/* ===== 基础重置与变量 ===== */
:root {
  --primary: #1a237e;
  --primary-light: #283593;
  --primary-dark: #0d1442;
  --accent: #ffd700;
  --accent-light: #ffe44d;
  --accent-dark: #c7a600;
  --bg-dark: #0a0e1a;
  --bg-card: rgba(26, 35, 126, 0.15);
  --bg-glass: rgba(10, 14, 26, 0.7);
  --text-primary: #f0f0f0;
  --text-secondary: #b0b0c0;
  --text-muted: #6b7280;
  --border-color: rgba(255, 215, 0, 0.2);
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
  --shadow-md: 0 8px 32px rgba(0,0,0,0.4);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.5);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

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

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

body {
  font-family: var(--font-sans);
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
}

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

a:hover, a:focus {
  color: var(--accent-light);
  outline: none;
}

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

ul, ol {
  list-style: none;
}

button, input, textarea, select {
  font: inherit;
  color: inherit;
  border: none;
  background: none;
  outline: none;
}

button {
  cursor: pointer;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

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

/* ===== 滚动条 ===== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-dark);
}

::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-light);
}

/* ===== 动画关键帧 ===== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(40px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes slideInLeft {
  from { opacity: 0; transform: translateX(-60px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes slideInRight {
  from { opacity: 0; transform: translateX(60px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50%      { transform: scale(1.05); }
}

@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-10px); }
}

@keyframes gradientShift {
  0%   { background-position: 0% 50%; }
  50%  { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* ===== 通用组件 ===== */
.section {
  padding: 100px 0;
  position: relative;
}

.section-alt {
  background: linear-gradient(135deg, rgba(26,35,126,0.08) 0%, rgba(13,20,66,0.12) 100%);
}

.section-title {
  font-size: 2.5rem;
  font-weight: 800;
  text-align: center;
  margin-bottom: 60px;
  position: relative;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

.section-title::after {
  content: '';
  display: block;
  width: 80px;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--accent-light));
  margin: 16px auto 0;
  border-radius: 2px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 1rem;
  transition: var(--transition);
  text-align: center;
  gap: 8px;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.15), transparent);
  transition: 0.5s;
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: var(--primary-dark);
  box-shadow: 0 4px 20px rgba(255, 215, 0, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(255, 215, 0, 0.4);
  color: var(--primary-dark);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.15);
  transform: translateY(-2px);
  color: var(--text-primary);
}

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

.btn-outline:hover {
  background: var(--accent);
  color: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(255, 215, 0, 0.3);
}

/* ===== Header / 导航 ===== */
#site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
  padding: 12px 20px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-primary);
  font-size: 1.4rem;
  font-weight: 800;
  transition: var(--transition);
}

.nav-logo:hover {
  transform: scale(1.02);
  color: var(--accent);
}

.nav-brand {
  letter-spacing: 1px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  background: transparent;
  border: none;
  cursor: pointer;
}

.nav-toggle-line {
  display: block;
  width: 28px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

.nav-menu {
  display: flex;
  gap: 8px;
  align-items: center;
}

.nav-link {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-weight: 500;
  transition: var(--transition);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 60%;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
  transition: var(--transition);
}

.nav-link:hover, .nav-link:focus {
  color: var(--accent);
  background: rgba(255, 215, 0, 0.05);
}

.nav-link:hover::after, .nav-link:focus::after {
  transform: translateX(-50%) scaleX(1);
}

/* ===== Hero 轮播 ===== */
.hero-section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding-top: 80px;
}

.hero-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: 
    radial-gradient(ellipse at 20% 50%, rgba(26,35,126,0.4) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 50%, rgba(255,215,0,0.1) 0%, transparent 60%);
  z-index: 0;
  animation: gradientShift 15s ease infinite;
  background-size: 200% 200%;
}

.hero-slider {
  position: relative;
  width: 100%;
  max-width: 1200px;
  padding: 0 20px;
  z-index: 1;
}

.hero-slide {
  display: none;
  animation: fadeIn 0.8s ease;
}

.hero-slide.active {
  display: block;
}

.hero-content {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
  padding: 60px 0;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 24px;
  letter-spacing: -1px;
  animation: fadeInUp 0.8s ease;
}

.hero-accent {
  background: linear-gradient(135deg, var(--accent), var(--accent-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-block;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-bottom: 40px;
  max-width: 650px;
  margin-left: auto;
  margin-right: auto;
  animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease 0.4s both;
}

.hero-controls {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 20px;
  z-index: 2;
}

.hero-prev, .hero-next {
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  color: var(--text-primary);
  width: 48px;
  height: 48px;
  border-radius: 50%;
  font-size: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  backdrop-filter: blur(10px);
}

.hero-prev:hover, .hero-next:hover {
  background: var(--accent);
  color: var(--primary-dark);
  border-color: var(--accent);
  transform: scale(1.1);
}

.hero-dots {
  display: flex;
  gap: 10px;
}

.hero-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: rgba(255,255,255,0.3);
  border: none;
  transition: var(--transition);
  cursor: pointer;
}

.hero-dot.active {
  background: var(--accent);
  transform: scale(1.2);
  box-shadow: 0 0 12px rgba(255,215,0,0.5);
}

/* ===== About 关于 ===== */
.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-bottom: 40px;
}

.about-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px;
  transition: var(--transition);
  animation: fadeInUp 0.6s ease both;
}

.about-card:nth-child(1) { animation-delay: 0.1s; }
.about-card:nth-child(2) { animation-delay: 0.2s; }
.about-card:nth-child(3) { animation-delay: 0.3s; }
.about-card:nth-child(4) { animation-delay: 0.4s; }

.about-card:hover {
  transform: translateY(-8px);
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
  background: rgba(26,35,126,0.25);
}

.about-card-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--accent);
}

.about-card p {
  color: var(--text-secondary);
  line-height: 1.7;
}

.about-meta {
  text-align: center;
  padding: 24px;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  margin-top: 20px;
  animation: fadeInUp 0.6s ease 0.5s both;
}

.about-meta p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin: 4px 0;
}

/* ===== Products 产品 ===== */
.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 30px;
}

.product-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  text-align: center;
  transition: var(--transition);
  animation: fadeInUp 0.6s ease both;
  position: relative;
  overflow: hidden;
}

.product-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--accent-light), var(--accent));
  opacity: 0;
  transition: var(--transition);
}

.product-card:hover::before {
  opacity: 1;
}

.product-card:nth-child(1) { animation-delay: 0.1s; }
.product-card:nth-child(2) { animation-delay: 0.2s; }
.product-card:nth-child(3) { animation-delay: 0.3s; }

.product-card:hover {
  transform: translateY(-10px);
  border-color: var(--accent);
  box-shadow: var(--shadow-lg);
  background: rgba(26,35,126,0.25);
}

.product-icon {
  margin-bottom: 20px;
  animation: float 3s ease-in-out infinite;
}

.product-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.product-desc {
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.7;
}

.product-features {
  text-align: left;
  margin-bottom: 24px;
  padding: 0;
}

.product-features li {
  position: relative;
  padding: 8px 0 8px 28px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.product-features li::before {
  content: '✦';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-size: 0.8rem;
}

/* ===== Services 服务 ===== */
.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 24px;
}

.service-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px;
  transition: var(--transition);
  animation: fadeInUp 0.6s ease both;
  position: relative;
  overflow: hidden;
}

.service-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--accent), transparent);
  opacity: 0;
  transition: var(--transition);
}

.service-card:hover::after {
  opacity: 1;
}

.service-card:nth-child(1) { animation-delay: 0.05s; }
.service-card:nth-child(2) { animation-delay: 0.1s; }
.service-card:nth-child(3) { animation-delay: 0.15s; }
.service-card:nth-child(4) { animation-delay: 0.2s; }
.service-card:nth-child(5) { animation-delay: 0.25s; }
.service-card:nth-child(6) { animation-delay: 0.3s; }

.service-card:hover {
  transform: translateY(-6px);
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
  background: rgba(26,35,126,0.2);
}

.service-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--accent);
}

.service-card p {
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===== Features 特色 ===== */
.features-list {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.feature-item {
  display: flex;
  gap: 24px;
  align-items: flex-start;
  padding: 28px 32px;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: var(--transition);
  animation: slideInLeft 0.6s ease both;
}

.feature-item:nth-child(1) { animation-delay: 0.1s; }
.feature-item:nth-child(2) { animation-delay: 0.2s; }
.feature-item:nth-child(3) { animation-delay: 0.3s; }
.feature-item:nth-child(4) { animation-delay: 0.4s; }

.feature-item:hover {
  transform: translateX(8px);
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
  background: rgba(26,35,126,0.2);
}

.feature-num {
  flex-shrink: 0;
  width: 60px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: var(--primary-dark);
  font-size: 1.5rem;
  font-weight: 800;
  border-radius: var(--radius-sm);
  font-family: monospace;
}

.feature-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.feature-item p {
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===== Testimonials 评价 ===== */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.testimonial-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px;
  transition: var(--transition);
  animation: fadeInUp 0.6s ease both;
  position: relative;
}

.testimonial-card::before {
  content: '"';
  position: absolute;
  top: 16px;
  left: 24px;
  font-size: 4rem;
  color: var(--accent);
  opacity: 0.2;
  font-family: serif;
  line-height: 1;
}

.testimonial-card:nth-child(1) { animation-delay: 0.1s; }
.testimonial-card:nth-child(2) { animation-delay: 0.2s; }
.testimonial-card:nth-child(3) { animation-delay: 0.3s; }

.testimonial-card:hover {
  transform: translateY(-6px);
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.testimonial-card p {
  font-style: italic;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
  padding-top: 20px;
}

.testimonial-author {
  color: var(--accent);
  font-weight: 600;
  font-style: normal;
}

/* ===== FAQ 常见问题 ===== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: var(--transition);
  animation: fadeInUp 0.6s ease both;
}

.faq-item[open] {
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
}

.faq-question {
  padding: 20px 24px;
  font-weight: 600;
  font-size: 1.05rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--text-primary);
  transition: var(--transition);
  user-select: none;
  list-style: none;
}

.faq-question::-webkit-details-marker {
  display: none;
}

.faq-question::after {
  content: '+';
  font-size: 1.5rem;
  color: var(--accent);
  transition: var(--transition);
  flex-shrink: 0;
}

.faq-item[open] .faq-question::after {
  content: '−';
  transform: rotate(180deg);
}

.faq-question:hover {
  background: rgba(255,215,0,0.05);
}

.faq-answer {
  padding: 0 24px 20px;
  color: var(--text-secondary);
  line-height: 1.7;
  animation: fadeIn 0.3s ease;
}

/* ===== Contact 联系 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}

.contact-info {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px;
  animation: fadeInUp 0.6s ease;
}

.contact-info h3 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--accent);
}

.contact-info p {
  margin-bottom: 12px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.contact-info strong {
  color: var(--text-primary);
}

.contact-form {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px;
  animation: fadeInUp 0.6s ease 0.2s both;
}

.contact-form h3 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--accent);
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 14px 16px;
  margin-bottom: 16px;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  transition: var(--transition);
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(255,215,0,0.1);
  background: rgba(255,255,255,0.08);
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: var(--text-muted);
}

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

.contact-form .btn {
  width: 100%;
}

/* ===== Footer 页脚 ===== */
#site-footer {
  background: linear-gradient(180deg, rgba(10,14,26,0.95), rgba(13,20,66,0.9));
  border-top: 1px solid var(--border-color);
  padding: 60px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--border-color);
}

.footer-col h4 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--accent);
}

.footer-col p {
  color: var(--text-secondary);
  line-height: 1.7;
  font-size: 0.95rem;
}

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

.footer-col ul li a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  transition: var(--transition);
}

.footer-col ul li a:hover {
  color: var(--accent);
  padding-left: 4px;
}

.footer-bottom {
  padding: 24px 0;
  text-align: center;
}

.footer-bottom p {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin: 4px 0;
}

/* ===== Back to Top ===== */
#back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: var(--primary-dark);
  font-size: 1.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 20px rgba(255,215,0,0.3);
  transition: var(--transition);
  z-index: 999;
  border: none;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
}

#back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

#back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(255,215,0,0.4);
}

/* ===== Search Modal ===== */
.modal {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(10,14,26,0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal.active {
  display: flex;
}

.modal-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px;
  width: 100%;
  max-width: 560px;
  position: relative;
  animation: fadeInUp 0.4s ease;
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(255,255,255,0.1);
  color: var(--text-primary);
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  border: none;
  cursor: pointer;
}

.modal-close:hover {
  background: var(--accent);
  color: var(--primary-dark);
}

.modal-content form {
  display: flex;
  gap: 12px;
}

.modal-content input {
  flex: 1;
  padding: 14px 16px;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 1rem;
}

.modal-content input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(255,215,0,0.1);
}

.modal-content input::placeholder {
  color: var(--text-muted);
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
  .hero-title {
    font-size: 2.8rem;
  }

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

@media (max-width: 768px) {
  .section {
    padding: 60px 0;
  }

  .section-title {
    font-size: 2rem;
    margin-bottom: 40px;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 16px;
    gap: 4px;
    border-bottom: 1px solid var(--border-color);
  }

  .nav-menu.active {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

  .hero-title {
    font-size: 2.2rem;
  }

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

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 300px;
  }

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

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

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

  .feature-item {
    flex-direction: column;
    align-items: flex-start;
    padding: 20px;
  }

  .feature-num {
    width: 48px;
    height: 48px;
    font-size: 1.2rem;
  }

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

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

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

  .modal-content {
    padding: 24px;
  }

  .modal-content form {
    flex-direction: column;
  }

  #back-to-top {
    bottom: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
    font-size: 1.2rem;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 1.8rem;
  }

  .section-title {
    font-size: 1.6rem;
  }

  .product-card {
    padding: 28px 20px;
  }

  .about-card {
    padding: 24px;
  }

  .service-card {
    padding: 24px;
  }

  .contact-info,
  .contact-form {
    padding: 24px;
  }
}

/* ===== 暗色模式增强 ===== */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-dark: #0a0e1a;
    --text-primary: #f0f0f0;
  }
}

/* ===== 滚动动画 ===== */
@media (prefers-reduced-motion: no-preference) {
  .section {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
  }

  .section.visible {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== 打印样式 ===== */
@media print {
  #site-header,
  #back-to-top,
  .hero-controls,
  .modal {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }

  .section {
    page-break-inside: avoid;
    opacity: 1 !important;
    transform: none !important;
  }
}