/* Yunloong - 极简风格样式 */

/* 字体导入 */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* CSS 变量 */
:root {
  --color-text: #1a1a1a;
  --color-text-secondary: #4a5568;
  --color-text-muted: #718096;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-primary-light: #dbeafe;
  --color-bg: #ffffff;
  --color-bg-subtle: #f7fafc;
  --color-bg-gradient-start: #f0f9ff;
  --color-bg-gradient-end: #ffffff;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --color-shadow-sm: rgba(0, 0, 0, 0.05);
  --color-shadow-md: rgba(0, 0, 0, 0.08);
  --color-shadow-lg: rgba(0, 0, 0, 0.12);
  --color-shadow-primary: rgba(37, 99, 235, 0.15);
  --font-sans: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', Consolas, monospace;
  --max-width: 900px;
  --max-width-wide: 1200px;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-xxl: 5rem;
  --spacing-xxxl: 7rem;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --transition-fast: 0.15s ease;
  --transition-base: 0.2s ease;
  --transition-slow: 0.3s ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-weight: 400;
  line-height: 1.75;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  letter-spacing: 0.01em;
}

/* 页面加载动画 */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeInUp 0.6s ease-out;
}

/* 容器 */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* 导航栏 */
.nav {
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--color-border-light);
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(12px) saturate(180%);
  -webkit-backdrop-filter: blur(12px) saturate(180%);
  box-shadow: 0 1px 3px var(--color-shadow-sm);
  z-index: 100;
  transition: all var(--transition-base);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.02em;
  transition: color var(--transition-base);
}

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

.nav-links {
  display: flex;
  gap: var(--spacing-md);
  list-style: none;
}

.nav-links a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 400;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-base);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 80%;
  height: 2px;
  background: var(--color-primary);
  transition: transform var(--transition-base);
}

.nav-links a:hover {
  color: var(--color-primary);
  background: var(--color-primary-light);
}

.nav-links a:hover::after {
  transform: translateX(-50%) scaleX(1);
}

/* 语言切换器 */
.lang-switcher {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  margin-left: var(--spacing-md);
  padding-left: var(--spacing-md);
  border-left: 1px solid var(--color-border);
}

.lang-switcher button {
  background: transparent;
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-base);
  font-family: var(--font-sans);
  min-width: 60px;
}

.lang-switcher button:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-light);
  transform: translateY(-1px);
}

.lang-switcher button.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
  box-shadow: 0 2px 4px var(--color-shadow-primary);
}

.lang-switcher button.active:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 8px var(--color-shadow-primary);
}

/* 主要内容区 */
main {
  padding: var(--spacing-xxl) 0;
  position: relative;
}

/* Hero 区域渐变背景 */
.hero-section {
  position: relative;
  padding: var(--spacing-xl) 0;
  margin: calc(var(--spacing-xxl) * -1) 0 var(--spacing-xxl);
  background: linear-gradient(135deg, var(--color-bg-gradient-start) 0%, var(--color-bg-gradient-end) 100%);
  border-radius: 0 0 24px 24px;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 30% 50%, rgba(37, 99, 235, 0.05) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  text-align: center;
  max-width: 600px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero-description {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
  line-height: 1.8;
}

.btn-large {
  font-size: 1rem;
  padding: 14px 32px;
}

/* CTA 区域 */
.cta-section {
  text-align: center;
  margin-top: var(--spacing-xxl);
  padding: var(--spacing-xl) 0;
  border-top: 2px solid var(--color-border-light);
}

.cta-title {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.cta-description {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  font-size: 1rem;
  line-height: 1.6;
}

/* 页眉区域 */
.page-header {
  text-align: center;
  margin-bottom: var(--spacing-xxl);
  animation: fadeInUp 0.8s ease-out;
}

.page-header h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
  line-height: 1.2;
}

.page-header .subtitle {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  color: var(--color-text-secondary);
  font-weight: 400;
  line-height: 1.6;
  max-width: 600px;
  margin: 0 auto;
}

/* 定价卡片 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-xl);
  margin-top: var(--spacing-xl);
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.pricing-card {
  border: 2px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-xl);
  text-align: center;
  background: var(--color-bg);
  transition: all var(--transition-slow);
  position: relative;
  overflow: hidden;
}

.pricing-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, transparent, var(--color-primary), transparent);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.pricing-card:hover {
  box-shadow: 0 12px 40px var(--color-shadow-md), 0 0 0 1px var(--color-border-light);
  transform: translateY(-4px);
  border-color: var(--color-border);
}

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

.pricing-card.featured {
  border-color: var(--color-primary);
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.02) 0%, rgba(255, 255, 255, 1) 100%);
  box-shadow: 0 8px 32px var(--color-shadow-primary);
  transform: scale(1.02);
}

.pricing-card.featured:hover {
  transform: scale(1.03) translateY(-4px);
  box-shadow: 0 16px 48px var(--color-shadow-primary);
}

.pricing-card.featured .featured-badge {
  position: absolute;
  top: 16px;
  right: 16px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-hover));
  color: white;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 20px;
  box-shadow: 0 2px 8px var(--color-shadow-primary);
  letter-spacing: 0.5px;
  z-index: 1;
}

.pricing-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.pricing-card .price {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--spacing-xs);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.pricing-card .price span {
  font-size: 0.5em;
  color: var(--color-text-muted);
  font-weight: 400;
  margin-left: 0.2em;
}

.pricing-card .billing {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-lg);
  font-weight: 400;
}

.pricing-card ul {
  list-style: none;
  text-align: left;
  margin-bottom: var(--spacing-lg);
}

.pricing-card ul li {
  padding: var(--spacing-sm) 0;
  color: var(--color-text-secondary);
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  line-height: 1.5;
}

.pricing-card ul li::before {
  content: '✓';
  color: var(--color-primary);
  font-weight: 700;
  font-size: 1.1em;
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-light);
  border-radius: 50%;
}

.btn {
  display: inline-block;
  padding: 14px 28px;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-base);
  cursor: pointer;
  border: none;
  position: relative;
  overflow: hidden;
  letter-spacing: 0.01em;
}

.btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

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

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-hover));
  color: white;
  box-shadow: 0 4px 12px var(--color-shadow-primary);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--color-primary-hover), var(--color-primary));
  box-shadow: 0 6px 20px var(--color-shadow-primary);
  transform: translateY(-2px);
}

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

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

.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-light);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px var(--color-shadow-sm);
}

/* 法律页面内容 */
.legal-content {
  max-width: 700px;
  margin: 0 auto;
}

.legal-content h1 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  letter-spacing: -0.02em;
  line-height: 1.3;
}

.legal-content .last-updated {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-lg);
  border-bottom: 2px solid var(--color-border-light);
}

.legal-content h2 {
  font-size: clamp(1.125rem, 2.5vw, 1.5rem);
  font-weight: 600;
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
  line-height: 1.4;
  padding-top: var(--spacing-md);
}

.legal-content p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
  line-height: 1.8;
  font-size: 0.95rem;
}

.legal-content ul, .legal-content ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-lg);
}

.legal-content li {
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
  padding-left: var(--spacing-xs);
}

.legal-content a {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 500;
  border-bottom: 1px solid transparent;
  transition: all var(--transition-base);
}

.legal-content a:hover {
  border-bottom-color: var(--color-primary);
  color: var(--color-primary-hover);
}

/* 页脚 */
.footer {
  border-top: 1px solid var(--color-border-light);
  padding: var(--spacing-xl) 0;
  margin-top: var(--spacing-xxl);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.footer-links {
  display: flex;
  gap: var(--spacing-md);
  list-style: none;
}

.footer-links a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--color-text);
}

.footer-copy {
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

/* 特性列表 */
.features {
  margin-top: var(--spacing-xxl);
  padding-top: var(--spacing-xl);
  border-top: 2px solid var(--color-border-light);
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

.features h2 {
  text-align: center;
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
  margin-bottom: var(--spacing-xl);
  letter-spacing: -0.01em;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--spacing-xl);
}

.feature-item {
  text-align: center;
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
  background: var(--color-bg);
}

.feature-item:hover {
  background: var(--color-bg-subtle);
  transform: translateY(-4px);
  box-shadow: 0 8px 24px var(--color-shadow-sm);
}

.feature-item h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.feature-item p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* 响应式 */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  .nav-inner {
    padding: 0 var(--spacing-sm);
  }
  
  .pricing-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
  
  .pricing-card.featured {
    transform: scale(1);
  }
  
  .pricing-card.featured:hover {
    transform: translateY(-4px);
  }
  
  .features-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
}

@media (max-width: 640px) {
  main {
    padding: var(--spacing-xl) 0;
  }
  
  .hero-section {
    margin: calc(var(--spacing-xl) * -1) calc(var(--spacing-sm) * -1) var(--spacing-xl);
    border-radius: 0;
    padding: var(--spacing-lg) var(--spacing-sm);
  }
  
  .nav-inner {
    flex-wrap: wrap;
  }
  
  .nav-links {
    gap: var(--spacing-xs);
    order: 3;
    width: 100%;
    margin-top: var(--spacing-sm);
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--color-border-light);
    justify-content: center;
  }
  
  .nav-links a {
    font-size: 0.85rem;
    padding: 0.5rem;
  }
  
  .lang-switcher {
    margin-left: auto;
    padding-left: var(--spacing-sm);
    border-left: 1px solid var(--color-border);
  }
  
  .lang-switcher button {
    padding: 5px 10px;
    font-size: 0.8rem;
    min-width: 50px;
  }
  
  .pricing-card {
    padding: var(--spacing-lg);
  }
  
  .btn {
    padding: 12px 24px;
    font-size: 0.9rem;
    width: 100%;
    max-width: 300px;
  }
  
  .footer-inner {
    flex-direction: column;
    text-align: center;
    gap: var(--spacing-md);
  }
  
  .footer-links {
    justify-content: center;
    flex-wrap: wrap;
  }
}

@media (min-width: 1200px) {
  .container {
    max-width: var(--max-width-wide);
  }
  
  .nav-inner {
    max-width: var(--max-width-wide);
  }
  
  .footer-inner {
    max-width: var(--max-width-wide);
  }
}