/* ================================================
   AI 学习助手 - 交互增强系统
   包含：微交互、骨架屏、入场动画、视觉反馈
   ================================================ */

/* ==================== 变量定义 ==================== */
:root {
  /* 动画时长 */
  --duration-fast: 0.15s;
  --duration-normal: 0.25s;
  --duration-slow: 0.4s;
  --duration-slower: 0.6s;

  /* 缓动函数 */
  --ease-default: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-in: cubic-bezier(0.4, 0, 1, 1);
  --ease-out: cubic-bezier(0, 0, 0.2, 1);
  --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);

  /* 阴影层级 */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.15);

  /* 主色调 */
  --primary-color: #667eea;
  --primary-dark: #5a67d8;
  --primary-light: #a3bffa;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
}

/* ==================== 1. 微交互系统 ==================== */

/* 按钮基础样式 */
.btn-interactive {
  position: relative;
  overflow: hidden;
  transition: all var(--duration-normal) var(--ease-default);
  cursor: pointer;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

/* 涟漪效果容器 */
.btn-interactive::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width var(--duration-slow) var(--ease-out),
              height var(--duration-slow) var(--ease-out);
}

.btn-interactive:active::before {
  width: 300px;
  height: 300px;
}

/* 按钮悬停 */
.btn-interactive:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* 按钮按下 */
.btn-interactive:active {
  transform: translateY(0) scale(0.98);
  box-shadow: var(--shadow-sm);
}

/* 按钮禁用 */
.btn-interactive:disabled,
.btn-interactive.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

.btn-interactive:disabled::before,
.btn-interactive.disabled::before {
  display: none;
}

/* 加载状态 */
.btn-interactive.loading {
  color: transparent !important;
  pointer-events: none;
}

.btn-interactive.loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 18px;
  height: 18px;
  margin: -9px 0 0 -9px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: btn-spin 0.8s linear infinite;
}

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

/* 输入框增强 */
.input-interactive {
  transition: all var(--duration-normal) var(--ease-default);
  border: 2px solid #e2e8f0;
}

.input-interactive:hover {
  border-color: var(--primary-light);
}

.input-interactive:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.15);
}

.input-interactive.error {
  border-color: var(--error-color);
  animation: shake 0.4s ease;
}

.input-interactive.success {
  border-color: var(--success-color);
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-5px); }
  40%, 80% { transform: translateX(5px); }
}

/* 卡片交互 */
.card-interactive {
  transition: all var(--duration-normal) var(--ease-default);
  cursor: pointer;
}

.card-interactive:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
}

.card-interactive:active {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* 标签切换 */
.tab-interactive {
  position: relative;
  transition: all var(--duration-normal) var(--ease-default);
}

.tab-interactive::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 3px;
  background: var(--primary-color);
  border-radius: 3px 3px 0 0;
  transform: translateX(-50%);
  transition: width var(--duration-normal) var(--ease-default);
}

.tab-interactive:hover::after,
.tab-interactive.active::after {
  width: 100%;
}

.tab-interactive.active {
  color: var(--primary-color);
  font-weight: 600;
}

/* 开关切换 */
.toggle-interactive {
  position: relative;
  width: 48px;
  height: 26px;
  background: #e2e8f0;
  border-radius: 13px;
  cursor: pointer;
  transition: background var(--duration-normal) var(--ease-default);
}

.toggle-interactive::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 20px;
  height: 20px;
  background: white;
  border-radius: 50%;
  box-shadow: var(--shadow-sm);
  transition: transform var(--duration-normal) var(--ease-bounce);
}

.toggle-interactive.active {
  background: var(--primary-color);
}

.toggle-interactive.active::after {
  transform: translateX(22px);
}

/* 复选框增强 */
.checkbox-interactive {
  position: relative;
  width: 20px;
  height: 20px;
  border: 2px solid #cbd5e0;
  border-radius: 5px;
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-default);
}

.checkbox-interactive::after {
  content: '✓';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0);
  color: white;
  font-size: 12px;
  font-weight: bold;
  transition: transform var(--duration-normal) var(--ease-bounce);
}

.checkbox-interactive:checked {
  background: var(--primary-color);
  border-color: var(--primary-color);
}

.checkbox-interactive:checked::after {
  transform: translate(-50%, -50%) scale(1);
}

/* ==================== 2. 骨架屏系统 ==================== */

.skeleton {
  background: linear-gradient(
    90deg,
    #f0f0f0 25%,
    #e0e0e0 50%,
    #f0f0f0 75%
  );
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s ease infinite;
  border-radius: 4px;
}

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

/* 骨架屏文本行 */
.skeleton-text {
  height: 14px;
  margin-bottom: 8px;
  border-radius: 4px;
}

.skeleton-text.title {
  height: 24px;
  width: 60%;
  margin-bottom: 16px;
}

.skeleton-text.short {
  width: 40%;
}

.skeleton-text.medium {
  width: 70%;
}

/* 骨架屏头像 */
.skeleton-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* 骨架屏卡片 */
.skeleton-card {
  background: white;
  border-radius: 12px;
  padding: 20px;
  box-shadow: var(--shadow-md);
}

.skeleton-card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.skeleton-card-body {
  margin-bottom: 12px;
}

/* 骨架屏列表 */
.skeleton-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.skeleton-list-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px;
  background: white;
  border-radius: 8px;
}

/* 骨架屏段落 */
.skeleton-paragraph {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

/* ==================== 3. 入场动画系统 ==================== */

/* 淡入上移动画 */
.fade-in-up {
  opacity: 0;
  transform: translateY(30px);
  animation: fadeInUp var(--duration-slower) var(--ease-out) forwards;
}

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

/* 淡入下移动画 */
.fade-in-down {
  opacity: 0;
  transform: translateY(-30px);
  animation: fadeInDown var(--duration-slower) var(--ease-out) forwards;
}

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

/* 淡入左移动画 */
.fade-in-left {
  opacity: 0;
  transform: translateX(-30px);
  animation: fadeInLeft var(--duration-slower) var(--ease-out) forwards;
}

@keyframes fadeInLeft {
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* 淡入右移动画 */
.fade-in-right {
  opacity: 0;
  transform: translateX(30px);
  animation: fadeInRight var(--duration-slower) var(--ease-out) forwards;
}

@keyframes fadeInRight {
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* 缩放入场 */
.scale-in {
  opacity: 0;
  transform: scale(0.9);
  animation: scaleIn var(--duration-slow) var(--ease-out) forwards;
}

@keyframes scaleIn {
  to {
    opacity: 1;
    transform: scale(1);
  }
}

/* 弹跳入场 */
.bounce-in {
  opacity: 0;
  transform: scale(0.3);
  animation: bounceIn var(--duration-slower) var(--ease-bounce) forwards;
}

@keyframes bounceIn {
  0% {
    opacity: 0;
    transform: scale(0.3);
  }
  50% {
    transform: scale(1.05);
  }
  70% {
    transform: scale(0.9);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

/* 滑块入场 */
.slide-in-right {
  opacity: 0;
  transform: translateX(100%);
  animation: slideInRight var(--duration-slow) var(--ease-out) forwards;
}

@keyframes slideInRight {
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* 翻转入场 */
.flip-in {
  opacity: 0;
  transform: perspective(400px) rotateX(-90deg);
  animation: flipIn var(--duration-slower) var(--ease-out) forwards;
}

@keyframes flipIn {
  to {
    opacity: 1;
    transform: perspective(400px) rotateX(0);
  }
}

/* 入场动画延迟类 */
.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }
.delay-5 { animation-delay: 0.5s; }
.delay-6 { animation-delay: 0.6s; }

/* 交错入场动画（用于列表） */
.stagger-enter > * {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp var(--duration-slow) var(--ease-out) forwards;
}

.stagger-enter > *:nth-child(1) { animation-delay: 0.05s; }
.stagger-enter > *:nth-child(2) { animation-delay: 0.1s; }
.stagger-enter > *:nth-child(3) { animation-delay: 0.15s; }
.stagger-enter > *:nth-child(4) { animation-delay: 0.2s; }
.stagger-enter > *:nth-child(5) { animation-delay: 0.25s; }
.stagger-enter > *:nth-child(6) { animation-delay: 0.3s; }
.stagger-enter > *:nth-child(7) { animation-delay: 0.35s; }
.stagger-enter > *:nth-child(8) { animation-delay: 0.4s; }
.stagger-enter > *:nth-child(9) { animation-delay: 0.45s; }
.stagger-enter > *:nth-child(10) { animation-delay: 0.5s; }

/* 滚动触发动画 */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all var(--duration-slower) var(--ease-out);
}

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

/* ==================== 4. 视觉反馈系统 ==================== */

/* 成功状态 */
.feedback-success {
  background: #ecfdf5 !important;
  border-color: var(--success-color) !important;
}

.feedback-success-icon {
  color: var(--success-color);
  animation: successPulse 0.5s ease;
}

@keyframes successPulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.2); }
}

/* 错误状态 */
.feedback-error {
  background: #fef2f2 !important;
  border-color: var(--error-color) !important;
}

.feedback-error-icon {
  color: var(--error-color);
  animation: errorShake 0.5s ease;
}

@keyframes errorShake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-3px); }
  40%, 80% { transform: translateX(3px); }
}

/* 警告状态 */
.feedback-warning {
  background: #fffbeb !important;
  border-color: var(--warning-color) !important;
}

.feedback-warning-icon {
  color: var(--warning-color);
}

/* 加载状态 */
.feedback-loading {
  position: relative;
  pointer-events: none;
  opacity: 0.7;
}

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

/* 震动反馈 */
.vibrate {
  animation: vibrate 0.5s ease;
}

@keyframes vibrate {
  0%, 100% { transform: translateX(0); }
  10%, 30%, 50%, 70%, 90% { transform: translateX(-2px); }
  20%, 40%, 60%, 80% { transform: translateX(2px); }
}

/* 点击波纹 */
.ripple {
  position: relative;
  overflow: hidden;
}

.ripple-effect {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  transform: scale(0);
  animation: ripple 0.6s linear;
  pointer-events: none;
}

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

/* 成功打勾动画 */
.checkmark {
  display: inline-block;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--success-color);
  position: relative;
}

.checkmark::after {
  content: '';
  position: absolute;
  left: 6px;
  top: 3px;
  width: 6px;
  height: 10px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
  animation: checkmark 0.3s ease forwards;
}

@keyframes checkmark {
  0% {
    height: 0;
    opacity: 0;
  }
  100% {
    height: 10px;
    opacity: 1;
  }
}

/* 工具提示 */
.tooltip {
  position: relative;
}

.tooltip::before {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%) translateY(5px);
  padding: 8px 12px;
  background: #1f2937;
  color: white;
  font-size: 12px;
  border-radius: 6px;
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transition: all var(--duration-fast) var(--ease-default);
  z-index: 100;
}

.tooltip::after {
  content: '';
  position: absolute;
  bottom: calc(100% + 2px);
  left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top-color: #1f2937;
  opacity: 0;
  visibility: hidden;
  transition: all var(--duration-fast) var(--ease-default);
}

.tooltip:hover::before,
.tooltip:hover::after {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

/* ==================== 5. 弹窗/模态框动画 ==================== */

.modal-animated {
  opacity: 0;
  visibility: hidden;
  transition: all var(--duration-normal) var(--ease-default);
}

.modal-animated.show {
  opacity: 1;
  visibility: visible;
}

.modal-animated .modal-content {
  transform: scale(0.9) translateY(20px);
  transition: transform var(--duration-normal) var(--ease-bounce);
}

.modal-animated.show .modal-content {
  transform: scale(1) translateY(0);
}

/* 侧边栏滑入 */
.sidebar-animated {
  position: fixed;
  top: 0;
  right: 0;
  height: 100%;
  width: 320px;
  max-width: 90vw;
  background: white;
  box-shadow: -5px 0 30px rgba(0, 0, 0, 0.2);
  transform: translateX(100%);
  transition: transform var(--duration-normal) var(--ease-out);
  z-index: 1001;
}

.sidebar-animated.show {
  transform: translateX(0);
}

.sidebar-animated.show ~ .modal-backdrop {
  opacity: 1;
  visibility: visible;
}

/* ==================== 6. 列表动画 ==================== */

.list-enter {
  animation: listItemEnter var(--duration-normal) var(--ease-out) forwards;
}

@keyframes listItemEnter {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.list-leave {
  animation: listItemLeave var(--duration-normal) var(--ease-in) forwards;
}

@keyframes listItemLeave {
  to {
    opacity: 0;
    transform: translateX(20px);
  }
}

/* ==================== 7. 数字滚动动画 ==================== */

.count-up {
  display: inline-block;
  transition: transform 0.3s var(--ease-bounce);
}

/* ==================== 8. 下拉菜单动画 ==================== */

.dropdown-animated {
  position: relative;
}

.dropdown-animated .dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 180px;
  background: white;
  border-radius: 8px;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all var(--duration-normal) var(--ease-default);
  z-index: 100;
}

.dropdown-animated.show .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(5px);
}

/* ==================== 9. 进度条动画 ==================== */

.progress-animated {
  position: relative;
  height: 8px;
  background: #e2e8f0;
  border-radius: 4px;
  overflow: hidden;
}

.progress-animated .progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color), var(--primary-dark));
  border-radius: 4px;
  transition: width var(--duration-slow) var(--ease-out);
}

/* ==================== 10. 响应式适配 ==================== */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

@media (max-width: 768px) {
  :root {
    --duration-slower: 0.4s;
  }

  .fade-in-up,
  .fade-in-down,
  .fade-in-left,
  .fade-in-right {
    transform: translateY(15px);
  }
}