```css
/* ===== 基础重置 & 全局变量 ===== */
:root {
  --bg-body: #F9FAFB;
  --bg-card: #FFFFFF;
  --bg-header: #FFFFFF;
  --bg-footer: #243447;
  --text-primary: #17202A;
  --text-secondary: #334155;
  --text-heading: #0F172A;
  --text-footer: #E2E8F0;
  --text-footer-heading: #FFFFFF;
  --text-link: #1D4ED8;
  --text-btn: #FFFFFF;
  --btn-bg: #1F2937;
  --border-light: #D1D5DB;
  --banner-overlay: rgba(0, 0, 0, 0.65);
  --code-bg: #F1F5F9;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.1);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 暗黑模式变量覆盖 */
body.dark-mode {
  --bg-body: #0B1120;
  --bg-card: #1E293B;
  --bg-header: #111827;
  --text-primary: #E2E8F0;
  --text-secondary: #CBD5E1;
  --text-heading: #F8FAFC;
  --text-link: #93C5FD;
  --btn-bg: #3B82F6;
  --border-light: #334155;
  --bg-footer: #0F172A;
  --text-footer: #CBD5E1;
  --text-footer-heading: #F1F5F9;
  --code-bg: #1E293B;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.6);
}

/* 基础重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.7;
  transition: background var(--transition-base), color var(--transition-base);
  overflow-x: hidden;
}

/* ===== 排版系统 ===== */
h1, h2, h3, h4, h5 {
  color: var(--text-heading);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.6rem;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 800;
  background: linear-gradient(135deg, #fff, #e2e8f0);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

h2 {
  font-size: clamp(1.5rem, 3vw, 1.9rem);
  margin-top: 2.5rem;
  border-left: 6px solid transparent;
  border-image: linear-gradient(180deg, #3B82F6, #8B5CF6) 1;
  padding-left: 1rem;
  position: relative;
}

h2::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, #3B82F6, transparent);
  border-radius: 2px;
}

h3 {
  font-size: clamp(1.2rem, 2vw, 1.4rem);
  margin-top: 1.5rem;
}

h4 {
  font-size: 1.1rem;
}

p {
  margin-bottom: 1.2rem;
  color: var(--text-primary);
}

a {
  color: var(--text-link);
  text-decoration: none;
  font-weight: 500;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

a:hover {
  border-bottom: 1px solid var(--text-link);
  color: var(--text-link);
}

/* 通用容器 */
.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== 头部导航 ===== */
.header {
  background: var(--bg-header);
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid var(--border-light);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  background-color: color-mix(in srgb, var(--bg-header) 80%, transparent);
  transition: background var(--transition-base);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0;
  flex-wrap: wrap;
  gap: 12px;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-area svg {
  transition: transform var(--transition-base);
  filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.15));
}

.logo-area svg:hover {
  transform: rotate(-5deg) scale(1.05);
}

.logo-text {
  font-weight: 800;
  font-size: 1.4rem;
  background: linear-gradient(135deg, var(--text-heading), var(--text-link));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  gap: 24px;
  align-items: center;
  flex-wrap: wrap;
  list-style: none;
}

.nav-links a {
  color: var(--text-primary);
  font-weight: 500;
  font-size: 0.95rem;
  position: relative;
  padding: 4px 0;
  border-bottom: none;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #3B82F6, #8B5CF6);
  transition: width var(--transition-base);
  border-radius: 2px;
}

.nav-links a:hover {
  color: var(--text-link);
  border-bottom: none;
}

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

/* 搜索框 */
.search-box {
  display: flex;
  align-items: center;
  background: var(--bg-body);
  border-radius: var(--radius-pill);
  padding: 4px 16px;
  border: 1px solid var(--border-light);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  backdrop-filter: blur(10px);
}

.search-box:focus-within {
  border-color: #3B82F6;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.search-box input {
  border: none;
  background: transparent;
  padding: 8px 10px;
  font-size: 0.9rem;
  color: var(--text-primary);
  outline: none;
  width: 160px;
  transition: width var(--transition-base);
}

.search-box input:focus {
  width: 180px;
}

.search-box input::placeholder {
  color: var(--text-secondary);
  opacity: 0.7;
}

.search-box button {
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--text-heading);
  font-size: 1rem;
  transition: transform var(--transition-fast);
  padding: 4px;
}

.search-box button:hover {
  transform: scale(1.2);
}

/* 主题切换按钮 */
.theme-toggle {
  background: var(--btn-bg);
  color: var(--text-btn);
  border: none;
  padding: 8px 18px;
  border-radius: var(--radius-pill);
  cursor: pointer;
  font-weight: 600;
  font-size: 0.9rem;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.theme-toggle:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  filter: brightness(1.1);
}

.theme-toggle:active {
  transform: translateY(0);
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.8rem;
  color: var(--text-heading);
  cursor: pointer;
  padding: 4px 8px;
  transition: transform var(--transition-fast);
}

.mobile-menu-btn:hover {
  transform: scale(1.1);
}

/* ===== 主视觉 Banner ===== */
.banner {
  background: linear-gradient(135deg, #1e293b, #334155, #1e293b);
  margin-top: 24px;
  border-radius: var(--radius-lg);
  padding: clamp(2rem, 5vw, 4rem) clamp(1.5rem, 4vw, 3rem);
  position: relative;
  overflow: hidden;
  color: white;
  box-shadow: var(--shadow-lg);
  background-size: 400% 400%;
  animation: gradientShift 12s ease infinite;
}

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

.banner::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.2), transparent 60%);
  animation: pulse 6s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 0.5; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.2); }
}

.banner-content {
  max-width: 750px;
  background: rgba(0, 0, 0, 0.35);
  padding: clamp(1.5rem, 3vw, 2.5rem);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  position: relative;
  z-index: 1;
  transition: transform var(--transition-slow), box-shadow var(--transition-slow);
}

.banner-content:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.banner h1 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  margin-bottom: 0.8rem;
  background: linear-gradient(135deg, #ffffff, #e2e8f0);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.2;
}

.banner h2 {
  color: white;
  font-size: clamp(1.5rem, 3.5vw, 2.3rem);
  border-left: none;
  padding-left: 0;
  margin-top: 0;
  -webkit-text-fill-color: white;
  background: none;
}

.banner p {
  color: #f1f5f9;
  font-size: clamp(1rem, 1.5vw, 1.2rem);
  margin-bottom: 1.5rem;
  opacity: 0.95;
}

/* 按钮组 */
.btn-group {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

.btn {
  background: linear-gradient(135deg, #2563EB, #3B82F6);
  color: white !important;
  padding: 12px 28px;
  border-radius: var(--radius-pill);
  font-weight: 600;
  border: none;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  transition: all var(--transition-base);
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
  font-size: 1rem;
  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, 0.2), transparent);
  transition: left var(--transition-slow);
}

.btn:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
  color: white !important;
  border-bottom: none;
}

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

.btn:active {
  transform: translateY(-1px) scale(0.98);
}

.btn-outline {
  background: transparent;
  border: 2px solid rgba(255, 255, 255, 0.8);
  color: white !important;
  box-shadow: none;
  backdrop-filter: blur(4px);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: white;
  box-shadow: 0 4px 15px rgba(255, 255, 255, 0.2);
}

/* ===== 卡片区域 ===== */
.section-title {
  margin: 3rem 0 1.5rem;
  position: relative;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 1.8rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(8px);
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, #3B82F6, #8B5CF6, #EC4899);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-slow);
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.card:hover::before {
  transform: scaleX(1);
}

.card h3, .card h4 {
  margin-bottom: 12px;
  font-weight: 700;
}

.card p {
  color: var(--text-primary);
  margin-bottom: 0;
  font-size: 0.95rem;
}

/* 悬浮标签 */
.badge {
  display: inline-block;
  background: linear-gradient(135deg, #E0E7FF, #C7D2FE);
  color: #1E3A8A;
  padding: 5px 16px;
  border-radius: var(--radius-pill);
  font-size: 0.8rem;
  font-weight: 600;
  transition: all var(--transition-base);
  cursor: default;
  border: 1px solid rgba(30, 58, 138, 0.1);
}

.badge:hover {
  transform: scale(1.05);
  box-shadow: 0 4px 12px rgba(30, 58, 138, 0.2);
}

body.dark-mode .badge {
  background: linear-gradient(135deg, #1e3a5f, #2d4a7a);
  color: #E0E7FF;
  border-color: rgba(224, 231, 255, 0.2);
}

/* ===== 文章列表 ===== */
.article-list {
  list-style: none;
}

.article-list li {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-light);
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  transition: all var(--transition-base);
  border-radius: var(--radius-sm);
  margin-bottom: 4px;
  background: transparent;
}

.article-list li:hover {
  background: var(--bg-card);
  padding-left: 28px;
  box-shadow: var(--shadow-sm);
  border-radius: var(--radius-md);
}

.article-date {
  color: var(--text-secondary);
  font-size: 0.9rem;
  min-width: 90px;
  font-family: 'SF Mono', 'Fira Code', monospace;
  opacity: 0.8;
}

.article-title {
  font-weight: 600;
  color: var(--text-heading);
  flex: 1;
  font-size: 1rem;
  border-bottom: none;
  transition: color var(--transition-fast);
}

.article-title:hover {
  color: var(--text-link);
  border-bottom: none;
}

.read-more {
  color: var(--text-link);
  font-size: 0.9rem;
  opacity: 0;
  transform: translateX(-10px);
  transition: all var(--transition-base);
  white-space: nowrap;
}

.article-list li:hover .read-more {
  opacity: 1;
  transform: translateX(0);
}

/* ===== FAQ 折叠面板 ===== */
details {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 1rem 1.5rem;
  margin-bottom: 12px;
  transition: all var(--transition-base);
  overflow: hidden;
  position: relative;
}

details:hover {
  border-color: var(--text-link);
  box-shadow: var(--shadow-md);
}

details[open] {
  border-color: var(--text-link);
  box-shadow: var(--shadow-md);
  background: var(--bg-card);
}

summary {
  font-weight: 600;
  cursor: pointer;
  color: var(--text-heading);
  font-size: 1.05rem;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 0;
  transition: color var(--transition-fast);
}

summary::-webkit-details-marker {
  display: none;
}

summary::after {
  content: '＋';
  font-size: 1.4rem;
  color: var(--text-link);
  transition: transform var(--transition-base);
  flex-shrink: 0;
  font-weight: 400;
}

details[open] summary::after {
  content: '－';
  transform: rotate(180deg);
}

summary:hover {
  color: var(--text-link);
}

details p {
  margin-top: 12px;
  color: var(--text-primary);
  padding-top: 12px;
  border-top: 1px solid var(--border-light);
  animation: fadeInUp 0.4s ease;
}

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

/* ===== 页脚 ===== */
.footer {
  background: var(--bg-footer);
  color: var(--text-footer);
  padding: 3rem 0 2rem;
  margin-top: 4rem;
  border-radius: 40px 40px 0 0;
  position: relative;
  overflow: hidden;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #3B82F6, #8B5CF6, #EC4899, #3B82F6);
  background-size: 300% 100%;
  animation: gradientMove 8s linear infinite;
}

@keyframes gradientMove {
  0% { background-position: 0% 50%; }
  100% { background-position: 300% 50%; }
}

.footer a {
  color: var(--text-footer);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  transition: all var(--transition-fast);
}

.footer a:hover {
  color: white;
  border-bottom-color: white;
}

.footer-columns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer h4 {
  color: var(--text-footer-heading);
  font-size: 1.1rem;
  margin-bottom: 1rem;
  position: relative;
  padding-bottom: 8px;
}

.footer h4::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 30px;
  height: 2px;
  background: #3B82F6;
  border-radius: 2px;
}

.footer p, .footer li {
  color: var(--text-footer);
  line-height: 2;
}

.footer ul {
  list-style: none;
}

.footer ul li {
  margin-bottom: 4px;
  transition: padding-left var(--transition-fast);
}

.footer ul li:hover {
  padding-left: 8px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: 2rem;
  padding-top: 1.5rem;
  font-size: 0.9rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  opacity: 0.9;
}

/* ===== 返回顶部 ===== */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: var(--btn-bg);
  color: white;
  border: none;
  border-radius: 50%;
  width: 50px;
  height: 50px;
  font-size: 1.4rem;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  transition: all var(--transition-base);
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
}

.back-to-top:hover {
  background: #2563EB;
  transform: translateY(-4px) scale(1.05);
  box-shadow: 0 8px 30px rgba(37, 99, 235, 0.4);
}

.back-to-top:active {
  transform: translateY(0) scale(0.95);
}

/* ===== SVG 占位图 ===== */
.svg-illustration {
  background: linear-gradient(135deg, #D9E2EF, #E2E8F0);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  min-height: 120px;
  transition: all var(--transition-base);
  border: 1px solid rgba(0, 0, 0, 0.05);
  position: relative;
  overflow: hidden;
}

.svg-illustration::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.1), transparent);
  animation: shimmer 3s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

.svg-illustration svg {
  transition: transform var(--transition-base);
}

.svg-illustration:hover svg {
  transform: scale(1.02);
}

/* ===== 步骤条 ===== */
.step {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.2rem;
  align-items: flex-start;
  padding: 12px;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
}

.step:hover {
  background: var(--code-bg);
}

.step-num {
  background: linear-gradient(135deg, #2563EB, #3B82F6);
  color: white;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
  font-size: 0.95rem;
}

/* ===== 滚动动画 ===== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all var(--transition-slow);
}

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

/* 为不同部分增加延迟 */
.reveal:nth-child(2) { transition-delay: 0.1s; }
.reveal:nth-child(3) { transition-delay: 0.2s; }
.reveal:nth-child(4) { transition-delay: 0.3s; }

/* ===== 通用工具样式 ===== */
section {
  margin-bottom: 2rem;
}

section > .container {
  padding-top: 2rem;
}

/* 强调文字 */
strong {
  color: var(--text-heading);
  font-weight: 700;
}

/* 区块背景区分 */
#intro, #products, #solutions, #cases, #articles, #howto, #faq, #contact {
  background: transparent;
  padding: 2rem 0;
  border-radius: var(--radius-lg);
  transition: background var(--transition-base);
}

/* 联系区域样式 */
#contact > div {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 2rem;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
}

#contact > div:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

#contact p {
  margin-bottom: 0.8rem;
  line-height: 1.8;
}

/* 分割线 */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-light), transparent);
  margin: 2rem 0;
  border: none;
}

/* ===== 响应式适配 ===== */
@media (max-width: 1024px) {
  .container {
    max-width: 100%;
  }

  .nav-links {
    gap: 16px;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 16px;
  }

  .header-inner {
    padding: 10px 0;
  }

  .nav-links {
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: flex-start;
    padding: 16px 0;
    gap: 12px;
    border-top: 1px solid var(--border-light);
    background: var(--bg-header);
    animation: slideDown 0.3s ease;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    padding: 20px;
    backdrop-filter: blur(20px);
    background-color: color-mix(in srgb, var(--bg-header) 90%, transparent);
  }

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

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

  .search-box {
    width: 100%;
    margin: 8px 0;
  }

  .search-box input {
    flex: 1;
    width: auto;
  }

  .search-box input:focus {
    width: auto;
  }

  .theme-toggle {
    width: 100%;
    margin-top: 8px;
  }

  .banner {
    margin-top: 16px;
    border-radius: 20px;
  }

  .banner-content {
    padding: 1.5rem;
  }

  .banner h1 {
    font-size: 1.6rem;
  }

  .banner p {
    font-size: 1rem;
  }

  .card-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .article-list li {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 14px;
  }

  .article-list li:hover {
    padding-left: 18px;
  }

  .article-date {
    min-width: auto;
    font-size: 0.85rem;
  }

  .read-more {
    opacity: 1;
    transform: none;
  }

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

  .footer {
    border-radius: 24px 24px 0 0;
    padding: 2rem 0 1.5rem;
  }

  .footer-columns {
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
    gap: 8px;
  }

  h2 {
    margin-top: 2rem;
  }

  section {
    margin-bottom: 1rem;
  }

  #contact > div {
    padding: 1.5rem;
  }

  .svg-illustration {
    min-height: 80px;
  }

  .step {
    flex-direction: row;
    padding: 8px;
  }
}

@media (max-width: 480px) {
  .footer-columns {
    grid-template-columns: 1fr;
  }

  .btn-group {
    flex-direction: column;
    width: 100%;
  }

  .btn {
    width: 100%;
    text-align: center;
  }

  h1 {
    font-size: 1.4rem;
  }

  .banner-content {
    padding: 1.2rem;
  }

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

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

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

::-webkit-scrollbar-thumb {
  background: linear-gradient(135deg, #94a3b8, #64748b);
  border-radius: 10px;
  border: 2px solid var(--bg-body);
}

::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(135deg, #3B82F6, #2563EB);
}

/* 暗色模式滚动条 */
body.dark-mode ::-webkit-scrollbar-thumb {
  background: linear-gradient(135deg, #475569, #334155);
  border-color: var(--bg-body);
}

/* 文本选中样式 */
::selection {
  background: rgba(59, 130, 246, 0.3);
  color: var(--text-heading);
}

/* 焦点可见性 */
:focus-visible {
  outline: 3px solid rgba(59, 130, 246, 0.5);
  outline-offset: 2px;
  border-radius: 4px;
}

/* 卡片 hover 光效 */
.card::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 0%, rgba(59, 130, 246, 0.1), transparent 60%);
  opacity: 0;
  transition: opacity var(--transition-base);
  pointer-events: none;
}

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

/* 图片和媒体元素响应式 */
img, svg, video {
  max-width: 100%;
  height: auto;
}

/* 打印样式 */
@media print {
  .header, .footer, .back-to-top, .btn-group, .search-box, .theme-toggle, .mobile-menu-btn {
    display: none !important;
  }

  body {
    background: white;
    color: black;
  }

  .container {
    max-width: 100%;
    padding: 0;
  }

  .banner {
    background: white;
    color: black;
    padding: 1rem;
  }

  .banner-content {
    background: white;
    border: 1px solid #ccc;
  }
}
```