/* ===== Reset & Base ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Inter", system-ui, sans-serif;
  color: #334155;
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
}

.section-alt {
  background: #f8fafc;
}

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

.section-header h2 {
  font-size: 2rem;
  color: #0f172a;
  font-weight: 700;
  margin-bottom: 8px;
}

.section-header .subtitle {
  font-size: 0.875rem;
  color: #64748b;
  letter-spacing: 2px;
  text-transform: uppercase;
}

.section-header .divider {
  width: 48px;
  height: 3px;
  background: #2563eb;
  margin: 16px auto 0;
  border-radius: 2px;
}

/* ===== Navbar ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: background 0.3s ease, box-shadow 0.3s ease, padding 0.3s ease;
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.97);
  box-shadow: 0 1px 12px rgba(15, 23, 42, 0.08);
  padding: 12px 0;
  backdrop-filter: blur(8px);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  transition: color 0.3s;
}

.navbar.scrolled .logo {
  color: #0f172a;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  color: #fff;
  font-weight: 800;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 32px;
}

.nav-links a {
  font-size: 0.9375rem;
  color: rgba(255, 255, 255, 0.9);
  transition: color 0.3s;
  position: relative;
}

.navbar.scrolled .nav-links a {
  color: #475569;
}

.nav-links a:hover,
.nav-links a.active {
  color: #2563eb;
}

.navbar.scrolled .nav-links a:hover,
.navbar.scrolled .nav-links a.active {
  color: #2563eb;
}

.nav-links a.active::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: #2563eb;
  border-radius: 1px;
}

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

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  transition: background 0.3s, transform 0.3s;
  border-radius: 1px;
}

.navbar.scrolled .hamburger span {
  background: #334155;
}

.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;
  justify-content: center;
  text-align: center;
  color: #fff;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: url("../assets/images/hero-banner.jpg") center/cover no-repeat;
  animation: kenBurns 20s ease-in-out infinite alternate;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: rgba(15, 23, 42, 0.6);
}

@keyframes kenBurns {
  from { transform: scale(1); }
  to { transform: scale(1.05); }
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  padding: 0 24px;
}

.hero-content h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  margin-bottom: 16px;
  opacity: 0;
  animation: fadeUp 0.8s ease forwards;
}

.hero-content .slogan {
  font-size: clamp(1.125rem, 2.5vw, 1.5rem);
  font-weight: 300;
  margin-bottom: 12px;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.2s forwards;
  letter-spacing: 2px;
}

.hero-content .desc {
  font-size: 1rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 40px;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.4s forwards;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.6s forwards;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.btn {
  display: inline-block;
  padding: 12px 32px;
  border-radius: 6px;
  font-size: 0.9375rem;
  font-weight: 600;
  transition: all 0.3s ease;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: #2563eb;
  color: #fff;
}

.btn-primary:hover {
  background: #1d4ed8;
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.4);
}

.btn-outline {
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255, 255, 255, 0.7);
}

.btn-outline:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
}

/* ===== About ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.about-image {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 32px rgba(15, 23, 42, 0.12);
}

.about-image img {
  width: 100%;
  height: 360px;
  object-fit: cover;
  background: #e2e8f0;
}

.about-text h3 {
  font-size: 1.5rem;
  color: #0f172a;
  margin-bottom: 16px;
}

.about-text p {
  margin-bottom: 16px;
  color: #475569;
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 32px;
}

.stat-item {
  text-align: center;
  padding: 20px;
  background: #f8fafc;
  border-radius: 8px;
  border: 1px solid #e2e8f0;
}

.stat-item .number {
  font-size: 2rem;
  font-weight: 800;
  color: #2563eb;
  display: block;
}

.stat-item .label {
  font-size: 0.875rem;
  color: #64748b;
  margin-top: 4px;
}

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

.service-card {
  background: #fff;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 2px 12px rgba(15, 23, 42, 0.06);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  border: 1px solid #e2e8f0;
}

.service-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(15, 23, 42, 0.12);
}

.service-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  background: #e2e8f0;
}

.service-card-body {
  padding: 24px;
}

.service-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}

.service-icon svg {
  width: 24px;
  height: 24px;
  fill: none;
  stroke: #fff;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.service-card-body h3 {
  font-size: 1.25rem;
  color: #0f172a;
  margin-bottom: 8px;
}

.service-card-body p {
  font-size: 0.9375rem;
  color: #64748b;
}

/* ===== Advantages ===== */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.advantage-item {
  text-align: center;
  padding: 32px 20px;
  background: #fff;
  border-radius: 12px;
  border: 1px solid #e2e8f0;
  transition: border-color 0.3s, box-shadow 0.3s;
}

.advantage-item:hover {
  border-color: #2563eb;
  box-shadow: 0 4px 20px rgba(37, 99, 235, 0.1);
}

.advantage-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  background: #eff6ff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.3s;
}

.advantage-item:hover .advantage-icon {
  background: #2563eb;
}

.advantage-icon svg {
  width: 28px;
  height: 28px;
  fill: none;
  stroke: #2563eb;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: stroke 0.3s;
}

.advantage-item:hover .advantage-icon svg {
  stroke: #fff;
}

.advantage-item h3 {
  font-size: 1.0625rem;
  color: #0f172a;
  margin-bottom: 8px;
}

.advantage-item p {
  font-size: 0.875rem;
  color: #64748b;
}

/* ===== Contact ===== */
.contact-content {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}

.contact-card {
  background: #fff;
  border-radius: 12px;
  padding: 48px;
  box-shadow: 0 4px 24px rgba(15, 23, 42, 0.08);
  border: 1px solid #e2e8f0;
}

.contact-item {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 16px;
}

.contact-item:last-child {
  margin-bottom: 0;
}

.contact-item svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: #2563eb;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex-shrink: 0;
}

.contact-item a {
  color: #2563eb;
  font-size: 1.0625rem;
  transition: color 0.3s;
}

.contact-item a:hover {
  color: #1d4ed8;
  text-decoration: underline;
}

.contact-item span {
  color: #475569;
  font-size: 1.0625rem;
}

/* ===== Footer ===== */
.footer {
  background: #0f172a;
  color: rgba(255, 255, 255, 0.7);
  padding: 32px 0;
  text-align: center;
  font-size: 0.875rem;
}

.footer p {
  margin-bottom: 8px;
}

.footer a {
  color: rgba(255, 255, 255, 0.7);
  transition: color 0.3s;
}

.footer a:hover {
  color: #fff;
}

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  background: #2563eb;
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.4);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s, transform 0.3s;
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: #1d4ed8;
  transform: translateY(-2px);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: #fff;
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ===== Scroll Animations ===== */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ===== Mobile Nav Overlay ===== */
.mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.95);
  z-index: 999;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 32px;
}

.mobile-menu.open {
  display: flex;
}

.mobile-menu a {
  color: #fff;
  font-size: 1.25rem;
  font-weight: 500;
  transition: color 0.3s;
}

.mobile-menu a:hover,
.mobile-menu a.active {
  color: #60a5fa;
}

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

@media (max-width: 768px) {
  .section {
    padding: 48px 0;
  }

  .nav-links {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .about-image img {
    height: 240px;
  }

  .stats {
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  .stat-item {
    padding: 12px 8px;
  }

  .stat-item .number {
    font-size: 1.5rem;
  }

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

  .advantages-grid {
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }

  .contact-card {
    padding: 32px 24px;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
  }
}

@media (max-width: 480px) {
  .advantages-grid {
    grid-template-columns: 1fr;
  }

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