/* ═══════════════════════════════════════════════════════════
   Yunnan Jinghu Environment Engineering — main.css
   ═══════════════════════════════════════════════════════════ */

/* ── RESET ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: 'DM Sans', 'Noto Sans SC', sans-serif;
  background: #f5f4f0;
  color: #1a1a18;
  overflow-x: hidden;
}
a { text-decoration: none; color: inherit; }
button { cursor: pointer; font-family: inherit; }

/* ── TOKENS ── */
:root {
  --blue-deep:  #042C53;
  --blue-mid:   #185FA5;
  --blue-lt:    #d6e9f8;
  --teal-deep:  #085041;
  --teal-mid:   #0F6E56;
  --teal-lt:    #d0ede5;
  --sand:       #f5f4f0;
  --sand-dark:  #eae9e4;
  --white:      #ffffff;
  --ink:        #1a1a18;
  --ink-muted:  #5a5a56;
  --ink-faint:  #9a9a94;
  --border:     rgba(26,26,24,0.10);
  --border-mid: rgba(26,26,24,0.18);
  --r-sm: 6px;
  --r-md: 10px;
  --r-lg: 16px;
  --r-xl: 24px;
  --shadow-sm: 0 1px 4px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
}

/* ═══════════════════════════════════════════════════════════
   LANGUAGE VISIBILITY
   Default: EN visible. html[lang="zh"] flips them.
   ═══════════════════════════════════════════════════════════ */
.zh-text   { display: none; }
.en-text   { display: block; }
.zh-inline { display: none; }
.en-inline { display: inline; }

html[lang="zh"] .zh-text   { display: block; }
html[lang="zh"] .en-text   { display: none; }
html[lang="zh"] .zh-inline { display: inline; }
html[lang="zh"] .en-inline { display: none; }

/* ═══════════════════════════════════════════════════════════
   NAVBAR
   ═══════════════════════════════════════════════════════════ */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 200;
  background: rgba(255,255,255,0.96);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 2rem; height: 64px;
  transition: box-shadow 0.2s;
}
nav.scrolled { box-shadow: var(--shadow-md); }

.nav-logo { display: flex; align-items: center; gap: 10px; }
.logo-mark {
  width: 36px; height: 36px; border-radius: 8px;
  background: var(--blue-deep);
  display: flex; align-items: center; justify-content: center;
  font-weight: 500; font-size: 13px; color: #fff; letter-spacing: 0.5px;
  flex-shrink: 0;
}
.logo-text .cn { font-size: 12px; font-weight: 500; color: var(--ink); line-height: 1.3; }
.logo-text .en { font-size: 10px; color: var(--ink-muted); }

.nav-links { display: flex; gap: 2px; }
.nav-links button {
  background: none; border: none;
  padding: 7px 13px; font-size: 13px;
  color: var(--ink-muted); border-radius: var(--r-sm);
  transition: background 0.15s, color 0.15s;
}
.nav-links button:hover  { background: var(--sand); color: var(--ink); }
.nav-links button.active { background: var(--blue-lt); color: var(--blue-mid); font-weight: 500; }

.nav-right { display: flex; align-items: center; gap: 10px; }

/* ── Language toggle switch ── */
.lang-switch {
  display: flex; align-items: center; gap: 8px;
  font-size: 12px; color: var(--ink-muted);
  user-select: none;
}
.lang-lbl { font-weight: 400; transition: color 0.15s, font-weight 0.15s; }
.lang-lbl.active { color: var(--ink); font-weight: 500; }

/* The pill track */
.toggle-track {
  position: relative;
  width: 40px; height: 22px;
  background: var(--border-mid);   /* default: EN active → track grey */
  border-radius: 100px;
  border: none; padding: 0;
  cursor: pointer;
  transition: background 0.2s;
  flex-shrink: 0;
}
/* When ZH is active, track turns blue */
html[lang="zh"] .toggle-track { background: var(--blue-mid); }

/* The sliding thumb */
.toggle-thumb {
  position: absolute; top: 3px; left: 3px;
  width: 16px; height: 16px;
  border-radius: 50%; background: #fff;
  transition: transform 0.2s;
  box-shadow: 0 1px 3px rgba(0,0,0,0.25);
  pointer-events: none;
}
/* EN → thumb sits LEFT (default, no translate) */
/* ZH → thumb slides RIGHT */
html[lang="zh"] .toggle-thumb { transform: translateX(18px); }

.nav-cta {
  background: var(--blue-deep); color: #fff;
  border: none; padding: 8px 18px;
  border-radius: var(--r-md); font-size: 13px; font-weight: 500;
  transition: opacity 0.15s;
}
.nav-cta:hover { opacity: 0.88; }

.nav-mobile-btn {
  display: none; background: none; border: none;
  font-size: 22px; color: var(--ink);
}

/* ═══════════════════════════════════════════════════════════
   PAGES
   ═══════════════════════════════════════════════════════════ */
.page { display: none; padding-top: 64px; min-height: 100vh; }
.page.active { display: block; }
section { padding: 5rem 2rem; max-width: 1040px; margin: 0 auto; }

/* ── Section header ── */
.sec-header { margin-bottom: 3rem; }
.sec-eyebrow {
  font-size: 11px; font-weight: 500; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--blue-mid); margin-bottom: 10px;
}
.sec-header h2 {
  font-family: 'Noto Serif SC', serif;
  font-size: 28px; font-weight: 600;
  line-height: 1.3; color: var(--ink); margin-bottom: 6px;
}
.sec-header .sub { font-size: 14px; color: var(--ink-muted); }
.sec-bar {
  width: 48px; height: 3px; border-radius: 2px;
  background: linear-gradient(90deg, var(--blue-mid), var(--teal-mid));
  margin-top: 14px;
}

/* ═══════════════════════════════════════════════════════════
   HERO
   ═══════════════════════════════════════════════════════════ */
.hero {
  min-height: 100vh; background: var(--blue-deep);
  display: flex; flex-direction: column;
  justify-content: center; align-items: center;
  text-align: center; padding: 6rem 2rem 4rem;
  position: relative; overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0; opacity: 0.07;
  background:
    radial-gradient(circle at 20% 20%, #185FA5 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, #0F6E56 0%, transparent 50%);
}
.hero-grid-bg {
  position: absolute; inset: 0; opacity: 0.04;
  background-image:
    linear-gradient(rgba(255,255,255,0.5) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.5) 1px, transparent 1px);
  background-size: 60px 60px;
}
.hero-content { position: relative; z-index: 1; max-width: 760px; }

.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(255,255,255,0.10); border: 1px solid rgba(255,255,255,0.20);
  border-radius: 100px; padding: 6px 16px;
  font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase;
  color: rgba(255,255,255,0.70); margin-bottom: 28px;
}
.hero-dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: #4ade80; flex-shrink: 0;
}
.hero h1 {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(30px, 5vw, 52px); font-weight: 600;
  color: #fff; line-height: 1.25; margin-bottom: 10px;
}
.hero-sub-line {
  color: rgba(255,255,255,0.50); font-weight: 400;
  font-size: 0.65em; display: block; margin-top: 10px;
}
.hero-desc {
  font-size: 15px; color: rgba(255,255,255,0.65);
  line-height: 1.75; max-width: 580px;
  margin: 24px auto 40px;
}
.hero-btns { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

.btn-solid {
  background: #fff; color: var(--blue-deep); border: none;
  padding: 13px 28px; border-radius: var(--r-md);
  font-size: 14px; font-weight: 500;
  transition: transform 0.15s, box-shadow 0.15s;
}
.btn-solid:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,0.22); }

.btn-ghost {
  background: transparent; color: #fff;
  border: 1px solid rgba(255,255,255,0.35);
  padding: 13px 28px; border-radius: var(--r-md); font-size: 14px;
  transition: background 0.15s;
}
.btn-ghost:hover { background: rgba(255,255,255,0.10); }

.hero-scroll {
  margin-top: 56px; color: rgba(255,255,255,0.28);
  font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase;
}
.scroll-arrow {
  margin: 8px auto 0; width: 20px;
  display: flex; justify-content: center;
  animation: bounce 1.8s infinite;
}
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(6px); }
}

/* ═══════════════════════════════════════════════════════════
   STATS BAR
   ═══════════════════════════════════════════════════════════ */
.stats-bar {
  background: var(--white); border-bottom: 1px solid var(--border);
  display: grid; grid-template-columns: repeat(4, 1fr);
}
.stat {
  padding: 2rem 1.5rem; text-align: center;
  border-right: 1px solid var(--border);
}
.stat:last-child { border-right: none; }
.stat-num {
  font-family: 'Noto Serif SC', serif;
  font-size: 36px; font-weight: 600;
  color: var(--blue-mid); line-height: 1;
}
.stat-label { font-size: 13px; color: var(--ink-muted); margin-top: 6px; }
.stat-sub   { font-size: 11px; color: var(--ink-faint); margin-top: 2px; }

/* ═══════════════════════════════════════════════════════════
   SERVICE GRID
   ═══════════════════════════════════════════════════════════ */
.service-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 1px; background: var(--border);
  border: 1px solid var(--border); border-radius: var(--r-lg); overflow: hidden;
}
.svc { background: var(--white); padding: 2rem; transition: background 0.2s; }
.svc:hover { background: var(--sand); }

.svc-icon {
  width: 40px; height: 40px; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 14px;
}
.svc-icon.blue { background: var(--blue-lt); }
.svc-icon.teal { background: var(--teal-lt); }
.svc-icon svg { width: 20px; height: 20px; fill: none; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; }
.svc-icon.blue svg { stroke: var(--blue-mid); }
.svc-icon.teal svg { stroke: var(--teal-mid); }

.svc h3 {
  font-family: 'Noto Serif SC', serif;
  font-size: 15px; font-weight: 500; margin-bottom: 6px;
}
.svc p { font-size: 13px; color: var(--ink-muted); line-height: 1.65; }

.svc-tag {
  display: inline-block; margin-top: 12px;
  font-size: 11px; padding: 3px 10px; border-radius: 100px;
}
.svc-tag.blue { background: var(--blue-lt); color: var(--blue-mid); }
.svc-tag.teal { background: var(--teal-lt); color: var(--teal-mid); }

/* ═══════════════════════════════════════════════════════════
   PARTNER SECTION
   ═══════════════════════════════════════════════════════════ */
.partner-section {
  background: var(--white); padding: 4rem 2rem;
  border-top: 1px solid var(--border);
}
.partner-inner { max-width: 1040px; margin: 0 auto; }
.partner-cat { margin-bottom: 2rem; }
.partner-cat-lbl {
  font-size: 11px; font-weight: 500; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--ink-faint); margin-bottom: 12px;
}
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  background: var(--sand); border: 1px solid var(--border);
  border-radius: 100px; padding: 6px 16px;
  font-size: 13px; color: var(--ink-muted);
  transition: border-color 0.15s, color 0.15s;
}
.chip:hover { border-color: var(--blue-mid); color: var(--blue-mid); }

/* ═══════════════════════════════════════════════════════════
   TECH ITEMS
   ═══════════════════════════════════════════════════════════ */
.tech-item {
  display: grid; grid-template-columns: 200px 1fr;
  background: var(--white); border: 1px solid var(--border);
  border-radius: var(--r-lg); overflow: hidden; margin-bottom: 16px;
}
.tech-panel {
  background: var(--blue-deep);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  padding: 2rem; gap: 14px; text-align: center;
}
.tech-panel.teal { background: var(--teal-deep); }

.tech-panel-icon {
  width: 52px; height: 52px; border-radius: 12px;
  background: rgba(255,255,255,0.12);
  display: flex; align-items: center; justify-content: center;
}
.tech-panel-icon svg {
  width: 26px; height: 26px; stroke: #fff;
  stroke-width: 1.5; fill: none;
  stroke-linecap: round; stroke-linejoin: round;
}
.tech-panel-label { font-size: 12px; color: rgba(255,255,255,0.50); line-height: 1.5; }

.tech-body { padding: 2rem; }
.tech-badge {
  display: inline-block; font-size: 11px; font-weight: 500;
  padding: 3px 12px; border-radius: 100px; margin-bottom: 12px;
}
.tech-badge.blue { background: var(--blue-lt); color: var(--blue-mid); }
.tech-badge.teal { background: var(--teal-lt); color: var(--teal-mid); }
.tech-body h3 {
  font-family: 'Noto Serif SC', serif;
  font-size: 16px; font-weight: 500; margin-bottom: 4px;
}
.tech-body .sub { font-size: 12px; color: var(--ink-muted); margin-bottom: 12px; }
.tech-body p    { font-size: 13px; color: var(--ink-muted); line-height: 1.70; }

.tech-specs { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 14px; }
.spec-pill {
  background: var(--sand); border: 1px solid var(--border);
  border-radius: var(--r-sm); padding: 4px 10px;
  font-size: 11px; color: var(--ink-muted);
}
.tech-section-label {
  font-size: 11px; font-weight: 500; letter-spacing: 0.09em;
  text-transform: uppercase; color: var(--ink-faint);
  margin-bottom: 14px;
}
.tech-section-label + .tech-section-label,
.tech-item + .tech-section-label { margin-top: 28px; }

/* ═══════════════════════════════════════════════════════════
   SOLUTION GRID
   ═══════════════════════════════════════════════════════════ */
.sol-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.sol-card {
  background: var(--white); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: 1.5rem;
  transition: box-shadow 0.2s, transform 0.2s;
}
.sol-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.sol-icon {
  width: 40px; height: 40px; border-radius: 10px;
  display: flex; align-items: center; justify-content: center; margin-bottom: 14px;
}
.sol-icon svg { width: 20px; height: 20px; stroke-width: 1.5; fill: none; stroke-linecap: round; stroke-linejoin: round; }
.sol-icon.blue { background: var(--blue-lt); }
.sol-icon.blue svg { stroke: var(--blue-mid); }
.sol-icon.teal { background: var(--teal-lt); }
.sol-icon.teal svg { stroke: var(--teal-mid); }
.sol-card h3 {
  font-family: 'Noto Serif SC', serif;
  font-size: 14px; font-weight: 500; margin-bottom: 6px;
}
.sol-card p { font-size: 12px; color: var(--ink-muted); line-height: 1.65; }

/* ═══════════════════════════════════════════════════════════
   CASE CARDS
   ═══════════════════════════════════════════════════════════ */
.case-card {
  background: var(--white); border: 1px solid var(--border);
  border-radius: var(--r-lg); overflow: hidden; margin-bottom: 20px;
}
.case-head {
  display: flex; align-items: start; justify-content: space-between;
  padding: 1.75rem 1.75rem 0; gap: 16px;
}
.case-head h3 {
  font-family: 'Noto Serif SC', serif;
  font-size: 16px; font-weight: 500; margin-bottom: 4px;
}
.case-head .sub { font-size: 12px; color: var(--ink-muted); }

.case-badge {
  flex-shrink: 0; font-size: 11px; font-weight: 500;
  padding: 4px 12px; border-radius: 100px; white-space: nowrap;
  background: var(--blue-lt); color: var(--blue-mid);
}
.case-badge.teal { background: var(--teal-lt); color: var(--teal-mid); }

.case-meta {
  display: flex; gap: 24px; flex-wrap: wrap;
  padding: 1.25rem 1.75rem;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  margin-top: 1.25rem;
}
.meta-kv label { font-size: 11px; color: var(--ink-faint); display: block; margin-bottom: 2px; }
.meta-kv span  { font-size: 13px; font-weight: 500; }

.case-list { padding: 1.25rem 1.75rem 1.75rem; list-style: none; }
.case-list li {
  font-size: 13px; color: var(--ink-muted);
  padding: 5px 0 5px 18px; position: relative; line-height: 1.6;
}
.case-list li::before {
  content: '—'; position: absolute; left: 0; top: 5px;
  color: var(--blue-mid); font-size: 11px;
}

/* ═══════════════════════════════════════════════════════════
   ABOUT BLOCKS
   ═══════════════════════════════════════════════════════════ */
.about-block {
  background: var(--white); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: 2rem; margin-bottom: 16px;
}
.about-block h3 {
  font-family: 'Noto Serif SC', serif;
  font-size: 16px; font-weight: 500; margin-bottom: 6px;
}
.about-block .sub { font-size: 12px; color: var(--ink-muted); margin-bottom: 16px; }
.about-block p    { font-size: 14px; color: var(--ink-muted); line-height: 1.75; }
.about-block p + p { margin-top: 12px; }

.office-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
  gap: 12px; margin-top: 1rem;
}
.office-card { background: var(--sand); border-radius: var(--r-md); padding: 14px; }
.office-card .country { font-size: 13px; font-weight: 500; margin-bottom: 3px; }
.office-card .type    { font-size: 11px; color: var(--ink-muted); margin-bottom: 4px; }
.office-card .addr    { font-size: 11px; color: var(--ink-faint); line-height: 1.45; }

.cert-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.cert-chip {
  background: var(--sand); border: 1px solid var(--border);
  border-radius: var(--r-sm); padding: 5px 12px;
  font-size: 12px; color: var(--ink-muted);
}

.about-mini-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 12px; margin-top: 1rem;
}
.about-mini-card { background: var(--sand); border-radius: var(--r-md); padding: 16px; }
.about-mini-icon {
  width: 36px; height: 36px; border-radius: 8px;
  display: flex; align-items: center; justify-content: center; margin-bottom: 10px;
}
.about-mini-icon.blue { background: var(--blue-lt); }
.about-mini-icon.blue svg { stroke: var(--blue-mid); }
.about-mini-icon.teal { background: var(--teal-lt); }
.about-mini-icon.teal svg { stroke: var(--teal-mid); }
.about-mini-icon svg { width: 18px; height: 18px; stroke-width: 1.5; fill: none; stroke-linecap: round; stroke-linejoin: round; }
.about-mini-card h4 { font-size: 13px; font-weight: 500; margin-bottom: 4px; }
.about-mini-card p  { font-size: 11px; color: var(--ink-muted); line-height: 1.5; }

/* ═══════════════════════════════════════════════════════════
   CONTACT
   ═══════════════════════════════════════════════════════════ */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.contact-card {
  background: var(--white); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: 2rem;
}
.contact-card h3 {
  font-family: 'Noto Serif SC', serif;
  font-size: 16px; font-weight: 500; margin-bottom: 4px;
}
.contact-card .sub { font-size: 12px; color: var(--ink-muted); margin-bottom: 20px; }

.contact-row { display: flex; gap: 12px; margin-bottom: 14px; font-size: 13px; align-items: start; }
.contact-ico {
  width: 32px; height: 32px; border-radius: 8px;
  background: var(--blue-lt);
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.contact-ico svg { width: 16px; height: 16px; stroke: var(--blue-mid); stroke-width: 1.5; fill: none; stroke-linecap: round; stroke-linejoin: round; }
.contact-detail { color: var(--ink-muted); line-height: 1.6; padding-top: 5px; }

/* ═══════════════════════════════════════════════════════════
   WHY US
   ═══════════════════════════════════════════════════════════ */
.why-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.why-card {
  background: var(--white); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: 1.5rem; text-align: center;
}
.why-icon {
  width: 44px; height: 44px; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 14px;
}
.why-icon.blue { background: var(--blue-lt); }
.why-icon.teal { background: var(--teal-lt); }
.why-icon svg { width: 22px; height: 22px; stroke-width: 1.5; fill: none; stroke-linecap: round; stroke-linejoin: round; }
.why-icon.blue svg { stroke: var(--blue-mid); }
.why-icon.teal svg { stroke: var(--teal-mid); }
.why-card h4 {
  font-family: 'Noto Serif SC', serif;
  font-size: 14px; font-weight: 500; margin-bottom: 8px;
}
.why-card p { font-size: 12px; color: var(--ink-muted); line-height: 1.6; }

/* ═══════════════════════════════════════════════════════════
   FOOTER
   ═══════════════════════════════════════════════════════════ */
footer {
  background: var(--blue-deep); color: rgba(255,255,255,0.55);
  padding: 2.5rem 2rem; text-align: center;
}
.foot-name {
  font-family: 'Noto Serif SC', serif;
  font-size: 15px; font-weight: 500; color: #fff; margin-bottom: 6px;
}
.foot-sub  { font-size: 12px; }
.foot-addr { font-size: 11px; margin-top: 10px; color: rgba(255,255,255,0.30); }
.foot-links {
  display: flex; justify-content: center; gap: 20px;
  margin-top: 16px; padding-top: 16px;
  border-top: 1px solid rgba(255,255,255,0.10);
}
.foot-links button {
  background: none; border: none;
  color: rgba(255,255,255,0.38); font-size: 12px;
  transition: color 0.15s;
}
.foot-links button:hover { color: rgba(255,255,255,0.80); }

/* ═══════════════════════════════════════════════════════════
   RESPONSIVE
   ═══════════════════════════════════════════════════════════ */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-mobile-btn { display: block; }

  nav.menu-open .nav-links {
    display: flex; flex-direction: column;
    position: fixed; top: 64px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--border);
    padding: 12px; gap: 4px; z-index: 150;
  }
  .nav-links button { width: 100%; text-align: left; }
  .nav-cta { display: none; }

  .stats-bar { grid-template-columns: repeat(2, 1fr); }
  .stat { border-right: none; border-bottom: 1px solid var(--border); }
  .stat:nth-child(odd)      { border-right: 1px solid var(--border); }
  .stat:nth-last-child(-n+2) { border-bottom: none; }

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

  .tech-item { grid-template-columns: 1fr; }
  .tech-panel {
    flex-direction: row; text-align: left;
    padding: 1.5rem; min-height: auto; gap: 16px;
  }

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

@media (max-width: 480px) {
  .sol-grid  { grid-template-columns: 1fr; }
  .why-grid  { grid-template-columns: 1fr; }
  .hero h1   { font-size: 26px; }
}

/* ═══════════════════════════════════════════════════════════
   2026 STATIC-SITE REFINEMENT
   A quiet, high-clarity visual system for engineering content.
   ═══════════════════════════════════════════════════════════ */
:root {
  --blue-deep: #06365d;
  --blue-mid: #0875bc;
  --blue-lt: #e1f3ff;
  --teal-deep: #075c58;
  --teal-mid: #087f79;
  --teal-lt: #def5ef;
  --sand: #f5f8f7;
  --sand-dark: #e5edeb;
  --white: #ffffff;
  --ink: #14272d;
  --ink-muted: #52666b;
  --ink-faint: #75868a;
  --border: rgba(20, 39, 45, 0.12);
  --border-mid: rgba(20, 39, 45, 0.22);
  --r-sm: 8px;
  --r-md: 14px;
  --r-lg: 22px;
  --r-xl: 32px;
  --shadow-sm: 0 3px 10px rgba(11, 47, 61, 0.07);
  --shadow-md: 0 16px 40px rgba(11, 47, 61, 0.12);
}

html { scroll-padding-top: 88px; }
body {
  background: var(--sand);
  letter-spacing: 0.002em;
  text-rendering: optimizeLegibility;
}
button, input, select, textarea { font: inherit; }
button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: 3px solid #f5b301;
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 1000;
  transform: translateY(-160%);
  padding: 10px 14px;
  border-radius: 8px;
  color: #062d50;
  background: #fff;
  box-shadow: var(--shadow-md);
  font-size: 14px;
  font-weight: 700;
  transition: transform 0.2s ease;
}
.skip-link:focus { transform: translateY(0); }

/* Explicit language choices remove any ambiguity about slider direction. */
.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  border: 1px solid rgba(20, 39, 45, 0.15);
  border-radius: 999px;
  background: #f1f7f8;
}
.lang-option {
  min-width: 42px;
  min-height: 30px;
  padding: 5px 9px;
  border: 0;
  border-radius: 999px;
  color: #587077;
  background: transparent;
  font-size: 12px;
  font-weight: 700;
  line-height: 1;
  transition: color 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}
.lang-option:hover { color: var(--blue-deep); }
.lang-option.active {
  color: #fff;
  background: var(--blue-deep);
  box-shadow: 0 2px 6px rgba(6, 54, 93, 0.2);
}

nav {
  height: 76px;
  padding: 0 clamp(1rem, 4vw, 4.5rem);
  background: rgba(255, 255, 255, 0.86);
  border-bottom-color: transparent;
  transition: box-shadow 0.25s ease, background 0.25s ease, border-color 0.25s ease;
}
nav.scrolled {
  box-shadow: 0 8px 28px rgba(5, 35, 54, 0.09);
  border-bottom-color: var(--border);
  background: rgba(255, 255, 255, 0.96);
}
.nav-logo { min-width: 0; gap: 12px; }
.logo-mark {
  width: 42px;
  height: 42px;
  border-radius: 13px;
  background: linear-gradient(145deg, #0b87c9, var(--blue-deep) 65%);
  box-shadow: 0 6px 16px rgba(6, 54, 93, 0.22);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
}
.logo-text .cn { font-size: 13px; letter-spacing: 0.015em; }
.logo-text .en { font-size: 9px; letter-spacing: 0.025em; margin-top: 2px; }
.nav-links { gap: 3px; }
.nav-links button {
  min-height: 36px;
  padding: 8px 12px;
  color: #456068;
  font-size: 13px;
  font-weight: 500;
}
.nav-links button:hover { color: var(--blue-deep); background: #eef8fc; }
.nav-links button.active { color: var(--blue-deep); background: #e1f3ff; }
.nav-right { gap: 14px; }
.lang-switch { gap: 2px; color: #5b6d72; }
.nav-cta {
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--blue-deep);
  box-shadow: 0 5px 14px rgba(6, 54, 93, 0.18);
}
.nav-cta:hover { opacity: 1; background: #08558f; }
.nav-mobile-btn { width: 40px; height: 40px; border-radius: 10px; color: var(--blue-deep); }
.nav-mobile-btn:hover { background: #eaf6fb; }

.page { padding-top: 76px; }
section { max-width: 1180px; padding: clamp(4.5rem, 9vw, 7.5rem) clamp(1.25rem, 4vw, 3rem); }
.sec-header { max-width: 760px; margin-bottom: clamp(2rem, 5vw, 3.75rem); }
.sec-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  border-radius: 999px;
  background: #e9f7f5;
  color: #05625f;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
}
.sec-header h2 { margin-top: 15px; font-size: clamp(30px, 4vw, 46px); line-height: 1.18; letter-spacing: -0.025em; }
.sec-header .sub { max-width: 680px; margin-top: 14px; font-size: 15px; line-height: 1.7; }
.sec-bar { width: 62px; height: 4px; margin-top: 20px; background: linear-gradient(90deg, #0a8dcc, #17a48d); }

.hero {
  isolation: isolate;
  min-height: max(690px, 100svh);
  align-items: stretch;
  justify-content: center;
  padding: clamp(8rem, 13vw, 11rem) clamp(1.25rem, 7vw, 8rem) clamp(5rem, 9vw, 7rem);
  text-align: left;
  background:
    radial-gradient(circle at 86% 22%, rgba(42, 183, 191, 0.34), transparent 26%),
    radial-gradient(circle at 12% 86%, rgba(11, 123, 177, 0.38), transparent 34%),
    linear-gradient(135deg, #03263f 0%, #063d69 48%, #064f69 100%);
}
.hero::before, .hero::after {
  position: absolute;
  z-index: -1;
  content: '';
  pointer-events: none;
  border: 1px solid rgba(195, 238, 246, 0.14);
  border-radius: 50%;
}
.hero::before { width: min(68vw, 760px); height: min(68vw, 760px); top: 14%; right: -16%; box-shadow: 0 0 0 70px rgba(178, 234, 241, 0.035), 0 0 0 150px rgba(178, 234, 241, 0.025); }
.hero::after { width: min(40vw, 520px); height: min(40vw, 520px); bottom: -22%; left: 8%; }
.hero-bg { opacity: 0.22; background: radial-gradient(circle at 18% 28%, #149ec5 0%, transparent 27%), radial-gradient(circle at 76% 68%, #11a486 0%, transparent 35%); }
.hero-grid-bg { opacity: 0.07; background-size: 72px 72px; }
.hero-content { max-width: 880px; margin: 0 auto; width: 100%; }
.hero-eyebrow { margin-bottom: 30px; background: rgba(231, 252, 252, 0.11); border-color: rgba(220, 249, 250, 0.25); color: rgba(244, 255, 255, 0.86); }
.hero-dot { box-shadow: 0 0 0 4px rgba(72, 222, 177, 0.14); }
.hero h1 { max-width: 840px; font-size: clamp(43px, 6.1vw, 76px); letter-spacing: -0.035em; line-height: 1.08; text-wrap: balance; }
.hero-sub-line { margin-top: 18px; font-family: 'DM Sans', 'Noto Sans SC', sans-serif; font-size: 0.34em; line-height: 1.4; letter-spacing: 0.055em; text-transform: uppercase; }
.hero-desc { max-width: 680px; margin: 28px 0 38px; font-size: clamp(15px, 1.5vw, 18px); line-height: 1.8; }
.hero-btns { justify-content: flex-start; gap: 12px; }
.btn-solid, .btn-ghost { min-height: 48px; padding: 13px 22px; border-radius: 999px; font-weight: 600; }
.btn-solid { color: #053d66; box-shadow: 0 9px 24px rgba(0, 0, 0, 0.18); }
.btn-solid:hover { box-shadow: 0 12px 28px rgba(0, 0, 0, 0.25); }
.btn-ghost:hover { background: rgba(255,255,255,0.16); }
.hero-scroll { display: flex; align-items: center; gap: 9px; margin-top: 64px; color: rgba(255,255,255,0.47); }
.scroll-arrow { margin: 0; }

.stats-bar {
  position: relative;
  z-index: 3;
  max-width: 1180px;
  margin: -36px auto 0;
  border: 1px solid rgba(8, 76, 95, 0.12);
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 18px 46px rgba(14, 60, 73, 0.14);
}
.stat { padding: 28px 20px; }
.stat-num { font-size: clamp(32px, 3vw, 44px); }
.stat-label { margin-top: 9px; font-weight: 600; color: #314e57; }
.stat-sub { margin-top: 4px; }

.service-grid { gap: 14px; background: transparent; border: 0; overflow: visible; }
.svc {
  min-height: 268px;
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-sm);
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}
.svc:hover { background: var(--white); border-color: rgba(8, 117, 188, 0.32); box-shadow: var(--shadow-md); transform: translateY(-5px); }
.svc-icon { width: 46px; height: 46px; border-radius: 14px; margin-bottom: 18px; }
.svc h3 { font-size: 18px; }
.svc p { font-size: 14px; line-height: 1.75; }
.svc-tag { margin-top: 16px; font-weight: 500; }

.partner-section { padding: clamp(4.5rem, 8vw, 7rem) clamp(1.25rem, 4vw, 3rem); background: #eaf5f5; border: 0; }
.partner-inner { max-width: 1120px; }
.partner-cat { margin-bottom: 24px; }
.partner-cat-lbl { color: #547176; font-weight: 700; }
.chip { padding: 8px 14px; border-radius: 10px; background: rgba(255,255,255,0.72); font-size: 13px; }
.chip:hover { background: #fff; }

.tech-section-label { margin: 48px 0 17px; color: #087371; font-weight: 700; }
.tech-item, .case-card, .about-block, .contact-card, .sol-card, .why-card {
  border-color: var(--border);
  box-shadow: var(--shadow-sm);
}
.tech-item { margin-bottom: 20px; border-radius: var(--r-lg); transition: box-shadow 0.2s ease, transform 0.2s ease; }
.tech-item:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.tech-panel { min-height: 220px; padding: 30px 24px; background: linear-gradient(145deg, #073b63, #075c75); }
.tech-panel.teal { background: linear-gradient(145deg, #075e59, #0a8279); }
.tech-body { padding: clamp(1.5rem, 3vw, 2.4rem); }
.tech-body h3, .case-head h3, .about-block h3, .contact-card h3 { font-size: 19px; }
.tech-body p, .about-block p { font-size: 14px; line-height: 1.82; }
.spec-pill { padding: 5px 10px; background: #f0f6f5; }
.sol-grid { gap: 18px; }
.sol-card { padding: 24px; }
.sol-card:hover { border-color: rgba(8, 117, 188, 0.3); }

.case-card { border-radius: var(--r-lg); margin-bottom: 24px; overflow: hidden; transition: transform 0.2s ease, box-shadow 0.2s ease; }
.case-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.case-head { padding: 28px 30px 0; }
.case-badge { background: #e5f3ff; color: #0569a9; }
.case-meta { padding: 20px 30px; margin-top: 22px; background: #f8fbfb; }
.case-list { padding: 22px 30px 30px; }
.case-list li { padding-top: 7px; padding-bottom: 7px; }
.case-list li::before { content: '•'; font-size: 19px; top: 4px; }

.about-block { padding: clamp(1.5rem, 3vw, 2.5rem); margin-bottom: 20px; }
.office-card, .about-mini-card { background: #f1f7f6; border: 1px solid transparent; }
.office-card:hover, .about-mini-card:hover { background: #fff; border-color: var(--border); }
.cert-chip { background: #f0f7f6; }

.contact-grid { gap: 24px; }
.contact-card { padding: clamp(1.5rem, 3vw, 2.5rem); }
.contact-detail { color: #415a61; }
.direct-contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: clamp(1.25rem, 3vw, 2.25rem);
  align-items: start;
  margin-top: 28px;
}
.phone-contact-slot { min-width: 0; }
.contact-slot-label {
  margin-bottom: 10px;
  color: #527078;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.phone-number-placeholder {
  display: flex;
  align-items: center;
  min-height: 72px;
  padding: 16px 18px;
  border: 1px dashed rgba(8, 117, 188, 0.42);
  border-radius: 14px;
  color: #42616a;
  background: linear-gradient(135deg, #eff9fc, #f6fbfa);
  font-family: 'DM Sans', 'Noto Sans SC', sans-serif;
  font-size: clamp(16px, 2vw, 20px);
  font-weight: 600;
  letter-spacing: 0.035em;
}
.phone-contact-slot p, .wechat-contact-slot p {
  margin-top: 9px;
  color: var(--ink-faint);
  font-size: 12px;
  line-height: 1.5;
}
.wechat-contact-slot { min-width: 164px; }
.wechat-qr-placeholder {
  display: grid;
  place-items: center;
  width: clamp(150px, 18vw, 184px);
  aspect-ratio: 1;
  border: 1px dashed rgba(8, 117, 188, 0.48);
  border-radius: 14px;
  color: #537179;
  background:
    linear-gradient(45deg, rgba(8, 117, 188, 0.045) 25%, transparent 25%, transparent 75%, rgba(8, 117, 188, 0.045) 75%),
    linear-gradient(45deg, rgba(8, 117, 188, 0.045) 25%, transparent 25%, transparent 75%, rgba(8, 117, 188, 0.045) 75%),
    #f9fcfc;
  background-position: 0 0, 12px 12px;
  background-size: 24px 24px;
  text-align: center;
  font-size: 13px;
  font-weight: 700;
  line-height: 1.45;
  letter-spacing: 0.08em;
}
.why-grid { gap: 18px; }
.why-card { padding: 24px 18px; }
.why-card:hover { box-shadow: var(--shadow-md); }

footer { padding: 46px 24px; background: linear-gradient(135deg, #042a48, #064b60); }
.foot-name { font-size: 17px; }
.foot-links { flex-wrap: wrap; gap: 10px 20px; }
.foot-links button { padding: 4px; }

@media (max-width: 980px) {
  .nav-links button { padding-right: 8px; padding-left: 8px; }
  .nav-cta { display: none; }
  .hero { min-height: 670px; }
  .service-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  nav { height: 68px; padding: 0 16px; }
  .page { padding-top: 68px; }
  .logo-mark { width: 38px; height: 38px; }
  .logo-text .en { display: none; }
  .nav-right { gap: 8px; }
  .lang-switch { gap: 2px; }
  nav.menu-open .nav-links { top: 68px; padding: 14px 16px 18px; box-shadow: 0 18px 30px rgba(4, 42, 72, 0.12); }
  nav.menu-open .nav-links button { min-height: 44px; padding: 11px 12px; }
  .hero { min-height: max(650px, 100svh); padding-top: 9rem; }
  .hero h1 { font-size: clamp(39px, 11.5vw, 57px); }
  .hero-desc { font-size: 16px; }
  .stats-bar { margin: -22px 14px 0; border-radius: 16px; }
  .stat { padding: 22px 10px; }
  .service-grid { grid-template-columns: 1fr; }
  .svc { min-height: 0; }
  .case-head, .case-meta, .case-list { padding-right: 20px; padding-left: 20px; }
  .direct-contact-grid { grid-template-columns: 1fr 1fr; }
  .wechat-contact-slot { min-width: 0; }
  .wechat-qr-placeholder { width: 100%; }
}

@media (max-width: 480px) {
  .nav-logo { gap: 9px; }
  .logo-text .cn { font-size: 11px; }
  .lang-option { min-width: 37px; padding-right: 7px; padding-left: 7px; font-size: 11px; }
  .hero-btns { align-items: stretch; flex-direction: column; }
  .hero-btns .btn-solid, .hero-btns .btn-ghost { width: 100%; text-align: center; }
  .stats-bar { margin-right: 10px; margin-left: 10px; }
  .case-head { flex-direction: column; }
  .case-badge { align-self: flex-start; }
  .direct-contact-grid { grid-template-columns: 1fr; }
  .wechat-qr-placeholder { width: min(184px, 100%); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}