/* ============================================
   千年艾官网 - 主样式表
   蕲春千年艾科技有限公司 qna1688.com
   ============================================ */

/* CSS Variables */
:root {
  /* Brand Colors */
  --color-primary: #2d6a4f;
  --color-primary-dark: #1b4332;
  --color-primary-light: #52b788;
  --color-accent: #c9a227;
  --color-accent-light: #e9c46a;

  /* Neutral Colors */
  --color-bg: #faf8f5;
  --color-bg-alt: #f0ede5;
  --color-surface: #ffffff;
  --color-text: #1a1a1a;
  --color-text-muted: #6c757d;
  --color-border: #e0ddd5;

  /* Typography */
  --font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-size-base: 16px;
  --line-height-base: 1.7;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;

  /* Layout */
  --container-max: 1200px;
  --radius: 8px;
  --radius-lg: 16px;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.12);
  --transition: all 0.3s ease;
}

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

html {
  font-size: var(--font-size-base);
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  line-height: var(--line-height-base);
  color: var(--color-text);
  background: var(--color-bg);
  overflow-x: hidden;
}

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

a:hover {
  color: var(--color-primary-dark);
}

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

ul, ol {
  list-style: none;
}

/* Container */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

/* ============================================
   Header / Navigation
   ============================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary-dark);
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.2rem;
}

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

.logo-text small {
  font-size: 0.7rem;
  color: var(--color-text-muted);
  font-weight: 400;
}

.nav-menu {
  display: flex;
  gap: var(--spacing-md);
  align-items: center;
}

.nav-menu a {
  color: var(--color-text);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.5rem 0;
  position: relative;
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: var(--transition);
}

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

.nav-cta {
  background: var(--color-primary);
  color: white !important;
  padding: 0.5rem 1.5rem !important;
  border-radius: var(--radius);
  font-weight: 600;
}

.nav-cta:hover {
  background: var(--color-primary-dark);
  transform: translateY(-1px);
}

/* Nav Dropdown */
.nav-menu > li.has-dropdown {
  position: relative;
}

.nav-menu > li.has-dropdown > a::after {
  content: ' ▾';
  font-size: 0.7em;
  color: var(--color-text-muted);
}

.nav-dropdown {
  display: none;
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  background: white;
  box-shadow: var(--shadow-md);
  border-radius: var(--radius);
  min-width: 160px;
  padding: 0.5rem 0;
  z-index: 100;
}

.nav-dropdown li {
  width: 100%;
}

.nav-dropdown a {
  display: block;
  padding: 0.6rem 1.5rem;
  font-size: 0.9rem;
  white-space: nowrap;
}

.nav-dropdown a::after {
  display: none;
}

.nav-dropdown a:hover {
  background: var(--color-bg-alt);
  color: var(--color-primary);
}

.nav-menu > li.has-dropdown:hover .nav-dropdown {
  display: block;
}

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

/* ============================================
   Hero Section
   ============================================ */
.hero {
  position: relative;
  min-height: 600px;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 50%, var(--color-primary-light) 100%);
  color: white;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.5;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 700px;
  padding: var(--spacing-lg) 0;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: var(--spacing-sm);
}

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

.hero-subtitle {
  font-size: 1.25rem;
  opacity: 0.9;
  margin-bottom: var(--spacing-md);
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 2rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
  border: 2px solid transparent;
}

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

.btn-primary:hover {
  background: var(--color-accent-light);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

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

.btn-green {
  background: var(--color-primary);
  color: white;
}

.btn-green:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
}

.hero-stats {
  display: flex;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-lg);
  flex-wrap: wrap;
}

.hero-stat {
  text-align: center;
}

.hero-stat .number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-accent-light);
}

.hero-stat .label {
  font-size: 0.9rem;
  opacity: 0.85;
}

/* ============================================
   Section Common
   ============================================ */
.section {
  padding: var(--spacing-xl) 0;
}

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

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto var(--spacing-lg);
}

.section-header h2 {
  font-size: 2.2rem;
  color: var(--color-primary-dark);
  margin-bottom: var(--spacing-xs);
}

.section-header .subtitle {
  color: var(--color-text-muted);
  font-size: 1.1rem;
}

.section-header .divider {
  width: 60px;
  height: 3px;
  background: var(--color-accent);
  margin: var(--spacing-sm) auto;
  border-radius: 2px;
}

/* ============================================
   Product Grid
   ============================================ */
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-md);
}

.product-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1px solid var(--color-border);
}

.product-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.product-card-image {
  width: 100%;
  height: 220px;
  background: linear-gradient(135deg, var(--color-bg-alt), var(--color-border));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: var(--color-primary);
}

.product-card-body {
  padding: var(--spacing-sm);
}

.product-card-category {
  font-size: 0.8rem;
  color: var(--color-primary);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.product-card h3 {
  font-size: 1.15rem;
  margin: 0.5rem 0;
  color: var(--color-text);
}

.product-card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-sm);
  line-height: 1.5;
}

.product-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--spacing-xs);
  border-top: 1px solid var(--color-border);
}

.product-card-footer .price {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-primary-dark);
}

.product-card-footer .buy-link {
  background: var(--color-primary);
  color: white;
  padding: 0.4rem 1rem;
  border-radius: var(--radius);
  font-size: 0.85rem;
  font-weight: 600;
}

.product-card-footer .buy-link:hover {
  background: var(--color-primary-dark);
}

/* ============================================
   Features/Advantages
   ============================================ */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-md);
}

.feature-card {
  text-align: center;
  padding: var(--spacing-md);
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 70px;
  height: 70px;
  margin: 0 auto var(--spacing-sm);
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
}

.feature-card h3 {
  font-size: 1.2rem;
  color: var(--color-primary-dark);
  margin-bottom: 0.5rem;
}

.feature-card p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* ============================================
   Timeline
   ============================================ */
.timeline {
  max-width: 800px;
  margin: 0 auto;
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(to bottom, var(--color-primary), var(--color-primary-light));
  border-radius: 2px;
}

.timeline-item {
  position: relative;
  padding-bottom: var(--spacing-md);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -2rem;
  top: 0.3rem;
  width: 16px;
  height: 16px;
  background: var(--color-accent);
  border: 3px solid var(--color-surface);
  border-radius: 50%;
  box-shadow: 0 0 0 3px var(--color-primary);
  transform: translateX(-7px);
}

.timeline-year {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 0.3rem;
}

.timeline-content h4 {
  font-size: 1.1rem;
  margin-bottom: 0.3rem;
}

.timeline-content p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* ============================================
   Certifications Grid
   ============================================ */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--spacing-sm);
}

.cert-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--spacing-sm);
  text-align: center;
  transition: var(--transition);
}

.cert-item:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.cert-icon {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.cert-item p {
  font-size: 0.85rem;
  color: var(--color-text);
  font-weight: 500;
}

/* ============================================
   News Cards
   ============================================ */
.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--spacing-md);
}

.news-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1px solid var(--color-border);
}

.news-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.news-card-image {
  width: 100%;
  height: 180px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 2rem;
}

.news-card-body {
  padding: var(--spacing-sm);
}

.news-date {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
}

.news-card h3 {
  font-size: 1.1rem;
  line-height: 1.4;
  margin-bottom: 0.5rem;
}

.news-card h3 a {
  color: var(--color-text);
}

.news-card h3 a:hover {
  color: var(--color-primary);
}

.news-card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* ============================================
   Contact Page
   ============================================ */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-md);
}

.contact-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  box-shadow: var(--shadow-sm);
  border-top: 4px solid var(--color-primary);
  transition: var(--transition);
}

.contact-card:hover {
  box-shadow: var(--shadow-md);
}

.contact-card h3 {
  font-size: 1.1rem;
  color: var(--color-primary-dark);
  margin-bottom: 0.3rem;
}

.contact-card .role {
  font-size: 0.85rem;
  color: var(--color-accent);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

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

.contact-card p strong {
  color: var(--color-text);
}

/* ============================================
   Breadcrumbs
   ============================================ */
.breadcrumbs {
  padding: var(--spacing-sm) 0;
  background: var(--color-bg-alt);
  font-size: 0.85rem;
}

.breadcrumbs ol {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

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

.breadcrumbs a:hover {
  color: var(--color-primary);
}

.breadcrumbs span {
  color: var(--color-text);
  font-weight: 500;
}

.breadcrumbs li::after {
  content: '/';
  margin-left: 0.5rem;
  color: var(--color-border);
}

.breadcrumbs li:last-child::after {
  display: none;
}

/* ============================================
   Page Header (inner pages)
   ============================================ */
.page-header {
  background: linear-gradient(135deg, var(--color-primary-dark), var(--color-primary));
  color: white;
  padding: var(--spacing-lg) 0;
  text-align: center;
}

.page-header h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.page-header p {
  font-size: 1.1rem;
  opacity: 0.85;
}

/* ============================================
   Article / Content
   ============================================ */
.article-content {
  max-width: 800px;
  margin: 0 auto;
  padding: var(--spacing-md) 0;
}

.article-content h2 {
  font-size: 1.8rem;
  color: var(--color-primary-dark);
  margin: var(--spacing-md) 0 var(--spacing-sm);
}

.article-content h3 {
  font-size: 1.3rem;
  color: var(--color-primary-dark);
  margin: var(--spacing-sm) 0 var(--spacing-xs);
}

.article-content p {
  margin-bottom: var(--spacing-sm);
  font-size: 1rem;
  line-height: 1.8;
  color: #333;
}

.article-content ul {
  list-style: disc;
  padding-left: 1.5rem;
  margin-bottom: var(--spacing-sm);
}

.article-content ul li {
  margin-bottom: 0.5rem;
}

.article-meta {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 1px solid var(--color-border);
}

/* ============================================
   CTA Banner
   ============================================ */
.cta-banner {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: white;
  text-align: center;
  padding: var(--spacing-lg) 0;
}

.cta-banner h2 {
  font-size: 2rem;
  margin-bottom: var(--spacing-sm);
}

.cta-banner p {
  font-size: 1.1rem;
  opacity: 0.9;
  margin-bottom: var(--spacing-md);
}

/* ============================================
   Footer
   ============================================ */
.site-footer {
  background: var(--color-primary-dark);
  color: rgba(255,255,255,0.85);
  padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.footer-col h4 {
  color: white;
  font-size: 1.1rem;
  margin-bottom: var(--spacing-sm);
}

.footer-col ul li {
  margin-bottom: 0.5rem;
}

.footer-col a {
  color: rgba(255,255,255,0.75);
  font-size: 0.9rem;
}

.footer-col a:hover {
  color: var(--color-accent-light);
}

.footer-col p {
  font-size: 0.9rem;
  line-height: 1.6;
  color: rgba(255,255,255,0.75);
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-sm);
  border-top: 1px solid rgba(255,255,255,0.1);
  font-size: 0.85rem;
  color: rgba(255,255,255,0.6);
}

.footer-bottom a {
  color: rgba(255,255,255,0.6);
}

/* ============================================
   Product Detail Page
   ============================================ */
.product-detail {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-lg);
  padding: var(--spacing-md) 0;
}

.product-detail-image {
  background: linear-gradient(135deg, var(--color-bg-alt), var(--color-border));
  border-radius: var(--radius-lg);
  min-height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 5rem;
  color: var(--color-primary);
}

.product-detail-info h1 {
  font-size: 2rem;
  color: var(--color-primary-dark);
  margin-bottom: var(--spacing-xs);
}

.product-detail-info .product-category {
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.product-detail-info .product-desc {
  font-size: 1rem;
  line-height: 1.8;
  color: #333;
  margin-bottom: var(--spacing-md);
}

.product-features {
  margin-bottom: var(--spacing-md);
}

.product-features li {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: start;
  gap: 0.5rem;
}

.product-features li::before {
  content: '\2713';
  color: var(--color-primary);
  font-weight: 700;
  flex-shrink: 0;
}

.product-actions {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  .nav-menu {
    position: fixed;
    top: 65px;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: var(--spacing-sm);
    gap: 0;
    box-shadow: var(--shadow-md);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
  }

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

  .nav-menu a {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--color-border);
    width: 100%;
  }

  .nav-cta {
    margin-top: var(--spacing-xs);
    text-align: center;
  }

  .nav-menu > li.has-dropdown > a::after {
    display: none;
  }

  .nav-dropdown {
    display: block;
    position: static;
    transform: none;
    box-shadow: none;
    padding: 0 0 0 1.5rem;
    min-width: auto;
  }

  .nav-dropdown a {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    border-bottom: 1px solid var(--color-border);
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .hero-stats {
    gap: var(--spacing-sm);
  }

  .hero-stat .number {
    font-size: 1.8rem;
  }

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

  .section-header h2 {
    font-size: 1.7rem;
  }

  .product-detail {
    grid-template-columns: 1fr;
  }

  .page-header h1 {
    font-size: 1.8rem;
  }

  .cta-banner h2 {
    font-size: 1.5rem;
  }

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

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.6rem;
  }

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

  .btn {
    width: 100%;
    justify-content: center;
  }

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