/* ==========================================
   统计分析工具箱 - 全局样式
   ========================================== */

/* CSS 变量 - 设计系统 */
:root {
  /* 主色调 */
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #3b82f6;
  
  /* 辅助色 */
  --success: #10b981;
  --success-light: #34d399;
  --warning: #f59e0b;
  --warning-light: #fbbf24;
  --danger: #ef4444;
  
  /* 中性色 */
  --gray-50: #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --gray-900: #0f172a;
  
  /* 背景与文字 */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  
  /* 间距 */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  
  /* 圆角 */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;
  
  /* 阴影 */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  /* 动画 */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms 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: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-secondary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 链接 */
a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* 列表 */
ul, ol {
  list-style: none;
}

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

/* ==========================================
   布局
   ========================================== */

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-3xl) 0;
}

/* ==========================================
   头部导航
   ========================================== */

.header {
  background: var(--bg-primary);
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  background: rgba(255, 255, 255, 0.95);
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.logo-icon {
  font-size: 1.5rem;
}

.nav {
  display: flex;
  gap: var(--space-lg);
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav-link:hover {
  color: var(--primary);
  background: var(--gray-100);
}

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

/* ==========================================
   Hero 区域
   ========================================== */

.hero {
  background: linear-gradient(135deg, var(--primary) 0%, #7c3aed 100%);
  color: white;
  padding: var(--space-3xl) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.5;
}

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

.hero-title {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: var(--space-md);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.hero-subtitle {
  font-size: 1.25rem;
  opacity: 0.9;
  margin-bottom: var(--space-xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  background: rgba(255, 255, 255, 0.2);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  margin-bottom: var(--space-lg);
  backdrop-filter: blur(4px);
}

/* ==========================================
   工具卡片
   ========================================== */

.tools-section {
  padding: var(--space-3xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-lg);
}

.tool-card {
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--gray-200);
  transition: all var(--transition-base);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--success));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: var(--primary);
}

.tool-card:hover::before {
  transform: scaleX(1);
}

.tool-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin-bottom: var(--space-md);
  background: linear-gradient(135deg, var(--primary) 0%, #7c3aed 100%);
  color: white;
}

.tool-card.green .tool-icon {
  background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
}

.tool-card.orange .tool-icon {
  background: linear-gradient(135deg, var(--warning) 0%, #ea580c 100%);
}

.tool-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.tool-description {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
  margin-bottom: var(--space-md);
}

.tool-tag {
  display: inline-block;
  background: var(--gray-100);
  color: var(--text-secondary);
  font-size: 0.75rem;
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-full);
}

.tool-tag.python {
  background: #3776ab20;
  color: #3776ab;
}

/* ==========================================
   特性区域
   ========================================== */

.features-section {
  background: var(--bg-primary);
  padding: var(--space-3xl) 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-xl);
}

.feature-item {
  text-align: center;
  padding: var(--space-lg);
}

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: var(--space-md);
}

.feature-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.feature-description {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* ==========================================
   CTA 区域
   ========================================== */

.cta-section {
  background: linear-gradient(135deg, var(--gray-800) 0%, var(--gray-900) 100%);
  color: white;
  padding: var(--space-3xl) 0;
  text-align: center;
}

.cta-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.cta-subtitle {
  opacity: 0.8;
  margin-bottom: var(--space-xl);
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

/* ==========================================
   按钮
   ========================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-xl);
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-lg);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.5);
  color: white;
}

.btn-secondary {
  background: white;
  color: var(--text-primary);
  box-shadow: var(--shadow-md);
}

.btn-secondary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  color: var(--text-primary);
}

.btn-outline {
  background: transparent;
  color: white;
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.5);
  color: white;
}

.btn-cta {
  background: var(--warning);
  color: var(--gray-900);
  box-shadow: 0 4px 14px rgba(245, 158, 11, 0.4);
}

.btn-cta:hover {
  background: var(--warning-light);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(245, 158, 11, 0.5);
  color: var(--gray-900);
}

/* ==========================================
   页脚
   ========================================== */

.footer {
  background: var(--gray-900);
  color: var(--gray-400);
  padding: var(--space-2xl) 0;
  text-align: center;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
}

.footer-links {
  display: flex;
  gap: var(--space-lg);
}

.footer-link {
  color: var(--gray-400);
  font-size: 0.9rem;
  transition: color var(--transition-fast);
}

.footer-link:hover {
  color: white;
}

.footer-copyright {
  font-size: 0.875rem;
  opacity: 0.7;
}

/* ==========================================
   响应式设计
   ========================================== */

@media (max-width: 768px) {
  .header .container {
    flex-direction: column;
    height: auto;
    padding: var(--space-md) var(--space-lg);
    gap: var(--space-md);
  }
  
  .nav {
    width: 100%;
    justify-content: center;
  }
  
  .hero-title {
    font-size: 1.75rem;
  }
  
  .hero-subtitle {
    font-size: 1rem;
  }
  
  .tools-grid {
    grid-template-columns: 1fr;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .section {
    padding: var(--space-2xl) 0;
  }
}

/* ==========================================
   加载动画
   ========================================== */

.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
}

.loading-spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--gray-300);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ==========================================
   Python/Pyodide 状态指示器
   ========================================== */

.python-status {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--gray-100);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.python-status.loading {
  color: var(--warning);
}

.python-status.ready {
  color: var(--success);
  background: #10b98120;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
}

.python-status.loading .status-dot {
  animation: pulse 1s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}