/* 全局样式 */
:root {
  --primary: #4CAF50;
  --primary-dark: #388E3C;
  --light: #f5f5f5;
  --white: #ffffff;
  --gray: #757575;
  --light-gray: #e0e0e0;
  --dark: #212121;
  --shadow: 0 2px 4px rgba(0,0,0,0.1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
  background-color: var(--white);
  color: var(--dark);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* 导航栏样式 */
nav {
  background-color: var(--white);
  box-shadow: var(--shadow);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.nav-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.brand {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
}

.nav-buttons {
  display: flex;
  gap: 0.5rem;
}

.nav-btn {
  padding: 0.5rem 1rem;
  background: transparent;
  color: var(--dark);
  border: 1px solid var(--primary);
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.3s;
  text-decoration: none;
  font-size: 0.9rem;
}

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

.nav-right {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.nav-link {
  padding: 0.5rem 1rem;
  color: var(--dark);
  text-decoration: none;
  border-radius: 4px;
  transition: all 0.3s;
}

.nav-link:hover {
  background: var(--light);
}

.nav-link.active {
  background: var(--primary);
  color: var(--white);
}

.language-selector {
  padding: 0.5rem;
  border: 1px solid var(--light-gray);
  border-radius: 4px;
  background: var(--white);
  color: var(--dark);
  cursor: pointer;
}

/* 主要内容样式 */
.hero {
  padding: 4rem 0;
  text-align: center;
  background: var(--light);
}

.title {
  font-size: 2.5rem;
  font-weight: bold;
  margin-bottom: 1rem;
  color: var(--dark);
}

.subtitle {
  font-size: 1.2rem;
  margin-bottom: 2rem;
  color: var(--gray);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  padding: 0.8rem 1.5rem;
  border-radius: 4px;
  text-decoration: none;
  font-weight: bold;
  transition: all 0.3s;
  display: inline-block;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
}

.btn-secondary {
  background: transparent;
  color: var(--dark);
  border: 1px solid var(--primary);
}

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

/* 内容区域 */
.content-section {
  padding: 3rem 0;
}

.section-title {
  font-size: 2rem;
  margin-bottom: 2rem;
  text-align: center;
  color: var(--dark);
}

/* 方案展示区样式 */
.pricing-container {
  display: flex;
  justify-content: center;
  gap: 2rem;
  flex-wrap: wrap;
}

.pricing-card {
  background-color: var(--white);
  border-radius: 8px;
  padding: 2rem;
  width: 300px;
  text-align: center;
  border: 1px solid var(--light-gray);
  box-shadow: var(--shadow);
}

.pricing-title {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: var(--dark);
}

.pricing-features {
  list-style: none;
  margin-bottom: 1.5rem;
  text-align: left;
}

.pricing-features li {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--light-gray);
}

.pricing-features li:last-child {
  border-bottom: none;
}

.pricing-btn {
  display: inline-block;
  padding: 0.8rem 1.5rem;
  background: var(--primary);
  color: var(--white);
  border-radius: 4px;
  text-decoration: none;
  font-weight: bold;
  width: 100%;
}

.pricing-btn:hover {
  background: var(--primary-dark);
}

/* 友情链接区域 */
.friendship-container {
  display: flex;
  justify-content: center;
  gap: 2rem;
  flex-wrap: wrap;
}

.friend-card {
  background: var(--white);
  border-radius: 8px;
  padding: 1.5rem;
  width: 200px;
  text-align: center;
  border: 1px solid var(--light-gray);
  box-shadow: var(--shadow);
}

.friend-icon {
  font-size: 2rem;
  margin-bottom: 1rem;
  color: var(--primary);
}

.friend-title {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  color: var(--dark);
}

.friend-desc {
  color: var(--gray);
  margin-bottom: 1rem;
}

.friend-link {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: rgba(76, 175, 80, 0.1);
  color: var(--primary);
  border-radius: 4px;
  text-decoration: none;
  border: 1px solid var(--primary);
}

.friend-link:hover {
  background: var(--primary);
  color: var(--white);
}

/* FAQ样式 */
.faq-container {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--white);
  border-radius: 8px;
  margin-bottom: 1rem;
  overflow: hidden;
  border: 1px solid var(--light-gray);
  box-shadow: var(--shadow);
}

.faq-question {
  padding: 1.5rem;
  font-size: 1.1rem;
  font-weight: bold;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--white);
}

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

.faq-answer {
  padding: 0 1.5rem;
  max-height: 0;
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-answer-content {
  padding: 1.5rem 0;
  border-top: 1px solid var(--light-gray);
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

.faq-item.active .faq-question i {
  transform: rotate(180deg);
}

/* 页脚 */
footer {
  background: var(--light);
  padding: 2rem 0;
  text-align: center;
  color: var(--gray);
  margin-top: 3rem;
  border-top: 1px solid var(--light-gray);
}

/* 响应式设计 */
@media (max-width: 768px) {
  .nav-container {
    flex-direction: column;
    gap: 1rem;
  }
  
  .nav-left, .nav-right {
    width: 100%;
    justify-content: center;
  }
  
  .nav-buttons {
    justify-content: center;
  }
  
  .title {
    font-size: 2rem;
  }
  
  .buttons {
    flex-direction: column;
  }
  
  .pricing-container {
    flex-direction: column;
    align-items: center;
  }
  
  .pricing-card {
    width: 100%;
    max-width: 400px;
  }
}