/* 引入字体库: Inter (英文) 和 Noto Sans SC (思源黑体) */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500&family=Noto+Sans+SC:wght@300;400;500&display=swap');

/* 全局配色变量定义 */
:root {
  --color-pearl-white: #FAFAFA;
  --color-sandstone-gray: #E8E8E8;
  --color-fog-blue: #7C90B0;
  --color-charcoal-black: #2A2A2A;
  --color-dark-gray: #555555;
}

/* 基础样式重置与字体设置 */
body {
  background-color: var(--color-pearl-white);
  color: var(--color-charcoal-black);
  font-family: 'Inter', 'Noto Sans SC', sans-serif;
  -webkit-font-smoothing: antialiased; /* 抗锯齿渲染 */
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden; /* 禁止水平滚动 */
  line-height: 1.6;
}

/* 页面淡入淡出过渡 (300ms) */
.page-fade-in {
  animation: fadeIn 300ms ease-in-out forwards;
}

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

/* 滚动触发的缓动动画 (滑入效果) */
.scroll-reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 1s cubic-bezier(0.22, 1, 0.36, 1), transform 1s cubic-bezier(0.22, 1, 0.36, 1);
}

.scroll-reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 图片悬停交互规范 */
.img-container {
  overflow: hidden;
  position: relative;
  background-color: var(--color-sandstone-gray); /* 图片加载前的占位色 */
}

.img-container img {
  transition: transform 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* 悬停放大 1.03 倍 */
.img-container:hover img {
  transform: scale(1.03);
}

/* 图片遮罩层 (悬停显示材质描述) */
.img-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.2);
  opacity: 0;
  transition: opacity 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
}

.img-container:hover .img-overlay {
  opacity: 1;
}

/* 全屏遮罩层 (点击图片后) */
.fullscreen-modal {
  position: fixed;
  inset: 0;
  background-color: rgba(250, 250, 250, 0.98); /* 珍珠白高透明度 */
  z-index: 100;
  display: flex;
  justify-content: center;
  align-items: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.fullscreen-modal.active {
  opacity: 1;
  pointer-events: auto;
}

/* 导航链接激活状态 */
.nav-link {
  position: relative;
  transition: color 0.3s ease;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background-color: var(--color-fog-blue);
  transition: width 0.3s ease;
}

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

.nav-link.active {
  color: var(--color-fog-blue);
}

/* 极简滚动条 */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background-color: #D1D5DB;
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background-color: var(--color-fog-blue);
}

/* 移动端汉堡菜单动画 */
.mobile-menu-enter {
  animation: slideDown 0.3s ease-out forwards;
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}