/* 全局颜色变量 */
:root {
  --color-primary: #F5F7FA;
  --color-secondary: #FFFFFF;
  --color-tertiary: #EFF2F6;
  --color-accent: #3B82F6;
  --color-text: #1F2937;
  --color-text-light: #6B7280;
  --transition-base: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background-color: var(--color-primary);
  color: var(--color-text);
  line-height: 1.6;
  overflow-x: hidden;
}

/* 滚动渐显动画 */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  animation: fadeInUp 0.8s ease-out forwards;
  opacity: 0;
}

.fade-in-up-delay-1 {
  animation-delay: 0.2s;
}

.fade-in-up-delay-2 {
  animation-delay: 0.4s;
}

.fade-in-up-delay-3 {
  animation-delay: 0.6s;
}

/* 卡片悬停效果 */
.card-hover {
  transition: var(--transition-base);
  cursor: pointer;
}

.card-hover:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 25px -5px rgba(59, 130, 246, 0.1), 0 10px 10px -5px rgba(59, 130, 246, 0.04);
}

/* 导航栏悬停下划线效果 */
.nav-link {
  position: relative;
  transition: var(--transition-base);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-accent);
  transition: width 0.3s ease;
}

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

/* 边框光效 */
.border-glow {
  border: 1px solid transparent;
  transition: var(--transition-base);
}

.border-glow:hover {
  border-color: var(--color-accent);
  box-shadow: 0 0 15px rgba(59, 130, 246, 0.2);
}

/* 动态渐变网格背景 */
.gradient-grid {
  background: linear-gradient(135deg, var(--color-tertiary) 0%, var(--color-secondary) 100%);
  position: relative;
  overflow: hidden;
}

.gradient-grid::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    linear-gradient(90deg, rgba(59, 130, 246, 0.03) 1px, transparent 1px),
    linear-gradient(rgba(59, 130, 246, 0.03) 1px, transparent 1px);
  background-size: 50px 50px;
  opacity: 0.5;
}

/* 响应式容器 */
.container-custom {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

@media (max-width: 768px) {
  .container-custom {
    padding: 0 1rem;
  }
}

/* 数字大标题样式 */
.stat-number {
  font-size: 3rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
}

@media (max-width: 640px) {
  .stat-number {
    font-size: 2rem;
  }
}

/* 时间轴样式 */
.timeline-item {
  position: relative;
  padding-left: 2rem;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.5rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background-color: var(--color-accent);
  border: 3px solid var(--color-secondary);
}

.timeline-item::after {
  content: '';
  position: absolute;
  left: 5px;
  top: 1.5rem;
  width: 2px;
  height: calc(100% + 1rem);
  background-color: var(--color-tertiary);
}

.timeline-item:last-child::after {
  display: none;
}

/* 标签样式 */
.tag {
  display: inline-block;
  padding: 0.5rem 1rem;
  border-radius: 9999px;
  background-color: var(--color-tertiary);
  color: var(--color-text);
  transition: var(--transition-base);
  cursor: pointer;
}

.tag:hover,
.tag.active {
  background-color: var(--color-accent);
  color: var(--color-secondary);
}

/* 图片容器 */
.img-container {
  position: relative;
  overflow: hidden;
  border-radius: 0.5rem;
}

.img-container img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

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

/* 加载占位动画 */
@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.5;
  }
}

.skeleton {
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
  background-color: var(--color-tertiary);
}

/* 响应式调整 */
@media (max-width: 1024px) {
  .grid-cols-3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .grid-cols-3,
  .grid-cols-2 {
    grid-template-columns: 1fr;
  }
  
  .text-5xl {
    font-size: 2.5rem;
  }
  
  .text-4xl {
    font-size: 2rem;
  }
}

/* 平滑滚动 */
html {
  scroll-behavior: smooth;
}

/* 文字选择样式 */
::selection {
  background-color: rgba(59, 130, 246, 0.2);
  color: var(--color-text);
}