/* ============================================
   博惠莱 BHL — 企业官网样式
   主色: #D85A30 (橙金/画册强调色)
   深色: #1a2332 (工业深蓝灰)
   辅助: #f5f6f8 (浅底)
   ============================================ */

/* ---------- RESET & BASE ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  color: #2c3e50;
  line-height: 1.7;
  background: #fff;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { text-decoration: none; color: inherit; transition: color .25s; }
ul { list-style: none; }

/* ---------- LAYOUT ---------- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}
.section { padding: 90px 0; }

/* ---------- SECTION HEADER ---------- */
.section-header { text-align: center; margin-bottom: 56px; }
.section-header.light h2, .section-header.light .sub { color: #fff; }
.tag {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: #D85A30;
  font-weight: 700;
  margin-bottom: 10px;
  position: relative;
  padding: 0 16px;
}
.tag::before, .tag::after {
  content: '';
  position: absolute;
  top: 50%;
  width: 28px;
  height: 1px;
  background: #D85A30;
  opacity: .4;
}
.tag::before { right: 100%; }
.tag::after  { left: 100%; }
.section-header h2 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  letter-spacing: 2px;
  color: #1a2332;
  margin-bottom: 8px;
}
.sub {
  font-size: 15px;
  color: #7a8699;
  letter-spacing: 1px;
}

/* ---------- BUTTONS ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all .3s ease;
  gap: 6px;
}
.btn-primary {
  background: linear-gradient(135deg, #D85A30, #e67e45);
  color: #fff;
  box-shadow: 0 4px 20px rgba(216,90,48,.3);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(216,90,48,.4);
}
.btn-outline {
  border-color: #D85A30;
  color: #D85A30;
  background: transparent;
}
.btn-outline:hover {
  background: #D85A30;
  color: #fff;
}
.btn-sm {
  padding: 8px 22px;
  font-size: 13px;
  border-radius: 6px;
  background: #fff;
  color: #D85A30;
  border: 1.5px solid #D85A30;
}
.btn-sm:hover { background: #D85A30; color: #fff; }
.btn-block { width: 100%; padding: 14px; font-size: 16px; }

/* ========== NAV ========== */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,.06);
  transition: all .35s ease;
}
.nav.scrolled { box-shadow: 0 2px 24px rgba(0,0,0,.08); }
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.logo-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  z-index: 101;
}
.logo-img { height: 38px; width: auto; object-fit: contain; }
.logo-text {
  font-size: 20px;
  font-weight: 800;
  color: #1a2332;
  letter-spacing: 1px;
}
.logo-sub {
  font-size: 11px;
  color: #D85A30;
  font-weight: 700;
  margin-left: 4px;
  vertical-align: super;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}
.nav-links a {
  font-size: 14px;
  font-weight: 500;
  color: #4a5568;
  position: relative;
  padding: 4px 0;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0;
  width: 0; height: 2px;
  background: #D85A30;
  transition: width .3s;
}
.nav-links a:hover { color: #D85A30; }
.nav-links a:hover::after { width: 100%; }
.btn-nav {
  background: #D85A30 !important;
  color: #fff !important;
  padding: 8px 20px;
  border-radius: 6px;
  font-weight: 600;
}
.btn-nav::after { display: none; }
.btn-nav:hover { background: #c04d26 !important; transform: translateY(-1px); }

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 101;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2.5px;
  background: #1a2332;
  border-radius: 2px;
  transition: all .3s;
}
.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ========== HERO ========== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: 68px;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(216,90,48,.08) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 20%, rgba(26,35,50,.05) 0%, transparent 50%),
    linear-gradient(180deg, #fafbfc 0%, #f0f2f5 100%);
  z-index: 0;
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: 720px;
}
.hero-tag {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: #D85A30;
  margin-bottom: 18px;
  padding: 6px 18px;
  border: 1.5px solid rgba(216,90,48,.25);
  border-radius: 30px;
  background: rgba(216,90,48,.04);
}
.hero-title {
  font-size: clamp(36px, 6vw, 58px);
  font-weight: 900;
  line-height: 1.15;
  color: #1a2332;
  margin-bottom: 22px;
  letter-spacing: -0.5px;
}
.hero-title sup { font-size: .5em; color: #D85A30; }
.br-m { display: none; }
@media(min-width:480px){ .br-m{display:inline;} }
.hero-desc {
  font-size: 17px;
  line-height: 1.8;
  color: #5a6577;
  margin-bottom: 34px;
  max-width: 580px;
}
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 52px; }

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  padding-top: 32px;
  border-top: 1px solid rgba(0,0,0,.07);
}
.stat text-align: center;
.stat .num {
  display: block;
  font-size: 32px;
  font-weight: 900;
  color: #D85A30;
  line-height: 1.2;
}
.stat .unit {
  font-size: 18px;
  font-weight: 700;
  color: #D85A30;
}
.stat small {
  display: block;
  font-size: 12px;
  color: #8892a4;
  margin-top: 2px;
}

.hero-scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
}
.hero-scroll i {
  display: block;
  width: 22px;
  height: 34px;
  border: 2px solid #b0b8c8;
  border-radius: 12px;
  position: relative;
}
.hero-scroll i::before {
  content: '';
  position: absolute;
  top: 6px; left: 50%; transform: translateX(-50%);
  width: 4px; height: 8px;
  background: #D85A30;
  border-radius: 2px;
  animation: scrollBounce 1.6s infinite;
}
@keyframes scrollBounce {
  0%,100% { top: 6px; opacity: 1; }
  50% { top: 16px; opacity: .3; }
}

/* ========== ABOUT ========== */
.about { background: #fff; }
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}
.about-text p {
  margin-bottom: 16px;
  font-size: 15px;
  color: #4a5568;
}
.about-text strong { color: #1a2332; }

.about-highlights {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 28px;
}
.hl-item {
  background: #f8f9fb;
  border-radius: 12px;
  padding: 20px 16px;
  text-align: center;
  border: 1px solid #eeeef2;
  transition: transform .3s, box-shadow .3s;
}
.hl-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 28px rgba(0,0,0,.07);
}
.hl-icon {
  font-size: 28px;
  margin-bottom: 8px;
  color: #D85A30;
}
.hl-item strong { font-size: 14px; display: block; margin-bottom: 4px; }
.hl-item div:last-child { font-size: 12px; color: #7a8699; }

.about-timeline {
  background: #1a2332;
  border-radius: 16px;
  padding: 36px 28px;
  color: #e8ecf2;
}
.about-timeline h3 {
  font-size: 18px;
  margin-bottom: 24px;
  color: #D85A30;
  letter-spacing: 1px;
}
.timeline { position: relative; padding-left: 20px; }
.timeline::before {
  content: '';
  position: absolute;
  left: 0; top: 4px; bottom: 4px;
  width: 2px;
  background: linear-gradient(to bottom, #D85A30, #e67e45, transparent);
  border-radius: 1px;
}
.tl-item {
  position: relative;
  padding-left: 20px;
  padding-bottom: 22px;
}
.tl-item:last-child { padding-bottom: 0; }
.tl-item::before {
  content: '';
  position: absolute;
  left: -24px; top: 4px;
  width: 10px; height: 10px;
  background: #D85A30;
  border-radius: 50%;
  border: 2px solid #1a2332;
}
.tl-year {
  display: inline-block;
  font-size: 15px;
  font-weight: 800;
  color: #D85A30;
  margin-right: 8px;
}
.tl-item p {
  font-size: 13px;
  color: #b0b8c8;
  display: inline;
}

/* ========== PRODUCTS ========== */
.products { background: #f8f9fb; }
.product-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.product-card {
  background: #fff;
  border-radius: 14px;
  overflow: hidden;
  border: 1px solid #eaecef;
  transition: transform .35s, box-shadow .35s;
  position: relative;
}
.product-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 48px rgba(0,0,0,.09);
}
.product-card.featured { border-color: rgba(216,90,48,.3); }
.product-card.wide { grid-column: 1 / -1; }

.pc-badge {
  position: absolute;
  top: 14px; left: 14px;
  z-index: 2;
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  color: #fff;
  background: #D85A30;
}
.pc-badge.new { background: #1a2332; }

.pc-img {
  height: 220px;
  background: #f5f6f8;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.pc-img img {
  max-height: 180px;
  object-fit: contain;
  filter: drop-shadow(0 4px 12px rgba(0,0,0,.08));
  transition: transform .4s;
}
.product-card:hover .pc-img img { transform: scale(1.05); }

.pc-body { padding: 24px; }
.pc-body-full { padding: 28px; }
.pc-body h3 {
  font-size: 19px;
  font-weight: 800;
  color: #1a2332;
  margin-bottom: 6px;
}
.pc-model {
  font-size: 13px;
  font-weight: 500;
  color: #D85A30;
  margin-left: 6px;
}
.pc-specs {
  font-size: 13px;
  color: #7a8699;
  margin-bottom: 14px;
  padding: 6px 0;
  border-bottom: 1px solid #f0f2f5;
}
.pc-features {
  margin-bottom: 18px;
}
.pc-features li {
  font-size: 13px;
  color: #555d6b;
  padding: 3px 0;
  padding-left: 16px;
  position: relative;
}
.pc-features li::before {
  content: '\2713';
  position: absolute;
  left: 0;
  color: #D85A30;
  font-weight: 700;
  font-size: 12px;
}

/* NB2500 special layout */
.nb-grid {
  display: grid;
  grid-template-columns: 1.2fr .8fr;
  gap: 28px;
  align-items: start;
}
.nb-diagram { background: #f8f9fb; border-radius: 10px; padding: 20px; }
.diagram-box h4 { font-size: 14px; margin-bottom: 12px; color: #1a2332; }
.wire-table {
  width: 100%; font-size: 13px; border-collapse: collapse;
}
.wire-table th, .wire-table td {
  padding: 6px 12px; border: 1px solid #e0e3e8; text-align: left;
}
.wire-table th { background: #1a2332; color: #fff; font-weight: 500; }
.wire-table td.red { color: #e53e3e; font-weight: 700; }
.wire-table td.black { color: #1a202c; font-weight: 700; }
.wire-table td.white { color: #718096; }
.wire-table td.green { color: #38a169; font-weight: 700; }

/* ========== SPECS ========== */
.specs {
  background: linear-gradient(165deg, #1a2332 0%, #243044 60%, #2d3c54 100%);
  color: #e8ecf2;
}
.specs-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  margin-bottom: 44px;
}
.spec-table-wrap, .compare-table-wrap {
  background: rgba(255,255,255,.05);
  border-radius: 14px;
  padding: 28px;
  border: 1px solid rgba(255,255,255,.08);
}
.spec-table-wrap h3, .compare-table-wrap h3 {
  font-size: 17px;
  margin-bottom: 18px;
  color: #D85A30;
}

.spec-table, .compare-table {
  width: 100%;
  font-size: 13px;
  border-collapse: collapse;
}
.spec-table th, .spec-table td,
.compare-table th, .compare-table td {
  padding: 10px 14px;
  border: 1px solid rgba(255,255,255,.08);
  text-align: left;
}
.spec-table th { background: rgba(216,90,48,.15); color: #D85A30; font-weight: 600; }
.compare-table th { background: rgba(255,255,255,.08); font-weight: 600; }
.compare-table tbody tr:hover { background: rgba(255,255,255,.03); }
.same { color: #8892a4; font-size: 12px; }
.win {
  color: #48bb78;
  font-weight: 700;
  font-size: 12px;
}
.win::before { content: '\2605 '; }

.advantages { margin-top: 20px; }
.advantages h3 {
  text-align: center;
  font-size: 22px;
  margin-bottom: 28px;
  color: #fff;
}
.adv-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.adv-card {
  background: rgba(255,255,255,.05);
  border: 1px solid rgba(255,255,255,.08);
  border-radius: 14px;
  padding: 28px 20px;
  text-align: center;
  transition: transform .3s, background .3s;
}
.adv-card:hover {
  transform: translateY(-4px);
  background: rgba(255,255,255,.08);
}
.adv-num {
  font-size: 36px;
  font-weight: 900;
  color: #D85A30;
  opacity: .6;
  margin-bottom: 10px;
}
.adv-card h4 {
  font-size: 15px;
  margin-bottom: 8px;
  color: #fff;
}
.adv-card p {
  font-size: 13px;
  color: #a0aec0;
  line-height: 1.6;
}

/* ========== CASES ========== */
.cases { background: #fff; }
.case-tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 36px;
}
.case-tab {
  padding: 10px 28px;
  border: 2px solid #e2e5ea;
  border-radius: 30px;
  background: #fff;
  font-size: 14px;
  font-weight: 600;
  color: #5a6577;
  cursor: pointer;
  transition: all .3s;
}
.case-tab.active, .case-tab:hover {
  background: #D85A30;
  border-color: #D85A30;
  color: #fff;
}
.case-panel { display: none; animation: fadeIn .4s ease; }
.case-panel.active { display: block; }
@keyframes fadeIn { from{opacity:0;transform:translateY(10px)} to{opacity:1;transform:none} }

.case-showcase {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px;
  align-items: center;
  background: #f8f9fb;
  border-radius: 16px;
  padding: 36px;
}
.case-img-wrap {
  border-radius: 12px;
  overflow: hidden;
  background: #ebedf0;
}
.case-img-wrap img {
  width: 100%;
  height: auto;
  object-fit: cover;
  transition: transform .5s;
}
.case-img-wrap:hover img { transform: scale(1.03); }
.case-info h3 {
  font-size: 20px;
  color: #1a2332;
  margin-bottom: 12px;
}
.case-info > p {
  font-size: 14px;
  color: #5a6577;
  margin-bottom: 14px;
  line-height: 1.8;
}
.case-info ul { list-style: none; }
.case-info ul li {
  font-size: 13px;
  color: #4a5568;
  padding: 5px 0;
  padding-left: 18px;
  position: relative;
}
.case-info ul li::before {
  content: '\25B6';
  position: absolute;
  left: 0;
  color: #D85A30;
  font-size: 10px;
  top: 9px;
}

/* ========== WORKSHOP ========== */
.workshop {
  background: #f5f6f8;
}
.workshop-gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 28px;
}
.gallery-item.lg { grid-column: span 2; grid-row: span 2; }
.gallery-item {
  border-radius: 12px;
  overflow: hidden;
  background: #ebedf0;
}
.gallery-item img {
  width: 100%;
  height: 100%;
  min-height: 180px;
  object-fit: cover;
  transition: transform .5s;
}
.gallery-item:hover img { transform: scale(1.05); }
.gallery-item figcaption {
  text-align: center;
  font-size: 12px;
  color: #7a8699;
  padding: 8px;
  background: rgba(255,255,255,.8);
}
.workshop-note {
  text-align: center;
  font-size: 13px;
  color: #8892a4;
  max-width: 680px;
  margin: 0 auto;
}

/* ========== CONTACT ========== */
.contact { background: #fff; }
.contact-grid {
  display: grid;
  grid-template-columns: 1.2fr .8fr;
  gap: 40px;
  align-items: start;
}
.contact-form {
  background: #f8f9fb;
  border-radius: 16px;
  padding: 36px;
  border: 1px solid #eaecef;
}
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.form-group { margin-bottom: 18px; }
.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: #3a4556;
  margin-bottom: 6px;
}
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 11px 14px;
  border: 1.5px solid #dde1e8;
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  color: #2c3e50;
  background: #fff;
  transition: border-color .3s, box-shadow .3s;
  outline: none;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: #D85A30;
  box-shadow: 0 0 0 3px rgba(216,90,48,.12);
}
.form-group textarea { resize: vertical; min-height: 100px; }
.form-note {
  text-align: center;
  font-size: 12px;
  color: #8892a4;
  margin-top: 12px;
}

.ci-card {
  background: linear-gradient(145deg, #1a2332, #2a3748);
  border-radius: 16px;
  padding: 36px;
  color: #e8ecf2;
  position: sticky;
  top: 88px;
}
.ci-card h4 {
  font-size: 20px;
  margin-bottom: 4px;
}
.ci-en {
  font-size: 12px;
  color: #8892a4;
  margin-bottom: 22px;
  letter-spacing: .5px;
}
.ci-card dl {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 6px 14px;
  font-size: 14px;
  margin-bottom: 24px;
}
.ci-card dt { color: #8892a4; font-size: 13px; }
.ci-card dd { color: #e8ecf2; }
.ci-card dd.hotline {
  font-size: 22px;
  font-weight: 900;
  color: #D85A30;
  letter-spacing: 1px;
}
.ci-slogan {
  border-top: 1px solid rgba(255,255,255,.1);
  padding-top: 18px;
  font-size: 16px;
  font-weight: 700;
  color: #D85A30;
  line-height: 1.6;
}
.ci-slogan small {
  font-size: 12px;
  color: #8892a4;
  font-weight: 400;
}

/* ========== FOOTER ========== */
.footer {
  background: #111820;
  color: #8892a4;
  padding-top: 56px;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1.2fr 2fr;
  gap: 40px;
  padding-bottom: 36px;
}
.footer-logo { height: 32px; margin-bottom: 12px; }
.footer-brand p { font-size: 13px; margin-bottom: 4px; }
.footer-copy { font-size: 12px; color: #555d6b; margin-top: 12px; }

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.footer-links h5 {
  font-size: 14px;
  color: #e8ecf2;
  margin-bottom: 14px;
  font-weight: 700;
}
.footer-links a {
  display: block;
  font-size: 13px;
  padding: 3px 0;
  color: #7a8699;
  transition: color .2s;
}
.footer-links a:hover { color: #D85A30; }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.06);
  padding: 16px 0;
  text-align: center;
  font-size: 12px;
  color: #555d6b;
}
.footer-bottom a { color: #7a8699; }
.footer-bottom a:hover { color: #D85A30; }

/* ========== RESPONSIVE ========== */
@media(max-width:1024px){
  .hero-stats { grid-template-columns: repeat(2,1fr); }
  .adv-grid { grid-template-columns: repeat(2,1fr); }
  .workshop-gallery { grid-template-columns: repeat(2,1fr); }
  .gallery-item.lg { grid-column: span 1; grid-row: span 1; }
}

@media(max-width:768px){
  .nav-links {
    position: fixed;
    top: 0; right: -100%; width: 78%;
    height: 100vh;
    background: #fff;
    flex-direction: column;
    align-items: stretch;
    padding: 80px 28px 28px;
    gap: 0;
    box-shadow: -4px 0 30px rgba(0,0,0,.12);
    transition: right .35s ease;
    z-index: 99;
  }
  .nav-links.open { right: 0; }
  .nav-links a {
    padding: 14px 0;
    font-size: 16px;
    border-bottom: 1px solid #f0f2f5;
  }
  .btn-nav { margin-top: 12px; text-align: center; }
  .hamburger { display: flex; }

  .about-grid { grid-template-columns: 1fr; }
  .about-timeline { order: -1; }
  .about-highlights { grid-template-columns: 1fr; }

  .product-grid { grid-template-columns: 1fr; }
  .product-card.wide { grid-column: auto; }
  .nb-grid { grid-template-columns: 1fr; }

  .specs-grid { grid-template-columns: 1fr; }
  .adv-grid { grid-template-columns: 1fr 1fr; }

  .case-showcase { grid-template-columns: 1fr; padding: 24px; }
  .case-img-wrap { order: -1; }

  .workshop-gallery { grid-template-columns: 1fr 1fr; }

  .contact-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }

  .footer-inner { grid-template-columns: 1fr; }
  .footer-links { grid-template-columns: repeat(2,1fr); }

  .hero-stats { grid-template-columns: repeat(2,1fr); gap: 12px; }
  .stat .num { font-size: 26px; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; justify-content: center; }
}

@media(max-width:480px){
  .section { padding: 56px 0; }
  .hero-title { font-size: 30px; }
  .hero-desc { font-size: 15px; }
  .adv-grid { grid-template-columns: 1fr; }
  .footer-links { grid-template-columns: 1fr; }
  .workshop-gallery { grid-template-columns: 1fr; }
  .case-tabs { flex-wrap: wrap; }
  .case-tab { font-size: 13px; padding: 8px 18px; }
}

/* ========== ANIMATIONS ========== */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity .6s ease, transform .6s ease;
}
.fade-up.visible {
  opacity: 1;
  transform: none;
}

/* ========== PATENTS ========== */
.patents { background: #fff; }
.patents-intro {
  text-align: center;
  font-size: 15px;
  color: #5a6577;
  max-width: 720px;
  margin: 0 auto 36px;
  line-height: 1.8;
}

.patent-stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin-bottom: 40px;
  padding: 28px;
  background: linear-gradient(135deg, #f8f9fb, #f0f2f5);
  border-radius: 14px;
  border: 1px solid #eaecef;
}
.ps-item {
  text-align: center;
}
.ps-item strong {
  font-size: 32px;
  font-weight: 900;
  color: #D85A30;
}
.ps-item span {
  color: #D85A30;
  font-weight: 700;
  font-size: 16px;
}
.ps-item small {
  display: block;
  font-size: 12px;
  color: #8892a4;
  margin-top: 2px;
}

.patent-tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}
.pt-tab {
  padding: 8px 22px;
  border: 1.5px solid #dde1e8;
  border-radius: 24px;
  background: #fff;
  font-size: 13px;
  font-weight: 600;
  color: #5a6577;
  cursor: pointer;
  transition: all .3s;
}
.pt-tab.active, .pt-tab:hover {
  background: #D85A30;
  border-color: #D85A30;
  color: #fff;
}

.patent-gallery {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.patent-card {
  border-radius: 12px;
  overflow: hidden;
  background: #f8f9fb;
  border: 1px solid #eaecef;
  cursor: pointer;
  transition: transform .35s, box-shadow .35s, opacity .3s;
  position: relative;
}
.patent-card:hover {
  transform: translateY(-6px) scale(1.02);
  box-shadow: 0 14px 40px rgba(0,0,0,.10);
}
.patent-card.hidden {
  opacity: 0;
  transform: scale(0.8);
  pointer-events: none;
  position: absolute;
  visibility: hidden;
}
.patent-card img {
  width: 100%;
  height: 260px;
  object-fit: cover;
  object-position: top center;
  transition: transform .5s;
  filter: drop-shadow(0 2px 6px rgba(0,0,0,.06));
}
.patent-card:hover img { transform: scale(1.06); }

.patent-card figcaption {
  padding: 14px 16px;
  background: #fff;
}
.pcat {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .5px;
  padding: 3px 10px;
  border-radius: 10px;
  margin-bottom: 6px;
}
.sw-tag { background: #ebf5ff; color: #2563eb; }
.patent-tag { background: #fef3c7; color: #b45309; }
.tm-tag { background: #fce7f3; color: #be185d; }
.iso-tag { background: #d1fae5; color: #047857; }

.patent-card h4 {
  font-size: 13px;
  font-weight: 700;
  color: #1a2332;
  margin-bottom: 4px;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.patent-card p {
  font-size: 11px;
  color: #8892a4;
}

/* Lightbox */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: none;
  align-items: center;
  justify-content: center;
}
.lightbox.active { display: flex; }
.lb-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,.82);
  backdrop-filter: blur(8px);
}
.lb-content {
  position: relative;
  z-index: 1;
  max-width: 90vw;
  max-height: 90vh;
  animation: lbIn .3s ease;
}
@keyframes lbIn {
  from { opacity: 0; transform: scale(.92); }
  to { opacity: 1; transform: none; }
}
.lb-img {
  max-width: 80vw;
  max-height: 80vh;
  border-radius: 8px;
  box-shadow: 0 20px 60px rgba(0,0,0,.4);
}
.lb-caption {
  text-align: center;
  color: #e8ecf2;
  font-size: 14px;
  margin-top: 12px;
  padding: 0 20px;
}
.lb-close {
  position: absolute;
  top: -40px; right: 0;
  background: none;
  border: none;
  color: #fff;
  font-size: 32px;
  cursor: pointer;
  width: 40px; height: 40px;
  line-height: 1;
  transition: transform .2s;
}
.lb-close:hover { transform: rotate(90deg); }
.lb-prev, .lb-next {
  position: absolute;
  top: 50%; transform: translateY(-50%);
  background: rgba(255,255,255,.15);
  border: none;
  color: #fff;
  font-size: 24px;
  width: 44px; height: 44px;
  border-radius: 50%;
  cursor: pointer;
  transition: background .2s;
  backdrop-filter: blur(4px);
}
.lb-prev { left: -60px; }
.lb-next { right: -60px; }
.lb-prev:hover, .lb-next:hover { background: rgba(216,90,48,.7); }

@media(max-width:1024px){
  .patent-gallery { grid-template-columns: repeat(3, 1fr); }
  .patent-stats { gap: 24px; flex-wrap: wrap; }
  .lb-prev { left: -50px; }
  .lb-next { right: -50px; }
}
@media(max-width:768px){
  .patent-gallery { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .patent-card img { height: 200px; }
  .patent-stats { gap: 16px; }
  .ps-item strong { font-size: 24px; }
  .lb-prev, .lb-next { display: none; } /* 移动端隐藏左右箭头，用滑动替代 */
  .lb-img { max-width: 95vw; max-height: 75vh; }
}
@media(max-width:480px){
  .patent-gallery { grid-template-columns: 1fr; }
  .patent-tabs { gap: 6px; }
  .pt-tab { font-size: 12px; padding: 6px 16px; }
}