/* 全局CSS变量定义 */
:root {
  --primary: #1a56db;
  --primary-dark: #1e40af;
  --secondary: #0e7490;
  --accent: #8b5cf6;
  --dark: #1e293b;
  --light: #f8fafc;
  --gray: #64748b;
  --success: #10b981;
  --transition: all 0.3s ease;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --container-width: 1200px;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
}

/* 全局重置与基础样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--font-sans);
  line-height: 1.6;
  color: var(--dark);
  background-color: var(--light);
  overflow-x: hidden;
}

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

/* 文字排版系统 */
h1, h2, h3, h4 {
  line-height: 1.2;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

h1 {
  font-size: 3.5rem;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

h2 {
  font-size: 2.5rem;
  color: var(--dark);
  position: relative;
  padding-bottom: 0.5rem;
}

h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 80px;
  height: 4px;
  background: var(--primary);
  border-radius: 2px;
}

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

/* 按钮系统 */
.cta-button {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  border: none;
  padding: 1rem 2rem;
  font-size: 1.1rem;
  border-radius: 8px;
  cursor: pointer;
  transition: var(--transition);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.cta-button:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 20px rgba(26, 86, 219, 0.2);
}

/* 响应式导航栏 */
.site-header {
  background: white;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 1.5rem 0;
}

.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  flex-direction: column;
}

.logo h1 {
  font-size: 1.8rem;
  background: none;
  -webkit-text-fill-color: var(--dark);
  margin-bottom: 0;
}

.tagline {
  font-size: 0.9rem;
  color: var(--gray);
  font-weight: normal;
}

.main-nav ul {
  display: flex;
  list-style: none;
  gap: 2.5rem;
}

.main-nav a {
  text-decoration: none;
  color: var(--dark);
  font-weight: 500;
  position: relative;
  transition: var(--transition);
  cursor: pointer;
}

.main-nav a:active {
  transform: scale(0.95);
  transition: transform 0.1s ease;
}

.main-nav a:hover {
  color: var(--primary);
}

.main-nav a.active {
  color: var(--primary);
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: var(--transition);
}

.main-nav a:hover::after,
.main-nav a.active::after {
  width: 100%;
}

/* 移动端菜单 */
.menu-toggle {
  display: none;
}

.hamburger {
  display: none;
  font-size: 1.8rem;
  cursor: pointer;
  padding: 0.5rem;
}

/* 首页横幅 */
.hero {
  background: linear-gradient(135deg, #f0f4ff 0%, #e6f7ff 100%);
  padding: 8rem 0;
}

.hero-content {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2rem;
  flex-wrap: wrap;
}

.hero-text {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hero-logo {
  height: 120px;
  width: auto;
  object-fit: contain;
  max-width: 100%;
}

.hero h2 {
  font-size: 3.5rem;
  margin-bottom: 1.5rem;
  color: var(--dark);
  text-align: left;
}

.hero p {
  font-size: 1.5rem;
  max-width: 700px;
  margin: 0 0 2.5rem;
  color: var(--gray);
  text-align: left;
}

/* 服务网格 */
.services {
  padding: var(--spacing-lg) 0;
}

.service-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2.5rem;
  margin-top: 3rem;
}

.service-card {
  background: white;
  border-radius: 12px;
  padding: 2.5rem;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
  transition: var(--transition);
  border: 1px solid rgba(0, 0, 0, 0.05);
}

.service-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 40px rgba(26, 86, 219, 0.15);
  border-color: rgba(26, 86, 219, 0.1);
}

.service-card h3 {
  font-size: 1.8rem;
  margin-bottom: 1.2rem;
  color: var(--dark);
}

/* 页脚 */
.site-footer {
  background: var(--dark);
  color: rgba(255, 255, 255, 0.8);
  padding: 4rem 0 2rem;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-section h4 {
  color: white;
  margin-bottom: 1.5rem;
  font-size: 1.3rem;
}

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

.footer-section li {
  margin-bottom: 0.8rem;
}

.footer-section a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  transition: var(--transition);
}

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

.copyright {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.9rem;
}

/* 响应式调整 */
@media (max-width: 768px) {
  .hamburger {
    display: block;
  }

  .main-nav ul {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 1rem 0;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  }

  .main-nav ul.show {
    display: flex;
  }

  .main-nav li {
    margin: 0.5rem 0;
    text-align: center;
  }

  h1 {
    font-size: 2.5rem;
  }

  h2 {
    font-size: 2rem;
  }

  .hero h2 {
    font-size: 2.5rem;
  }

  .hero p {
    font-size: 1.2rem;
  }
}