/* 颜色系统 */
:root {
  --cement-gray: #2F2F2F;
  --bone-white: #F5F5F0;
  --tungsten: #424242;
  --sand: #E6E2D6;
  --haze-blue: #7B8B8E;
}

/* 字体系统 */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;700&display=swap');

body {
  font-family: 'Helvetica Now Display', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bone-white);
  color: var(--cement-gray);
}

/* 标题字体 */
h1, h2, h3, h4, h5, h6 {
  font-weight: 500;
}

/* 过渡效果 */
.transition-all {
  transition: all 0.3s ease;
}

/* 悬停效果 */
.hover-scale:hover {
  transform: scale(1.05);
}

/* 淡入淡出 */
.fade-in {
  animation: fadeIn 0.4s ease-in;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* 微震动画 */
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

.shake {
  animation: shake 0.3s ease-in-out;
}

/* 自定义滚动条 */
::-webkit-scrollbar {
  width: 8px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--tungsten);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--cement-gray);
}

/* 响应式字体大小 */
.text-responsive {
  font-size: clamp(1rem, 2.5vw, 1.5rem);
}

/* 图片懒加载占位 */
.lazy-load {
  background: linear-gradient(90deg, var(--sand) 25%, var(--bone-white) 50%, var(--sand) 75%);
  background-size: 200% 100%;
  animation: loading 1.5s infinite;
}

@keyframes loading {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* 页面切换效果 */
.page-transition {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.4s ease, transform 0.4s ease;
}

.page-transition.active {
  opacity: 1;
  transform: translateY(0);
}