/* 通用门户网站高端现代样式表 */
/* 采用深色科技感配色与玻璃拟态设计，符合现代网页美学 */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&display=swap');

:root {
  /* 基础配色 */
  --bg-primary: #0b0f19;
  --bg-secondary: #121826;
  --text-primary: #f3f4f6;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  
  /* 品牌主色 (渐变蓝绿，象征科技与生态水资源) */
  --accent-color: #10b981;
  --accent-secondary: #06b6d4;
  --accent-gradient: linear-gradient(135deg, #10b981 0%, #0284c7 50%, #06b6d4 100%);
  --accent-gradient-hover: linear-gradient(135deg, #059669 0%, #0369a1 50%, #0891b2 100%);
  --text-gradient: linear-gradient(135deg, #34d399 0%, #38bdf8 100%);
  
  /* 玻璃拟态 (Glassmorphism) 参数 */
  --glass-bg: rgba(18, 24, 38, 0.7);
  --glass-bg-hover: rgba(25, 33, 52, 0.85);
  --glass-border: rgba(255, 255, 255, 0.06);
  --glass-border-hover: rgba(16, 185, 129, 0.3);
  
  /* 阴影与特效 */
  --shadow-main: 0 8px 32px 0 rgba(0, 0, 0, 0.5);
  --shadow-neon: 0 0 20px rgba(16, 185, 129, 0.2);
  --shadow-neon-strong: 0 0 30px rgba(6, 182, 212, 0.4);
  
  /* 其他变量 */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-title: 'Outfit', 'Inter', sans-serif;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  --max-width: 1200px;
}

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

html {
  scroll-behavior: smooth;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: radial-gradient(circle at 50% 0%, rgba(6, 182, 212, 0.08) 0%, rgba(16, 185, 129, 0.04) 50%, rgba(11, 15, 25, 0) 100%);
  background-attachment: fixed;
}

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

button, input, textarea {
  font-family: inherit;
  color: inherit;
  background: none;
  border: none;
}

/* Utility Classes */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

.text-gradient {
  background: var(--text-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  box-shadow: var(--shadow-main);
  transition: var(--transition-normal);
}

.glass-card:hover {
  border-color: var(--glass-border-hover);
  transform: translateY(-5px);
  box-shadow: var(--shadow-main), 0 10px 20px rgba(0, 0, 0, 0.2);
}

/* Header & Navigation */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(11, 15, 25, 0.5);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
  transition: var(--transition-normal);
}

header.scrolled {
  background: rgba(11, 15, 25, 0.85);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 80px;
  transition: var(--transition-normal);
}

header.scrolled .nav-container {
  height: 65px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.logo-img {
  height: 44px;
  width: auto;
  object-fit: contain;
  filter: drop-shadow(0 0 8px rgba(16, 185, 129, 0.2));
  transition: var(--transition-normal);
}

header.scrolled .logo-img {
  height: 36px;
}

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

.logo-main {
  font-family: var(--font-title);
  font-weight: 800;
  font-size: 1.4rem;
  letter-spacing: 0.5px;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.2;
}

.logo-sub {
  font-size: 0.6rem;
  color: var(--text-muted);
  letter-spacing: 0.2px;
  margin-top: 1px;
  text-transform: uppercase;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 2.5rem;
}

nav a {
  font-size: 1rem;
  font-weight: 500;
  position: relative;
  padding: 0.5rem 0;
  color: var(--text-secondary);
}

nav a:hover, nav a.active {
  color: var(--text-primary);
}

nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-gradient);
  border-radius: 2px;
  transition: var(--transition-normal);
}

nav a:hover::after, nav a.active::after {
  width: 100%;
}

/* Mobile Menu Toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 30px;
  height: 21px;
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  height: 3px;
  width: 100%;
  background-color: var(--text-primary);
  border-radius: 3px;
  transition: var(--transition-normal);
}

/* Main Content Area */
main {
  flex: 1;
  margin-top: 80px; /* Offset for sticky header */
}

/* Pages Styling & Transitions */
.page {
  display: none;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
  padding: 4rem 0;
}

.page.active {
  display: block;
  opacity: 1;
  transform: translateY(0);
}

/* Hero Section */
.hero-section {
  position: relative;
  padding: 8rem 0 6rem 0;
  text-align: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  background-size: cover;
  background-position: center;
  opacity: 0.2;
  filter: blur(4px) brightness(0.6);
}

.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  background: linear-gradient(180deg, rgba(11, 15, 25, 0.4) 0%, var(--bg-primary) 100%);
}

.hero-title {
  font-family: var(--font-title);
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  letter-spacing: -1px;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 800px;
  margin: 0 auto 3rem auto;
  line-height: 1.8;
}

.btn-primary {
  display: inline-block;
  padding: 1rem 2.5rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: 50px;
  background: var(--accent-gradient);
  box-shadow: var(--shadow-neon);
  cursor: pointer;
  transition: var(--transition-normal);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-neon-strong);
  filter: brightness(1.1);
}

/* Home Section Layouts */
.section-title {
  font-family: var(--font-title);
  font-size: 2.25rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 1rem;
}

.section-subtitle {
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 4rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  font-size: 1.05rem;
}

.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-bottom: 6rem;
}

.advantage-card {
  padding: 2.5rem;
  text-align: center;
}

.advantage-icon {
  font-size: 3rem;
  margin-bottom: 1.5rem;
  display: inline-block;
  text-shadow: var(--shadow-neon);
}

.advantage-card h3 {
  font-size: 1.35rem;
  margin-bottom: 1rem;
  font-family: var(--font-title);
}

.advantage-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.sectors-container {
  padding: 2rem 0;
}

.sectors-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.sector-card {
  overflow: hidden;
  border-radius: 16px;
  display: flex;
  flex-direction: column;
}

.sector-image {
  height: 200px;
  background-size: cover;
  background-position: center;
  transition: var(--transition-normal);
}

.sector-card:hover .sector-image {
  transform: scale(1.05);
}

.sector-content {
  padding: 2rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.sector-content h3 {
  font-family: var(--font-title);
  font-size: 1.25rem;
  margin-bottom: 1rem;
}

.sector-content p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Product Page Styling */
.filter-tabs {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 3rem;
}

.tab-btn {
  padding: 0.6rem 1.5rem;
  border-radius: 30px;
  border: 1px solid var(--glass-border);
  background: var(--glass-bg);
  cursor: pointer;
  font-weight: 500;
  transition: var(--transition-fast);
}

.tab-btn:hover, .tab-btn.active {
  background: var(--accent-gradient);
  border-color: transparent;
  color: white;
  box-shadow: var(--shadow-neon);
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2.5rem;
}

.product-card {
  display: flex;
  overflow: hidden;
  height: 320px;
}

.product-img-wrapper {
  width: 40%;
  overflow: hidden;
  position: relative;
}

.product-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition-normal);
}

.product-card:hover .product-img {
  transform: scale(1.08);
}

.product-info {
  width: 60%;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.product-category {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--accent-color);
  letter-spacing: 1px;
  margin-bottom: 0.5rem;
}

.product-name {
  font-family: var(--font-title);
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 1rem;
  line-height: 1.3;
}

.product-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
  margin-bottom: 1rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.product-features-btn {
  align-self: flex-start;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  transition: var(--transition-fast);
}

.product-features-btn:hover {
  color: var(--accent-color);
}

/* Product Detail Modal */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(11, 15, 25, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  z-index: 2000;
  justify-content: center;
  align-items: center;
  padding: 2rem;
}

.modal.active {
  display: flex;
}

.modal-content {
  width: 100%;
  max-width: 800px;
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
  padding: 3rem;
}

.close-modal {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  font-size: 2rem;
  cursor: pointer;
  color: var(--text-secondary);
  transition: var(--transition-fast);
}

.close-modal:hover {
  color: var(--text-primary);
}

.modal-body h2 {
  font-family: var(--font-title);
  font-size: 2rem;
  margin-bottom: 1.5rem;
}

.modal-body p {
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 2rem;
}

.modal-features-list {
  list-style: none;
}

.modal-features-list li {
  position: relative;
  padding-left: 2rem;
  margin-bottom: 1rem;
  font-size: 1rem;
  line-height: 1.6;
}

.modal-features-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--accent-color);
  font-weight: bold;
}

/* Cooperation Page Styling */
.cooperation-intro {
  margin-bottom: 6rem;
}

.process-timeline {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

.process-card {
  padding: 2.5rem 2rem;
  position: relative;
}

.process-step {
  font-family: var(--font-title);
  font-size: 3rem;
  font-weight: 800;
  opacity: 0.15;
  position: absolute;
  top: 1rem;
  right: 1.5rem;
  color: var(--accent-color);
}

.process-card h3 {
  font-family: var(--font-title);
  font-size: 1.25rem;
  margin-top: 1rem;
  margin-bottom: 1rem;
}

.process-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}

.partners-section {
  margin-top: 6rem;
}

.partners-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 1.5rem;
}

.partner-logo-box {
  height: 90px;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 1rem;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-secondary);
  border: 1px dashed var(--glass-border);
  background: rgba(255, 255, 255, 0.02);
}

.partner-logo-box:hover {
  border-color: var(--accent-color);
  color: var(--text-primary);
  background: var(--glass-bg);
}

.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 4rem;
  margin-top: 6rem;
}

.contact-info-panel {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 2rem;
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 1.5rem;
}

.contact-icon {
  font-size: 1.8rem;
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent-color);
  box-shadow: var(--shadow-neon);
}

.contact-details h4 {
  font-family: var(--font-title);
  font-size: 1.1rem;
  margin-bottom: 0.4rem;
}

.contact-details p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.5;
}

.contact-form-panel {
  padding: 3rem;
}

.contact-form-panel h3 {
  font-family: var(--font-title);
  font-size: 1.5rem;
  margin-bottom: 2rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.form-input {
  width: 100%;
  padding: 0.85rem 1.2rem;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  font-size: 0.95rem;
  transition: var(--transition-fast);
}

.form-input:focus {
  outline: none;
  border-color: var(--accent-color);
  box-shadow: var(--shadow-neon);
  background: rgba(255, 255, 255, 0.05);
}

textarea.form-input {
  resize: vertical;
  min-height: 120px;
}

.submit-btn {
  width: 100%;
  padding: 1rem;
  border-radius: 8px;
  background: var(--accent-gradient);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-normal);
}

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

/* About Us Page Styling */
.about-hero {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 4rem;
  margin-bottom: 6rem;
  align-items: center;
}

.about-text h2 {
  font-family: var(--font-title);
  font-size: 2.25rem;
  margin-bottom: 1.5rem;
}

.about-text p {
  color: var(--text-secondary);
  line-height: 1.8;
  font-size: 1.05rem;
  margin-bottom: 2rem;
}

.about-values-card {
  padding: 2.5rem;
  border-left: 4px solid var(--accent-color);
}

.about-values-card h3 {
  font-family: var(--font-title);
  font-size: 1.35rem;
  margin-bottom: 1.5rem;
}

.value-item {
  margin-bottom: 1.2rem;
}

.value-item strong {
  color: var(--accent-color);
  font-size: 1.1rem;
}

.value-item p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-top: 0.3rem;
}

.timeline-section {
  margin-top: 6rem;
}

.timeline {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 0;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 2px;
  background: var(--glass-border);
  transform: translateX(-50%);
}

.timeline-item {
  position: relative;
  margin-bottom: 4rem;
  width: 50%;
  padding: 0 3rem;
}

.timeline-item:nth-child(odd) {
  left: 0;
  text-align: right;
}

.timeline-item:nth-child(even) {
  left: 50%;
  text-align: left;
}

.timeline-badge {
  position: absolute;
  top: 0;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent-color);
  border: 4px solid var(--bg-primary);
  box-shadow: var(--shadow-neon);
  z-index: 10;
}

.timeline-item:nth-child(odd) .timeline-badge {
  right: -10px;
}

.timeline-item:nth-child(even) .timeline-badge {
  left: -10px;
}

.timeline-year {
  font-family: var(--font-title);
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--accent-color);
  margin-bottom: 0.5rem;
}

.timeline-card {
  padding: 2rem;
}

.timeline-card p {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--text-secondary);
}

/* Footer Styling */
footer {
  margin-top: auto;
  background: #060a12;
  border-top: 1px solid var(--glass-border);
  padding: 4rem 0 2rem 0;
  color: var(--text-secondary);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: 4rem;
  margin-bottom: 3rem;
}

.footer-logo {
  margin-bottom: 1.5rem;
}

.footer-logo-container {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.footer-logo-img {
  height: 36px;
  width: auto;
  object-fit: contain;
}

.footer-desc {
  font-size: 0.9rem;
  line-height: 1.6;
  max-width: 350px;
}

.footer-links h4, .footer-contact h4 {
  font-family: var(--font-title);
  color: var(--text-primary);
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
}

.footer-links ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

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

.footer-contact p {
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 0.8rem;
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.03);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Responsive Design */
@media (max-width: 1024px) {
  .products-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .product-card {
    height: auto;
    flex-direction: column;
  }
  .product-img-wrapper {
    width: 100%;
    height: 220px;
  }
  .product-info {
    width: 100%;
    padding: 1.5rem;
  }
  .contact-layout {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  .about-hero {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
}

@media (max-width: 768px) {
  .nav-container {
    height: 70px;
  }
  nav {
    position: fixed;
    top: 70px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 70px);
    background: var(--bg-secondary);
    z-index: 999;
    transition: var(--transition-normal);
  }
  nav.active {
    left: 0;
  }
  nav ul {
    flex-direction: column;
    align-items: center;
    padding-top: 4rem;
    gap: 2rem;
  }
  .menu-toggle {
    display: flex;
  }
  /* Mobile menu active states */
  .menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
  }
  .menu-toggle.active span:nth-child(2) {
    opacity: 0;
  }
  .menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -7px);
  }
  
  .hero-title {
    font-size: 2.25rem;
  }
  .hero-subtitle {
    font-size: 1.05rem;
  }
  .advantages-grid, .sectors-grid {
    grid-template-columns: 1fr;
  }
  .process-timeline {
    grid-template-columns: 1fr;
  }
  .partners-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .timeline::before {
    left: 20px;
  }
  .timeline-item {
    width: 100%;
    padding-left: 50px;
    padding-right: 0;
  }
  .timeline-item:nth-child(odd) {
    text-align: left;
  }
  .timeline-item:nth-child(even) {
    left: 0;
  }
  .timeline-item:nth-child(odd) .timeline-badge,
  .timeline-item:nth-child(even) .timeline-badge {
    left: 10px;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}