/* ============================================================
   蓝莓视频 - 企业视频营销与品牌传播专业平台
   风格：现代科技 · 渐变 · 毛玻璃 · 暗色模式
   作者：资深UI/UX设计师
   ============================================================ */

/* ---------- 全局重置 & 基础变量 ---------- */
:root {
  --primary: #1a73e8;
  --primary-dark: #0d47a1;
  --primary-light: #4a9eff;
  --accent: #ff6f00;
  --accent-dark: #e65100;
  --bg: #ffffff;
  --bg-card: #f5f5f5;
  --bg-card-alt: #f9f9f9;
  --text: #333333;
  --text-light: #666666;
  --text-muted: #888888;
  --border: #eeeeee;
  --glass-bg: rgba(255, 255, 255, 0.75);
  --glass-border: rgba(255, 255, 255, 0.3);
  --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);
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 8px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

body.dark-mode {
  --bg: #1a1a2e;
  --bg-card: #2a2a3e;
  --bg-card-alt: #2a2a3e;
  --text: #e0e0e0;
  --text-light: #aaaaaa;
  --text-muted: #888888;
  --border: #333333;
  --glass-bg: rgba(26, 26, 46, 0.75);
  --glass-border: rgba(255, 255, 255, 0.1);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
}

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

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

body {
  font-family: var(--font);
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  transition: background var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

body.dark-mode a:hover {
  color: var(--primary-light);
}

ul {
  list-style: none;
}

/* ---------- 容器 & 通用 ---------- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
  border-bottom: 1px solid var(--border);
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  margin-bottom: 40px;
  text-align: center;
  color: var(--primary);
  letter-spacing: -0.5px;
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 2px;
  margin: 12px auto 0;
}

body.dark-mode .section-title {
  color: var(--primary-light);
}

.section-desc {
  text-align: center;
  margin-bottom: 40px;
  font-size: 1.1rem;
  color: var(--text-light);
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-block;
  padding: 14px 36px;
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: #fff;
  text-decoration: none;
  border-radius: 50px;
  font-weight: 700;
  font-size: 1rem;
  transition: all var(--transition);
  box-shadow: 0 4px 15px rgba(255, 111, 0, 0.35);
  border: none;
  cursor: pointer;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(255, 111, 0, 0.45);
  color: #fff;
}

.btn:active {
  transform: translateY(0);
}

/* ---------- 导航 ---------- */
nav {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  padding: 0 24px;
  transition: all var(--transition);
  position: relative;
  z-index: 1001;
}

nav.sticky {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
  backdrop-filter: blur(12px);
  background: linear-gradient(135deg, rgba(26, 115, 232, 0.95), rgba(13, 71, 161, 0.95));
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
  height: 68px;
}

.logo a {
  display: flex;
  align-items: center;
}

.logo img {
  height: 44px;
  width: auto;
  border-radius: var(--radius-xs);
}

.nav-menu {
  display: flex;
  gap: 6px;
}

.nav-menu li a {
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: 50px;
  transition: all var(--transition);
  position: relative;
}

.nav-menu li a:hover {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
}

.search-box form {
  display: flex;
  align-items: center;
}

.search-box input {
  padding: 8px 16px;
  border: none;
  border-radius: 50px 0 0 50px;
  font-size: 0.9rem;
  background: rgba(255, 255, 255, 0.2);
  color: #fff;
  outline: none;
  width: 180px;
  transition: all var(--transition);
}

.search-box input::placeholder {
  color: rgba(255, 255, 255, 0.6);
}

.search-box input:focus {
  background: rgba(255, 255, 255, 0.3);
  width: 220px;
}

.search-box button {
  padding: 8px 18px;
  background: var(--primary-dark);
  color: #fff;
  border: none;
  border-radius: 0 50px 50px 0;
  cursor: pointer;
  font-weight: 600;
  transition: background var(--transition);
}

.search-box button:hover {
  background: #0a3d8f;
}

.theme-toggle {
  cursor: pointer;
  font-size: 1.5rem;
  color: #fff;
  padding: 4px 8px;
  border-radius: 50px;
  transition: background var(--transition);
  user-select: none;
}

.theme-toggle:hover {
  background: rgba(255, 255, 255, 0.15);
}

.mobile-menu-toggle {
  display: none;
  cursor: pointer;
  font-size: 1.8rem;
  color: #fff;
  padding: 4px 8px;
  user-select: none;
}

/* ---------- Banner 渐变轮播 ---------- */
.banner {
  position: relative;
  overflow: hidden;
  height: 560px;
  background: linear-gradient(135deg, #0d47a1 0%, #1a73e8 50%, #4a9eff 100%);
}

body.dark-mode .banner {
  background: linear-gradient(135deg, #0a0a1a 0%, #16213e 50%, #1a3a5c 100%);
}

.banner-slider {
  position: relative;
  height: 100%;
}

.banner-slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.8s ease;
  will-change: opacity;
}

.banner-slide.active {
  opacity: 1;
}

.banner-content {
  text-align: center;
  color: #fff;
  padding: 40px 24px;
  max-width: 800px;
  background: var(--glass-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
}

.banner-content h1,
.banner-content h2 {
  font-size: 2.8rem;
  font-weight: 800;
  margin-bottom: 16px;
  letter-spacing: -1px;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.15);
}

.banner-content p {
  font-size: 1.25rem;
  margin-bottom: 32px;
  opacity: 0.9;
  line-height: 1.7;
}

.banner-dots {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 12px;
}

.dot {
  width: 14px;
  height: 14px;
  background: rgba(255, 255, 255, 0.4);
  border-radius: 50%;
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
}

.dot.active {
  background: #fff;
  border-color: var(--accent);
  transform: scale(1.2);
}

.banner-arrows {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 100%;
  display: flex;
  justify-content: space-between;
  padding: 0 24px;
  pointer-events: none;
}

.arrow-left,
.arrow-right {
  pointer-events: all;
  font-size: 3.5rem;
  color: #fff;
  cursor: pointer;
  opacity: 0.5;
  transition: all var(--transition);
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.2);
  border-radius: 50%;
  backdrop-filter: blur(4px);
}

.arrow-left:hover,
.arrow-right:hover {
  opacity: 1;
  background: rgba(0, 0, 0, 0.4);
  transform: scale(1.1);
}

/* ---------- 品牌介绍 ---------- */
.brand-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 28px;
}

.brand-card {
  background: var(--bg-card);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  border: 1px solid transparent;
}

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

body.dark-mode .brand-card:hover {
  border-color: var(--primary-light);
}

.brand-card h3 {
  color: var(--primary);
  margin-bottom: 16px;
  font-size: 1.3rem;
  font-weight: 700;
}

body.dark-mode .brand-card h3 {
  color: var(--primary-light);
}

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

/* ---------- 产品服务 ---------- */
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 28px;
}

.product-item {
  background: var(--bg-card-alt);
  padding: 32px;
  border-radius: var(--radius);
  border-left: 5px solid var(--primary);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

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

.product-item h3 {
  color: var(--primary);
  margin-bottom: 14px;
  font-size: 1.25rem;
  font-weight: 700;
}

body.dark-mode .product-item h3 {
  color: var(--primary-light);
}

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

/* ---------- 解决方案 ---------- */
.solution-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 28px;
}

.solution-item {
  background: var(--bg-card);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.solution-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--primary), var(--accent));
  border-radius: 0 2px 2px 0;
}

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

.solution-item h3 {
  color: var(--primary);
  margin-bottom: 14px;
  font-size: 1.2rem;
  font-weight: 700;
}

body.dark-mode .solution-item h3 {
  color: var(--primary-light);
}

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

/* ---------- 行业应用 ---------- */
.app-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 20px;
}

.app-item {
  background: linear-gradient(135deg, var(--bg-card), var(--bg-card-alt));
  padding: 24px 20px;
  border-radius: var(--radius-sm);
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  border: 1px solid transparent;
}

.app-item:hover {
  transform: translateY(-4px) scale(1.02);
  box-shadow: var(--shadow-md);
  border-color: var(--primary);
  background: linear-gradient(135deg, var(--bg-card-alt), var(--bg-card));
}

.app-item h3 {
  color: var(--primary);
  margin-bottom: 8px;
  font-size: 1.1rem;
  font-weight: 700;
}

body.dark-mode .app-item h3 {
  color: var(--primary-light);
}

.app-item p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* ---------- 客户案例 ---------- */
.case-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 28px;
}

.case-card {
  background: var(--bg-card);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  position: relative;
}

.case-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.case-card h3 {
  color: var(--primary);
  margin-bottom: 14px;
  font-size: 1.2rem;
  font-weight: 700;
}

body.dark-mode .case-card h3 {
  color: var(--primary-light);
}

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

/* ---------- 客户评价 ---------- */
.testimonial-list {
  display: grid;
  gap: 24px;
}

.testimonial-item {
  background: var(--bg-card-alt);
  padding: 32px 36px;
  border-radius: var(--radius);
  border-left: 5px solid var(--accent);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  position: relative;
}

.testimonial-item:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-md);
}

.testimonial-item p {
  font-style: italic;
  margin-bottom: 16px;
  font-size: 1.05rem;
  color: var(--text);
  line-height: 1.7;
}

.testimonial-item cite {
  color: var(--text-light);
  font-style: normal;
  font-weight: 600;
  display: block;
}

/* ---------- 文章中心 ---------- */
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 28px;
}

.article-item {
  background: var(--bg-card);
  padding: 28px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

.article-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.article-item h3 {
  margin-bottom: 8px;
  font-size: 1.15rem;
}

.article-item h3 a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition);
}

.article-item h3 a:hover {
  color: var(--accent);
}

body.dark-mode .article-item h3 a {
  color: var(--primary-light);
}

body.dark-mode .article-item h3 a:hover {
  color: var(--accent);
}

.article-item time {
  color: var(--text-muted);
  font-size: 0.85rem;
  display: block;
  margin-bottom: 12px;
}

.article-item p {
  color: var(--text-light);
  line-height: 1.7;
  margin-bottom: 16px;
}

.read-more {
  color: var(--accent);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.95rem;
  transition: all var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

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

/* ---------- FAQ ---------- */
.faq-list {
  display: grid;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition);
}

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

.faq-question {
  padding: 20px 28px;
  cursor: pointer;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--primary);
  position: relative;
  transition: background var(--transition);
  user-select: none;
}

body.dark-mode .faq-question {
  color: var(--primary-light);
}

.faq-question:hover {
  background: rgba(26, 115, 232, 0.05);
}

body.dark-mode .faq-question:hover {
  background: rgba(74, 158, 255, 0.08);
}

.faq-question::after {
  content: '+';
  position: absolute;
  right: 28px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.6rem;
  font-weight: 300;
  transition: transform var(--transition);
  color: var(--text-muted);
}

.faq-question.active::after {
  transform: translateY(-50%) rotate(45deg);
  color: var(--accent);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
  padding: 0 28px;
}

.faq-answer.open {
  max-height: 600px;
  padding: 0 28px 24px;
}

.faq-answer p {
  color: var(--text-light);
  line-height: 1.7;
  margin: 0;
}

/* ---------- HowTo ---------- */
.howto-steps {
  display: grid;
  gap: 24px;
  margin-bottom: 40px;
}

.step {
  background: var(--bg-card);
  padding: 28px 32px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  position: relative;
  padding-left: 56px;
}

.step::before {
  content: attr(data-step);
  position: absolute;
  left: 20px;
  top: 28px;
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 700;
}

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

.step h3 {
  color: var(--primary);
  margin-bottom: 10px;
  font-size: 1.15rem;
  font-weight: 700;
}

body.dark-mode .step h3 {
  color: var(--primary-light);
}

.step p {
  color: var(--text-light);
  line-height: 1.7;
}

.howto-notes {
  background: var(--bg-card-alt);
  padding: 36px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.howto-notes h3 {
  color: var(--primary);
  margin-top: 24px;
  margin-bottom: 12px;
  font-size: 1.15rem;
  font-weight: 700;
}

body.dark-mode .howto-notes h3 {
  color: var(--primary-light);
}

.howto-notes h3:first-child {
  margin-top: 0;
}

.howto-notes ul {
  padding-left: 24px;
  margin-bottom: 20px;
}

.howto-notes li {
  margin-bottom: 8px;
  color: var(--text-light);
  line-height: 1.6;
}

.howto-notes p {
  color: var(--text-light);
  line-height: 1.7;
}

/* ---------- 联系我们 ---------- */
.contact-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.contact-item {
  background: var(--bg-card);
  padding: 28px 24px;
  border-radius: var(--radius-sm);
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

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

.contact-item h3 {
  color: var(--primary);
  margin-bottom: 12px;
  font-size: 1.1rem;
  font-weight: 700;
}

body.dark-mode .contact-item h3 {
  color: var(--primary-light);
}

.contact-item p {
  color: var(--text-light);
  font-size: 0.95rem;
}

/* ---------- 网站地图 ---------- */
.sitemap-list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

.sitemap-list a {
  color: var(--primary);
  text-decoration: none;
  padding: 10px 22px;
  background: var(--bg-card);
  border-radius: 50px;
  transition: all var(--transition);
  font-weight: 500;
  font-size: 0.95rem;
  box-shadow: var(--shadow-sm);
}

.sitemap-list a:hover {
  background: var(--primary);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

body.dark-mode .sitemap-list a:hover {
  background: var(--primary-light);
  color: #1a1a2e;
}

/* ---------- 友情链接 ---------- */
.friend-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
}

.friend-links a {
  color: var(--text-light);
  text-decoration: none;
  padding: 6px 14px;
  border-radius: 50px;
  transition: all var(--transition);
  font-size: 0.9rem;
}

.friend-links a:hover {
  color: var(--primary);
  background: var(--bg-card);
}

/* ---------- 页脚 ---------- */
footer {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  padding: 60px 0 24px;
}

body.dark-mode footer {
  background: linear-gradient(135deg, #0a0a1a, #16213e);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-section h3 {
  margin-bottom: 18px;
  font-size: 1.2rem;
  font-weight: 700;
  position: relative;
  padding-bottom: 10px;
}

.footer-section h3::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

.footer-section p {
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.7;
  font-size: 0.95rem;
}

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

.footer-section ul a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  transition: all var(--transition);
  font-size: 0.95rem;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
}

.footer-bottom p {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
}

.footer-links {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  font-size: 0.85rem;
  transition: color var(--transition);
}

.footer-links a:hover {
  color: #fff;
}

/* ---------- 返回顶部 ---------- */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(26, 115, 232, 0.4);
  z-index: 999;
  transition: all var(--transition);
  border: none;
  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) scale(1.05);
  box-shadow: 0 8px 30px rgba(26, 115, 232, 0.5);
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .banner {
    height: 480px;
  }

  .banner-content h1,
  .banner-content h2 {
    font-size: 2.2rem;
  }

  .section {
    padding: 60px 0;
  }

  .section-title {
    font-size: 1.8rem;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    padding: 20px 24px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
    z-index: 1000;
  }

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

  .nav-menu li a {
    padding: 12px 16px;
    border-radius: var(--radius-xs);
  }

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

  .search-box {
    display: none;
  }

  .banner {
    height: 380px;
  }

  .banner-content {
    padding: 28px 20px;
    margin: 0 16px;
  }

  .banner-content h1,
  .banner-content h2 {
    font-size: 1.6rem;
  }

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

  .arrow-left,
  .arrow-right {
    width: 40px;
    height: 40px;
    font-size: 2rem;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .brand-grid,
  .product-grid,
  .solution-list,
  .case-grid,
  .article-grid {
    grid-template-columns: 1fr;
  }

  .app-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .step {
    padding-left: 48px;
  }

  .step::before {
    left: 14px;
    width: 24px;
    height: 24px;
    font-size: 0.75rem;
  }

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

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

  .footer-links {
    justify-content: center;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
    font-size: 1.3rem;
  }
}

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

  .banner {
    height: 320px;
  }

  .banner-content h1,
  .banner-content h2 {
    font-size: 1.3rem;
  }

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

  .section {
    padding: 40px 0;
  }

  .section-title {
    font-size: 1.3rem;
  }

  .app-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .app-item {
    padding: 16px 12px;
  }

  .app-item h3 {
    font-size: 1rem;
  }

  .testimonial-item {
    padding: 24px;
  }

  .howto-notes {
    padding: 24px;
  }
}

/* ---------- 滚动条美化 ---------- */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

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

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

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

body.dark-mode ::-webkit-scrollbar-thumb {
  background: var(--primary-light);
}

/* ---------- 选中样式 ---------- */
::selection {
  background: var(--primary);
  color: #fff;
}

body.dark-mode ::selection {
  background: var(--primary-light);
  color: #1a1a2e;
}