/* 全局样式定义 */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@100;300;400;500;700;900&display=swap');

/* 自定义CSS变量 */
:root {
  --accent-color: #dc2626;
  --text-primary: #000000;
  --text-secondary: #666666;
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f5;
  --border-color: #e5e5e5;
}

/* 基础字体设置 */
body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  font-weight: 300;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 标题字重 */
h1, h2, h3, h4, h5, h6 {
  font-weight: 500;
  letter-spacing: -0.02em;
}

/* 悬停动画效果 */
.hover-lift {
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1),
              opacity 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.hover-lift:hover {
  transform: translateY(-4px) scale(1.02);
  opacity: 0.95;
}

.hover-underline {
  position: relative;
  transition: color 0.3s ease;
}

.hover-underline::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background-color: var(--accent-color);
  transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.hover-underline:hover::after {
  width: 100%;
}

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

.image-hover img {
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1),
              filter 0.3s ease;
}

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

/* 渐入动画 */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeIn 0.8s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

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

/* 色彩过渡效果 */
.color-transition {
  transition: background-color 0.4s cubic-bezier(0.4, 0, 0.2, 1),
              color 0.3s ease,
              border-color 0.3s ease;
}

/* 导航链接样式 */
.nav-link {
  position: relative;
  padding: 0.5rem 0;
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 400;
  letter-spacing: 0.02em;
  transition: color 0.3s ease;
}

.nav-link:hover {
  color: var(--accent-color);
}

/* 卡片悬停效果 */
.card-hover {
  transition: box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.card-hover:hover {
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
  transform: translateY(-2px);
}

/* 按钮悬停效果 */
.btn-hover {
  background-color: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 0.75rem 1.5rem;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
}

.btn-hover:hover {
  background-color: var(--accent-color);
  color: white;
  border-color: var(--accent-color);
  transform: translateY(-1px);
}

/* 滚动条样式 */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: #cccccc;
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: #999999;
}

/* 选择文本样式 */
::selection {
  background-color: var(--accent-color);
  color: white;
}

/* 焦点样式 */
.focus-visible:focus-visible {
  outline: 2px solid var(--accent-color);
  outline-offset: 2px;
}