```css
:root {
  --bg-primary: #f5f7fa;
  --bg-secondary: #ffffff;
  --bg-tertiary: #ecf0f3;
  --text-primary: #1e2b3a;
  --text-secondary: #3e5366;
  --text-muted: #7a8b9b;
  --accent: #1a5c9e;
  --accent-hover: #134a7a;
  --accent-light: #6ab0f7;
  --border: #e2e8f0;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.06);
  --shadow-lg: 0 12px 28px rgba(0,0,0,0.08);
  --shadow-xl: 0 20px 40px rgba(0,0,0,0.12);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.6s ease;
  --gradient-primary: linear-gradient(135deg, #1a5c9e 0%, #2e7d5e 50%, #c07a3c 100%);
  --gradient-soft: linear-gradient(135deg, #e8f0fe 0%, #e1f0e8 50%, #f5e6d9 100%);
  --gradient-dark: linear-gradient(135deg, #1a3b5c 0%, #1e2b3a 100%);
  --glass-bg: rgba(255, 255, 255, 0.72);
  --glass-border: rgba(255, 255, 255, 0.4);
  --glass-blur: blur(16px);
}

body.dark-mode {
  --bg-primary: #1a1e24;
  --bg-secondary: #22272e;
  --bg-tertiary: #2d333b;
  --text-primary: #d0d7de;
  --text-secondary: #b0bec5;
  --text-muted: #8b9aab;
  --accent: #6ab0f7;
  --accent-hover: #8ec6ff;
  --accent-light: #6ab0f7;
  --border: #3d444d;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.3);
  --shadow-lg: 0 12px 28px rgba(0,0,0,0.4);
  --shadow-xl: 0 20px 40px rgba(0,0,0,0.5);
  --gradient-soft: linear-gradient(135deg, #1a2a3a 0%, #1a2e28 50%, #2e2418 100%);
  --gradient-dark: linear-gradient(135deg, #0d1117 0%, #1a1e24 100%);
  --glass-bg: rgba(34, 39, 46, 0.78);
  --glass-border: rgba(255, 255, 255, 0.08);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-base), color var(--transition-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

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

ul, ol {
  list-style: none;
}

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

/* ========== 导航吸顶 ========== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--shadow-sm);
  transition: background var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-primary);
  transition: color var(--transition-base);
  flex-shrink: 0;
}

.logo svg {
  width: 36px;
  height: 36px;
  transition: transform var(--transition-base);
}

.logo:hover svg {
  transform: rotate(-10deg) scale(1.08);
}

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

body.dark-mode .logo span {
  background: linear-gradient(135deg, #6ab0f7 0%, #5ecf9e 50%, #f0c040 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.nav-links {
  display: flex;
  gap: 28px;
  font-size: 0.95rem;
}

.nav-links a {
  color: var(--text-secondary);
  font-weight: 500;
  position: relative;
  padding: 4px 0;
  transition: color var(--transition-fast);
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  transition: width var(--transition-base);
}

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

.nav-links a:hover::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.search-box {
  display: flex;
  align-items: center;
  background: var(--bg-tertiary);
  border-radius: var(--radius-full);
  padding: 4px 16px;
  transition: background var(--transition-base), box-shadow var(--transition-fast);
  border: 1px solid transparent;
}

.search-box:focus-within {
  box-shadow: 0 0 0 3px rgba(26, 92, 158, 0.15);
  border-color: var(--accent);
}

body.dark-mode .search-box:focus-within {
  box-shadow: 0 0 0 3px rgba(106, 176, 247, 0.2);
}

.search-box input {
  border: none;
  background: transparent;
  padding: 8px 0;
  font-size: 0.9rem;
  outline: none;
  width: 140px;
  color: var(--text-primary);
  transition: width var(--transition-base);
}

.search-box input::placeholder {
  color: var(--text-muted);
}

.search-box button {
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-fast);
}

.search-box button:hover {
  transform: scale(1.15);
}

.search-box button svg {
  stroke: var(--text-muted);
  transition: stroke var(--transition-fast);
}

.search-box button:hover svg {
  stroke: var(--accent);
}

.dark-toggle {
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  padding: 6px;
  border-radius: 50%;
  transition: background var(--transition-fast), transform var(--transition-fast);
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.dark-toggle:hover {
  background: var(--bg-tertiary);
  transform: rotate(20deg) scale(1.1);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.8rem;
  cursor: pointer;
  color: var(--text-primary);
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
  line-height: 1;
}

.mobile-menu-btn:hover {
  background: var(--bg-tertiary);
}

/* ========== 面包屑 ========== */
.breadcrumb {
  padding: 14px 0;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.breadcrumb li:not(:last-child)::after {
  content: "›";
  margin-left: 6px;
  color: var(--text-muted);
  opacity: 0.6;
}

.breadcrumb a {
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.breadcrumb a:hover {
  color: var(--accent);
}

/* ========== Banner轮播 ========== */
.banner-carousel {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  margin: 20px 0 40px;
  background: var(--gradient-soft);
  min-height: 340px;
  box-shadow: var(--shadow-lg);
  transition: background var(--transition-base), box-shadow var(--transition-base);
}

.banner-carousel::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 20% 30%, rgba(26, 92, 158, 0.08) 0%, transparent 50%),
              radial-gradient(circle at 80% 70%, rgba(46, 125, 94, 0.06) 0%, transparent 50%);
  pointer-events: none;
  z-index: 0;
}

body.dark-mode .banner-carousel::before {
  background: radial-gradient(circle at 20% 30%, rgba(106, 176, 247, 0.06) 0%, transparent 50%),
              radial-gradient(circle at 80% 70%, rgba(94, 207, 158, 0.04) 0%, transparent 50%);
}

.banner-slide {
  display: none;
  padding: 48px 40px;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
  min-height: 340px;
  position: relative;
  z-index: 1;
}

.banner-slide.active {
  display: flex;
  animation: bannerFadeIn 0.6s ease forwards;
}

@keyframes bannerFadeIn {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.banner-text {
  flex: 1 1 300px;
}

.banner-text h1 {
  font-size: 2.2rem;
  color: var(--text-primary);
  margin-bottom: 12px;
  line-height: 1.3;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.banner-text p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.75;
}

.banner-text .btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 12px 28px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  transition: background var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
  box-shadow: 0 4px 14px rgba(26, 92, 158, 0.3);
}

.banner-text .btn:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(26, 92, 158, 0.4);
  color: #fff;
}

body.dark-mode .banner-text .btn {
  box-shadow: 0 4px 14px rgba(106, 176, 247, 0.25);
}

body.dark-mode .banner-text .btn:hover {
  box-shadow: 0 8px 24px rgba(106, 176, 247, 0.35);
}

.banner-image {
  flex: 1 1 260px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.banner-image svg {
  width: 100%;
  max-width: 280px;
  transition: transform var(--transition-slow);
  filter: drop-shadow(0 8px 24px rgba(26, 92, 158, 0.12));
}

.banner-slide.active .banner-image svg {
  animation: floatImage 4s ease-in-out infinite;
}

@keyframes floatImage {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-12px);
  }
}

.banner-dots {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
  z-index: 2;
}

.banner-dots span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.15);
  cursor: pointer;
  transition: background var(--transition-fast), transform var(--transition-fast), width var(--transition-base);
}

.banner-dots span:hover {
  transform: scale(1.2);
}

.banner-dots span.active {
  background: var(--accent);
  width: 28px;
  border-radius: var(--radius-full);
}

body.dark-mode .banner-dots span {
  background: rgba(255, 255, 255, 0.15);
}

body.dark-mode .banner-dots span.active {
  background: var(--accent-light);
}

/* ========== 通用区块 ========== */
.section {
  margin: 56px 0;
}

.section-title {
  font-size: 1.8rem;
  margin-bottom: 28px;
  color: var(--text-primary);
  position: relative;
  padding-bottom: 10px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.section-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 60px;
  height: 4px;
  background: var(--gradient-primary);
  border-radius: 2px;
  transition: width var(--transition-base);
}

.section:hover .section-title::after {
  width: 100px;
}

/* ========== 卡片网格 ========== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 28px;
}

.card {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base), background var(--transition-base);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-primary);
  opacity: 0;
  transition: opacity var(--transition-base);
}

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

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

.card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
  color: var(--text-primary);
  font-weight: 700;
  transition: color var(--transition-fast);
}

.card:hover h3 {
  color: var(--accent);
}

.card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

.card ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 0.95rem;
}

.card ul a {
  color: var(--text-secondary);
  transition: color var(--transition-fast), padding-left var(--transition-fast);
  display: inline-block;
}

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

/* ========== 文章列表 ========== */
.article-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}

.article-item {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
  display: flex;
  flex-direction: column;
}

.article-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent);
}

.article-item h4 {
  font-size: 1.1rem;
  margin-bottom: 8px;
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.5;
  transition: color var(--transition-fast);
}

.article-item:hover h4 {
  color: var(--accent);
}

.article-item .meta {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.article-item p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  margin-bottom: 14px;
  line-height: 1.7;
  flex: 1;
}

.read-more {
  font-weight: 600;
  color: var(--accent);
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap var(--transition-fast), color var(--transition-fast);
  align-self: flex-start;
}

.read-more:hover {
  gap: 8px;
  color: var(--accent-hover);
}

/* ========== FAQ手风琴 ========== */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base), border-color var(--transition-base);
}

.faq-item:hover {
  box-shadow: var(--shadow-md);
}

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

.faq-question {
  padding: 18px 24px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 1rem;
  color: var(--text-primary);
  transition: background var(--transition-fast), color var(--transition-fast);
  user-select: none;
  gap: 16px;
}

.faq-question:hover {
  background: var(--bg-tertiary);
}

.faq-item.open .faq-question {
  color: var(--accent);
}

.faq-question .icon {
  font-size: 1.4rem;
  transition: transform var(--transition-base), color var(--transition-fast);
  flex-shrink: 0;
  line-height: 1;
  color: var(--text-muted);
}

.faq-item.open .faq-question .icon {
  transform: rotate(45deg);
  color: var(--accent);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding var(--transition-base);
  padding: 0 24px;
  background: var(--bg-tertiary);
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

.faq-item.open .faq-answer {
  max-height: 400px;
  padding: 16px 24px 22px;
}

/* ========== HowTo ========== */
.howto-steps {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.howto-step {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.howto-step:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}

.step-number {
  width: 42px;
  height: 42px;
  background: var(--gradient-primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
  font-size: 1.1rem;
  box-shadow: 0 4px 12px rgba(26, 92, 158, 0.3);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.howto-step:hover .step-number {
  transform: scale(1.1) rotate(-8deg);
  box-shadow: 0 6px 20px rgba(26, 92, 158, 0.4);
}

.step-content h4 {
  font-size: 1.1rem;
  margin-bottom: 6px;
  color: var(--text-primary);
  font-weight: 700;
}

.step-content p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

/* ========== 数字动画 ========== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 24px;
  text-align: center;
}

.stat-item {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 28px 16px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

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

.stat-item .stat-number {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1.2;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

body.dark-mode .stat-item .stat-number {
  background: linear-gradient(135deg, #6ab0f7 0%, #5ecf9e 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.stat-item .stat-label {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-top: 6px;
}

/* ========== 客户评价 ========== */
.testimonial-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.testimonial {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
  position: relative;
}

.testimonial::before {
  content: "\201C";
  position: absolute;
  top: 12px;
  right: 20px;
  font-size: 4rem;
  line-height: 1;
  color: var(--accent);
  opacity: 0.12;
  font-family: Georgia, serif;
  pointer-events: none;
}

.testimonial:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent);
}

.testimonial p {
  font-style: italic;
  margin-bottom: 12px;
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.75;
  position: relative;
  z-index: 1;
}

.testimonial .author {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--accent);
}

/* ========== 联系信息 ========== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 28px;
}

.contact-item {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.contact-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent);
}

.contact-item svg {
  width: 36px;
  height: 36px;
  margin: 0 auto 12px;
  stroke: var(--accent);
  transition: transform var(--transition-base);
}

.contact-item:hover svg {
  transform: scale(1.15) rotate(-5deg);
}

.contact-item h4 {
  font-size: 1rem;
  margin-bottom: 6px;
  color: var(--text-primary);
  font-weight: 700;
}

.contact-item p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ========== 页脚 ========== */
footer {
  background: var(--gradient-dark);
  color: #c0ccda;
  padding: 48px 0 24px;
  margin-top: 60px;
  font-size: 0.9rem;
  position: relative;
  overflow: hidden;
}

footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-primary);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 36px;
  margin-bottom: 36px;
}

.footer-col h4 {
  color: #fff;
  margin-bottom: 14px;
  font-size: 1rem;
  font-weight: 700;
  position: relative;
  padding-bottom: 8px;
}

.footer-col h4::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 28px;
  height: 2px;
  background: var(--accent-light);
  border-radius: 1px;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-col a {
  color: #a0b3c7;
  transition: color var(--transition-fast), padding-left var(--transition-fast);
  display: inline-block;
}

.footer-col a:hover {
  color: #fff;
  padding-left: 4px;
}

.footer-col p {
  font-size: 0.88rem;
  color: #a0b3c7;
  line-height: 1.7;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 24px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  font-size: 0.82rem;
  color: #8b9aab;
}

/* ========== 返回顶部 ========== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(26, 92, 158, 0.35);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base), background var(--transition-fast), transform var(--transition-fast);
  z-index: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--accent-hover);
  transform: translateY(-4px) scale(1.08);
  box-shadow: 0 10px 28px rgba(26, 92, 158, 0.45);
}

.back-to-top:active {
  transform: translateY(-2px) scale(1.02);
}

/* ========== 滚动动画 ========== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
  will-change: opacity, transform;
}

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

/* ========== 图片懒加载占位 ========== */
.lazy-svg {
  background: var(--bg-tertiary);
  border-radius: var(--radius-sm);
  min-height: 160px;
  animation: shimmer 1.8s infinite;
}

@keyframes shimmer {
  0% {
    background-position: -400px 0;
  }
  100% {
    background-position: 400px 0;
  }
}

/* ========== 响应式布局 ========== */
@media (max-width: 1024px) {
  .banner-text h1 {
    font-size: 1.9rem;
  }

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

@media (max-width: 820px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--glass-bg);
    -webkit-backdrop-filter: var(--glass-blur);
    backdrop-filter: var(--glass-blur);
    flex-direction: column;
    padding: 20px 24px;
    box-shadow: var(--shadow-lg);
    gap: 18px;
    border-bottom: 1px solid var(--glass-border);
    animation: slideDown 0.3s ease forwards;
  }

  @keyframes slideDown {
    from {
      opacity: 0;
      transform: translateY(-10px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .nav-links.open {
    display: flex;
  }

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

  .mobile-menu-btn {
    display: block;
  }

  .search-box input {
    width: 100px;
  }

  .banner-slide {
    padding: 36px 24px;
    flex-direction: column-reverse;
    text-align: center;
  }

  .banner-text h1 {
    font-size: 1.7rem;
  }

  .banner-text p {
    font-size: 0.98rem;
  }

  .banner-image svg {
    max-width: 200px;
  }

  .section {
    margin: 40px 0;
  }

  .section-title {
    font-size: 1.45rem;
  }

  .card-grid,
  .article-list,
  .testimonial-grid,
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .howto-step {
    flex-direction: column;
    gap: 14px;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 28px;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 42px;
    height: 42px;
    font-size: 1.2rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .navbar .container {
    height: 60px;
  }

  .logo {
    font-size: 1.05rem;
  }

  .logo svg {
    width: 30px;
    height: 30px;
  }

  .search-box {
    display: none;
  }

  .banner-carousel {
    min-height: 280px;
    border-radius: var(--radius-md);
  }

  .banner-slide {
    padding: 28px 18px;
    min-height: 280px;
  }

  .banner-text h1 {
    font-size: 1.4rem;
  }

  .banner-text p {
    font-size: 0.9rem;
  }

  .banner-text .btn {
    padding: 10px 22px;
    font-size: 0.88rem;
  }

  .section-title {
    font-size: 1.25rem;
  }

  .card {
    padding: 22px 18px;
  }

  .card h3 {
    font-size: 1.1rem;
  }

  .article-item {
    padding: 18px;
  }

  .article-item h4 {
    font-size: 1rem;
  }

  .faq-question {
    padding: 14px 18px;
    font-size: 0.92rem;
  }

  .faq-answer {
    padding: 0 18px;
    font-size: 0.88rem;
  }

  .faq-item.open .faq-answer {
    padding: 14px 18px 18px;
  }

  .stat-item .stat-number {
    font-size: 1.9rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .howto-step {
    padding: 18px;
  }

  .step-number {
    width: 36px;
    height: 36px;
    font-size: 0.95rem;
  }
}

/* ========== 无障碍与打印 ========== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .fade-in {
    opacity: 1;
    transform: none;
  }
}

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

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

body.dark-mode ::selection {
  background: var(--accent-light);
  color: #1a1e24;
}

/* 滚动条美化 */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--text-muted);
  border-radius: var(--radius-full);
  border: 2px solid var(--bg-primary);
  transition: background var(--transition-fast);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}
```