:root {
  --primary-blue: #001F3F;
  --ocean-teal: #4ECDC4;
  --coral-pink: #FF6B9D;
  --sunset-orange: #FFA07A;
  --deep-purple: #5B2C6F;
  --seafoam-green: #1ABC9C;
  --pearl-white: #F8F9FA;
  --golden-sand: #FFD700;
  --dark-navy: #0A1929;
  --light-blue: #E3F2FD;

  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;

  --font-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  --font-heading: 'Microsoft YaHei', 'PingFang SC', sans-serif;

  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;

  --border-radius-sm: 8px;
  --border-radius-md: 12px;
  --border-radius-lg: 16px;
  --border-radius-xl: 24px;

  --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.2);
  --shadow-xl: 0 12px 40px rgba(0,0,0,0.25);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-primary);
  line-height: 1.6;
  color: #333;
  background: linear-gradient(135deg, #E3F2FD 0%, #BBDEFB 50%, #90CAF9 100%);
  background-attachment: fixed;
  min-height: 100vh;
  overflow-x: hidden;
}

body.dark-mode {
  background: linear-gradient(135deg, var(--dark-navy) 0%, var(--primary-blue) 50%, var(--deep-purple) 100%);
  color: var(--pearl-white);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

a {
  color: var(--ocean-teal);
  text-decoration: none;
  transition: var(--transition-fast);
}

a:hover {
  color: var(--seafoam-green);
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  font-size: 1rem;
  transition: var(--transition-fast);
}

.main-header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 0;
  z-index: 1000;
  animation: slideDown 0.5s ease;
}

body.dark-mode .main-header {
  background: rgba(10, 25, 41, 0.95);
}

@keyframes slideDown {
  from {
    transform: translateY(-100%);
  }
  to {
    transform: translateY(0);
  }
}

.navbar {
  padding: var(--spacing-sm) 0;
}

.nav-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.logo h1 {
  font-size: 1.75rem;
  background: linear-gradient(135deg, var(--ocean-teal), var(--seafoam-green));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin: 0;
  cursor: pointer;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
  margin: 0;
}

.nav-link {
  color: #333;
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  transition: var(--transition-fast);
  position: relative;
}

body.dark-mode .nav-link {
  color: var(--pearl-white);
}

.nav-link:hover,
.nav-link.active {
  background: linear-gradient(135deg, var(--ocean-teal), var(--seafoam-green));
  color: white;
  text-decoration: none;
  transform: translateY(-2px);
}

.search-container {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  background: white;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  flex: 1;
  max-width: 400px;
}

body.dark-mode .search-container {
  background: rgba(255, 255, 255, 0.1);
}

#searchInput {
  border: none;
  outline: none;
  flex: 1;
  padding: var(--spacing-xs);
  font-size: 1rem;
  background: transparent;
}

body.dark-mode #searchInput {
  color: white;
}

#searchInput::placeholder {
  color: #999;
}

.search-btn,
.theme-toggle {
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  background: linear-gradient(135deg, var(--ocean-teal), var(--seafoam-green));
  color: white;
  font-size: 1.2rem;
  transition: var(--transition-fast);
}

.search-btn:hover,
.theme-toggle:hover {
  transform: scale(1.1) rotate(10deg);
  box-shadow: var(--shadow-md);
}

.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  padding: var(--spacing-xs);
}

.mobile-menu-toggle span {
  width: 25px;
  height: 3px;
  background: var(--ocean-teal);
  border-radius: 2px;
  transition: var(--transition-fast);
}

.main-content {
  max-width: 1400px;
  margin: var(--spacing-xl) auto;
  padding: 0 var(--spacing-md);
  min-height: calc(100vh - 400px);
}

.loading {
  text-align: center;
  padding: var(--spacing-xl);
  font-size: 1.5rem;
  color: var(--ocean-teal);
}

.hero-section {
  background: linear-gradient(135deg, var(--ocean-teal), var(--seafoam-green));
  border-radius: var(--border-radius-xl);
  padding: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
  color: white;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-xl);
}

.hero-section::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
  animation: wave 15s ease-in-out infinite;
}

@keyframes wave {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  50% { transform: translate(20px, -20px) rotate(180deg); }
}

.hero-section h2 {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-md);
  position: relative;
  z-index: 1;
}

.hero-section p {
  font-size: 1.2rem;
  opacity: 0.95;
  position: relative;
  z-index: 1;
}

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

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-sm);
  border-bottom: 3px solid var(--ocean-teal);
}

.section-title {
  font-size: 2rem;
  color: var(--primary-blue);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

body.dark-mode .section-title {
  color: var(--ocean-teal);
}

.section-title::before {
  content: '';
  width: 8px;
  height: 2rem;
  background: linear-gradient(180deg, var(--ocean-teal), var(--seafoam-green));
  border-radius: 4px;
}

.view-more {
  color: var(--ocean-teal);
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-md);
  border: 2px solid var(--ocean-teal);
  border-radius: var(--border-radius-lg);
  transition: var(--transition-fast);
}

.view-more:hover {
  background: var(--ocean-teal);
  color: white;
  text-decoration: none;
  transform: translateX(5px);
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.video-card {
  background: white;
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: var(--transition-normal);
  cursor: pointer;
  position: relative;
}

body.dark-mode .video-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
}

.video-card:hover {
  transform: translateY(-10px) scale(1.02);
  box-shadow: var(--shadow-xl);
}

.video-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, var(--ocean-teal), var(--coral-pink));
  opacity: 0;
  transition: var(--transition-normal);
  z-index: 1;
  pointer-events: none;
}

.video-card:hover::before {
  opacity: 0.1;
}

.video-thumbnail {
  position: relative;
  padding-top: 56.25%;
  overflow: hidden;
  background: linear-gradient(135deg, var(--light-blue), var(--ocean-teal));
}

.video-thumbnail img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition-normal);
}

.video-card:hover .video-thumbnail img {
  transform: scale(1.1);
}

.video-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.7) 0%, transparent 60%);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: var(--transition-normal);
}

.video-card:hover .video-overlay {
  opacity: 1;
}

.play-icon {
  width: 60px;
  height: 60px;
  background: rgba(255, 255, 255, 0.9);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: var(--ocean-teal);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.1); }
}

.video-info {
  padding: var(--spacing-md);
}

.video-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  color: #333;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

body.dark-mode .video-title {
  color: var(--pearl-white);
}

.video-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  font-size: 0.9rem;
  color: #666;
  margin-bottom: var(--spacing-xs);
}

body.dark-mode .video-meta {
  color: #ccc;
}

.video-category {
  display: inline-block;
  padding: 4px 12px;
  background: linear-gradient(135deg, var(--ocean-teal), var(--seafoam-green));
  color: white;
  border-radius: var(--border-radius-lg);
  font-size: 0.85rem;
  font-weight: 500;
}

.video-rating {
  display: flex;
  align-items: center;
  gap: 4px;
}

.star {
  color: var(--golden-sand);
}

.video-description {
  font-size: 0.9rem;
  color: #666;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-top: var(--spacing-xs);
}

body.dark-mode .video-description {
  color: #aaa;
}

.featured-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: var(--spacing-xl);
}

.featured-card {
  background: white;
  border-radius: var(--border-radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  transition: var(--transition-normal);
  position: relative;
}

body.dark-mode .featured-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
}

.featured-card:hover {
  transform: translateY(-15px);
  box-shadow: var(--shadow-xl);
}

.carousel-container {
  position: relative;
  overflow: hidden;
  border-radius: var(--border-radius-lg);
  margin-bottom: var(--spacing-lg);
}

.carousel-track {
  display: flex;
  transition: transform 0.5s ease;
  gap: var(--spacing-md);
}

.carousel-item {
  min-width: 100%;
  position: relative;
}

.carousel-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255, 255, 255, 0.9);
  color: var(--ocean-teal);
  padding: var(--spacing-md);
  border-radius: 50%;
  font-size: 1.5rem;
  z-index: 10;
  transition: var(--transition-fast);
}

.carousel-btn:hover {
  background: var(--ocean-teal);
  color: white;
  transform: translateY(-50%) scale(1.1);
}

.carousel-btn.prev {
  left: var(--spacing-md);
}

.carousel-btn.next {
  right: var(--spacing-md);
}

.horizontal-scroll {
  display: flex;
  gap: var(--spacing-md);
  overflow-x: auto;
  padding-bottom: var(--spacing-md);
  scroll-behavior: smooth;
  scrollbar-width: thin;
  scrollbar-color: var(--ocean-teal) transparent;
}

.horizontal-scroll::-webkit-scrollbar {
  height: 8px;
}

.horizontal-scroll::-webkit-scrollbar-track {
  background: rgba(0, 0, 0, 0.1);
  border-radius: 4px;
}

.horizontal-scroll::-webkit-scrollbar-thumb {
  background: var(--ocean-teal);
  border-radius: 4px;
}

.horizontal-scroll::-webkit-scrollbar-thumb:hover {
  background: var(--seafoam-green);
}

.scroll-card {
  min-width: 250px;
  flex-shrink: 0;
}

.timeline-container {
  position: relative;
  padding-left: var(--spacing-xl);
}

.timeline-item {
  position: relative;
  padding-bottom: var(--spacing-xl);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -28px;
  top: 8px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--ocean-teal);
  border: 3px solid white;
  box-shadow: 0 0 0 3px var(--ocean-teal);
  z-index: 1;
}

.timeline-item::after {
  content: '';
  position: absolute;
  left: -21px;
  top: 24px;
  width: 2px;
  height: calc(100% - 16px);
  background: linear-gradient(180deg, var(--ocean-teal), var(--seafoam-green));
}

.timeline-item:last-child::after {
  display: none;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
}

.category-card {
  background: white;
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  text-align: center;
  box-shadow: var(--shadow-md);
  transition: var(--transition-normal);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

body.dark-mode .category-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, var(--ocean-teal), var(--coral-pink));
  opacity: 0.1;
  transition: var(--transition-normal);
}

.category-card:hover {
  transform: translateY(-8px) rotate(2deg);
  box-shadow: var(--shadow-xl);
}

.category-card:hover::before {
  opacity: 0.2;
}

.category-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-sm);
}

.category-name {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--primary-blue);
}

body.dark-mode .category-name {
  color: var(--pearl-white);
}

.video-player-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-lg);
}

.player-wrapper {
  position: relative;
  padding-top: 56.25%;
  background: #000;
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-xl);
  margin-bottom: var(--spacing-xl);
}

#videoPlayer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.player-controls {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.8), transparent);
  padding: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  opacity: 0;
  transition: var(--transition-normal);
}

.player-wrapper:hover .player-controls {
  opacity: 1;
}

.control-btn {
  color: white;
  font-size: 1.5rem;
  padding: var(--spacing-xs);
  transition: var(--transition-fast);
}

.control-btn:hover {
  color: var(--ocean-teal);
  transform: scale(1.1);
}

.progress-bar {
  flex: 1;
  height: 6px;
  background: rgba(255, 255, 255, 0.3);
  border-radius: 3px;
  cursor: pointer;
  position: relative;
}

.progress-filled {
  height: 100%;
  background: var(--ocean-teal);
  border-radius: 3px;
  transition: width 0.1s linear;
}

.video-details {
  background: white;
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  margin-bottom: var(--spacing-xl);
}

body.dark-mode .video-details {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
}

.video-details h1 {
  color: var(--primary-blue);
  margin-bottom: var(--spacing-md);
}

body.dark-mode .video-details h1 {
  color: var(--ocean-teal);
}

.detail-meta {
  display: flex;
  gap: var(--spacing-lg);
  flex-wrap: wrap;
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-lg);
  border-bottom: 2px solid var(--light-blue);
}

body.dark-mode .detail-meta {
  border-bottom-color: rgba(255, 255, 255, 0.1);
}

.meta-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: #666;
}

body.dark-mode .meta-item {
  color: #ccc;
}

.review-section {
  background: var(--light-blue);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-md);
  margin-top: var(--spacing-lg);
}

body.dark-mode .review-section {
  background: rgba(78, 205, 196, 0.1);
}

.review-text {
  line-height: 1.8;
  text-indent: 2em;
  color: #444;
}

body.dark-mode .review-text {
  color: #ddd;
}

.related-videos {
  background: white;
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
}

body.dark-mode .related-videos {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
}

.info-page {
  background: white;
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  max-width: 900px;
  margin: 0 auto;
  line-height: 1.8;
}

body.dark-mode .info-page {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
}

.info-page h2 {
  color: var(--ocean-teal);
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 3px solid var(--ocean-teal);
}

.info-page h3 {
  color: var(--primary-blue);
  margin-top: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

body.dark-mode .info-page h3 {
  color: var(--seafoam-green);
}

.info-page ul {
  padding-left: var(--spacing-lg);
  margin: var(--spacing-md) 0;
}

.info-page li {
  margin-bottom: var(--spacing-xs);
}

.contact-info {
  background: var(--light-blue);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-md);
  margin: var(--spacing-lg) 0;
}

body.dark-mode .contact-info {
  background: rgba(78, 205, 196, 0.1);
}

.main-footer {
  background: linear-gradient(135deg, var(--primary-blue), var(--deep-purple));
  color: white;
  margin-top: var(--spacing-xl);
  padding: var(--spacing-xl) 0 var(--spacing-md);
}

.footer-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-lg);
}

.footer-section h3 {
  color: var(--ocean-teal);
  margin-bottom: var(--spacing-md);
  font-size: 1.3rem;
}

.footer-section ul {
  list-style: none;
}

.footer-section li {
  margin-bottom: var(--spacing-xs);
}

.footer-section a {
  color: rgba(255, 255, 255, 0.8);
  transition: var(--transition-fast);
}

.footer-section a:hover {
  color: var(--ocean-teal);
  text-decoration: none;
  padding-left: 5px;
}

.social-links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
}

.footer-bottom a {
  color: var(--ocean-teal);
}

.back-to-top {
  position: fixed;
  bottom: var(--spacing-lg);
  right: var(--spacing-lg);
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--ocean-teal), var(--seafoam-green));
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: var(--transition-normal);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

.bubbles-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.bubble {
  position: absolute;
  bottom: -100px;
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.3), rgba(78, 205, 196, 0.2));
  border-radius: 50%;
  opacity: 0.6;
  animation: rise linear infinite;
}

@keyframes rise {
  to {
    bottom: 110%;
    transform: translateX(50px) rotate(360deg);
  }
}

.fade-in {
  animation: fadeIn 0.6s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.page-transition {
  animation: pageTransition 0.5s ease;
}

@keyframes pageTransition {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@media (max-width: 1024px) {
  html {
    font-size: 15px;
  }

  .nav-container {
    flex-wrap: wrap;
  }

  .search-container {
    order: 3;
    flex: 100%;
    max-width: none;
  }

  .video-grid {
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: var(--spacing-md);
  }

  .featured-grid {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  }
}

@media (max-width: 768px) {
  html {
    font-size: 14px;
  }

  .mobile-menu-toggle {
    display: flex;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: var(--spacing-md);
    box-shadow: var(--shadow-lg);
    gap: var(--spacing-sm);
  }

  body.dark-mode .nav-menu {
    background: var(--dark-navy);
  }

  .nav-menu.active {
    display: flex;
  }

  .hero-section h2 {
    font-size: 1.8rem;
  }

  .hero-section p {
    font-size: 1rem;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .video-grid {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--spacing-sm);
  }

  .category-grid {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  }

  .footer-container {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .carousel-btn {
    padding: var(--spacing-sm);
    font-size: 1.2rem;
  }
}

@media (max-width: 480px) {
  html {
    font-size: 13px;
  }

  h1 { font-size: 1.8rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.3rem; }

  .video-grid {
    grid-template-columns: 1fr;
  }

  .category-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .detail-meta {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .back-to-top {
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
  }
}

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

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

.error-message {
  background: #ffebee;
  color: #c62828;
  padding: var(--spacing-md);
  border-radius: var(--border-radius-md);
  border-left: 4px solid #c62828;
  margin: var(--spacing-md) 0;
}

body.dark-mode .error-message {
  background: rgba(198, 40, 40, 0.2);
  color: #ff5252;
}

.success-message {
  background: #e8f5e9;
  color: #2e7d32;
  padding: var(--spacing-md);
  border-radius: var(--border-radius-md);
  border-left: 4px solid #2e7d32;
  margin: var(--spacing-md) 0;
}

body.dark-mode .success-message {
  background: rgba(46, 125, 50, 0.2);
  color: #69f0ae;
}

.masonry-grid {
  column-count: 3;
  column-gap: var(--spacing-md);
}

.masonry-item {
  break-inside: avoid;
  margin-bottom: var(--spacing-md);
}

@media (max-width: 1024px) {
  .masonry-grid {
    column-count: 2;
  }
}

@media (max-width: 640px) {
  .masonry-grid {
    column-count: 1;
  }
}

.badge {
  display: inline-block;
  padding: 4px 10px;
  border-radius: var(--border-radius-lg);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-new {
  background: linear-gradient(135deg, #ff6b6b, #ee5a6f);
  color: white;
}

.badge-hot {
  background: linear-gradient(135deg, #ffa500, #ff6347);
  color: white;
}

.badge-trending {
  background: linear-gradient(135deg, var(--coral-pink), var(--sunset-orange));
  color: white;
}

::-moz-selection {
  background: var(--ocean-teal);
  color: white;
}

::selection {
  background: var(--ocean-teal);
  color: white;
}