.ui-style-7 {
  --primary-color: #2563eb;
  --secondary-color: #1d4ed8;
  --bg-color: #f5f5f5;
  --card-bg: #ffffff;
  --text-color: #333333;
}

body {
  transition: background-color 0.3s ease;
}

.container {
  animation: fadeIn 0.5s ease-in;
}

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

.video-card {
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid #e5e7eb;
}

.video-card:hover {
  border-color: var(--primary-color);
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.15);
}

.video-title a {
  transition: color 0.2s ease;
  position: relative;
}

.video-title a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary-color);
  transition: width 0.3s ease;
}

.video-title a:hover::after {
  width: 100%;
}

.tag {
  transition: all 0.2s ease;
  cursor: default;
}

.tag:hover {
  background: var(--primary-color);
  color: white;
  transform: translateY(-2px);
}

nav a {
  position: relative;
  overflow: hidden;
}

nav a::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--primary-color);
  transform: translateX(-50%);
  transition: width 0.3s ease;
}

nav a:hover::before {
  width: 80%;
}

.section-title {
  animation: slideInLeft 0.6s ease;
  position: relative;
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.intro-section {
  animation: fadeInUp 0.7s ease;
  border-left: 4px solid var(--primary-color);
}

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

article {
  animation: fadeIn 0.5s ease;
}

.video-grid {
  animation: fadeIn 0.8s ease;
}

@media (max-width: 768px) {
  nav ul {
    overflow-x: visible;
    flex-wrap: nowrap;
  }

  nav a {
    font-size: 13px;
    padding: 6px 8px;
    white-space: nowrap;
  }

  .logo {
    font-size: 20px;
  }

  .section-title {
    font-size: 22px;
    padding-left: 10px;
  }

  .intro-section {
    padding: 20px;
    font-size: 14px;
  }

  article {
    padding: 25px 20px;
  }

  .video-title {
    font-size: 16px;
  }

  .video-meta,
  .video-desc {
    font-size: 13px;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .video-grid {
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  }
}

header {
  transition: box-shadow 0.3s ease;
}

header:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

footer {
  animation: fadeIn 1s ease;
}

.video-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.video-card {
  position: relative;
}

.video-card:hover::before {
  transform: scaleX(1);
}