/* 全局基础设置 */
:root {
  --color-primary: #2C3E50;
  --color-secondary: #666666;
  --color-accent: #8B0000;
  --color-bg: #FFFFFF;
}

body {
  font-family: Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-color: var(--color-bg);
  color: var(--color-primary);
  overflow-x: hidden;
}

/* 文本选区颜色 - 雾霾蓝 */
::selection {
  background: #E3F2FD;
  color: #2C3E50;
}

/* 自定义滚动条 - 极简风格 */
::-webkit-scrollbar {
  width: 4px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: #D1D5DB;
  border-radius: 2px;
}
::-webkit-scrollbar-thumb:hover {
  background: #9CA3AF;
}

/* 交互动画：淡入上浮 */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-fade-in-up {
  opacity: 0; /* 初始隐藏，由动画控制显示 */
  animation: fadeInUp 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

/* 动画延迟工具类 */
.delay-100 { animation-delay: 100ms; }
.delay-200 { animation-delay: 200ms; }
.delay-300 { animation-delay: 300ms; }
.delay-500 { animation-delay: 500ms; }

/* 导航链接动效 */
.nav-link {
  position: relative;
  display: inline-block;
}
.nav-link::after {
  content: '';
  position: absolute;
  width: 0;
  height: 1px;
  bottom: -4px;
  left: 50%;
  background-color: currentColor;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  transform: translateX(-50%);
}
.nav-link:hover::after {
  width: 100%;
}

/* 图片悬停效果：轻微放大 + 亮度 */
.img-hover-container {
  overflow: hidden;
  position: relative;
}
.img-hover-container img {
  transition: transform 0.7s cubic-bezier(0.16, 1, 0.3, 1), filter 0.5s ease;
  will-change: transform;
}
.img-hover-container:hover img {
  transform: scale(1.03);
  filter: brightness(0.98) contrast(1.02);
}

/* 图片懒加载骨架屏占位 */
.skeleton-loader {
  background: #f0f0f0;
  position: relative;
  overflow: hidden;
}
.skeleton-loader::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  transform: translateX(-100%);
  background-image: linear-gradient(
    90deg,
    rgba(255, 255, 255, 0) 0,
    rgba(255, 255, 255, 0.2) 20%,
    rgba(255, 255, 255, 0.5) 60%,
    rgba(255, 255, 255, 0)
  );
  animation: shimmer 2s infinite;
}
@keyframes shimmer {
  100% {
    transform: translateX(100%);
  }
}