/* ============================================================
   郑州市观途物联网科技有限公司
   设计：简约清新 · 现代科技
   ============================================================ */

:root {
  --primary: #1e3a5f;
  --blue: #2563eb;
  --blue-light: #3b82f6;
  --accent: #0ea5e9;
  --white: #fff;
  --bg: #f8fafc;
  --bg-light: #f1f5f9;
  --border: #e2e8f0;
  --text: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,.06);
  --shadow-lg: 0 12px 32px rgba(0,0,0,.08);
  --transition: .25s ease;
  --max-width: 1200px;
  --header-h: 68px;
}

*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
ul, ol { list-style: none; }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* ---------- Section ---------- */
.section { padding: 96px 0; }

.section-header { text-align: center; margin-bottom: 56px; }

.section-tag {
  font-size: .8rem;
  font-weight: 600;
  color: var(--blue);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 12px;
}

.section-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: #1e3a5f;
  border-bottom: 1px solid rgba(255,255,255,.1);
  height: var(--header-h);
  display: flex;
  align-items: center;
}

.site-header.scrolled { box-shadow: 0 4px 24px rgba(0,0,0,.3); }

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

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

.logo-icon {
  width: 38px;
  height: 38px;
  background: var(--blue);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-size: 1rem;
}

.logo-text h1 { font-size: 1.1rem; font-weight: 700; color: #fff; line-height: 1.2; }
.logo-text small { font-size: .65rem; color: rgba(255,255,255,.5); letter-spacing: 1px; }

.nav-links { display: flex; align-items: center; gap: 32px; }

.nav-links a {
  font-size: .9rem;
  font-weight: 500;
  color: rgba(255,255,255,.65);
  transition: var(--transition);
  padding: 6px 0;
  border-bottom: 2px solid transparent;
}

.nav-links a:hover,
.nav-links a.active {
  color: #fff;
  border-bottom-color: var(--blue);
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 6px;
  border: none;
  background: none;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
  transition: var(--transition);
}

.menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 11px 26px;
  font-size: .9rem;
  font-weight: 600;
  border-radius: 6px;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}

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

.btn-primary:hover {
  background: #1d4ed8;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37,99,235,.3);
}

.btn-outline {
  border: 1.5px solid var(--border);
  color: var(--text);
  background: var(--white);
}

.btn-outline:hover {
  border-color: var(--blue);
  color: var(--blue);
}

.btn-white {
  background: var(--white);
  color: var(--primary);
  font-weight: 600;
}

.btn-white:hover { transform: translateY(-1px); box-shadow: var(--shadow-md); }

.btn-lg { padding: 14px 32px; font-size: .95rem; }

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(160deg, #f0f7ff 0%, #e8f4fd 50%, #f8fafc 100%);
  padding: 0;
  display: flex;
  align-items: center;
  min-height: 560px;
}

.hero .container {
  display: flex;
  align-items: center;
  width: 100%;
}

.hero-content h2 {
  font-size: 2.8rem;
  font-weight: 800;
  line-height: 1.2;
  color: var(--primary);
  margin-bottom: 16px;
}

.hero-content h2 .hl {
  color: var(--blue);
}

.hero-content p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 32px;
  max-width: 460px;
}

.hero-btns { display: flex; gap: 12px; flex-wrap: wrap; }


/* ---------- Stats ---------- */
.stats-strip {
  border-bottom: 1px solid var(--border);
}

.stats-strip .container {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}

.stat-item {
  text-align: center;
  padding: 36px 20px;
  border-right: 1px solid var(--bg-light);
}

.stat-item:last-child { border-right: none; }

.stat-number {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--blue);
  line-height: 1;
}

.stat-number .unit { font-size: 1rem; font-weight: 400; }

.stat-label { font-size: .85rem; color: var(--text-muted); margin-top: 6px; }

/* ---------- Service Cards ---------- */
.service-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.service-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  transition: var(--transition);
}

.service-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: #cbd5e1;
}

.service-card .card-icon {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  background: #eff6ff;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.service-card .card-icon svg {
  width: 24px;
  height: 24px;
  stroke: var(--blue);
  fill: none;
  stroke-width: 1.8;
}

.service-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
}

.service-card p {
  font-size: .88rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ---------- Advantage ---------- */
.advantage-section {
  background: var(--bg);
}

.advantage-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.advantage-item {
  display: flex;
  gap: 18px;
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px;
  border: 1px solid var(--border);
  transition: var(--transition);
}

.advantage-item:hover {
  box-shadow: var(--shadow-md);
}

.advantage-num {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: #eff6ff;
  color: var(--blue);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
}

.advantage-info h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}

.advantage-info p {
  font-size: .88rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ---------- Case Cards ---------- */
.case-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.case-card {
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
  border: 1px solid var(--border);
  transition: var(--transition);
}

.case-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.case-thumb {
  height: 200px;
  background: var(--bg);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.case-thumb img { width: 100%; height: 100%; object-fit: cover; }

.case-thumb .case-tag {
  position: absolute;
  top: 14px;
  left: 14px;
  background: rgba(37,99,235,.9);
  color: #fff;
  padding: 3px 12px;
  border-radius: 4px;
  font-size: .75rem;
  font-weight: 600;
}

.case-thumb-bg {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #eff6ff, #dbeafe);
}

.case-thumb-bg svg {
  width: 56px;
  height: 56px;
  stroke: var(--blue);
  fill: none;
  stroke-width: 1.2;
  opacity: .5;
}

.case-body { padding: 22px; }

.case-body h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 6px;
}

.case-body p {
  font-size: .85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ---------- CTA ---------- */
.cta-banner {
  background: var(--primary);
  padding: 72px 0;
  text-align: center;
}

.cta-banner h2 { color: #fff; font-size: 2rem; font-weight: 700; margin-bottom: 12px; }

.cta-banner p { color: rgba(255,255,255,.7); font-size: 1rem; margin-bottom: 32px; }

/* ---------- Page Banner ---------- */
.page-banner {
  background: linear-gradient(160deg, #f0f7ff, #e8f4fd);
  padding: 64px 0;
  text-align: center;
}

.page-banner h2 { color: var(--primary); font-size: 2.2rem; font-weight: 800; margin-bottom: 8px; }

.breadcrumb { color: var(--text-muted); font-size: .88rem; }

.breadcrumb a { color: var(--blue); }

.breadcrumb span { margin: 0 6px; }

/* ---------- About ---------- */
.about-intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}

.about-image {
  border-radius: var(--radius);
  overflow: hidden;
  background: linear-gradient(135deg, #eff6ff, #dbeafe);
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
}

.about-image .placeholder-text { text-align: center; }
.about-image .placeholder-text .pi { font-size: 3rem; margin-bottom: 12px; }

.about-text h3 {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 16px;
}

.about-text p {
  color: var(--text-secondary);
  margin-bottom: 14px;
  line-height: 1.75;
}

/* Timeline */
.timeline {
  position: relative;
  padding-left: 32px;
  max-width: 640px;
  margin: 0 auto;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 11px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border);
}

.timeline-item { position: relative; margin-bottom: 32px; padding-left: 32px; }

.timeline-item::before {
  content: '';
  position: absolute;
  left: -25px;
  top: 4px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--white);
  border: 3px solid var(--blue);
}

.timeline-year {
  font-size: .82rem;
  font-weight: 700;
  color: var(--blue);
  margin-bottom: 2px;
}

.timeline-title { font-size: 1.05rem; font-weight: 700; color: var(--primary); margin-bottom: 2px; }

.timeline-desc { font-size: .88rem; color: var(--text-secondary); }

/* ---------- Business ---------- */
.business-category { margin-bottom: 56px; }

.business-cat-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 24px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
}

.business-cat-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: #eff6ff;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.business-cat-icon svg {
  width: 22px;
  height: 22px;
  stroke: var(--blue);
  fill: none;
  stroke-width: 1.8;
}

.business-cat-header h3 { font-size: 1.3rem; font-weight: 700; color: var(--primary); }

.business-items { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }

.business-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 20px;
  background: var(--bg);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--blue);
  transition: var(--transition);
}

.business-item:hover { background: #fff; box-shadow: var(--shadow); }

.business-item .bi-icon svg {
  width: 18px;
  height: 18px;
  stroke: var(--blue);
  fill: none;
  stroke-width: 2;
  flex-shrink: 0;
  margin-top: 2px;
}

.business-item .bi-content h5 {
  font-size: .95rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 3px;
}

.business-item .bi-content p {
  font-size: .84rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ---------- Products ---------- */
.product-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }

.product-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
}

.product-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }

.product-thumb {
  height: 160px;
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
}

.product-thumb-bg {
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #eff6ff;
  border-radius: 50%;
}

.product-thumb-bg svg {
  width: 30px;
  height: 30px;
  stroke: var(--blue);
  fill: none;
  stroke-width: 1.5;
}

.product-body { padding: 18px; }

.product-body h4 { font-size: .95rem; font-weight: 700; color: var(--primary); margin-bottom: 6px; }

.product-body p { font-size: .82rem; color: var(--text-secondary); line-height: 1.55; margin-bottom: 10px; }

.product-tags { display: flex; flex-wrap: wrap; gap: 5px; }

.product-tags span {
  font-size: .7rem;
  padding: 2px 8px;
  background: #eff6ff;
  color: var(--blue);
  border-radius: 4px;
}

/* ---------- Case Filter ---------- */
.case-filter { display: flex; justify-content: center; gap: 10px; margin-bottom: 36px; flex-wrap: wrap; }

.case-filter button {
  padding: 7px 20px;
  border: 1px solid var(--border);
  background: var(--white);
  border-radius: 20px;
  font-size: .85rem;
  cursor: pointer;
  transition: var(--transition);
  color: var(--text-secondary);
}

.case-filter button:hover,
.case-filter button.active {
  background: var(--blue);
  color: #fff;
  border-color: var(--blue);
}

/* ---------- Contact ---------- */
.contact-layout { display: grid; grid-template-columns: 1fr 1.2fr; gap: 40px; }

.contact-info-cards { display: flex; flex-direction: column; gap: 14px; }

.contact-info-card {
  display: flex;
  gap: 14px;
  padding: 20px;
  background: var(--bg);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.contact-info-card:hover { background: #fff; box-shadow: var(--shadow); }

.contact-icon {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: #eff6ff;
  display: flex;
  align-items: center;
  justify-content: center;
}

.contact-icon svg { width: 20px; height: 20px; stroke: var(--blue); fill: none; stroke-width: 1.8; }

.contact-detail h5 { font-size: .95rem; font-weight: 700; color: var(--primary); margin-bottom: 2px; }

.contact-detail p { font-size: .84rem; color: var(--text-secondary); }

.contact-form-wrap {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
}

.contact-form-wrap h3 { font-size: 1.4rem; font-weight: 700; color: var(--primary); margin-bottom: 6px; }

.contact-form-wrap > p { color: var(--text-secondary); margin-bottom: 24px; font-size: .88rem; }

.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }

.form-group { margin-bottom: 14px; }

.form-group label {
  display: block;
  font-size: .84rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 5px;
}

.form-group .required { color: #ef4444; }

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: .9rem;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
  transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(37,99,235,.1);
  background: var(--white);
}

.form-group textarea { resize: vertical; min-height: 110px; }

.form-submit { text-align: right; }

.has-error input,
.has-error select,
.has-error textarea { border-color: #ef4444 !important; }

/* ---------- Map ---------- */
.map-placeholder {
  width: 100%;
  height: 280px;
  background: var(--bg);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: .88rem;
  margin-top: 40px;
  border: 1px solid var(--border);
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--primary);
  color: rgba(255,255,255,.65);
  padding: 56px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 36px;
  padding-bottom: 36px;
  border-bottom: 1px solid rgba(255,255,255,.1);
}

.footer-about h3 { color: #fff; font-size: 1.15rem; margin-bottom: 14px; }

.footer-about p { font-size: .84rem; line-height: 1.7; margin-bottom: 14px; }

.footer-col h4 { color: #fff; font-size: .95rem; font-weight: 600; margin-bottom: 16px; }

.footer-col ul li { margin-bottom: 10px; }

.footer-col ul li a { font-size: .84rem; transition: var(--transition); }

.footer-col ul li a:hover { color: #fff; padding-left: 3px; }

.footer-qr {
  width: 88px;
  height: 88px;
  background: rgba(255,255,255,.05);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .65rem;
  color: rgba(255,255,255,.3);
  text-align: center;
}

.footer-bottom {
  padding: 20px 0;
  text-align: center;
  font-size: .78rem;
  color: rgba(255,255,255,.4);
}

/* ---------- Back to Top ---------- */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 40px;
  height: 40px;
  border-radius: 8px;
  background: var(--white);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 1.1rem;
  box-shadow: var(--shadow);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: var(--transition);
  z-index: 99;
  display: flex;
  align-items: center;
  justify-content: center;
}

.back-to-top.visible { opacity: 1; visibility: visible; transform: translateY(0); }

.back-to-top:hover { border-color: var(--blue); color: var(--blue); }

/* ---------- Animations ---------- */
.fade-in-up {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .5s ease, transform .5s ease;
}

.fade-in-up.revealed { opacity: 1; transform: translateY(0); }

/* Toast */
.toast {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: #10b981;
  color: #fff;
  padding: 12px 24px;
  border-radius: 8px;
  font-weight: 600;
  font-size: .9rem;
  z-index: 9999;
  box-shadow: 0 8px 24px rgba(16,185,129,.25);
  animation: toastIn .3s ease, toastOut .3s ease 2.5s forwards;
}

@keyframes toastIn { from { opacity: 0; transform: translateX(-50%) translateY(-12px); } to { opacity: 1; transform: translateX(-50%) translateY(0); } }
@keyframes toastOut { from { opacity: 1; transform: translateX(-50%) translateY(0); } to { opacity: 0; transform: translateX(-50%) translateY(-12px); } }

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .service-grid, .case-grid { grid-template-columns: repeat(2, 1fr); }
  .product-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero-content h2 { font-size: 2.2rem; }
  .advantage-grid { grid-template-columns: 1fr; }
  .contact-layout { grid-template-columns: 1fr; }
  .about-intro { grid-template-columns: 1fr; }
  .about-image { height: 300px; }
  .stats-strip .container { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .section { padding: 64px 0; }
  .section-title { font-size: 1.7rem; }
  .hero { min-height: auto; padding: 72px 0; }
  .hero-content h2 { font-size: 1.7rem; }
  .hero-btns { flex-direction: column; }
  .hero-btns .btn { justify-content: center; }

  .menu-toggle { display: flex; }
  .nav-links {
    position: fixed;
    top: var(--header-h);
    left: 0;
    width: 100%;
    background: #1e3a5f;
    flex-direction: column;
    gap: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height .35s ease;
    box-shadow: 0 8px 24px rgba(0,0,0,.3);
  }
  .nav-links.open { max-height: 440px; }
  .nav-links a { padding: 14px 24px; border-bottom: 1px solid rgba(255,255,255,.08); color: rgba(255,255,255,.7); }
  .nav-links a:hover,
  .nav-links a.active { color: #fff; border-bottom-color: rgba(255,255,255,.08); }

  .service-grid, .case-grid, .business-items, .product-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .contact-form-wrap { padding: 24px; }
  .stats-strip .container { grid-template-columns: repeat(2, 1fr); }
  .stat-number { font-size: 1.8rem; }
  .page-banner h2 { font-size: 1.8rem; }
}