:root {
  --primary: #2ecc71;
  --secondary: #27ae60;
  --accent: #e74c3c;
  --bg: #ecf0f1;
  --text: #2c3e50;
  --text-light: #7f8c8d;
  --border: #bdc3c7;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.15);
  --radius-sm: 4px;
  --radius-md: 8px;
  --transition: 0.3s ease;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

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

a:hover {
  color: var(--secondary);
}

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

/* Header & Navigation */
header {
  background: #fff;
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 20px;
  background: var(--secondary);
  color: #fff;
  font-size: 0.85rem;
}

.logo {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-tagline {
  font-size: 0.75rem;
  color: var(--text-light);
  display: block;
}

nav {
  display: flex;
  gap: 24px;
  padding: 16px 20px;
  align-items: center;
}

nav a {
  font-weight: 600;
  color: var(--text);
  position: relative;
}

nav a:after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width var(--transition);
}

nav a:hover:after {
  width: 100%;
}

.search-bar {
  display: flex;
  gap: 0;
  max-width: 300px;
  border-radius: 24px;
  overflow: hidden;
  border: 2px solid var(--primary);
  background: #fff;
}

.search-bar input {
  flex: 1;
  border: none;
  padding: 8px 16px;
  font-size: 0.9rem;
  outline: none;
}

.search-bar button {
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 8px 16px;
  cursor: pointer;
  font-weight: 600;
}

/* Hero Section */
.hero {
  position: relative;
  min-height: 600px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  color: #fff;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
}

.hero-bg {
  position: absolute;
  inset: 0;
  background-image: url('/images/banner.jpg');
  background-size: cover;
  background-position: center;
  opacity: 0.3;
  z-index: 0;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 800px;
  padding: 40px 20px;
}

.hero h1 {
  font-size: 3.2rem;
  margin-bottom: 16px;
  font-weight: 900;
  line-height: 1.2;
}

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

.hero-desc {
  font-size: 1.1rem;
  line-height: 1.8;
  opacity: 0.9;
  margin-bottom: 32px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  padding: 12px 32px;
  border-radius: var(--radius-md);
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  font-size: 0.95rem;
}

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

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

.btn-secondary {
  background: #fff;
  color: var(--primary);
  border: 2px solid var(--primary);
}

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

/* Section Styles */
.section {
  padding: 60px 20px;
  max-width: 1200px;
  margin: 0 auto;
}

.section-alt {
  background: #fff;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 40px;
  text-align: center;
  color: var(--text);
}

.section-title span {
  color: var(--primary);
}

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}

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

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

/* Video Card */
.video-card {
  background: #fff;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  cursor: pointer;
}

.video-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-md);
}

.video-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
  background: #1a1a2e;
}

.video-thumb video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 0.3s;
}

.video-thumb:hover video {
  opacity: 1;
}

.video-play-btn {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition);
  background: rgba(0,0,0,0.25);
}

.video-card:hover .video-play-btn {
  opacity: 1;
}

.play-icon {
  width: 60px;
  height: 60px;
  background: rgba(255,255,255,0.9);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  color: var(--primary);
}

.video-info {
  padding: 16px;
}

.video-title {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-meta {
  font-size: 0.8rem;
  color: var(--text-light);
  display: flex;
  gap: 12px;
}

/* Feature Card */
.feature-card {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  font-size: 2.4rem;
  margin-bottom: 16px;
  color: var(--primary);
}

.feature-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text);
}

.feature-desc {
  font-size: 0.9rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* Expert Card */
.expert-card {
  background: #fff;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

.expert-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-md);
}

.expert-avatar {
  position: relative;
  aspect-ratio: 4/3;
  overflow: hidden;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
}

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

.expert-info {
  padding: 16px;
}

.expert-name {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 4px;
  color: var(--text);
}

.expert-role {
  font-size: 0.85rem;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 8px;
}

.expert-desc {
  font-size: 0.8rem;
  color: var(--text-light);
  line-height: 1.6;
  margin-bottom: 12px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.expert-actions {
  display: flex;
  gap: 8px;
  font-size: 0.8rem;
}

.expert-actions a {
  flex: 1;
  padding: 6px 8px;
  background: var(--bg);
  border-radius: var(--radius-sm);
  text-align: center;
  color: var(--primary);
  font-weight: 600;
}

/* FAQ */
.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  background: #fff;
}

.faq-question {
  padding: 16px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 600;
  background: var(--bg);
  transition: background var(--transition);
}

.faq-question:hover {
  background: #fff;
}

.faq-toggle {
  font-size: 1.2rem;
  color: var(--primary);
  transition: transform var(--transition);
}

.faq-item.open .faq-toggle {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.25s;
  padding: 0 16px;
}

.faq-item.open .faq-answer {
  max-height: 500px;
  padding: 16px;
}

.faq-answer p {
  color: var(--text-light);
  line-height: 1.8;
}

/* Review Card */
.review-card {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  border-left: 4px solid var(--primary);
}

.review-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.review-author {
  font-weight: 700;
  color: var(--text);
}

.review-rating {
  color: #f39c12;
  font-size: 0.9rem;
}

.review-text {
  color: var(--text-light);
  line-height: 1.8;
  font-size: 0.95rem;
}

/* Footer */
footer {
  background: var(--text);
  color: #fff;
  padding: 40px 20px;
  margin-top: 60px;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 40px;
  margin-bottom: 40px;
}

.footer-section h3 {
  font-size: 1.1rem;
  margin-bottom: 16px;
  color: var(--primary);
}

.footer-section a {
  display: block;
  margin-bottom: 8px;
  font-size: 0.9rem;
  opacity: 0.8;
  transition: opacity var(--transition);
}

.footer-section a:hover {
  opacity: 1;
}

.footer-qr {
  display: flex;
  gap: 20px;
  justify-content: center;
  margin-bottom: 20px;
}

.qr-item {
  text-align: center;
}

.qr-item img {
  width: 120px;
  height: 120px;
  margin-bottom: 8px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
}

.qr-label {
  font-size: 0.8rem;
  opacity: 0.7;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 20px;
  text-align: center;
  font-size: 0.85rem;
  opacity: 0.7;
}

/* Back to Top */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 44px;
  height: 44px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0;
  transform: translateY(10px);
  transition: all var(--transition);
  z-index: 800;
  pointer-events: none;
}

.back-to-top.show {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

/* Fade In Animation */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

/* Responsive */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2rem;
  }
  
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .section-title {
    font-size: 1.6rem;
  }
  
  nav {
    gap: 12px;
    font-size: 0.9rem;
  }
  
  .search-bar {
    max-width: 200px;
  }
  
  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.5rem;
  }
  
  .section {
    padding: 40px 16px;
  }
  
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
  }
}


/* 干扰标签隔离：标签保留在 DOM 模板中，但不参与渲染、布局和无障碍树。 */
.interference-pool,
.interference-pool * {
  display: none !important;
  width: 0 !important;
  height: 0 !important;
  margin: 0 !important;
  padding: 0 !important;
  border: 0 !important;
  overflow: hidden !important;
}