/* ============================================================
   苏州强领技术有限公司官网 — 精密工业 · 浅色高级感
   主色：藏青   强调：工业信号橙   底色：暖纸白
   ============================================================ */
:root {
  --paper: #f7f8f6;
  --tint: #f0f2f4;
  --white: #ffffff;
  --ink: #131920;
  --ink-2: #3d4650;
  --muted: #6d7681;
  --line: #e3e6e9;
  --navy: #0f3465;
  --navy-deep: #0c2a52;
  --orange: #e8590c;
  --radius: 14px;
  --maxw: 1240px;
  --nav-h: 72px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 16px); }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
.wrap { width: min(var(--maxw), calc(100% - 48px)); margin: 0 auto; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-block;
  padding: 14px 36px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 2px;
  transition: transform .25s cubic-bezier(.22,1,.36,1), background .25s, color .25s, border-color .25s, box-shadow .25s;
}
.btn:hover { transform: translateY(-2px); }
.btn-navy { background: var(--navy); color: #fff; }
.btn-navy:hover { background: var(--navy-deep); box-shadow: 0 12px 28px rgba(15, 52, 101, .25); }
.btn-line { border: 1.5px solid rgba(19, 25, 32, .25); color: var(--ink); }
.btn-line:hover { border-color: var(--navy); color: var(--navy); }

/* ---------- 导航 ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s, box-shadow .3s;
}
.nav.scrolled { border-bottom-color: var(--line); box-shadow: 0 6px 24px rgba(19, 25, 32, .06); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: var(--nav-h); }
.brand { display: flex; align-items: center; gap: 12px; }
.brand-logo { height: 40px; width: auto; object-fit: contain; filter: brightness(0) saturate(100%); }
.brand-text { font-size: 16px; font-weight: 700; letter-spacing: 1px; line-height: 1.3; color: var(--ink); }
.brand-text em { display: block; font-style: normal; font-size: 9px; letter-spacing: 2.4px; color: var(--muted); font-weight: 500; }
.nav-links { display: flex; align-items: center; gap: 34px; font-size: 15px; }
.nav-item { position: relative; padding: 26px 0; }
.nav-item > a { color: var(--ink-2); font-weight: 500; position: relative; transition: color .25s; }
.nav-item > a::after {
  content: ""; position: absolute; left: 0; bottom: -8px;
  width: 0; height: 2px; background: var(--orange); transition: width .3s cubic-bezier(.22,1,.36,1);
}
.nav-item > a:hover { color: var(--ink); }
.nav-item > a:hover::after { width: 100%; }
.nav-cta {
  padding: 10px 26px;
  background: var(--navy); color: #fff;
  border-radius: 9px; font-weight: 600; font-size: 14.5px;
  transition: background .25s, transform .25s, box-shadow .25s;
}
.nav-cta:hover { background: var(--navy-deep); transform: translateY(-1px); box-shadow: 0 10px 22px rgba(15, 52, 101, .28); }
.nav-toggle { display: none; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 24px; height: 2px; background: var(--ink); margin: 5px 0; transition: .3s; }

/* 下拉菜单 */
.dropdown {
  position: absolute; top: 100%; left: 50%;
  transform: translate(-50%, 10px);
  min-width: 260px;
  padding: 10px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: 0 24px 56px rgba(19, 25, 32, .12);
  opacity: 0; visibility: hidden;
  transition: opacity .25s ease, transform .25s cubic-bezier(.22,1,.36,1), visibility 0s linear .25s;
  z-index: 60;
}
.nav-item:hover .dropdown, .dropdown:hover {
  opacity: 1; visibility: visible;
  transform: translate(-50%, 0);
  transition: opacity .25s ease, transform .25s cubic-bezier(.22,1,.36,1), visibility 0s;
}
.dropdown a {
  display: block;
  padding: 11px 16px;
  border-radius: 8px;
  transition: background .2s;
}
.dropdown a b { display: block; font-size: 14px; color: var(--ink); font-weight: 600; }
.dropdown a span { display: block; font-size: 12px; color: var(--muted); margin-top: 1px; }
.dropdown a:hover { background: var(--tint); }

/* ---------- 首屏 ---------- */
.hero { padding: calc(var(--nav-h) + 76px) 0 0; }
.hero-grid {
  display: grid;
  grid-template-columns: 1.02fr .98fr;
  gap: 64px;
  align-items: center;
}
.eyebrow {
  color: var(--orange);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 4px;
  margin-bottom: 22px;
}
.eyebrow::before { content: ""; display: inline-block; width: 26px; height: 2px; background: var(--orange); vertical-align: middle; margin-right: 12px; }
.hero h1 {
  font-size: clamp(42px, 5.2vw, 68px);
  line-height: 1.18;
  letter-spacing: 2px;
  font-weight: 800;
  color: var(--ink);
}
.hero h1 em {
  font-style: normal;
  position: relative;
  white-space: nowrap;
}
.hero h1 em::after {
  content: "";
  position: absolute; left: 2%; right: 2%; bottom: 4px;
  height: 12px;
  background: rgba(232, 89, 12, .28);
  z-index: -1;
}
.hero-sub { color: var(--muted); font-size: clamp(15px, 1.4vw, 17px); margin: 26px 0 38px; max-width: 34em; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-figure { position: relative; margin: 0; }
.hero-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  box-shadow: 0 32px 64px rgba(19, 25, 32, .14);
}
.hero-figure figcaption {
  display: inline-flex; align-items: center; gap: 10px;
  margin-top: 16px;
  font-size: 13px; color: var(--muted); letter-spacing: 1px;
}
.hero-figure figcaption::before { content: ""; width: 18px; height: 2px; background: var(--orange); }
/* 工程图纸十字定位标 */
.hero-figure::before, .hero-figure::after {
  content: "+";
  position: absolute;
  font-size: 20px; font-weight: 300;
  color: #b9c0c7;
  line-height: 1;
}
.hero-figure::before { top: -26px; left: -30px; }
.hero-figure::after { bottom: 22px; right: -30px; }

/* 数据条 */
.stats {
  margin-top: 84px;
  display: grid; grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line);
}
.stat { padding: 30px 12px 34px; border-left: 1px solid var(--line); text-align: center; }
.stat:first-child { border-left: 0; }
.stat b {
  display: block;
  font-size: clamp(26px, 2.6vw, 36px);
  font-weight: 800;
  color: var(--navy);
  font-variant-numeric: tabular-nums;
  letter-spacing: .5px;
  line-height: 1.2;
}
.stat span { color: var(--muted); font-size: 13.5px; letter-spacing: 1.5px; }

/* ---------- 通用区块 ---------- */
.section { padding: 112px 0; }
.section-tint { background: var(--tint); }
.sec-head {
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 20px;
  margin-bottom: 64px;
  align-items: start;
}
.sec-num {
  font-size: 14px;
  font-weight: 700;
  color: var(--orange);
  letter-spacing: 3px;
  padding-top: 14px;
  border-top: 2px solid var(--orange);
  font-variant-numeric: tabular-nums;
}
.sec-head h2 {
  font-size: clamp(30px, 3.4vw, 42px);
  letter-spacing: 2px;
  font-weight: 800;
  color: var(--ink);
  line-height: 1.25;
}
.sec-head p:not(.sec-num) { color: var(--muted); margin-top: 12px; max-width: 44em; font-size: 15.5px; }

/* ---------- 01 公司背景 ---------- */
.about-grid {
  display: grid;
  grid-template-columns: .92fr 1.08fr;
  gap: 64px;
  align-items: center;
}
.about-copy h3 { font-size: clamp(24px, 2.4vw, 30px); letter-spacing: 1px; line-height: 1.4; margin-bottom: 18px; }
.about-copy > p { color: var(--muted); font-size: 15px; margin-bottom: 26px; }
.about-list { list-style: none; }
.about-list li {
  border-top: 1px solid var(--line);
  padding: 13px 2px;
  font-size: 15px;
  color: var(--ink-2);
  font-weight: 500;
  display: flex; align-items: center; gap: 14px;
  transition: padding-left .25s, color .25s;
}
.about-list li:last-child { border-bottom: 1px solid var(--line); }
.about-list li::before { content: ""; width: 8px; height: 8px; border: 1.5px solid var(--orange); flex: 0 0 auto; }
.about-list li:hover { padding-left: 10px; color: var(--navy); }
.about-media { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.about-media img {
  width: 100%; height: 100%;
  min-height: 260px; max-height: 420px;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
}
.about-points {
  margin-top: 88px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
}
.point { border-top: 2px solid var(--ink); padding-top: 22px; }
.point-num { font-size: 13px; font-weight: 700; color: var(--orange); letter-spacing: 3px; margin-bottom: 10px; font-variant-numeric: tabular-nums; }
.point h4 { font-size: 17.5px; letter-spacing: 1px; margin-bottom: 8px; }
.point p { color: var(--muted); font-size: 14px; }

/* ---------- 02 产品中心 ---------- */
.prod {
  display: grid;
  grid-template-columns: .88fr 1.12fr;
  gap: 60px;
  padding: 72px 0;
  border-top: 1px solid var(--line);
  align-items: center;
}
.prod:first-of-type { border-top: 0; padding-top: 8px; }
.prod-flip .prod-media { order: 2; }
.prod-flip .prod-body { order: 1; }
.prod-media {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px 28px;
  display: flex;
  gap: 18px;
  align-items: center;
  justify-content: center;
}
.prod-media img {
  flex: 1 1 0;
  min-width: 0;
  max-height: 280px;
  object-fit: contain;
}
.prod-tag { color: var(--orange); font-size: 13px; font-weight: 700; letter-spacing: 3px; margin-bottom: 10px; }
.prod-body h3 { font-size: clamp(23px, 2.3vw, 29px); letter-spacing: 1px; margin-bottom: 12px; }
.prod-desc { color: var(--muted); font-size: 15px; margin-bottom: 24px; }
.prod-range { list-style: none; display: grid; grid-template-columns: 1fr 1fr; gap: 8px 32px; margin-bottom: 22px; }
.prod-range li {
  display: flex; align-items: baseline; justify-content: space-between; gap: 12px;
  border-bottom: 1px dashed var(--line);
  padding: 7px 0;
}
.prod-range b { font-size: 13.5px; color: var(--ink-2); font-weight: 600; white-space: nowrap; }
.prod-range span { font-size: 14.5px; font-weight: 700; color: var(--navy); font-variant-numeric: tabular-nums; white-space: nowrap; }

/* 参数折叠面板 */
.specs {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  overflow: hidden;
}
.specs summary {
  list-style: none;
  cursor: pointer;
  padding: 13px 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  display: flex; align-items: center; justify-content: space-between;
  user-select: none;
  transition: background .2s;
}
.specs summary::-webkit-details-marker { display: none; }
.specs summary::after {
  content: "+";
  font-size: 18px; font-weight: 400;
  color: var(--orange);
  transition: transform .3s;
}
.specs[open] summary::after { transform: rotate(45deg); }
.specs summary:hover { background: var(--tint); }
.specs .table-note { padding: 0 18px 14px; }
.specs table { width: 100%; border-collapse: collapse; font-size: 13px; border-top: 1px solid var(--line); }
.specs th, .specs td { border-bottom: 1px solid var(--line); padding: 9px 18px; text-align: left; vertical-align: top; }
.specs th { background: #f6f8fa; color: var(--navy); font-weight: 600; white-space: nowrap; }
.specs td { color: var(--ink-2); }
.specs tr:last-child th, .specs tr:last-child td { border-bottom: 0; }
.table-note { color: var(--muted); font-size: 12px; padding-top: 10px; line-height: 1.7; }

.prod-link {
  display: inline-flex; align-items: center; gap: 8px;
  margin-top: 26px;
  font-size: 14.5px; font-weight: 700;
  color: var(--navy);
  border-bottom: 2px solid var(--orange);
  padding-bottom: 4px;
  transition: gap .25s;
}
.prod-link:hover { gap: 14px; }
.prod-link i { font-style: normal; }

/* ---------- 03 技术优势 ---------- */
.tech-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0 52px;
}
.tech-item { border-top: 1px solid var(--line); padding: 30px 0 40px; }
.tech-num {
  font-size: 44px;
  font-weight: 800;
  color: transparent;
  -webkit-text-stroke: 1.2px #b9c1c9;
  line-height: 1;
  margin-bottom: 18px;
  font-variant-numeric: tabular-nums;
}
.tech-item h4 { font-size: 18px; letter-spacing: 1px; margin-bottom: 8px; }
.tech-item p { color: var(--muted); font-size: 14px; }
.tech-cta {
  margin-top: 72px;
  background: var(--navy);
  border-radius: 16px;
  padding: 44px 52px;
  display: flex; align-items: center; justify-content: space-between; gap: 36px;
}
.tech-cta h3 { color: #fff; font-size: 22px; letter-spacing: 2px; margin-bottom: 6px; }
.tech-cta p { color: rgba(255, 255, 255, .68); font-size: 14.5px; max-width: 36em; }
.tech-cta .btn { background: #fff; color: var(--navy); flex: 0 0 auto; }
.tech-cta .btn:hover { background: var(--orange); color: #fff; box-shadow: 0 12px 28px rgba(0, 0, 0, .25); }

/* ---------- 04 应用场景 ---------- */
.app-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.app-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform .3s cubic-bezier(.22,1,.36,1), box-shadow .3s;
}
.app-card:hover { transform: translateY(-6px); box-shadow: 0 24px 48px rgba(19, 25, 32, .12); }
.app-card img { width: 100%; height: 200px; object-fit: cover; transition: transform .5s cubic-bezier(.22,1,.36,1); }
.app-card:hover img { transform: scale(1.05); }
.app-body { padding: 20px 22px 24px; }
.app-body h3 { font-size: 17px; letter-spacing: 1px; margin-bottom: 7px; position: relative; padding-bottom: 10px; }
.app-body h3::after { content: ""; position: absolute; left: 0; bottom: 0; width: 22px; height: 2px; background: var(--orange); }
.app-body p { color: var(--muted); font-size: 13.5px; margin-top: 10px; }

/* ---------- 05 合作客户 ---------- */
#clients { padding-bottom: 120px; }
.logo-marquee {
  overflow: hidden;
  padding: 34px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  -webkit-mask: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
  mask: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
}
.logo-track {
  display: flex;
  align-items: center;
  gap: clamp(56px, 6vw, 92px);
  width: max-content;
  animation: marquee 34s linear infinite;
}
.logo-marquee:hover .logo-track { animation-play-state: paused; }
@keyframes marquee { to { transform: translateX(-50%); } }
.logo-track img {
  height: 44px; width: auto;
  object-fit: contain;
  filter: grayscale(1);
  opacity: .68;
  mix-blend-mode: multiply;
  transition: filter .3s, opacity .3s, transform .3s;
}
.logo-track img:hover { filter: grayscale(0); opacity: 1; transform: scale(1.06); }

/* ---------- 06 联系我们 ---------- */
.contact { background: var(--navy-deep); padding: 116px 0; }
.contact-inner { text-align: center; }
.contact-num {
  display: inline-block;
  font-size: 13px; font-weight: 700; letter-spacing: 3px;
  color: var(--orange);
  border-top: 2px solid var(--orange);
  padding-top: 10px;
  margin-bottom: 20px;
  font-variant-numeric: tabular-nums;
}
.contact h2 { color: #fff; font-size: clamp(30px, 3.6vw, 44px); letter-spacing: 3px; }
.contact-sub { color: rgba(255, 255, 255, .6); margin-top: 14px; font-size: 15px; }
.contact-row {
  margin-top: 56px;
  display: inline-flex;
  border: 1px solid rgba(255, 255, 255, .18);
  border-radius: 14px;
  overflow: hidden;
  background: rgba(255, 255, 255, .03);
}
.contact-item { padding: 28px 44px; border-left: 1px solid rgba(255, 255, 255, .14); }
.contact-item:first-child { border-left: 0; }
.contact-item b {
  display: block;
  font-size: 12px; font-weight: 600;
  color: rgba(255, 255, 255, .5);
  letter-spacing: 3px;
  margin-bottom: 6px;
}
.contact-item span { font-size: 17px; color: #fff; font-variant-numeric: tabular-nums; }
.contact-item a { transition: color .25s; }
.contact-item a:hover { color: #ffa06b; }

/* ---------- 页脚 ---------- */
.footer { background: #081e38; padding-top: 72px; }
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 48px;
}
.f-brand img { height: 46px; width: auto; object-fit: contain; margin-bottom: 14px; }
.f-name { color: #fff; font-size: 15.5px; font-weight: 700; letter-spacing: 1px; }
.f-slogan { color: rgba(255, 255, 255, .45); font-size: 12.5px; letter-spacing: 2px; margin-top: 5px; }
.f-col h5 {
  color: #fff;
  font-size: 13.5px; letter-spacing: 2.5px;
  margin-bottom: 18px;
  padding-bottom: 10px;
  position: relative;
}
.f-col h5::after { content: ""; position: absolute; left: 0; bottom: 0; width: 22px; height: 2px; background: var(--orange); }
.f-col a {
  display: block;
  color: rgba(255, 255, 255, .58);
  font-size: 13.5px;
  padding: 5px 0;
  transition: color .25s, padding-left .25s;
}
.f-col a:hover { color: #fff; padding-left: 6px; }
.footer-copy {
  margin-top: 60px;
  padding: 26px 0;
  border-top: 1px solid rgba(255, 255, 255, .1);
  text-align: center;
  color: rgba(255, 255, 255, .38);
  font-size: 12.5px;
  letter-spacing: 1px;
}

/* ---------- 滚动显现 ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .8s cubic-bezier(.22,1,.36,1), transform .8s cubic-bezier(.22,1,.36,1); }
.reveal.visible { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
  .nav-links { gap: 22px; font-size: 14px; }
  .app-grid { grid-template-columns: 1fr 1fr; }
  .tech-list { grid-template-columns: 1fr 1fr; gap: 0 44px; }
}
@media (max-width: 920px) {
  .hero-grid, .about-grid { grid-template-columns: 1fr; gap: 44px; }
  .hero-figure::before, .hero-figure::after { display: none; }
  .prod, .prod-flip { grid-template-columns: 1fr; gap: 32px; padding: 56px 0; }
  .prod-flip .prod-media { order: 1; }
  .prod-flip .prod-body { order: 2; }
  .about-points { grid-template-columns: 1fr; gap: 28px; margin-top: 56px; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat:nth-child(3) { border-left: 0; }
  .stat { border-top: 1px solid var(--line); }
  .stat:nth-child(-n+2) { border-top: 0; }
  .tech-cta { flex-direction: column; align-items: flex-start; padding: 36px; }
}
@media (max-width: 720px) {
  .section { padding: 76px 0; }
  .hero { padding-top: calc(var(--nav-h) + 48px); }
  .sec-head { grid-template-columns: 1fr; gap: 8px; margin-bottom: 40px; }
  .sec-num { padding-top: 0; border-top: 0; }
  .nav-links {
    position: fixed; top: var(--nav-h); right: 0; left: 0;
    flex-direction: column;
    align-items: stretch;
    background: #fff;
    padding: 18px 24px 28px;
    gap: 4px;
    border-bottom: 1px solid var(--line);
    box-shadow: 0 24px 48px rgba(19, 25, 32, .12);
    transform: translateY(-130%);
    transition: transform .35s cubic-bezier(.22,1,.36,1);
    overflow-y: auto;
    max-height: calc(100vh - var(--nav-h));
  }
  .nav-links.open { transform: none; }
  .nav-item { padding: 0; border-bottom: 1px solid var(--line); }
  .nav-item > a { display: block; padding: 14px 0; font-size: 15.5px; }
  .nav-item > a::after { display: none; }
  .dropdown {
    position: static;
    transform: none;
    opacity: 1; visibility: visible;
    border: 0; box-shadow: none;
    padding: 0 0 12px;
    min-width: 0;
  }
  .dropdown a { padding: 6px 0 6px 14px; border-left: 2px solid var(--line); border-radius: 0; }
  .dropdown a b { font-size: 13.5px; font-weight: 500; display: inline; }
  .dropdown a span { display: none; }
  .nav-cta { display: block; text-align: center; margin-top: 18px; }
  .nav-toggle { display: block; }
  .stats { grid-template-columns: 1fr 1fr; }
  .app-grid, .tech-list { grid-template-columns: 1fr; }
  .tech-item { padding-bottom: 28px; }
  .prod-range { grid-template-columns: 1fr; }
  .about-media { grid-template-columns: 1fr; }
  .about-media img { min-height: 0; height: auto; }
  .contact-row { display: grid; grid-template-columns: 1fr 1fr; }
  .contact-item { border-left: 0; border-top: 1px solid rgba(255, 255, 255, .14); padding: 20px 16px; }
  .contact-item:nth-child(-n+2) { border-top: 0; }
  .contact-item:nth-child(even) { border-left: 1px solid rgba(255, 255, 255, .14); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 36px; }
}
@media (max-width: 400px) {
  .btn { padding: 13px 26px; font-size: 14px; }
  .contact-row { grid-template-columns: 1fr; }
  .contact-item { border-left: 0 !important; }
}
/* 动效降级 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .logo-track { animation: none; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn, .app-card, .app-card img { transition: none; }
}