/* Base Variables */
:root {
  --primary-color: #1a365d; /* Deep Navy Blue */
  --secondary-color: #2c5282; /* Lighter Navy */
  --accent-color: #ed8936; /* Orange */
  --accent-hover: #dd6b20;
  --text-dark: #2d3748;
  --text-light: #4a5568;
  --bg-light: #f7fafc;
  --bg-white: #ffffff;
  --border-color: #e2e8f0;
  --font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --transition: all 0.3s ease;
  --header-height: 80px;
}

/* Reset & Global */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  color: var(--text-dark);
  line-height: 1.6;
  background-color: var(--bg-light);
}

a {
  text-decoration: none;
  color: inherit;
  transition: var(--transition);
}

ul {
  list-style: none;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

h2.section-title {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 3rem;
  position: relative;
  padding-bottom: 15px;
}

h2.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background-color: var(--accent-color);
}

.section-subtitle {
  text-align: center;
  color: var(--text-light);
  margin-top: -2rem;
  margin-bottom: 3rem;
  font-size: 1.1rem;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 12px 30px;
  border-radius: 4px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  border: none;
}

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

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

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

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

.btn-outline {
  background-color: transparent;
  border: 2px solid var(--primary-color);
  color: var(--primary-color);
}

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

/* Header & Navigation */
header {
  background-color: var(--bg-white);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
  position: sticky;
  top: 0;
  z-index: 1000;
  height: var(--header-height);
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 15px;
}

.logo img {
  height: 50px;
}

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

.logo-text .cn {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--primary-color);
  letter-spacing: 1px;
}

.logo-text .en {
  font-size: 0.7rem;
  color: var(--text-light);
  text-transform: uppercase;
}

/* Desktop Navigation */
.nav-menu {
  display: flex;
  height: 100%;
}

.nav-item {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
}

.nav-link {
  padding: 0 20px;
  font-weight: 500;
  color: var(--text-dark);
  height: 100%;
  display: flex;
  align-items: center;
}

.nav-item:hover .nav-link, .nav-item.active .nav-link {
  color: var(--accent-color);
}

/* Dropdown Menu */
.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  background-color: var(--bg-white);
  min-width: 220px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  border-top: 3px solid var(--accent-color);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: var(--transition);
  z-index: 1001;
}

.nav-item:hover .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-item {
  display: block;
  padding: 12px 20px;
  color: var(--text-dark);
  border-bottom: 1px solid var(--border-color);
  font-size: 0.95rem;
}

.dropdown-item:last-child {
  border-bottom: none;
}

.dropdown-item:hover {
  background-color: var(--bg-light);
  color: var(--accent-color);
  padding-left: 25px;
}

/* Header Utilities */
.header-utils {
  display: flex;
  align-items: center;
  gap: 15px;
}

.header-contact {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  color: var(--primary-color);
}

.header-contact i {
  color: var(--accent-color);
  font-size: 1.2rem;
}

.mobile-toggle {
  display: none;
  font-size: 1.5rem;
  color: var(--primary-color);
  cursor: pointer;
}

/* Page Hero Header */
.page-hero {
  height: 400px;
  background-size: cover;
  background-position: center;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #fff;
}

.page-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(26, 54, 93, 0.7);
}

.page-hero-content {
  position: relative;
  z-index: 1;
}

.page-hero-content h1 {
  color: #fff;
  font-size: 3rem;
  margin-bottom: 1rem;
}

.page-hero-content p {
  font-size: 1.2rem;
  max-width: 600px;
  margin: 0 auto;
  opacity: 0.9;
}

/* ==========================================================================
   Hero Section (Index)
   ========================================================================== */
.hero {
    height: 100vh;
    min-height: 600px;
    background: linear-gradient(rgba(10, 37, 88, 0.85), rgba(10, 37, 88, 0.85)), url('../img/hero_home.png') no-repeat center center/cover;
    display: flex;
    align-items: center;
    color: #fff;
    position: relative;
    overflow: hidden;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
}

/* Animations for hero text */
@keyframes slideUpFade {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
    opacity: 0;
    animation: slideUpFade 1s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    animation-delay: 0.2s;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 40px;
    color: #e2e8f0;
    line-height: 1.6;
    opacity: 0;
    animation: slideUpFade 1s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    animation-delay: 0.5s;
}

.hero-btns {
    display: flex;
    gap: 20px;
    opacity: 0;
    animation: slideUpFade 1s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    animation-delay: 0.8s;
}

/* Content Sections */
.section-padding {
  padding: 80px 0;
}

/* Footer */
footer {
  background-color: var(--primary-color);
  color: #fff;
  padding: 60px 0 0;
}

.footer-top {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-col h3 {
  color: #fff;
  font-size: 1.2rem;
  margin-bottom: 20px;
  position: relative;
  padding-bottom: 10px;
}

.footer-col h3::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 30px;
  height: 2px;
  background-color: var(--accent-color);
}

.footer-info p {
  margin-bottom: 15px;
  color: #cbd5e0;
  display: flex;
  gap: 10px;
}

.footer-info i {
  color: var(--accent-color);
  margin-top: 5px;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: #cbd5e0;
}

.footer-links a:hover {
  color: var(--accent-color);
  padding-left: 5px;
}

.footer-bottom {
  background-color: #11243e;
  padding: 20px 0;
  text-align: center;
  color: #a0aec0;
  font-size: 0.9rem;
}

.footer-bottom-links {
  margin-top: 10px;
}

.footer-bottom-links a {
  color: #a0aec0;
  margin: 0 10px;
}

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

/* Animations */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

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

/* Premium Glow Effect for Contact Images */
.contact-img-glow {
    position: relative;
    display: inline-block;
    filter: drop-shadow(0 0 8px rgba(237, 137, 54, 0.4));
    transition: all 0.3s ease;
}

.contact-img-glow:hover {
    filter: drop-shadow(0 0 12px rgba(237, 137, 54, 0.8));
    transform: scale(1.02);
}

@keyframes subtlePulse {
    0% { filter: drop-shadow(0 0 5px rgba(237, 137, 54, 0.3)); }
    50% { filter: drop-shadow(0 0 15px rgba(237, 137, 54, 0.6)); }
    100% { filter: drop-shadow(0 0 5px rgba(237, 137, 54, 0.3)); }
}

.contact-img-glow.animated {
    animation: subtlePulse 3s infinite ease-in-out;
}

/* Responsive */
@media (max-width: 1024px) {
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background-color: var(--bg-white);
    flex-direction: column;
    height: auto;
    box-shadow: 0 10px 15px rgba(0,0,0,0.1);
  }
  
  .nav-menu.active {
    display: flex;
  }
  
  .nav-item {
    height: auto;
    flex-direction: column;
    align-items: flex-start;
    width: 100%;
  }
  
  .nav-link {
    padding: 15px 20px;
    width: 100%;
    border-bottom: 1px solid var(--border-color);
  }
  
  .dropdown-menu {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    border-top: none;
    width: 100%;
    display: none;
    background-color: var(--bg-light);
  }
  
  .nav-item.active-mobile .dropdown-menu {
    display: block;
  }
  
  .header-utils {
    display: none;
  }
  
  .mobile-toggle {
    display: block;
  }
  
  .footer-top {
    grid-template-columns: 1fr;
  }
  
  .page-hero h1 {
    font-size: 2rem;
  }
}