/* 全局设计令牌 */
:root {
  /* 主色调 - 黑白灰 */
  --color-black: #212529;
  --color-gray-900: #495057;
  --color-gray-500: #e9ecef;
  --color-gray-100: #f8f9fa;
  --color-white: #ffffff;
  
  /* 辅助色 - 低饱和度自然色系 */
  --color-terracotta: #c77c5a;
  --color-olive: #7d826c;
  --color-navy: #2c3e50;
  --color-charcoal: #36454f;
  
  /* 间距系统 */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 8rem;
  
  /* 字体 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  
  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
  
  /* 过渡 */
  --transition: all 0.3s ease;
}

/* 基础样式重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-black);
  background-color: var(--color-white);
  line-height: 1.6;
}

/* 响应式容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

/* 导航栏样式 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  z-index: 1000;
  transition: var(--transition);
}

.navbar a {
  color: var(--color-black);
  text-decoration: none;
  transition: var(--transition);
}

.navbar a:hover {
  color: var(--color-olive);
}

/* 图片悬停效果 */
.image-hover {
  overflow: hidden;
  cursor: pointer;
}

.image-hover img {
  transition: transform 0.5s ease;
}

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

/* 图片覆盖层 */
.image-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.image-hover:hover .image-overlay {
  opacity: 1;
}

/* 标签样式 */
.tag {
  background: rgba(255, 255, 255, 0.9);
  color: var(--color-black);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 4px;
  font-size: 0.875rem;
}

/* 按钮样式 */
.btn-primary {
  background-color: var(--color-black);
  color: var(--color-white);
  padding: var(--spacing-sm) var(--spacing-md);
  border: none;
  border-radius: 4px;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  display: inline-block;
}

.btn-primary:hover {
  background-color: var(--color-gray-900);
}

/* 页脚样式 */
footer {
  border-top: 1px solid var(--color-gray-500);
  text-align: center;
  padding: var(--spacing-md);
  color: var(--color-gray-900);
  font-size: 0.875rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-xs);
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  h3 {
    font-size: 1.25rem;
  }
}

/* 懒加载淡入效果 */
.fade-in {
  animation: fadeIn 0.8s ease-in;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 全屏英雄图像 */
.hero {
  height: 100vh;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.3);
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  color: var(--color-white);
  padding: var(--spacing-md);
}

/* 瀑布流布局 */
.masonry {
  column-count: 3;
  column-gap: var(--spacing-sm);
}

@media (max-width: 1024px) {
  .masonry {
    column-count: 2;
  }
}

@media (max-width: 768px) {
  .masonry {
    column-count: 1;
  }
}

.masonry-item {
  break-inside: avoid;
  margin-bottom: var(--spacing-sm);
}

/* 全屏滚动 */
.fullscreen-section {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

/* 网格布局 */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-sm);
}

@media (max-width: 768px) {
  .grid-3 {
    grid-template-columns: 1fr;
  }
}

/* 筛选按钮 */
.filter-btn {
  background: transparent;
  color: var(--color-black);
  border: 1px solid var(--color-gray-500);
  padding: var(--spacing-xs) var(--spacing-sm);
  margin: 0 var(--spacing-xs);
  cursor: pointer;
  transition: var(--transition);
  border-radius: 4px;
}

.filter-btn:hover,
.filter-btn.active {
  background: var(--color-black);
  color: var(--color-white);
}