/* ============================================
   登录页
   ============================================ */
.login-page {
  display: none;
  min-height: 100vh;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 0;
  position: relative;
  overflow: hidden;
}

.login-page.active {
  display: flex;
  align-items: center;
  justify-content: center;
}

.login-bg-shapes {
  position: absolute;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.login-bg-shapes .shape {
  position: absolute;
  border-radius: 50%;
  opacity: 0.1;
  background: white;
}

.login-bg-shapes .shape:nth-child(1) {
  width: 200px; height: 200px; top: -50px; left: -50px;
  animation: float 4s ease-in-out infinite;
}

.login-bg-shapes .shape:nth-child(2) {
  width: 150px; height: 150px; top: 20%; right: -30px;
  animation: float 5s ease-in-out infinite 1s;
}

.login-bg-shapes .shape:nth-child(3) {
  width: 100px; height: 100px; bottom: 20%; left: 10%;
  animation: float 6s ease-in-out infinite 2s;
}

.login-container {
  width: 90%;
  max-width: 420px;
  z-index: 1;
}

.login-logo {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.login-logo .logo-emoji {
  font-size: 72px;
  display: block;
  margin-bottom: var(--space-md);
  animation: bounceIn 0.8s ease;
}

.login-logo h1 {
  color: var(--white);
  font-size: var(--font-size-2xl);
  font-weight: 800;
}

.login-logo p {
  color: rgba(255, 255, 255, 0.8);
  font-size: var(--font-size-base);
  margin-top: var(--space-xs);
}

.login-card {
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  box-shadow: var(--shadow-lg);
  animation: slideUp 0.6s ease;
}

.login-tabs {
  display: flex;
  background: var(--gray-100);
  border-radius: var(--radius-full);
  padding: 4px;
  margin-bottom: var(--space-xl);
}

.login-tab {
  flex: 1;
  padding: var(--space-sm) var(--space-md);
  text-align: center;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: var(--font-size-base);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-normal);
}

.login-tab.active {
  background: var(--white);
  color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.form-group {
  position: relative;
}

.form-group .form-icon {
  position: absolute;
  left: var(--space-md);
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  pointer-events: none;
}

.form-input {
  width: 100%;
  padding: var(--space-md) var(--space-md) var(--space-md) 48px;
  background: var(--gray-100);
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  color: var(--text-primary);
  border: 2px solid transparent;
  transition: all var(--transition-normal);
  min-height: 52px;
}

.form-input:focus {
  border-color: var(--primary-light);
  background: var(--white);
  box-shadow: 0 0 0 4px rgba(255, 107, 107, 0.1);
}

.form-input::placeholder {
  color: var(--gray-400);
}

.login-form .btn {
  margin-top: var(--space-sm);
  width: 100%;
}

.avatar-picker {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}

.avatar-option {
  width: 56px;
  height: 56px;
  font-size: 32px;
  border-radius: 50%;
  border: 3px solid var(--gray-200);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.avatar-option:hover,
.avatar-option.selected {
  border-color: var(--primary);
  transform: scale(1.1);
  box-shadow: 0 0 0 4px rgba(255, 107, 107, 0.15);
}

/* ============================================
   首页
   ============================================ */
.home-page .home-header {
  text-align: center;
  padding: var(--space-xl) 0;
}

.home-page .welcome-text {
  font-size: var(--font-size-xl);
  color: var(--text-secondary);
  margin-bottom: var(--space-xs);
}

.home-page .user-name {
  font-size: var(--font-size-2xl);
  font-weight: 800;
  color: var(--text-primary);
}

.home-page .user-avatar {
  font-size: 56px;
  margin-bottom: var(--space-md);
}

.home-banner {
  background: linear-gradient(135deg, var(--primary), var(--accent-orange));
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  color: var(--white);
  margin-bottom: var(--space-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
  overflow: hidden;
}

.home-banner::after {
  content: '';
  position: absolute;
  right: -20px;
  bottom: -20px;
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
}

.home-banner .banner-text h2 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-xs);
}

.home-banner .banner-text p {
  font-size: var(--font-size-base);
  opacity: 0.9;
}

.home-banner .banner-emoji {
  font-size: 64px;
  z-index: 1;
  animation: float 3s ease-in-out infinite;
}

.section-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-lg);
}

.section-title h2 {
  font-size: var(--font-size-xl);
  font-weight: 800;
}

.section-title .see-all {
  font-size: var(--font-size-sm);
  color: var(--primary);
  font-weight: 600;
  cursor: pointer;
}

.home-section {
  margin-bottom: var(--space-xl);
}

/* 快速入口 */
.quick-entries {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
}

.quick-entry {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  border-radius: var(--radius-lg);
  background: var(--white);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: all var(--transition-normal);
}

.quick-entry:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.quick-entry:active {
  transform: scale(0.95);
}

.quick-entry .entry-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
}

.quick-entry .entry-label {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--text-primary);
}

/* 最近学习 横向滚动 */
.recent-scroll {
  display: flex;
  gap: var(--space-md);
  overflow-x: auto;
  padding-bottom: var(--space-md);
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.recent-scroll::-webkit-scrollbar {
  display: none;
}

.recent-scroll .course-card {
  min-width: 240px;
  scroll-snap-align: start;
  flex-shrink: 0;
}

/* ============================================
   课程分类页
   ============================================ */
.category-page .categories-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
  max-width: 600px;
  margin: 0 auto;
}

/* ============================================
   课程列表页
   ============================================ */
.course-list-header {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
}

.course-list-header .cat-emoji {
  font-size: 48px;
}

.course-list-header .cat-info h1 {
  font-size: var(--font-size-xl);
  font-weight: 800;
}

.course-list-header .cat-info p {
  color: var(--text-secondary);
  font-size: var(--font-size-base);
}

.course-list-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-lg);
}

/* ============================================
   学习(播放)页
   ============================================ */
.learn-page .learn-content {
  max-width: 900px;
  margin: 0 auto;
}

.learn-title {
  font-size: var(--font-size-xl);
  font-weight: 800;
  text-align: center;
  margin: var(--space-xl) 0 var(--space-md);
}

.learn-info {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

.learn-actions {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
}

.learn-playlist {
  margin-top: var(--space-xl);
}

.learn-playlist h3 {
  font-size: var(--font-size-lg);
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.playlist-items {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.playlist-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md);
  background: var(--white);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-normal);
  border: 2px solid transparent;
}

.playlist-item:hover {
  border-color: var(--primary-light);
}

.playlist-item.active {
  border-color: var(--primary);
  background: #FFF5F5;
}

.playlist-item .item-index {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--gray-100);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  flex-shrink: 0;
}

.playlist-item.active .item-index {
  background: var(--primary);
  color: var(--white);
}

.playlist-item .item-name {
  flex: 1;
  font-weight: 600;
}

.playlist-item .item-type {
  font-size: 20px;
}

/* ============================================
   成就展示页
   ============================================ */
.achievement-section {
  margin-top: var(--space-xl);
}

.achievement-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: var(--space-md);
}

.achievement-badge {
  text-align: center;
  padding: var(--space-lg);
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.achievement-badge:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.achievement-badge .badge-icon {
  font-size: 48px;
  margin-bottom: var(--space-sm);
}

.achievement-badge .badge-name {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--text-primary);
}

.achievement-badge.locked {
  opacity: 0.4;
  filter: grayscale(1);
}

@media (max-width: 768px) {
  .quick-entries { grid-template-columns: repeat(2, 1fr); }
  .category-page .categories-grid { grid-template-columns: 1fr; }
  .home-banner { flex-direction: column; text-align: center; }
  .home-banner .banner-emoji { font-size: 48px; }
}