*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0
}

html {
  scroll-behavior: smooth
}

body {
  font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
  color: #333;
  line-height: 1.6;
  overflow-x: hidden
}

a {
  text-decoration: none;
  color: inherit
}

img {
  max-width: 100%;
  display: block
}

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px
}

:root {
  --primary: #1a5490;
  --primary-dark: #0d2f4f;
  --primary-light: #2874a6;
  --accent: #e67e22;
  --dark: #0d1b2a;
  --dark-2: #1b2838;
  --gray: #666;
  --gray-light: #f5f6f8;
  --border: #e0e0e0;
  --text: #333;
  --white: #fff;
}

/* ===== NAVIGATION ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(13, 27, 42, .95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(255, 255, 255, .1);
  transition: all .3s
}

.nav.scrolled {
  box-shadow: 0 2px 20px rgba(0, 0, 0, .3)
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  max-width: 100%;
  padding: 0 200px;
  position: relative
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  color: #fff;
  font-weight: 700;
  font-size: 18px
}

.logo-img {
  height: 62px;
  width: auto;
  flex-shrink: 0;
  border-radius: 6px;
  display: block
}

.logo-text {
  line-height: 1.2
}

.logo-cn {
  font-size: 14px;
  font-weight: 400;
  color: #aaa;
  letter-spacing: 1px
}

.menu {
  display: flex;
  list-style: none;
  gap: 4px;
  position: absolute;
  left: 50%;
  transform: translateX(-50%)
}

.menu a {
  color: #ddd;
  padding: 10px 16px;
  border-radius: 4px;
  font-size: 14px;
  font-weight: 500;
  transition: all .2s;
  display: inline-block
}

.menu a:hover {
  color: #fff;
  background: rgba(255, 255, 255, .08)
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 12px
}

.lang-toggle {
  display: flex;
  background: rgba(255, 255, 255, .1);
  border-radius: 4px;
  overflow: hidden
}

.lang-toggle button {
  background: none;
  border: none;
  color: #ccc;
  padding: 8px 12px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all .2s
}

.lang-toggle button.active {
  background: var(--primary);
  color: #fff
}

.mobile-btn {
  display: none;
  background: none;
  border: none;
  color: #fff;
  font-size: 24px;
  cursor: pointer
}

.menu-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, .5);
  z-index: 998;
  opacity: 0;
  transition: opacity .3s
}

.menu-overlay.show {
  display: block;
  opacity: 1
}

/* ===== MEGA MENU ===== */
.has-mega {
  position: relative
}

.mega {
  position: fixed;
  top: 100%;
  left: 50%;
  padding-top: 20px;
  opacity: 0;
  visibility: hidden;
  transform: translateX(-50%) translateY(10px);
  transition: all .25s ease;
  z-index: 1001
}

.has-mega:hover .mega {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0)
}

.mega-panel {
  width: 960px;
  max-width: calc(100vw - 48px);
  background: var(--dark);
  border: 1px solid rgba(255, 255, 255, .1);
  border-top: 3px solid var(--accent);
  border-radius: 2px;
  box-shadow: 0 24px 60px rgba(0, 0, 0, .5);
  padding: 24px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px 16px
}

.menu a.mega-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px;
  border: 1px solid transparent;
  border-radius: 2px;
  color: #ddd;
  transition: all .3s
}

.menu a.mega-item:hover {
  background: rgba(255, 255, 255, .06);
  border-color: var(--primary-light);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, .35)
}

.mega-item img {
  width: 64px;
  height: 64px;
  object-fit: cover;
  border-radius: 2px;
  flex-shrink: 0;
  background: var(--dark-2)
}

.mega-item-title {
  font-size: 14px;
  font-weight: 700;
  color: #fff
}

.mega-item-desc {
  font-size: 12px;
  color: #8a9bb0;
  margin-top: 3px;
  line-height: 1.55
}

.mega-item-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: 7px
}

.mega-tag {
  font-size: 10px;
  line-height: 1;
  padding: 4px 6px;
  border: 1px solid rgba(255, 255, 255, .15);
  border-radius: 2px;
  color: #9fb2c7;
  background: rgba(255, 255, 255, .05);
  white-space: nowrap
}

/* ===== PAGE HERO ===== */
.page-hero {
  padding: 170px 0 90px;
  color: #fff;
  background-color: var(--dark)
}

.breadcrumb {
  font-size: 13px;
  color: rgba(255, 255, 255, .55);
  margin-bottom: 26px;
  letter-spacing: .5px
}

.breadcrumb a {
  color: rgba(255, 255, 255, .75);
  transition: color .2s
}

.breadcrumb a:hover {
  color: var(--accent)
}

.page-hero h1 {
  font-size: clamp(30px, 4.5vw, 48px);
  font-weight: 800;
  margin-bottom: 22px;
  letter-spacing: -.5px
}

.hero-lead {
  font-size: clamp(16px, 2vw, 20px);
  font-weight: 600;
  color: #fff;
  max-width: 840px;
  margin-bottom: 22px
}

.hero-sub {
  color: rgba(255, 255, 255, .78);
  max-width: 840px;
  font-size: 16px;
  margin-bottom: 12px
}

.hero-actions {
  margin-top: 38px
}

.btn {
  display: inline-block;
  padding: 14px 32px;
  background: var(--accent);
  color: #fff;
  border-radius: 2px;
  font-weight: 600;
  font-size: 14px;
  letter-spacing: 1px;
  text-transform: uppercase;
  transition: all .3s;
  border: none;
  cursor: pointer
}

.btn:hover {
  background: #d35400;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(230, 126, 34, .4)
}

.btn-outline {
  background: transparent;
  border: 2px solid #fff;
  color: #fff;
  margin-left: 12px
}

.btn-outline:hover {
  background: #fff;
  color: var(--dark)
}

/* ===== SECTION BASICS ===== */
.section-sub {
  font-size: 13px;
  color: var(--primary);
  letter-spacing: 3px;
  text-transform: uppercase;
  font-weight: 700;
  margin-bottom: 16px
}

.section-title {
  font-size: clamp(26px, 3.5vw, 40px);
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 20px;
  line-height: 1.2
}

.section-desc {
  max-width: 720px;
  margin: 0 auto;
  color: var(--gray);
  font-size: 17px
}

.section-head {
  text-align: center;
  margin-bottom: 24px
}

/* ===== HOW IT WORKS ===== */
.how {
  padding: 100px 0;
  background: var(--gray-light)
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 56px
}

.step {
  background: #fff;
  border: 1px solid var(--border);
  padding: 36px 28px;
  position: relative;
  transition: all .3s
}

.step::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .4s
}

.step:hover::before {
  transform: scaleX(1)
}

.step:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
  box-shadow: 0 16px 36px rgba(13, 27, 42, .1)
}

.step-num {
  font-size: 44px;
  font-weight: 800;
  color: rgba(26, 84, 144, .15);
  line-height: 1;
  margin-bottom: 16px
}

.step h3 {
  font-size: 17px;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 10px
}

.step p {
  font-size: 14px;
  color: var(--gray);
  line-height: 1.7
}

/* ===== PRODUCT LISTING ===== */
.portfolio {
  padding: 100px 0;
  background: #fff
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 56px
}

.p-card {
  background: #fff;
  border: 1px solid var(--border);
  transition: all .4s;
  display: flex;
  flex-direction: column;
  cursor: pointer
}

.p-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 40px rgba(13, 27, 42, .12);
  border-color: var(--primary)
}

.p-visual {
  height: 210px;
  position: relative;
  overflow: hidden;
  background: var(--gray-light)
}

.p-visual img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  transition: transform .5s
}

.p-card:hover .p-visual img {
  transform: scale(1.05)
}

.p-badge {
  position: absolute;
  top: 14px;
  left: 14px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  color: #fff;
  padding: 5px 12px;
  border-radius: 2px;
  z-index: 2
}

.badge-hot {
  background: var(--accent)
}

.badge-stock {
  background: #1e8449
}

.badge-up {
  background: var(--primary)
}

.p-body {
  padding: 24px 24px 20px;
  display: flex;
  flex-direction: column;
  flex: 1
}

.p-model {
  font-size: 12px;
  color: var(--primary);
  font-weight: 700;
  letter-spacing: 1px;
  margin-bottom: 6px;
  text-transform: uppercase
}

.p-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 10px;
  display: block;
  transition: color .2s
}

.p-card:hover .p-title {
  color: var(--primary)
}

.p-desc {
  font-size: 13.5px;
  color: var(--gray);
  line-height: 1.65
}

.p-feat {
  list-style: none;
  margin-top: 12px
}

.p-feat li {
  font-size: 13px;
  color: var(--gray);
  padding-left: 16px;
  position: relative;
  margin-bottom: 5px
}

.p-feat li::before {
  content: '▪';
  color: var(--accent);
  position: absolute;
  left: 0
}

.p-cap {
  margin-top: auto;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  font-size: 14px;
  font-weight: 700;
  color: var(--accent)
}

.p-cap span {
  font-size: 12px;
  color: var(--gray);
  font-weight: 400;
  margin-left: 6px
}

/* ===== FEATURES ===== */
.features {
  padding: 100px 0;
  background: var(--dark);
  color: #fff
}

.features .section-title {
  color: #fff
}

.features .section-sub {
  color: var(--accent)
}

.features .section-desc {
  color: rgba(255, 255, 255, .7)
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 56px
}

.f-card {
  background: rgba(255, 255, 255, .05);
  border: 1px solid rgba(255, 255, 255, .1);
  padding: 36px 30px;
  transition: all .3s;
  position: relative;
  overflow: hidden
}

.f-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .4s
}

.f-card:hover::before {
  transform: scaleX(1)
}

.f-card:hover {
  background: rgba(255, 255, 255, .08);
  border-color: rgba(230, 126, 34, .3)
}

.f-icon {
  font-size: 34px;
  margin-bottom: 18px;
  opacity: .9
}

.f-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 12px
}

.f-card p {
  font-size: 14px;
  color: rgba(255, 255, 255, .65);
  line-height: 1.7
}

.addons-title {
  text-align: center;
  margin-top: 56px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 2px;
  color: rgba(255, 255, 255, .85);
  text-transform: uppercase;
  margin-bottom: 24px
}

.addons {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center
}

.addon {
  font-size: 13px;
  padding: 10px 20px;
  border: 1px solid rgba(255, 255, 255, .2);
  border-radius: 2px;
  color: rgba(255, 255, 255, .75);
  transition: all .2s
}

.addon:hover {
  border-color: var(--accent);
  color: var(--accent)
}

/* ===== SERVICES ===== */
.services {
  padding: 100px 0;
  background: var(--gray-light)
}

.service-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 56px
}

.s-card {
  background: #fff;
  border: 1px solid var(--border);
  padding: 40px 32px;
  text-align: center;
  transition: all .3s
}

.s-card:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
  box-shadow: 0 16px 36px rgba(13, 27, 42, .1)
}

.s-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 20px;
  background: linear-gradient(135deg, var(--primary-light), var(--primary));
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  color: #fff
}

.s-card h3 {
  font-size: 17px;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 12px
}

.s-card p {
  font-size: 14px;
  color: var(--gray)
}

/* ===== CTA ===== */
.cta-section {
  padding: 80px 0;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  text-align: center
}

.cta-section h2 {
  font-size: clamp(24px, 3.5vw, 36px);
  font-weight: 800;
  margin-bottom: 16px
}

.cta-section p {
  font-size: 17px;
  color: rgba(255, 255, 255, .85);
  margin-bottom: 32px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto
}

.cta-section .btn {
  background: #fff;
  color: var(--primary);
  padding: 16px 40px
}

.cta-section .btn:hover {
  background: #f0f0f0;
  color: var(--primary-dark)
}

/* ===== FOOTER ===== */
.footer {
  background: var(--dark-2);
  color: #aaa;
  padding: 80px 0 30px
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 60px
}

.footer-brand {
  color: #fff
}

.footer-brand .logo {
  margin-bottom: 20px
}

.footer-brand p {
  font-size: 14px;
  line-height: 1.8;
  color: #888;
  margin-bottom: 20px
}

.footer-social {
  display: flex;
  gap: 12px
}

.footer-social a {
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, .08);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  color: #aaa;
  transition: all .2s
}

.footer-social a:hover {
  background: var(--primary);
  color: #fff
}

.footer-col h4 {
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 24px;
  letter-spacing: 1px;
  text-transform: uppercase
}

.footer-col ul {
  list-style: none
}

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

.footer-col a {
  font-size: 14px;
  color: #888;
  transition: color .2s
}

.footer-col a:hover {
  color: #fff
}

.footer-col p {
  font-size: 14px;
  color: #888;
  margin-bottom: 6px
}

.footer-col .phone {
  color: var(--accent);
  font-weight: 600;
  font-size: 15px
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, .08);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: #666
}

.footer-bottom a:hover {
  color: #fff
}

/* ===== RESPONSIVE ===== */
@media(max-width:1400px) {
  .nav-inner {
    padding: 0 48px
  }
}

@media(max-width:1024px) {
  .steps {
    grid-template-columns: repeat(2, 1fr)
  }

  .product-grid,
  .feature-grid,
  .service-grid {
    grid-template-columns: repeat(2, 1fr)
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr
  }
}

@media(max-width:768px) {
  .nav-inner {
    padding: 0 20px
  }

  .mega {
    display: none
  }

  .menu {
    display: none;
    position: fixed;
    top: 72px;
    left: auto;
    right: 0;
    bottom: 0;
    width: 280px;
    background: var(--dark-2);
    flex-direction: column;
    padding: 24px 16px;
    gap: 4px;
    z-index: 999;
    transform: translateX(100%);
    transition: transform .3s
  }

  .menu.show {
    transform: translateX(0)
  }

  .menu li {
    width: 100%
  }

  .menu a {
    display: block;
    padding: 14px 16px;
    font-size: 15px;
    border-bottom: 1px solid rgba(255, 255, 255, .06)
  }

  .mobile-btn {
    display: block
  }

  .page-hero {
    padding: 130px 0 60px
  }

  .steps,
  .product-grid,
  .feature-grid,
  .service-grid {
    grid-template-columns: 1fr
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 36px
  }

  .footer-bottom {
    flex-direction: column;
    gap: 12px;
    text-align: center
  }

  .how,
  .portfolio,
  .features,
  .services,
  .footer {
    padding: 60px 0
  }

  .btn {
    padding: 12px 22px;
    font-size: 13px
  }

  .btn-outline {
    margin-left: 0;
    margin-top: 12px
  }
}

@media(max-width:480px) {
  .logo-text {
    font-size: 14px
  }

  .logo-cn {
    font-size: 11px
  }
}

/* ===== ANIMATIONS ===== */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: all .7s ease
}

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