/* 2024长三角国际新能源汽车与智能交通产业博览会 - 全局样式 */

/* 根变量定义 */
:root {
  /* 主题色彩系统 */
  --primary-gradient-start: #10b981;
  --primary-gradient-end: #3b82f6;
  --secondary-gradient-start: #8b5cf6;
  --secondary-gradient-end: #ec4899;
  --accent-gradient-start: #f59e0b;
  --accent-gradient-end: #ef4444;
  
  /* 中性色 */
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* 间距系统 */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* 动画时长 */
  --transition-fast: 150ms;
  --transition-base: 300ms;
  --transition-slow: 500ms;
  --transition-slower: 700ms;
  
  /* 阴影 */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-base: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  
  /* 圆角 */
  --radius-sm: 0.375rem;
  --radius-base: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  line-height: 1.6;
  color: var(--gray-800);
  background-color: var(--gray-50);
}

/* 渐变背景动画 */
@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.gradient-bg {
  background: linear-gradient(-45deg, 
    var(--primary-gradient-start), 
    var(--primary-gradient-end), 
    var(--secondary-gradient-start), 
    var(--secondary-gradient-end));
  background-size: 400% 400%;
  animation: gradientShift 15s ease infinite;
}

.gradient-primary {
  background: linear-gradient(135deg, var(--primary-gradient-start), var(--primary-gradient-end));
}

.gradient-secondary {
  background: linear-gradient(135deg, var(--secondary-gradient-start), var(--secondary-gradient-end));
}

.gradient-accent {
  background: linear-gradient(135deg, var(--accent-gradient-start), var(--accent-gradient-end));
}

/* 导航栏样式 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-base);
  transition: all var(--transition-base) ease;
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.98);
  box-shadow: var(--shadow-lg);
}

.nav-link {
  position: relative;
  padding: var(--spacing-xs) var(--spacing-sm);
  color: var(--gray-700);
  text-decoration: none;
  transition: color var(--transition-fast) ease;
  overflow: hidden;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary-gradient-start), var(--primary-gradient-end));
  transform: translateX(-50%);
  transition: width var(--transition-base) ease;
}

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

/* 卡片动画效果 */
@keyframes cardFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.card {
  background: white;
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-base);
  transition: all var(--transition-base) ease;
  position: relative;
  overflow: hidden;
}

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

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

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

/* 按钮样式 */
.btn {
  display: inline-block;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-full);
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-base) ease;
  position: relative;
  overflow: hidden;
  cursor: pointer;
  border: none;
  outline: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-gradient-start), var(--primary-gradient-end));
  color: white;
  box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
}

.btn-secondary {
  background: white;
  color: var(--gray-700);
  border: 2px solid var(--gray-200);
}

.btn-secondary:hover {
  background: var(--gray-50);
  border-color: var(--primary-gradient-start);
  color: var(--primary-gradient-start);
}

/* 波纹效果 */
@keyframes ripple {
  0% {
    transform: scale(0);
    opacity: 1;
  }
  100% {
    transform: scale(4);
    opacity: 0;
  }
}

.ripple {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.5);
  animation: ripple 0.6s ease-out;
  pointer-events: none;
}

/* 加载动画 */
@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.spinner {
  display: inline-block;
  width: 40px;
  height: 40px;
  border: 4px solid var(--gray-200);
  border-top-color: var(--primary-gradient-start);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

/* 数字滚动动画 */
@keyframes countUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.count-up {
  animation: countUp var(--transition-slow) ease-out;
}

/* 淡入动画 */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn var(--transition-slower) ease-out;
}

/* 滑入动画 */
@keyframes slideInLeft {
  from { opacity: 0; transform: translateX(-50px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes slideInRight {
  from { opacity: 0; transform: translateX(50px); }
  to { opacity: 1; transform: translateX(0); }
}

.slide-in-left {
  animation: slideInLeft var(--transition-slow) ease-out;
}

.slide-in-right {
  animation: slideInRight var(--transition-slow) ease-out;
}

/* 脉冲动画 */
@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.05); opacity: 0.9; }
}

.pulse {
  animation: pulse 2s ease-in-out infinite;
}

/* 光晕效果 */
@keyframes glow {
  0%, 100% { box-shadow: 0 0 20px rgba(16, 185, 129, 0.5); }
  50% { box-shadow: 0 0 40px rgba(16, 185, 129, 0.8); }
}

.glow {
  animation: glow 2s ease-in-out infinite;
}

/* 时间线样式 */
.timeline {
  position: relative;
  padding-left: var(--spacing-xl);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 15px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--primary-gradient-start), var(--primary-gradient-end));
}

.timeline-item {
  position: relative;
  padding-bottom: var(--spacing-xl);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -25px;
  top: 5px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--primary-gradient-start);
  border: 3px solid white;
  box-shadow: var(--shadow-base);
}

/* 网格布局动画 */
.grid-item {
  opacity: 0;
  transform: scale(0.9);
  animation: gridFadeIn var(--transition-slow) ease-out forwards;
}

@keyframes gridFadeIn {
  to {
    opacity: 1;
    transform: scale(1);
  }
}

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

/* 响应式设计 */
@media (max-width: 768px) {
  :root {
    font-size: 14px;
  }
  
  .card {
    padding: var(--spacing-md);
  }
  
  .timeline {
    padding-left: var(--spacing-lg);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* 打印样式 */
@media print {
  .navbar,
  .btn,
  .no-print {
    display: none !important;
  }
  
  body {
    font-size: 12pt;
    color: black;
    background: white;
  }
  
  .card {
    box-shadow: none;
    border: 1px solid #ddd;
    page-break-inside: avoid;
  }
}

/* 辅助类 */
.text-gradient {
  background: linear-gradient(135deg, var(--primary-gradient-start), var(--primary-gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hover-scale {
  transition: transform var(--transition-base) ease;
}

.hover-scale:hover {
  transform: scale(1.05);
}

.hover-lift {
  transition: transform var(--transition-base) ease;
}

.hover-lift:hover {
  transform: translateY(-5px);
}

.overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(180deg, transparent, rgba(0, 0, 0, 0.7));
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}