/*
==============================================
  众鑫官网 - 蓝色主题样式表
  Created: 2026-04-22
  Color Scheme: #0052CC (Deep Blue) + #00A86B (Emerald Green)
==============================================
*/

/* Back to Top Button */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #0052CC, #004099);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  font-size: 20px;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 999;
  transition: all 0.3s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.back-to-top:hover {
  background: linear-gradient(135deg, #004099, #003080);
  transform: translateY(-3px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}

.back-to-top.show {
  display: flex;
}

@media (max-width: 767px) {
  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 45px;
    height: 45px;
    font-size: 18px;
  }
}

/* ============ CSS 变量定义 ============ */
:root {
  /* 主色彩 - 高端蓝色 */
  --primary-color: #0052CC;
  --primary-dark: #003D99;
  --primary-light: #E8F0FF;

  /* 强调色 - 深绿色（替代橘色） */
  --accent-color: #00A86B;
  --accent-light: #D4F1E4;

  /* 中性色 */
  --dark: #1a1a1a;
  --dark-gray: #333333;
  --gray: #666666;
  --light-gray: #F5F5F5;
  --border-gray: #E0E0E0;
  --white: #FFFFFF;

  /* 字体 */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;

  /* 尺寸 */
  --spacing-xs: 8px;
  --spacing-sm: 12px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-xxl: 48px;

  /* 圆角 */
  --border-radius-sm: 4px;
  --border-radius-md: 8px;
  --border-radius-lg: 12px;

  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);

  /* 过渡 */
  --transition: all 0.3s ease;
}

/* ============ 重置样式 ============ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.6;
  color: var(--dark-gray);
  background-color: var(--white);
}

/* ============ 全局样式 ============ */
a {
  color: var(--primary-color);
  text-decoration: none;
  transition: var(--transition);
}

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

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

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--dark);
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: 48px;
}

h2 {
  font-size: 36px;
}

h3 {
  font-size: 28px;
}

h4 {
  font-size: 22px;
}

h5 {
  font-size: 18px;
}

h6 {
  font-size: 16px;
  font-weight: 600;
}

p {
  margin-bottom: var(--spacing-md);
  color: var(--gray);
}

/* ============ 容器和栅格 ============ */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.section {
  padding: var(--spacing-xxl) 0;
}

.section-light {
  background-color: var(--light-gray);
}

.section-dark {
  background-color: var(--dark);
  color: var(--white);
}

.section-dark h2,
.section-dark h3 {
  color: var(--white);
}

/* 栅格系统 */
.grid {
  display: grid;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

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

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

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

/* ============ 按钮样式 ============ */
.btn {
  display: inline-block;
  padding: 12px 32px;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--border-radius-md);
  transition: var(--transition);
  cursor: pointer;
  border: none;
  text-align: center;
  line-height: 1.5;
}

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

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

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

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

.btn-accent {
  background-color: var(--accent-color);
  color: var(--white);
}

.btn-accent:hover {
  background-color: #E55A2B;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-large {
  padding: 16px 48px;
  font-size: 16px;
}

.btn-block {
  display: block;
  width: 100%;
}

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

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-md) 0;
}

.logo {
  font-size: 24px;
  font-weight: 700;
  color: var(--primary-color);
}

.logo img {
  height: 50px;
  width: auto;
}

nav {
  display: flex;
  gap: var(--spacing-xl);
  align-items: center;
}

nav a {
  font-weight: 500;
  color: var(--dark-gray);
}

nav a:hover,
nav a.active {
  color: var(--primary-color);
  border-bottom: 2px solid var(--primary-color);
}

.language-switch {
  display: flex;
  gap: var(--spacing-sm);
}

.language-switch a {
  padding: 6px 12px;
  border-radius: var(--border-radius-sm);
}

.language-switch a.active {
  background-color: var(--primary-color);
  color: var(--white);
}

/* 移动端菜单 */
.mobile-menu {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--primary-color);
}

/* ============ Hero Section ============ */
.hero {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
  color: var(--white);
  padding: 80px 0;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  right: -100px;
  top: -100px;
  width: 400px;
  height: 400px;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 600px;
}

.hero h1 {
  color: var(--white);
  margin-bottom: var(--spacing-lg);
  font-size: 52px;
}

.hero p {
  color: rgba(255, 255, 255, 0.9);
  font-size: 18px;
  margin-bottom: var(--spacing-xl);
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

/* ============ 卡片组件 ============ */
.card {
  background: var(--white);
  border: 1px solid var(--border-gray);
  border-radius: var(--border-radius-md);
  overflow: hidden;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

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

.card-image {
  width: 100%;
  height: 240px;
  overflow: hidden;
  background-color: var(--light-gray);
}

.card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.card-body {
  padding: var(--spacing-lg);
}

.card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--dark);
  margin-bottom: var(--spacing-sm);
}

.card-category {
  display: inline-block;
  font-size: 12px;
  color: var(--primary-color);
  background-color: var(--primary-light);
  padding: 4px 8px;
  border-radius: var(--border-radius-sm);
  margin-bottom: var(--spacing-md);
}

.card-description {
  font-size: 14px;
  color: var(--gray);
  margin-bottom: var(--spacing-md);
  line-height: 1.6;
}

.card-footer {
  padding: 0 var(--spacing-lg) var(--spacing-lg);
}

.card-link {
  color: var(--primary-color);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.card-link:hover {
  color: var(--primary-dark);
}

/* ============ Features Section ============ */
.feature {
  text-align: center;
}

.feature-icon {
  width: 60px;
  height: 60px;
  background-color: var(--primary-light);
  border-radius: var(--border-radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--spacing-lg);
  font-size: 32px;
}

.feature h4 {
  margin-bottom: var(--spacing-md);
  color: var(--dark);
}

.feature p {
  font-size: 14px;
  color: var(--gray);
}

/* ============ CTA Section ============ */
.cta {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
  color: var(--white);
  text-align: center;
  padding: var(--spacing-xxl) 0;
  margin: var(--spacing-xxl) 0 0;
}

.cta h2 {
  color: var(--white);
  margin-bottom: var(--spacing-lg);
}

.cta p {
  color: rgba(255, 255, 255, 0.9);
  font-size: 18px;
  margin-bottom: var(--spacing-xl);
}

/* ============ Footer ============ */
footer {
  background-color: var(--dark);
  color: rgba(255, 255, 255, 0.7);
  padding: var(--spacing-xxl) 0 var(--spacing-lg);
  margin-top: var(--spacing-xxl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer-section h4 {
  color: var(--white);
  font-size: 16px;
  margin-bottom: var(--spacing-md);
}

.footer-section ul {
  list-style: none;
}

.footer-section ul li {
  margin-bottom: var(--spacing-sm);
}

.footer-section a {
  color: rgba(255, 255, 255, 0.7);
}

.footer-section a:hover {
  color: var(--white);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--spacing-lg);
  text-align: center;
  font-size: 14px;
}

.social-links {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  margin-top: var(--spacing-lg);
}

.social-links a {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
}

.social-links a:hover {
  background-color: var(--primary-color);
  color: var(--white);
}

/* ============ 表单样式 ============ */
form {
  display: flex;
  flex-direction: column;
}

label {
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--dark);
  font-size: 14px;
}

input,
textarea,
select {
  padding: 12px var(--spacing-md);
  border: 1px solid var(--border-gray);
  border-radius: var(--border-radius-sm);
  font-family: var(--font-family);
  font-size: 14px;
  transition: var(--transition);
  margin-bottom: var(--spacing-lg);
}

input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(0, 82, 204, 0.1);
}

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

/* ============ 分页 ============ */
.pagination {
  display: flex;
  justify-content: center;
  gap: var(--spacing-sm);
  margin: var(--spacing-xl) 0;
}

.pagination a,
.pagination span {
  padding: 8px 12px;
  border: 1px solid var(--border-gray);
  border-radius: var(--border-radius-sm);
  transition: var(--transition);
}

.pagination a:hover,
.pagination a.active {
  background-color: var(--primary-color);
  color: var(--white);
  border-color: var(--primary-color);
}

/* ============ 工具类 ============ */
.text-center {
  text-align: center;
}

.text-right {
  text-align: right;
}

.mt-0 { margin-top: 0; }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.hidden {
  display: none;
}

.visible {
  display: block;
}

/* ============ 响应式设计 ============ */

/* 平板 (768px - 991px) */
@media (max-width: 991px) {
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

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

  nav {
    gap: var(--spacing-lg);
  }

  h1 {
    font-size: 40px;
  }

  h2 {
    font-size: 28px;
  }
}

/* 手机 (小于 768px) */
@media (max-width: 767px) {
  .container {
    padding: 0 var(--spacing-md);
  }

  .section {
    padding: var(--spacing-xl) 0;
  }

  nav {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    flex-direction: column;
    background-color: var(--white);
    gap: 0;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
  }

  nav.active {
    display: flex;
  }

  nav a {
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--border-gray);
  }

  .mobile-menu {
    display: block;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

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

  .hero {
    padding: 50px 0;
  }

  .hero h1 {
    font-size: 36px;
  }

  .hero p {
    font-size: 16px;
  }

  .hero-buttons {
    flex-direction: column;
  }

  .hero-buttons .btn {
    width: 100%;
  }

  h1 {
    font-size: 32px;
  }

  h2 {
    font-size: 24px;
  }

  h3 {
    font-size: 20px;
  }

  .card-image {
    height: 200px;
  }

  .cta {
    padding: var(--spacing-xl) 0;
  }

  .cta h2 {
    font-size: 24px;
  }
}

/* 超小屏幕 (小于 576px) */
@media (max-width: 575px) {
  .container {
    padding: 0 var(--spacing-sm);
  }

  .btn-large {
    padding: 12px 24px;
    font-size: 14px;
  }

  h1 {
    font-size: 28px;
  }

  h2 {
    font-size: 22px;
  }
}

/* ============================================================
   OPTIMIZATION ADDITIONS — Hero Split, Stats, Clients, Certs, Nav Dropdown, RFQ, Animations
   ============================================================ */

/* Hero Split Layout */
.hero-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xxl);
  align-items: center;
}

.hero-right {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.hero-metric-card {
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-lg) var(--spacing-xl);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  backdrop-filter: blur(4px);
  transition: var(--transition);
}

.hero-metric-card:hover {
  background: rgba(255, 255, 255, 0.18);
  transform: translateX(4px);
}

.hero-metric-number {
  font-size: 40px;
  font-weight: 700;
  color: var(--white);
  line-height: 1;
  min-width: 90px;
}

.hero-metric-label {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.85);
  line-height: 1.4;
}

.hero-metric-icon {
  font-size: 28px;
}

/* Stats Counter Bar */
.stats-bar {
  background: var(--white);
  border-bottom: 3px solid var(--primary-light);
  padding: var(--spacing-xl) 0;
  box-shadow: var(--shadow-md);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
}

.stat-item {
  text-align: center;
  padding: var(--spacing-lg);
  border-right: 1px solid var(--border-gray);
}

.stat-item:last-child {
  border-right: none;
}

.stat-number {
  font-size: 48px;
  font-weight: 700;
  color: var(--primary-color);
  line-height: 1;
  display: block;
  margin-bottom: var(--spacing-sm);
}

.stat-suffix {
  color: var(--accent-color);
}

.stat-label {
  font-size: 14px;
  color: var(--gray);
  font-weight: 500;
}

/* Client Logo Strip */
.clients-strip {
  padding: var(--spacing-xl) 0;
  background: var(--light-gray);
  border-top: 1px solid var(--border-gray);
  border-bottom: 1px solid var(--border-gray);
  overflow: hidden;
}

.clients-strip h3 {
  text-align: center;
  font-size: 13px;
  font-weight: 600;
  color: var(--gray);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-lg);
}

.clients-scroll {
  display: flex;
  gap: var(--spacing-lg);
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
}

.client-logo {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--white);
  border: 1px solid var(--border-gray);
  border-radius: var(--border-radius-md);
  min-width: 120px;
  text-align: center;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.client-logo:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
  transform: translateY(-2px);
}

.client-logo-icon {
  font-size: 26px;
  color: var(--gray);
}

.client-logo-name {
  font-size: 11px;
  font-weight: 600;
  color: var(--dark-gray);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Certification Badge Cards */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-lg);
}

.cert-badge {
  background: var(--white);
  border: 2px solid var(--border-gray);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-xl) var(--spacing-lg);
  text-align: center;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  text-decoration: none;
  display: block;
  color: inherit;
}

.cert-badge:hover {
  border-color: var(--primary-color);
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.cert-badge-seal {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--spacing-md);
  font-size: 20px;
  font-weight: 700;
}

.cert-badge-seal.blue {
  background: var(--primary-light);
  color: var(--primary-color);
  border: 3px solid var(--primary-color);
}

.cert-badge-seal.orange {
  background: var(--accent-light);
  color: var(--accent-color);
  border: 3px solid var(--accent-color);
}

.cert-badge h4 {
  font-size: 16px;
  margin-bottom: var(--spacing-sm);
  color: var(--dark);
}

.cert-badge p {
  font-size: 13px;
  color: var(--gray);
  margin-bottom: var(--spacing-sm);
}

.cert-badge-link {
  font-size: 12px;
  color: var(--primary-color);
  font-weight: 600;
  text-decoration: underline;
}

/* Navigation Dropdown */
.nav-item {
  position: relative;
}

.nav-item > a {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-item > a::after {
  content: '▾';
  font-size: 10px;
  transition: transform 0.2s ease;
}

.nav-item:hover > a::after {
  transform: rotate(180deg);
}

.nav-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%) translateY(-4px);
  background: var(--white);
  border: 1px solid var(--border-gray);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-lg);
  min-width: 180px;
  padding: var(--spacing-sm) 0;
  z-index: 200;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s ease, visibility 0.2s ease, transform 0.2s ease;
  transform: translateX(-50%) translateY(-4px);
}

.nav-item:hover .nav-dropdown,
.nav-item:focus-within .nav-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.nav-dropdown a {
  display: block;
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: 14px;
  color: var(--dark-gray);
  white-space: nowrap;
  border-bottom: none !important;
}

.nav-dropdown a:hover {
  background: var(--primary-light);
  color: var(--primary-color);
  border-bottom: none !important;
}

/* Floating RFQ Button */
.rfq-float {
  position: fixed;
  bottom: 90px;
  right: 30px;
  z-index: 998;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.rfq-float a {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  background: var(--accent-color);
  color: var(--white);
  border-radius: 50%;
  box-shadow: 0 4px 12px rgba(255, 107, 53, 0.4);
  transition: var(--transition);
  text-decoration: none;
  font-size: 22px;
}

.rfq-float a:hover {
  background: #E55A2B;
  transform: scale(1.08);
  box-shadow: 0 6px 16px rgba(255, 107, 53, 0.5);
}

.rfq-float-label {
  font-size: 10px;
  font-weight: 700;
  color: var(--accent-color);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* Scroll-triggered Animations */
.fade-in-up {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

.fade-in-up.delay-1 { transition-delay: 0.1s; }
.fade-in-up.delay-2 { transition-delay: 0.2s; }
.fade-in-up.delay-3 { transition-delay: 0.3s; }
.fade-in-up.delay-4 { transition-delay: 0.4s; }

/* Responsive additions for optimizations */
@media (max-width: 991px) {
  .hero-split {
    grid-template-columns: 1fr;
  }

  .hero-right {
    display: none;
  }

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

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

@media (max-width: 767px) {
  .hero-split {
    grid-template-columns: 1fr;
  }

  .hero-right {
    display: none;
  }

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

  .stat-number {
    font-size: 36px;
  }

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

  .clients-scroll {
    gap: var(--spacing-md);
  }

  .client-logo {
    min-width: 100px;
    padding: var(--spacing-sm) var(--spacing-md);
  }

  .rfq-float {
    bottom: 80px;
    right: 20px;
  }

  .rfq-float a {
    width: 50px;
    height: 50px;
    font-size: 20px;
  }

  /* Mobile nav dropdown */
  .nav-item .nav-dropdown {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    border: none;
    padding: 0 0 0 var(--spacing-lg);
    background: transparent;
  }

  .nav-item > a::after {
    display: none;
  }
}

/* ============================================================
   PREMIUM ANIMATION & DESIGN ENHANCEMENTS (高级动画与设计优化)
   ============================================================ */

/* 1. 高级按钮样式 - 多种类型 */
.btn {
  position: relative;
  overflow: hidden;
  font-weight: 600;
  letter-spacing: 0.5px;
  transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: rgba(255, 255, 255, 0.2);
  transition: left 0.4s ease;
}

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

.btn-primary {
  background: linear-gradient(135deg, #0052CC, #0066FF);
  box-shadow: 0 8px 24px rgba(0, 82, 204, 0.3);
}

.btn-primary:hover {
  box-shadow: 0 12px 32px rgba(0, 82, 204, 0.5);
  transform: translateY(-2px);
}

.btn-secondary {
  border: 2px solid #0052CC;
  color: #0052CC;
  transition: all 0.3s ease;
}

.btn-secondary:hover {
  background: #0052CC;
  color: white;
  transform: translateY(-2px);
}

.btn-accent {
  background: linear-gradient(135deg, #00A86B, #00D680);
  box-shadow: 0 8px 24px rgba(0, 168, 107, 0.3);
}

.btn-accent:hover {
  box-shadow: 0 12px 32px rgba(255, 107, 53, 0.5);
  transform: translateY(-2px);
}

/* 2. 文本动画 */
@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.7;
  }
}

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

@keyframes glow {
  0%, 100% {
    box-shadow: 0 0 20px rgba(0, 82, 204, 0.4);
  }
  50% {
    box-shadow: 0 0 30px rgba(0, 82, 204, 0.8);
  }
}

/* 3. 英雄区域优化 - 大气简洁 */
.hero {
  background: linear-gradient(135deg, #0052CC 0%, #004099 50%, #003366 100%);
  padding: 120px 0;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(ellipse at 20% 50%, rgba(255, 107, 53, 0.1) 0%, transparent 50%),
              radial-gradient(ellipse at 80% 80%, rgba(0, 102, 255, 0.1) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-content h1 {
  font-size: 52px;
  line-height: 1.2;
  margin-bottom: 24px;
  animation: slideInLeft 0.8s ease 0.2s both;
  font-weight: 700;
  letter-spacing: -1px;
}

.hero-content > p {
  font-size: 20px;
  line-height: 1.6;
  max-width: 600px;
  margin-bottom: 40px;
  animation: slideInLeft 0.8s ease 0.4s both;
  color: rgba(255, 255, 255, 0.95);
  font-weight: 300;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  animation: slideInUp 0.8s ease 0.6s both;
}

@media (max-width: 768px) {
  .hero {
    padding: 80px 0;
  }

  .hero-content h1 {
    font-size: 36px;
  }

  .hero-content > p {
    font-size: 16px;
  }

  .hero-buttons {
    flex-direction: column;
  }

  .hero-buttons .btn {
    width: 100%;
  }
}

/* 4. 卡片动画 - 高级hover效果 */
.card {
  position: relative;
  overflow: hidden;
  border-radius: 12px;
  transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
  border: 1px solid rgba(0, 82, 204, 0.1);
}

.card::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.3) 0%, transparent 70%);
  opacity: 0;
  transition: opacity 0.5s ease;
  pointer-events: none;
}

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

.card:hover {
  transform: translateY(-12px) scale(1.02);
  box-shadow: 0 20px 50px rgba(0, 82, 204, 0.2);
  border-color: rgba(0, 82, 204, 0.3);
}

.card-image {
  overflow: hidden;
  height: 240px;
  background: linear-gradient(135deg, #E3F2FD, #F3E5F5);
}

.card-image img {
  transition: transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
  width: 100%;
  height: 100%;
}

.card:hover .card-image img {
  transform: scale(1.1) rotate(2deg);
}

/* 5. 标题动画 */
h2 {
  position: relative;
  display: inline-block;
  animation: slideInUp 0.6s ease 0.2s both;
}

h2::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 0;
  height: 3px;
  background: linear-gradient(90deg, #0052CC, #00A86B);
  transition: width 0.6s ease;
}

h2:hover::after {
  width: 100%;
}

/* 6. Section间距优化 - 简洁大气 */
.section {
  padding: 100px 0;
  position: relative;
}

.section-light {
  background: linear-gradient(180deg, #F8FAFB 0%, #FFFFFF 100%);
}

.section.cta-featured {
  padding: 120px 0;
}

/* 7. 容器和网格 - 高级排版 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 40px;
}

.grid {
  display: grid;
  gap: 32px;
}

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

.grid-3 > * {
  animation: slideInUp 0.6s ease;
}

.grid-3 > *:nth-child(1) { animation-delay: 0.1s; }
.grid-3 > *:nth-child(2) { animation-delay: 0.2s; }
.grid-3 > *:nth-child(3) { animation-delay: 0.3s; }
.grid-3 > *:nth-child(4) { animation-delay: 0.4s; }
.grid-3 > *:nth-child(5) { animation-delay: 0.5s; }
.grid-3 > *:nth-child(6) { animation-delay: 0.6s; }

@media (max-width: 991px) {
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .container {
    padding: 0 30px;
  }
}

@media (max-width: 767px) {
  .grid-3 {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 60px 0;
  }

  .container {
    padding: 0 20px;
  }
}

/* 8. CTA优化 - 更多按钮和变体 */
.cta-inline {
  display: inline-flex;
  gap: 12px;
  align-items: center;
  padding: 12px 24px;
  background: rgba(0, 82, 204, 0.08);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
  font-size: 14px;
  font-weight: 600;
  color: #0052CC;
  text-decoration: none;
}

.cta-inline:hover {
  background: rgba(0, 82, 204, 0.15);
  transform: translateX(4px);
}

.cta-section {
  background: linear-gradient(135deg, #0052CC 0%, #00A86B 100%);
  padding: 80px 0;
  color: white;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
  animation: float 6s ease-in-out infinite;
}

.cta-section-content {
  position: relative;
  z-index: 1;
}

.cta-section h2 {
  color: white;
  font-size: 42px;
  margin-bottom: 20px;
}

.cta-section p {
  font-size: 18px;
  margin-bottom: 32px;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.6;
}

.cta-section .btn {
  display: inline-block;
  animation: pulse 2s ease-in-out infinite;
}

/* 9. 细节动画 */
.metric-number {
  font-size: 48px;
  font-weight: 700;
  color: #0052CC;
  animation: scaleIn 0.8s ease 0.3s both;
}

.metric-label {
  font-size: 14px;
  color: #666;
  margin-top: 8px;
  animation: slideInUp 0.8s ease 0.4s both;
}

/* 10. 交互反馈 */
.stat-item {
  transition: all 0.3s ease;
  cursor: pointer;
}

.stat-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 82, 204, 0.1);
}

.stat-item:hover .stat-number {
  color: #00A86B;
}

/* 11. 粘性导航增强 */
header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: white;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  animation: slideInDown 0.6s ease;
}

@keyframes slideInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 12. 列表项动画 */
ul li {
  animation: slideInLeft 0.5s ease;
  animation-fill-mode: both;
}

ul li:nth-child(1) { animation-delay: 0.1s; }
ul li:nth-child(2) { animation-delay: 0.2s; }
ul li:nth-child(3) { animation-delay: 0.3s; }
ul li:nth-child(4) { animation-delay: 0.4s; }
ul li:nth-child(5) { animation-delay: 0.5s; }

/* 13. 响应式图像 */
img {
  max-width: 100%;
  height: auto;
  transition: all 0.4s ease;
}

/* 14. 背景渐变动画 */
@keyframes gradientShift {
  0%, 100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

.gradient-animated {
  background: linear-gradient(-45deg, #0052CC, #00A86B, #0052CC, #00A86B);
  background-size: 300% 300%;
  animation: gradientShift 8s ease infinite;
}

/* 15. 加载动画 */
@keyframes shimmer {
  0% {
    background-position: -1000px 0;
  }
  100% {
    background-position: 1000px 0;
  }
}

.loading {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 1000px 100%;
  animation: shimmer 2s infinite;
}

/* 16. 文本阴影增强 */
h1, h2, h3 {
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

/* 17. 链接动画 */
a {
  position: relative;
  text-decoration: none;
}

a:not(.btn)::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: #0052CC;
  transition: width 0.3s ease;
}

a:not(.btn):hover::after {
  width: 100%;
}

/* 18. Tooltip动画 */
[title] {
  position: relative;
}

[title]:hover::after {
  content: attr(title);
  position: absolute;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);
  padding: 8px 12px;
  background: #333;
  color: white;
  border-radius: 4px;
  font-size: 12px;
  white-space: nowrap;
  z-index: 1000;
  animation: slideInUp 0.3s ease;
}

/* 19. 输入框焦点动画 */
input, textarea, select {
  transition: all 0.3s ease;
  border: 1px solid #ddd;
  border-radius: 6px;
}

input:focus, textarea:focus, select:focus {
  border-color: #0052CC;
  box-shadow: 0 0 0 3px rgba(0, 82, 204, 0.1);
  transform: translateY(-2px);
}

/* 20. 打字动画 */
@keyframes typing {
  from {
    width: 0;
  }
  to {
    width: 100%;
  }
}

.typing {
  overflow: hidden;
  border-right: 3px solid #0052CC;
  animation: typing 3s steps(40, end);
}

/* ============================================================
   ENHANCED INTERACTION EFFECTS
   ============================================================ */

/* Button Enhancement */
.btn {
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.btn:active::before {
  width: 300px;
  height: 300px;
}

/* Card Enhancement */
.card {
  position: relative;
  overflow: hidden;
}

.card::after {
  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 0.5s;
}

.card:hover::after {
  left: 100%;
}

/* Link Underline Animation */
a {
  position: relative;
  text-decoration: none;
}

a:not(.btn):not(.card-link)::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background-color: var(--primary-color);
  transition: width 0.3s ease;
}

a:not(.btn):not(.card-link):hover::after {
  width: 100%;
}

/* Enhanced Input Focus */
input:focus,
textarea:focus,
select:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(0, 168, 107, 0.1);
  border-color: var(--accent-color) !important;
  transition: all 0.3s ease;
}

/* Smooth Transitions */
* {
  transition-property: background-color, border-color, color, box-shadow;
  transition-duration: 0.3s;
  transition-timing-function: ease;
}

/* Disable for animations */
.animated,
[class*='animate-'] {
  transition: none !important;
}