/* =====================================================================
 * animations.css — 全局动画过渡效果 (v2.0 升级版)
 * 
 * 升级原则 (frontend-design skill):
 *   - 100/300/500 时长规则
 *   - 指数级缓动函数 (quart/quint/expo)
 *   - 仅动画 transform + opacity
 *   - 所有交互元素 5 种状态 (default/hover/active/focus/disabled)
 *   - 移除 bounce/elastic 缓动 (过时感)
 * ===================================================================== */

/* ===== CSS 变量体系 (100/300/500 规则) ===== */
:root {
  /* -- 时长分级 -- */
  --duration-instant: 100ms;   /* 按压反馈、图标切换 */
  --duration-fast:    150ms;   /* 悬停状态、颜色变化 */
  --duration-normal:  250ms;   /* 菜单开关、tooltip、展开 */
  --duration-slow:    400ms;   /* 模态框、抽屉、手风琴 */
  --duration-entrance: 500ms;  /* 入场动画、hero 揭示 */
  
  /* -- 指数缓动函数 (模拟真实物理: 摩擦 + 减速) -- */
  /* 元素进入 / 悬停展开 → ease-out 变体 */
  --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);    /* 推荐默认 */
  --ease-out-quint: cubic-bezier(0.22, 1, 0.36, 1);   /* 更有力度 */
  --ease-out-expo:  cubic-bezier(0.16, 1, 0.3, 1);    /* 干脆自信 */
  
  /* 元素离开 / 收起 → ease-in 变体 */
  --ease-in-quart:  cubic-bezier(0.5, 0, 0.75, 0);
  --ease-in-quint:  cubic-bezier(0.64, 0, 0.78, 0);
  --ease-in-expo:   cubic-bezier(0.7, 0, 0.84, 0);
  
  /* 双向状态切换 (开→关 来回) */
  --ease-in-out-quart: cubic-bezier(0.76, 0, 0.24, 1);
  
  /* 旧变量别名 (向后兼容) */
  --ease-out:    var(--ease-out-expo);
  --ease-in-out: var(--ease-in-out-quart);
  
  /* -- 层级 -- */
  --z-nav: 100;
  --z-overlay: 200;
  --z-modal: 300;
}

/* ===== 1. 页面滚动动画体系 ===== */
html {
  scroll-behavior: smooth;
}

/* 区块入场动画 — 使用指数级 ease-out，视觉更自然 */
.section-animate {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--duration-slow) var(--ease-out-quint),
              transform var(--duration-slow) var(--ease-out-quint);
}

.section-animate.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 错开延迟 — 使用 CSS 自定义属性，更灵活 */
.section-animate.delay-1 { transition-delay: 0.05s; }
.section-animate.delay-2 { transition-delay: 0.1s; }
.section-animate.delay-3 { transition-delay: 0.15s; }
.section-animate.delay-4 { transition-delay: 0.2s; }

/* 章节错开容器 */
.chapter-stagger > * {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              transform var(--duration-slow) var(--ease-out-quart);
}

.chapter-stagger.visible > *:nth-child(1) { transition-delay: 0s;    opacity: 1; transform: translateY(0); }
.chapter-stagger.visible > *:nth-child(2) { transition-delay: 0.08s; opacity: 1; transform: translateY(0); }
.chapter-stagger.visible > *:nth-child(3) { transition-delay: 0.16s; opacity: 1; transform: translateY(0); }
.chapter-stagger.visible > *:nth-child(4) { transition-delay: 0.24s; opacity: 1; transform: translateY(0); }
.chapter-stagger.visible > *:nth-child(5) { transition-delay: 0.32s; opacity: 1; transform: translateY(0); }
.chapter-stagger.visible > *:nth-child(6) { transition-delay: 0.40s; opacity: 1; transform: translateY(0); }

/* 淡入上升关键帧 */
@keyframes fade-in-up {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}

.fade-in-up {
  animation: fade-in-up var(--duration-entrance) var(--ease-out-quint) forwards;
}

/* 淡入缩放关键帧 (用于卡片入场) */
@keyframes fade-in-scale {
  from { opacity: 0; transform: scale(0.92); }
  to   { opacity: 1; transform: scale(1); }
}

.fade-in-scale {
  animation: fade-in-scale var(--duration-slow) var(--ease-out-quart) forwards;
}

/* ===== 2. 滚动指示器动画 ===== */
@keyframes scroll-wheel-pulse {
  0%   { opacity: 1; transform: translateY(0); }
  50%  { opacity: 0.6; transform: translateY(6px); }
  100% { opacity: 1; transform: translateY(0); }
}

.scroll-mouse-wheel {
  animation: scroll-wheel-pulse 2.4s var(--ease-in-out-quart) infinite;
}

/* ===== 3. 导航栏动画体系 ===== */

/* 导航容器 — 统一过渡属性 */
.nav {
  transition: transform var(--duration-normal) var(--ease-out-quart),
              background var(--duration-fast) var(--ease-out-quart),
              backdrop-filter var(--duration-fast) var(--ease-out-quart),
              box-shadow var(--duration-fast) var(--ease-out-quart);
}

/* 滚动后导航背景 */
.nav.scrolled {
  background: linear-gradient(180deg,
    var(--paper) 0%,
    var(--paper) 85%,
    transparent 100%);
  backdrop-filter: blur(12px);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

/* 向下滚动隐藏导航 */
.nav.hidden {
  transform: translateY(-100%);
}

/* 导航链接 — 5 状态完整设计 */
.nav-links a {
  position: relative;
  transition: color var(--duration-instant) var(--ease-out-quart);
}

/* Hover — 颜色微调 + 上移 */
.nav-links a:hover {
  color: var(--monet-pond);
  transform: translateY(-1px);
}

/* Active/按压 — 微缩 + 颜色加深 */
.nav-links a:active {
  transform: translateY(0) scale(0.97);
  color: var(--monet-pond);
  opacity: 0.8;
}

/* Focus — 可见焦点环 */
.nav-links a:focus-visible {
  outline: 2px solid var(--monet-pond);
  outline-offset: 4px;
  border-radius: 4px;
}

/* Active 当前页 — 底部指示条 */
.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 50%;
  transform: translateX(-50%);
  width: 60%;
  height: 2px;
  background: var(--monet-pond);
  border-radius: 1px;
  transition: width var(--duration-fast) var(--ease-out-quart);
}

/* ===== 4. 移动端菜单动画 (仅 transform + opacity) ===== */
.mobile-menu {
  transform: translateX(100%);
  transition: transform var(--duration-normal) var(--ease-out-quint);
}

.mobile-menu.open {
  transform: translateX(0);
}

/* 遮罩层 */
.nav-overlay {
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--duration-normal) var(--ease-out-quart);
}

.nav-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

/* 汉堡菜单图标 — 三线到X的变形 */
.hamburger {
  transition: transform var(--duration-fast) var(--ease-out-quart);
}

.hamburger:hover {
  transform: scale(1.1);
}

.hamburger:active {
  transform: scale(0.95);
}

/* 汉堡菜单三线旋转 */
.hamburger.active .hamburger-line:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
  transition: transform var(--duration-normal) var(--ease-out-quart);
}

.hamburger.active .hamburger-line:nth-child(2) {
  opacity: 0;
  transition: opacity var(--duration-instant) var(--ease-out-quart);
}

.hamburger.active .hamburger-line:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
  transition: transform var(--duration-normal) var(--ease-out-quart);
}

.hamburger-line {
  transition: transform var(--duration-normal) var(--ease-out-quart),
              opacity var(--duration-instant) var(--ease-out-quart);
}

/* ===== 5. 按钮交互动画体系 (全面升级) ===== */

/* -- 主按钮 (btn-primary) — 5 状态 -- */
.btn-primary {
  transition: transform var(--duration-fast) var(--ease-out-quart),
              box-shadow var(--duration-fast) var(--ease-out-quart),
              background var(--duration-fast) var(--ease-out-quart),
              opacity var(--duration-fast) var(--ease-out-quart);
  position: relative;
  overflow: hidden;
}

/* Hover — 微上浮 + 柔和阴影 */
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
}

/* Active — 按压感: 回到原位 + 缩小 */
.btn-primary:active {
  transform: translateY(0) scale(0.97);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
  transition-duration: 80ms; /* <100ms 瞬时反馈 */
}

/* Focus — 可见焦点环 */
.btn-primary:focus-visible {
  outline: 2px solid var(--monet-pond);
  outline-offset: 3px;
}

/* Disabled — 降低透明度 + 禁用光标 */
.btn-primary:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

/* -- 波纹效果 — 使用 transform + opacity，纯 GPU 动画 -- */
.btn-ripple {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: scale(0);
  opacity: 1;
  pointer-events: none;
  animation: ripple-expand 600ms var(--ease-out-quart) forwards;
}

@keyframes ripple-expand {
  to {
    transform: scale(4);
    opacity: 0;
  }
}

/* -- 幽灵按钮 (btn-ghost) — 5 状态 -- */
.btn-ghost {
  transition: transform var(--duration-fast) var(--ease-out-quart),
              color var(--duration-fast) var(--ease-out-quart),
              border-color var(--duration-fast) var(--ease-out-quart),
              background var(--duration-fast) var(--ease-out-quart);
}

.btn-ghost:hover {
  transform: translateY(-1px);
  border-color: var(--monet-pond);
  color: var(--monet-pond);
}

.btn-ghost:active {
  transform: translateY(0) scale(0.97);
  transition-duration: 80ms;
}

.btn-ghost:focus-visible {
  outline: 2px solid var(--monet-pond);
  outline-offset: 2px;
}

.btn-ghost:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
}

/* ===== 6. 主题切换按钮动画 ===== */

/* 主题切换按钮 */
.theme-toggle,
#nav-theme-toggle,
#yardon-theme-toggle,
#fab-theme-toggle {
  transition: transform var(--duration-fast) var(--ease-out-quart),
              color var(--duration-fast) var(--ease-out-quart);
  cursor: pointer;
}

.theme-toggle:hover,
#nav-theme-toggle:hover,
#yardon-theme-toggle:hover,
#fab-theme-toggle:hover {
  transform: rotate(15deg) scale(1.15);
  color: var(--monet-gold);
}

.theme-toggle:active,
#nav-theme-toggle:active,
#yardon-theme-toggle:active,
#fab-theme-toggle:active {
  transform: rotate(0deg) scale(0.9);
  transition-duration: 80ms;
}

.theme-toggle:focus-visible,
#nav-theme-toggle:focus-visible {
  outline: 2px solid var(--monet-gold);
  outline-offset: 3px;
  border-radius: 50%;
}

/* 主题切换图标旋转动画 */
@keyframes theme-icon-spin {
  from { transform: rotate(0deg) scale(0.8); opacity: 0; }
  to   { transform: rotate(360deg) scale(1); opacity: 1; }
}

.theme-icon-transition {
  animation: theme-icon-spin var(--duration-normal) var(--ease-out-quart) forwards;
}

/* ===== 7. 语言切换按钮动画 ===== */

.lang-switch,
#nav-lang-switch,
#fab-lang-switch {
  transition: transform var(--duration-fast) var(--ease-out-quart),
              color var(--duration-fast) var(--ease-out-quart),
              background var(--duration-fast) var(--ease-out-quart);
  cursor: pointer;
}

.lang-switch:hover,
#nav-lang-switch:hover {
  transform: translateY(-1px);
  color: var(--monet-pond);
}

.lang-switch:active,
#nav-lang-switch:active {
  transform: translateY(0) scale(0.95);
  transition-duration: 80ms;
}

/* ===== 8. 通用卡片 hover 效果 ===== */

.card-hover {
  transition: transform var(--duration-normal) var(--ease-out-quart),
              box-shadow var(--duration-normal) var(--ease-out-quart);
}

.card-hover:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.12);
}

.card-hover:active {
  transform: translateY(-1px) scale(0.98);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  transition-duration: 80ms;
}

.card-hover:focus-visible {
  outline: 2px solid var(--monet-pond);
  outline-offset: 4px;
  border-radius: var(--radius-md);
}

/* ===== 9. 开关/切换 (Toggle/Switch) 组件动画 ===== */

/* 通用开关轨道 */
.toggle-track {
  transition: background var(--duration-fast) var(--ease-out-quart);
}

/* 开关滑块 — 仅动画 transform */
.toggle-thumb {
  transition: transform var(--duration-normal) var(--ease-out-quint);
}

/* ===== 10. 博客列表页动画 ===== */

/* 系列过滤标签 — 5 状态 */
.series-filter {
  transition: transform var(--duration-fast) var(--ease-out-quart),
              color var(--duration-fast) var(--ease-out-quart),
              background var(--duration-fast) var(--ease-out-quart),
              box-shadow var(--duration-fast) var(--ease-out-quart);
  cursor: pointer;
  position: relative;
}

.series-filter:hover {
  transform: translateY(-1px);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.series-filter:active {
  transform: translateY(0) scale(0.96);
  transition-duration: 80ms;
}

.series-filter.active {
  /* 移除 pulse-active bounce 动画，改用静态强调 */
  color: var(--paper);
  background: var(--monet-pond);
  font-weight: 600;
}

.series-filter:focus-visible {
  outline: 2px solid var(--monet-pond);
  outline-offset: 2px;
}

/* 文章卡片过滤 — 仅动画 opacity + transform */
.post-item {
  transition: opacity var(--duration-normal) var(--ease-out-quart),
              transform var(--duration-normal) var(--ease-out-quart);
}

.post-item.hiding {
  opacity: 0;
  transform: scale(0.95);
  pointer-events: none;
}

.post-item.showing {
  opacity: 1;
  transform: scale(1);
}

/* 排序按钮 */
.sort-btn {
  transition: transform var(--duration-fast) var(--ease-out-quart),
              color var(--duration-fast) var(--ease-out-quart),
              background var(--duration-fast) var(--ease-out-quart);
}

.sort-btn:hover {
  transform: translateY(-1px);
}

.sort-btn:active {
  transform: translateY(0) scale(0.96);
  transition-duration: 80ms;
}

.sort-btn.active {
  color: var(--monet-pond);
  font-weight: 600;
}

/* ===== 11. 项目详情页动画 ===== */

/* 图片 hover 放大 */
.project-image-hover {
  transition: transform var(--duration-normal) var(--ease-out-quart);
  will-change: transform;
}

.project-image-hover:hover {
  transform: scale(1.04);
}

.project-image-hover:active {
  transform: scale(0.98);
  transition-duration: 80ms;
}

/* 内容区块入场 */
.project-section {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--duration-slow) var(--ease-out-quint),
              transform var(--duration-slow) var(--ease-out-quint);
}

.project-section.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 截图横向滚动 */
.screenshots-row {
  scroll-behavior: smooth;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.screenshot-card {
  scroll-snap-align: start;
  transition: transform var(--duration-fast) var(--ease-out-quart),
              box-shadow var(--duration-fast) var(--ease-out-quart);
}

.screenshot-card:hover {
  transform: scale(1.02);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.screenshot-card:active {
  transform: scale(0.98);
  transition-duration: 80ms;
}

/* 移动端项目卡片 scroll-snap */
.projects-grid {
  scroll-behavior: smooth;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
}

.project-card {
  scroll-snap-align: center;
  transition: transform var(--duration-normal) var(--ease-out-quart),
              box-shadow var(--duration-normal) var(--ease-out-quart);
}

/* ===== 12. 学习路径图动画 ===== */

.lp-card {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              transform var(--duration-slow) var(--ease-out-quart);
}

.lp-card.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 使用 CSS 自定义属性实现更干净的错开延迟 */
.lp-step-entry .lp-card:nth-child(1) { transition-delay: 0.05s; }
.lp-step-entry .lp-card:nth-child(2) { transition-delay: 0.15s; }
.lp-step-entry .lp-card:nth-child(3) { transition-delay: 0.25s; }

.lp-step-advanced .lp-card:nth-child(1) { transition-delay: 0.35s; }
.lp-step-advanced .lp-card:nth-child(2) { transition-delay: 0.45s; }
.lp-step-advanced .lp-card:nth-child(3) { transition-delay: 0.55s; }

.lp-step-practice .lp-card:nth-child(1) { transition-delay: 0.65s; }
.lp-step-practice .lp-card:nth-child(2) { transition-delay: 0.75s; }
.lp-step-practice .lp-card:nth-child(3) { transition-delay: 0.85s; }

/* SVG 连线绘制 — 平滑展开 */
.lp-connection {
  stroke-dasharray: 1000;
  stroke-dashoffset: 1000;
  animation: draw-line var(--duration-entrance) var(--ease-out-quart) forwards;
  animation-delay: 0.6s;
}

@keyframes draw-line {
  to { stroke-dashoffset: 0; }
}

/* ===== 13. 博客文章页面动画 ===== */

/* TOC 目录面板滑入 */
.toc-panel {
  transform: translateX(100%);
  transition: transform var(--duration-normal) var(--ease-out-quint);
}

.toc-panel.open {
  transform: translateX(0);
}

/* TOC 切换按钮 */
.toc-toggle {
  transition: transform var(--duration-fast) var(--ease-out-quart),
              background var(--duration-fast) var(--ease-out-quart);
}

.toc-toggle:hover {
  transform: scale(1.1);
}

.toc-toggle:active {
  transform: scale(0.92);
  transition-duration: 80ms;
}

/* ===== 14. 页面转场动画 ===== */

.page-transition {
  position: fixed;
  inset: 0;
  background: var(--paper);
  z-index: 9999;
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--duration-normal) var(--ease-out-quart);
}

.page-transition.active {
  opacity: 1;
  pointer-events: all;
}

/* 预加载器淡出 */
@keyframes preloader-fade-out {
  to {
    opacity: 0;
    visibility: hidden;
  }
}

.preloader {
  animation: preloader-fade-out var(--duration-slow) var(--ease-out-quart) forwards;
  animation-delay: 0.3s;
}

/* ===== 15. FAB 浮动按钮组动画 ===== */

#fab-rail {
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  transition: opacity var(--duration-normal) var(--ease-out-quart),
              transform var(--duration-normal) var(--ease-out-quart);
}

#fab-rail.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

/* FAB 按钮项 */
.fab-item {
  transition: transform var(--duration-fast) var(--ease-out-quart),
              background var(--duration-fast) var(--ease-out-quart),
              box-shadow var(--duration-fast) var(--ease-out-quart);
}

.fab-item:hover {
  transform: scale(1.12);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.fab-item:active {
  transform: scale(0.9);
  transition-duration: 80ms;
}

/* ===== 16. 滚动进度条动画 ===== */

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 0%;
  background: var(--monet-pond);
  z-index: 1000;
  transform-origin: left;
  transition: width 80ms linear; /* <100ms 瞬时跟手反馈 */
}

/* ===== 17. 跑马灯动画 (仅 transform) ===== */

@keyframes marquee-scroll {
  0%   { transform: translateX(0); }
  100% { transform: translateX(-33.333%); }
}

.marquee-track {
  animation: marquee-scroll 60s linear infinite;
}

/* 暂停动画 (悬停时) 提升可读性 */
.marquee-track:hover {
  animation-play-state: paused;
}

/* ===== 18. 回到顶部按钮 ===== */

.back-to-top {
  transition: opacity var(--duration-normal) var(--ease-out-quart),
              transform var(--duration-normal) var(--ease-out-quart);
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
}

.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top:hover {
  transform: scale(1.1);
}

.back-to-top:active {
  transform: scale(0.9);
  transition-duration: 80ms;
}

/* ===== 19. 键盘快捷键面板 ===== */

#shortcuts-overlay {
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--duration-normal) var(--ease-out-quart);
}

#shortcuts-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

/* ===== 20. 性能优化层 ===== */

/* 需要动画的元素才添加 will-change */
.animating {
  will-change: transform;
}

.animating-opacity {
  will-change: opacity;
}

/* 3D 卡片倾斜 */
.project-card {
  transition: transform var(--duration-normal) var(--ease-out-quart),
              box-shadow var(--duration-normal) var(--ease-out-quart);
  transform-style: preserve-3d;
}

/* 卡片光源效果 */
.project-card-light {
  opacity: 0;
  transition: opacity var(--duration-fast) var(--ease-out-quart);
  pointer-events: none;
}

.project-card-light.visible {
  opacity: 1;
}

/* ===== 21. 响应式适配 ===== */
@media (max-width: 768px) {
  .section-animate {
    transform: translateY(20px);
  }

  .card-hover:hover {
    transform: translateY(-2px);
  }

  .btn-primary:hover {
    transform: translateY(-1px);
  }
}

/* ===== 22. 无障碍：减少运动偏好 ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .section-animate,
  .card-hover,
  .btn-hover,
  .btn-primary,
  .btn-ghost {
    transition: none !important;
    animation: none !important;
  }

  /* 新增：所有滚动动画类直接显示 */
  .fade-in,
  .fade-in-left,
  .fade-in-right,
  .scale-up,
  .scale-down,
  .rotate-in,
  .blur-in,
  .clip-reveal,
  .clip-reveal-bottom,
  .stagger-group > *,
  .chapter-stagger > *,
  .section-animate {
    opacity: 1 !important;
    transform: none !important;
    filter: none !important;
    clip-path: none !important;
    transition: none !important;
    animation: none !important;
  }

  /* 保留功能性动画 (仅 opacity 淡入) */
  .preloader {
    animation: preloader-fade-out 200ms ease-out forwards;
  }
}

/* ===== 23. View Transition API 增强 (渐进增强) ===== */
@supports (view-transition-name: none) {
  ::view-transition-old(root) {
    animation: fade-out var(--duration-normal) var(--ease-in-quart) forwards;
  }

  ::view-transition-new(root) {
    animation: fade-in-up var(--duration-normal) var(--ease-out-quart) forwards;
  }

  @keyframes fade-out {
    to { opacity: 0; transform: scale(0.98); }
  }
}

/* ===== 24. 多样化滚动动画系统 (新增) ===== */

/* 左侧滑入 */
@keyframes fade-in-left {
  from { opacity: 0; transform: translateX(-40px); }
  to   { opacity: 1; transform: translateX(0); }
}

.fade-in-left {
  opacity: 0;
  transform: translateX(-40px);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              transform var(--duration-slow) var(--ease-out-quart);
}

.fade-in-left.visible {
  opacity: 1;
  transform: translateX(0);
}

/* 右侧滑入 */
@keyframes fade-in-right {
  from { opacity: 0; transform: translateX(40px); }
  to   { opacity: 1; transform: translateX(0); }
}

.fade-in-right {
  opacity: 0;
  transform: translateX(40px);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              transform var(--duration-slow) var(--ease-out-quart);
}

.fade-in-right.visible {
  opacity: 1;
  transform: translateX(0);
}

/* 缩放进入 */
@keyframes scale-up {
  from { opacity: 0; transform: scale(0.85); }
  to   { opacity: 1; transform: scale(1); }
}

.scale-up {
  opacity: 0;
  transform: scale(0.85);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              transform var(--duration-slow) var(--ease-out-quart);
}

.scale-up.visible {
  opacity: 1;
  transform: scale(1);
}

/* 缩放退出 */
@keyframes scale-down {
  from { opacity: 0; transform: scale(1.15); }
  to   { opacity: 1; transform: scale(1); }
}

.scale-down {
  opacity: 0;
  transform: scale(1.15);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              transform var(--duration-slow) var(--ease-out-quart);
}

.scale-down.visible {
  opacity: 1;
  transform: scale(1);
}

/* 旋转进入 */
@keyframes rotate-in {
  from { opacity: 0; transform: rotate(-8deg) scale(0.9); }
  to   { opacity: 1; transform: rotate(0deg) scale(1); }
}

.rotate-in {
  opacity: 0;
  transform: rotate(-8deg) scale(0.9);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              transform var(--duration-slow) var(--ease-out-quart);
}

.rotate-in.visible {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

/* 模糊到清晰 */
@keyframes blur-in {
  from { opacity: 0; filter: blur(8px); }
  to   { opacity: 1; filter: blur(0); }
}

.blur-in {
  opacity: 0;
  filter: blur(8px);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              filter var(--duration-slow) var(--ease-out-quart);
}

.blur-in.visible {
  opacity: 1;
  filter: blur(0);
}

/* 裁剪揭示 */
@keyframes clip-reveal {
  from { opacity: 0; clip-path: inset(0 100% 0 0); }
  to   { opacity: 1; clip-path: inset(0 0 0 0); }
}

.clip-reveal {
  opacity: 0;
  clip-path: inset(0 100% 0 0);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              clip-path var(--duration-slow) var(--ease-out-quart);
}

.clip-reveal.visible {
  opacity: 1;
  clip-path: inset(0 0 0 0);
}

/* 底部裁剪揭示 */
@keyframes clip-reveal-bottom {
  from { opacity: 0; clip-path: inset(100% 0 0 0); }
  to   { opacity: 1; clip-path: inset(0 0 0 0); }
}

.clip-reveal-bottom {
  opacity: 0;
  clip-path: inset(100% 0 0 0);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              clip-path var(--duration-slow) var(--ease-out-quart);
}

.clip-reveal-bottom.visible {
  opacity: 1;
  clip-path: inset(0 0 0 0);
}

/* 交错延迟组 */
.stagger-group > * {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--duration-slow) var(--ease-out-quart),
              transform var(--duration-slow) var(--ease-out-quart);
}

.stagger-group.visible > *:nth-child(1) { transition-delay: 0s; opacity: 1; transform: translateY(0); }
.stagger-group.visible > *:nth-child(2) { transition-delay: 0.06s; opacity: 1; transform: translateY(0); }
.stagger-group.visible > *:nth-child(3) { transition-delay: 0.12s; opacity: 1; transform: translateY(0); }
.stagger-group.visible > *:nth-child(4) { transition-delay: 0.18s; opacity: 1; transform: translateY(0); }
.stagger-group.visible > *:nth-child(5) { transition-delay: 0.24s; opacity: 1; transform: translateY(0); }
.stagger-group.visible > *:nth-child(6) { transition-delay: 0.30s; opacity: 1; transform: translateY(0); }
.stagger-group.visible > *:nth-child(7) { transition-delay: 0.36s; opacity: 1; transform: translateY(0); }
.stagger-group.visible > *:nth-child(8) { transition-delay: 0.42s; opacity: 1; transform: translateY(0); }
.stagger-group.visible > *:nth-child(9) { transition-delay: 0.48s; opacity: 1; transform: translateY(0); }

/* ===== 25. 响应式动画适配 ===== */
@media (max-width: 768px) {
  .fade-in-left,
  .fade-in-right {
    transform: translateY(20px);
  }
  
  .scale-up,
  .scale-down {
    transform: scale(0.95);
  }
  
  .rotate-in {
    transform: rotate(-4deg) scale(0.95);
  }
  
  .blur-in {
    filter: blur(4px);
  }
  
  .clip-reveal,
  .clip-reveal-bottom {
    clip-path: inset(0);
  }
}

/* ===== 26. 性能优化 ===== */

/* GPU 加速提示 — 仅在元素即将动画时启用 */
.fade-in-left,
.fade-in-right,
.scale-up,
.scale-down,
.rotate-in {
  will-change: transform, opacity;
}

.blur-in {
  will-change: opacity, filter;
}

.clip-reveal,
.clip-reveal-bottom {
  will-change: opacity, clip-path;
}

/* 动画完成后清除 will-change 以释放 GPU 资源 */
.fade-in-left.visible,
.fade-in-right.visible,
.scale-up.visible,
.scale-down.visible,
.rotate-in.visible,
.blur-in.visible,
.clip-reveal.visible,
.clip-reveal-bottom.visible {
  will-change: auto;
}

/* 节省布局计算 — 使用 content-visibility 对视口外的区块 */
.section-animate,
.fade-in,
.scale-up,
.rotate-in {
  content-visibility: auto;
  contain-intrinsic-size: auto 300px;
}

/* 避免大面积布局抖动 */
.stagger-group,
.chapter-stagger {
  contain: layout style;
}

/* 确保动画元素使用合成层提升 */
.page-fade {
  will-change: opacity;
}

/* ===== 27. 滚动进度指示器 ===== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--monet-pond), var(--monet-lotus));
  z-index: 9999;
  opacity: 0;
  transition: opacity var(--duration-fast) var(--ease-out-quart);
}

/* 返回顶部按钮 */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-primary, #C75B4A);
  color: #fff;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--duration-normal) var(--ease-out-quart),
              transform var(--duration-normal) var(--ease-out-quart);
  z-index: 100;
}

.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--monet-lotus);
  transform: translateY(-3px);
}

/* ===== 28. 文字逐字显现 ===== */
[data-typewriter] {
  visibility: hidden;
}

[data-typewriter].typing {
  visibility: visible;
}

/* ===== 29. 骨架屏加载 ===== */
.skeleton {
  background: linear-gradient(90deg, 
    rgba(255, 255, 255, 0.1) 25%, 
    rgba(255, 255, 255, 0.2) 50%, 
    rgba(255, 255, 255, 0.1) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite;
  border-radius: var(--radius-sm);
}

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

.skeleton-text {
  height: 1em;
  margin-bottom: 0.5em;
}

.skeleton-title {
  height: 2em;
  width: 60%;
  margin-bottom: 1em;
}

.skeleton-image {
  height: 200px;
  margin-bottom: 1em;
}

/* ===== 30. 卡片光泽反射 ===== */
.card-gloss {
  position: relative;
  overflow: hidden;
}

.card-gloss::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(
    circle at var(--gloss-x, 50%) var(--gloss-y, 50%),
    rgba(255, 255, 255, 0.3) 0%,
    transparent 50%
  );
  opacity: 0;
  transition: opacity var(--duration-normal) var(--ease-out-quart);
  pointer-events: none;
  z-index: 1;
}

.card-gloss:hover::before {
  opacity: 1;
}

/* ===== 31. 按钮波纹效果 ===== */
.btn-ripple,
.btn-primary,
.btn-ghost {
  position: relative;
  overflow: hidden;
}

.ripple-effect {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: scale(0);
  animation: ripple-animation 0.6s ease-out;
  pointer-events: none;
}

@keyframes ripple-animation {
  to {
    transform: scale(4);
    opacity: 0;
  }
}

/* ===== 32. 输入框焦点动画 ===== */
.input-group {
  position: relative;
}

.input-group.input-focused .input-label {
  color: var(--monet-pond);
  transform: translateY(-1.5em) scale(0.8);
}

.input-group.input-filled .input-label {
  transform: translateY(-1.5em) scale(0.8);
}

.input-label {
  position: absolute;
  left: 1em;
  top: 50%;
  transform: translateY(-50%);
  transition: transform var(--duration-normal) var(--ease-out-quart),
              color var(--duration-normal) var(--ease-out-quart);
  pointer-events: none;
  background: var(--paper);
  padding: 0 0.5em;
}

/* ===== 33. 背景粒子画布 ===== */
.particle-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  opacity: 0.5;
}

/* ===== 34. 渐变流动背景 ===== */
.gradient-flow {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -2;
  opacity: 0.1;
  transition: background 0.5s ease;
}

/* ===== 35. 打字机效果 ===== */
.typewriter-text {
  display: inline-block;
  border-right: 2px solid var(--monet-pond);
  animation: blink-caret 0.75s step-end infinite;
}

@keyframes blink-caret {
  from, to { border-color: transparent; }
  50% { border-color: var(--monet-pond); }
}

/* ===== 36. 章节导航高亮 ===== */
.chapter-nav a {
  transition: color var(--duration-fast) var(--ease-out-quart),
              transform var(--duration-fast) var(--ease-out-quart);
}

.chapter-nav a.active {
  color: var(--monet-pond);
  transform: scale(1.05);
}

/* ===== 37. 滑动方向转场 ===== */
.slide-transition {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 9998;
  pointer-events: none;
}

.slide-transition-left {
  background: var(--monet-pond);
  transform: translateX(-100%);
  transition: transform 0.6s var(--ease-out-expo);
}

.slide-transition-right {
  background: var(--monet-lotus);
  transform: translateX(100%);
  transition: transform 0.6s var(--ease-out-expo);
}

.slide-transition.active .slide-transition-left,
.slide-transition.active .slide-transition-right {
  transform: translateX(0);
}

/* ===== 38. 深度阴影变化 ===== */
.card-depth {
  transition: transform var(--duration-normal) var(--ease-out-quart),
              box-shadow var(--duration-normal) var(--ease-out-quart);
}

.card-depth:hover {
  transform: translateY(-8px);
  box-shadow: 
    0 12px 24px rgba(0, 0, 0, 0.15),
    0 4px 8px rgba(0, 0, 0, 0.1);
}

/* ===== 39. 状态变化动画 ===== */
.status-indicator {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--monet-willow);
  animation: status-pulse 2s infinite;
}

@keyframes status-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

.status-indicator.online {
  background: #4CAF50;
}

.status-indicator.offline {
  background: #F44336;
  animation: none;
}

/* ===== 40. 光线扫描效果 ===== */
.light-sweep {
  position: relative;
  overflow: hidden;
}

.light-sweep::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.2),
    transparent
  );
  animation: light-sweep 3s infinite;
}

@keyframes light-sweep {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

/* ===== 41. 几何图形背景 ===== */
.geometric-bg {
  position: relative;
}

.geometric-bg::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    radial-gradient(circle at 25% 25%, var(--monet-pond) 1px, transparent 1px),
    radial-gradient(circle at 75% 75%, var(--monet-lotus) 1px, transparent 1px);
  background-size: 50px 50px;
  opacity: 0.1;
  pointer-events: none;
  z-index: -1;
}

/* ===== 42. 模糊玻璃效果 ===== */
.glass-effect {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-md);
}

/* ===== 43. 禁用状态反馈 ===== */
.btn-disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
  filter: grayscale(50%);
}

/* ===== 44. 验证状态动画 ===== */
.input-valid {
  border-color: #4CAF50;
  animation: valid-pulse 0.5s ease;
}

.input-invalid {
  border-color: #F44336;
  animation: invalid-shake 0.5s ease;
}

@keyframes valid-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(76, 175, 80, 0.4); }
  50% { box-shadow: 0 0 0 4px rgba(76, 175, 80, 0.2); }
}

@keyframes invalid-shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

/* ===== 45. 提交按钮状态 ===== */
.btn-submit {
  position: relative;
}

.btn-submit.loading {
  color: transparent;
  pointer-events: none;
}

.btn-submit.loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 20px;
  height: 20px;
  margin: -10px 0 0 -10px;
  border: 2px solid var(--paper);
  border-top-color: transparent;
  border-radius: 50%;
  animation: submit-spin 0.8s linear infinite;
}

@keyframes submit-spin {
  to { transform: rotate(360deg); }
}

.btn-submit.success {
  background: #4CAF50;
  animation: submit-success 0.5s ease;
}

@keyframes submit-success {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}