22px 90px; }
  .sol-grid, .cap-grid, .case-grid, .about-points { grid-template-columns: 1fr; }
  /* Compact numeric cards stay paired so these sections don't run several
     screens long once everything else stacks. */
  .case-data, .stat-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .case-photo { height: 220px; }
  .road { flex-direction: column; }
  .road__step + .road__step::before { left: 22px; right: 22px; top: 0; bottom: auto; width: auto; height: 1px; }
}