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

:root {
  --primary: #1a4f6e;
  --primary-dark: #143d56;
  --accent: #4a7c59;
  --accent-light: #5a9469;
  --bg: #f4f6f8;
  --bg-alt: #eef1f4;
  --surface: #ffffff;
  --text: #2d3748;
  --text-muted: #718096;
  --text-light: #f7fafc;
  --border: #e2e8f0;
  --shadow: 0 4px 24px rgba(26, 79, 110, 0.08);
  --shadow-lg: 0 12px 48px rgba(26, 79, 110, 0.12);
  --radius: 12px;
  --header-h: 72px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
}

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

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

ul {
  list-style: none;
}

.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 96px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-dark {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 50%, #2d5a3d 100%);
  color: var(--text-light);
}

.section-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-label.light {
  color: rgba(247, 250, 252, 0.7);
}

.section h2 {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 16px;
  line-height: 1.3;
}

.section-dark h2,
.section-dark .section-label {
  color: var(--text-light);
}

.section-desc {
  color: var(--text-muted);
  max-width: 600px;
  margin-bottom: 48px;
}

.center {
  text-align: center;
}

.center.sub {
  color: rgba(247, 250, 252, 0.75);
  margin-bottom: 56px;
}

.lead {
  font-size: 1.1rem;
  color: var(--text);
  margin-bottom: 16px;
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, box-shadow 0.3s;
}

.header.scrolled {
  border-color: var(--border);
  box-shadow: var(--shadow);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
}

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

.logo-icon {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 700;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.logo-text strong {
  font-size: 1rem;
  color: var(--primary);
}

.logo-text small {
  font-size: 0.65rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

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

.nav-links a {
  font-size: 0.92rem;
  color: var(--text);
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--accent);
}

.nav-cta {
  background: var(--accent) !important;
  color: #fff !important;
  padding: 8px 20px;
  border-radius: 8px;
  font-weight: 600;
}

.nav-cta:hover {
  background: var(--accent-light) !important;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--primary);
  transition: 0.3s;
}

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--header-h);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
}

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

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(26, 79, 110, 0.92) 0%,
    rgba(26, 79, 110, 0.85) 50%,
    rgba(74, 124, 89, 0.75) 100%
  );
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 80px 24px;
  max-width: 720px;
  color: var(--text-light);
}

.hero-tag {
  display: inline-block;
  background: rgba(74, 124, 89, 0.4);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: clamp(2.8rem, 6vw, 4.2rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 24px;
}

.hero h1 span {
  color: var(--accent-light);
  display: block;
}

.hero-desc {
  font-size: 1.1rem;
  opacity: 0.9;
  margin-bottom: 36px;
  max-width: 560px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-quote {
  font-size: 0.9rem;
  opacity: 0.7;
  border-left: 3px solid var(--accent);
  padding-left: 16px;
  font-style: italic;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all 0.2s;
  font-family: inherit;
}

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

.btn-primary:hover {
  background: var(--accent-light);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.5);
}

.btn-outline:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.1);
}

.btn-block {
  width: 100%;
}

/* Stats */
.stats {
  padding: 0;
  margin-top: -60px;
  position: relative;
  z-index: 2;
}

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

.stat-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  box-shadow: var(--shadow-lg);
}

.stat-num {
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--primary);
  font-variant-numeric: tabular-nums;
}

.stat-suffix {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
}

.stat-card p {
  margin-top: 8px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* About */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 64px;
  align-items: center;
}

.about-visual {
  position: relative;
}

.about-visual img {
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
}

.about-badge {
  position: absolute;
  bottom: -20px;
  right: -20px;
  background: var(--accent);
  color: #fff;
  padding: 20px 28px;
  border-radius: var(--radius);
  text-align: center;
  box-shadow: var(--shadow);
}

.about-badge strong {
  display: block;
  font-size: 1.5rem;
}

.about-badge span {
  font-size: 0.85rem;
  opacity: 0.9;
}

.about-text p {
  color: var(--text-muted);
  margin-bottom: 16px;
}

.about-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 32px;
}

.about-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  border-top: 3px solid var(--primary);
}

.about-card:nth-child(2) {
  border-top-color: var(--accent);
}

.about-card-num {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.1em;
}

.about-card h3 {
  font-size: 0.95rem;
  color: var(--primary);
  margin: 8px 0;
}

.about-card p {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin: 0;
}

/* Philosophy */
.philosophy-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.philosophy-item {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  transition: transform 0.3s, background 0.3s;
}

.philosophy-item:hover {
  transform: translateY(-4px);
  background: rgba(255, 255, 255, 0.12);
}

.philosophy-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.philosophy-item h3 {
  font-size: 1.2rem;
  margin-bottom: 12px;
}

.philosophy-item p {
  font-size: 0.9rem;
  opacity: 0.85;
  line-height: 1.6;
}

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

.service-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px 28px;
  border: 1px solid var(--border);
  transition: transform 0.3s, box-shadow 0.3s;
}

.service-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.service-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, rgba(26, 79, 110, 0.1), rgba(74, 124, 89, 0.1));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--primary);
}

.service-icon svg {
  width: 24px;
  height: 24px;
}

.service-card h3 {
  font-size: 1.1rem;
  color: var(--primary);
  margin-bottom: 12px;
}

.service-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Solutions */
.solutions-header {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  margin-bottom: 40px;
}

.solutions-img {
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  aspect-ratio: 16/10;
  object-fit: cover;
}

.solutions-tabs {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
}

.tab-btn {
  padding: 10px 28px;
  border: 2px solid var(--border);
  background: var(--surface);
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.tab-btn.active,
.tab-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: rgba(26, 79, 110, 0.05);
}

.tab-panel {
  display: none;
}

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

.solution-detail {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 36px 40px;
  border-left: 4px solid var(--accent);
  box-shadow: var(--shadow);
}

.solution-detail h3 {
  font-size: 1.3rem;
  color: var(--primary);
  margin-bottom: 20px;
}

.solution-detail li {
  padding: 10px 0;
  padding-left: 24px;
  position: relative;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border);
}

.solution-detail li:last-child {
  border-bottom: none;
}

.solution-detail li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

.solution-detail strong {
  color: var(--primary);
}

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

.case-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: var(--shadow);
  transition: transform 0.3s;
}

.case-card:hover {
  transform: translateY(-4px);
}

.case-tag {
  display: inline-block;
  background: rgba(74, 124, 89, 0.12);
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 4px;
  margin-bottom: 16px;
}

.case-card h3 {
  font-size: 1.15rem;
  color: var(--primary);
  margin-bottom: 12px;
}

.case-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Partners */
.partners-list {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.partners-list span {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 14px 24px;
  border-radius: 8px;
  font-size: 0.9rem;
  color: var(--text);
  transition: border-color 0.2s, color 0.2s;
}

.partners-list span:hover {
  border-color: var(--accent);
  color: var(--primary);
}

/* Advantages */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.advantage-item {
  text-align: center;
  padding: 32px 20px;
  background: var(--surface);
  border-radius: var(--radius);
  border-top: 3px solid var(--accent);
  box-shadow: var(--shadow);
}

.advantage-item h3 {
  font-size: 1rem;
  color: var(--primary);
  margin-bottom: 12px;
}

.advantage-item p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.contact-info p {
  opacity: 0.85;
  margin-bottom: 32px;
}

.contact-list li {
  padding: 16px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

.contact-list strong {
  display: block;
  font-size: 0.8rem;
  opacity: 0.6;
  margin-bottom: 4px;
}

.contact-form {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 36px;
  color: var(--text);
}

.contact-form h3 {
  color: var(--primary);
  margin-bottom: 24px;
  font-size: 1.3rem;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color 0.2s;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
}

.form-note {
  font-size: 0.78rem;
  color: var(--text-muted);
  text-align: center;
  margin-top: 12px;
}

/* Footer */
.footer {
  background: #0f2d3d;
  color: rgba(255, 255, 255, 0.7);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-brand strong {
  color: #fff;
  display: block;
}

.footer-brand p {
  font-size: 0.85rem;
  opacity: 0.6;
}

.footer-copy {
  font-size: 0.85rem;
}

/* Reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 1024px) {
  .stats-grid,
  .services-grid,
  .cases-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .about-grid,
  .solutions-header,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .philosophy-grid {
    grid-template-columns: 1fr;
  }

  .about-cards {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .section {
    padding: 64px 0;
  }

  .nav-links {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    padding: 24px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
    transform: translateY(-120%);
    opacity: 0;
    transition: 0.3s;
    pointer-events: none;
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-toggle {
    display: flex;
  }

  .stats-grid,
  .services-grid,
  .cases-grid,
  .advantages-grid {
    grid-template-columns: 1fr;
  }

  .stats {
    margin-top: -40px;
  }

  .hero h1 {
    font-size: 2.4rem;
  }

  .solutions-img {
    order: -1;
  }
}