:root {
  --color-primary: #1e3a8a;
  --color-primary-dark: #162961;
  --color-accent: #0ea5e9;
  --color-accent-soft: rgba(14, 165, 233, 0.1);
  --color-bg: #f3f4f6;
  --color-surface: #ffffff;
  --color-text: #1f2937;
  --color-muted: #6b7280;
  --color-border: #e5e7eb;
  --color-highlight: #dbeafe;
  --gradient-primary: linear-gradient(135deg, #1e3a8a, #0f172a);
  --gradient-accent: linear-gradient(135deg, #0ea5e9, #2563eb);
  --shadow-soft: 0 10px 30px rgba(15, 23, 42, 0.08);
  --shadow-bold: 0 20px 45px rgba(15, 23, 42, 0.12);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-xl: 28px;
  --radius-full: 999px;
  --spacing-section: 80px;
  --header-height: 82px;
  --max-width: 1200px;
}

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

body {
  font-family: "PingFang SC", "Source Han Sans", "Microsoft YaHei", sans-serif;
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.6;
  font-size: 16px;
}

img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius-sm);
}

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

ul {
  list-style: none;
}

.container {
  width: min(100%, var(--max-width));
  margin: 0 auto;
  padding: 0 24px;
}

main {
  margin-top: var(--header-height);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-full, 999px);
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-soft);
}

.btn-gradient {
  background: var(--gradient-accent);
  color: #fff;
}

.btn-outline {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.4);
  color: #fff;
}

.btn-secondary {
  background: rgba(30, 58, 138, 0.1);
  color: var(--color-primary);
}

.section {
  padding: var(--spacing-section) 0;
}

.section-heading {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 48px;
}

.section-title {
  font-size: 34px;
  color: var(--color-primary);
  margin-bottom: 16px;
}

.section-desc {
  color: var(--color-muted);
}

.grid {
  display: grid;
  gap: 28px;
}

.grid-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card {
  background: var(--color-surface);
  padding: 32px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-soft);
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.card-media img {
  border-radius: var(--radius-md);
}

.card-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-primary);
}

.card-text {
  color: var(--color-muted);
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 14px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  background: var(--color-highlight);
  color: var(--color-primary);
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(30, 58, 138, 0.1);
  color: var(--color-primary);
  font-size: 13px;
}

.site-header {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 1px 20px rgba(15, 23, 42, 0.08);
  z-index: 20;
}

.header-inner {
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  font-weight: 700;
  color: var(--color-primary);
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.logo span:first-child {
  font-size: 18px;
  letter-spacing: 1px;
}

.logo span:last-child {
  font-size: 12px;
  color: var(--color-muted);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 20px;
}

.nav-link {
  color: var(--color-text);
  font-weight: 500;
  padding: 10px 8px;
  position: relative;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: all 0.3s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 80%;
  left: 10%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 6px;
  border: none;
  background: transparent;
}

.nav-toggle span {
  width: 26px;
  height: 2px;
  background: var(--color-text);
}

.hero-banner {
  position: relative;
  min-height: 620px;
  overflow: hidden;
  background: #0f172a;
  color: #fff;
}

.hero-slide {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  padding: 0 5%;
  background-size: cover;
  background-position: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.8s ease;
}

.hero-slide.active {
  opacity: 1;
  pointer-events: auto;
}

.hero-content {
  max-width: 520px;
  background: rgba(15, 23, 42, 0.68);
  padding: 32px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-soft);
}

.hero-content h1 {
  font-size: 40px;
  margin-bottom: 16px;
}

.hero-content p {
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 20px;
}

.hero-stats {
  display: flex;
  gap: 24px;
  margin-top: 24px;
}

.hero-stat {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.7);
}

.hero-stat span {
  display: block;
  font-size: 26px;
  font-weight: 700;
  color: #fff;
}

.hero-controls {
  position: absolute;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 12px;
}

.hero-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.6);
  background: transparent;
  cursor: pointer;
}

.hero-dot.active {
  background: #fff;
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 24px;
}

.stat-card {
  background: var(--color-surface);
  padding: 28px;
  border-radius: var(--radius-md);
  text-align: center;
  box-shadow: var(--shadow-soft);
}

.stat-number {
  font-size: 36px;
  font-weight: 700;
  color: var(--color-primary);
}

.stat-label {
  color: var(--color-muted);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid var(--color-border);
}

.feature-card h3 {
  font-size: 18px;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.solution-card {
  background: var(--color-surface);
  padding: 24px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-soft);
}

.solution-card img {
  margin-bottom: 18px;
}

.case-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.case-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
}

.case-body {
  padding: 24px;
}

.case-meta {
  display: flex;
  justify-content: space-between;
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 12px;
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.news-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
}

.news-body {
  padding: 24px;
}

.partners-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 20px;
  align-items: center;
}

.partner-card {
  background: var(--color-surface);
  padding: 24px;
  border-radius: var(--radius-md);
  text-align: center;
  box-shadow: var(--shadow-soft);
}

.cta-panel {
  background: var(--gradient-primary);
  color: #fff;
  border-radius: var(--radius-xl);
  padding: 48px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  text-align: center;
}

.sub-hero {
  background-size: cover;
  background-position: center;
  color: #fff;
  padding: 120px 0 80px;
  position: relative;
}

.sub-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(15, 23, 42, 0.5);
}

.sub-hero .container {
  position: relative;
  z-index: 1;
}

.sub-hero h1 {
  font-size: 40px;
  margin-bottom: 12px;
}

.breadcrumbs {
  display: flex;
  gap: 10px;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.7);
}

.intro-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
  align-items: center;
}

.timeline {
  border-left: 2px solid var(--color-border);
  margin-left: 12px;
  padding-left: 28px;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.timeline-item {
  position: relative;
}

.timeline-item::before {
  content: "";
  position: absolute;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-primary);
  left: -35px;
  top: 6px;
}

.timeline-year {
  font-size: 18px;
  color: var(--color-primary);
  font-weight: 600;
}

.culture-grid,
.honor-grid,
.branch-grid,
.job-grid,
.download-grid,
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.culture-card,
.honor-card,
.download-card,
.branch-card,
.job-card {
  background: var(--color-surface);
  padding: 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

.download-card a {
  color: var(--color-accent);
  font-weight: 600;
}

.product-specs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.spec-item {
  background: var(--color-bg);
  padding: 18px;
  border-radius: var(--radius-sm);
}

.inquiry-form {
  background: var(--color-surface);
  padding: 32px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-soft);
}

.inquiry-form form {
  display: grid;
  gap: 18px;
}

input,
textarea,
select {
  width: 100%;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 14px;
  font-size: 15px;
  font-family: inherit;
}

textarea {
  min-height: 140px;
  resize: vertical;
}

.case-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 24px;
}

.case-filter button {
  border: 1px solid var(--color-border);
  background: #fff;
  border-radius: 999px;
  padding: 8px 18px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.case-filter button.active {
  background: var(--color-primary);
  color: #fff;
  border-color: transparent;
}

.news-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.news-item {
  background: var(--color-surface);
  padding: 24px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-soft);
}

.news-meta {
  display: flex;
  gap: 12px;
  font-size: 13px;
  color: var(--color-muted);
  margin-bottom: 12px;
}

.contact-grid {
  align-items: stretch;
}

.contact-card {
  background: var(--color-surface);
  padding: 28px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-soft);
}

.map-placeholder {
  background: url('images/contact_city_night.png') center/cover;
  border-radius: var(--radius-md);
  min-height: 260px;
}

.footer {
  background: #0f172a;
  color: rgba(255, 255, 255, 0.75);
  padding: 60px 0 30px;
  margin-top: 60px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
}

.footer h3 {
  color: #fff;
  margin-bottom: 12px;
}

.footer a {
  color: rgba(255, 255, 255, 0.7);
  font-size: 14px;
}

.footer-bottom {
  margin-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 20px;
  font-size: 14px;
  text-align: center;
}

.chat-widget {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 30;
}

.chat-trigger {
  background: var(--gradient-accent);
  color: #fff;
  border: none;
  padding: 12px 20px;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: var(--shadow-bold);
}

.chat-panel {
  display: none;
  position: absolute;
  right: 0;
  bottom: 60px;
  width: 260px;
  background: var(--color-surface);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-bold);
  padding: 20px;
  font-size: 14px;
}

.chat-panel.active {
  display: block;
}

@media (max-width: 1024px) {
  .grid-3,
  .grid-4,
  .grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  }
}

@media (max-width: 768px) {
  :root {
    --spacing-section: 60px;
  }

  .header-inner {
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-links {
    flex-direction: column;
    align-items: flex-start;
    width: 100%;
    display: none;
    padding-bottom: 16px;
  }

  .nav-links.active {
    display: flex;
  }

  .hero-content h1 {
    font-size: 30px;
  }

  .hero-stats {
    flex-direction: column;
  }

  .section-title {
    font-size: 28px;
  }

  .cta-panel {
    padding: 32px;
  }

  .chat-widget {
    right: 12px;
    bottom: 12px;
  }
}