/* ========================================
   YOUTUBE VIDEOS SECTION - 유튜브 영상 섹션
   ======================================== */

.youtube-videos {
  padding: var(--space-16) 0;
  background: linear-gradient(135deg, var(--color-neutral-50) 0%, var(--color-neutral-100) 100%);
  position: relative;
  overflow: hidden;
}

.youtube-videos::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="20" height="20" patternUnits="userSpaceOnUse"><path d="M 20 0 L 0 0 0 20" fill="none" stroke="%23e5e7eb" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
  opacity: 0.3;
  z-index: 1;
}

.youtube-videos__container {
  position: relative;
  z-index: 2;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.youtube-videos__header {
  text-align: center;
  margin-bottom: var(--space-12);
}

.youtube-videos__title {
  font-family: var(--font-family-pretendard);
  font-size: var(--font-size-2xl);
  font-weight: 700;
  line-height: 1.2;
  color: #0F172A;
  margin-bottom: var(--space-4);
  letter-spacing: -0.02em;
  text-shadow: 0 2px 4px rgba(15, 23, 42, 0.15);
}

.youtube-videos__subtitle {
  font-size: var(--font-size-lg);
  line-height: 1.6;
  color: #475569;
  max-width: 600px;
  margin: 0 auto;
  font-weight: var(--font-weight-medium);
  text-shadow: 0 1px 2px rgba(71, 85, 105, 0.1);
}

.youtube-videos__slider {
  position: relative;
  margin-bottom: var(--space-12);
}

.youtube-videos__slider-container {
  position: relative;
  border-radius: var(--border-radius-2xl);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  min-height: 400px;
}

.youtube-video-card {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  background: var(--color-white);
  transition: all 0.3s ease;
  opacity: 0;
  visibility: hidden;
  transform: translateX(100%);
  z-index: 1;
}

.youtube-video-card.active {
  opacity: 1;
  visibility: visible;
  transform: translateX(0);
  z-index: 2;
}

.youtube-video-card__player {
  position: relative;
  width: 100%;
  aspect-ratio: 16/9;
  background: var(--color-neutral-900);
  overflow: hidden;
}

.youtube-video-card__player iframe {
  width: 100%;
  height: 100%;
  border: none;
}

.youtube-video-card__info {
  padding: var(--space-6);
  text-align: center;
}

.youtube-video-card__title {
  font-family: var(--font-family-pretendard);
  font-size: var(--font-size-xl);
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-neutral-900);
  margin: 0;
}

/* Slider Navigation */
.youtube-videos__nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 48px;
  height: 48px;
  background: rgba(255, 255, 255, 0.9);
  border: none;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-neutral-700);
  font-size: 20px;
  cursor: pointer;
  transition: all 0.3s ease;
  z-index: 10;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-lg);
}

.youtube-videos__nav:hover {
  background: var(--color-white);
  color: var(--color-neutral-900);
  transform: translateY(-50%) scale(1.1);
}

.youtube-videos__nav svg {
  width: 24px;
  height: 24px;
}

.youtube-videos__nav--prev {
  left: var(--space-4);
}

.youtube-videos__nav--next {
  right: var(--space-4);
}

/* Slider Indicators */
.youtube-videos__indicators {
  display: flex;
  justify-content: center;
  gap: var(--space-2);
  margin-top: var(--space-6);
}

.youtube-videos__indicator {
  width: 12px;
  height: 12px;
  border: none;
  border-radius: 50%;
  background: var(--color-neutral-300);
  cursor: pointer;
  transition: all 0.3s ease;
}

.youtube-videos__indicator.active {
  background: var(--color-accent-500);
  transform: scale(1.2);
}

.youtube-videos__indicator:hover {
  background: var(--color-accent-400);
}

.youtube-videos__cta {
  text-align: center;
}

.youtube-videos__cta .btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--font-size-lg);
  padding: var(--space-4) var(--space-8);
  border-radius: var(--border-radius-xl);
  transition: all 0.3s ease;
}

.youtube-videos__cta .btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* ========================================
   RESPONSIVE DESIGN - 반응형 디자인
   ======================================== */

/* Tablet (768px 이상) */
@media (min-width: 768px) {
  .youtube-videos {
    padding: var(--space-20) 0;
  }
  
  .youtube-videos__container {
    padding: 0 var(--space-6);
  }
  
  .youtube-videos__title {
    font-size: var(--font-size-3xl);
  }
  
  .youtube-videos__nav {
    width: 56px;
    height: 56px;
  }
  
  .youtube-videos__nav svg {
    width: 28px;
    height: 28px;
  }
}

/* Desktop (1024px 이상) */
@media (min-width: 1024px) {
  .youtube-videos__container {
    padding: 0 var(--space-8);
  }
  
  .youtube-videos__title {
    font-size: var(--font-size-4xl);
  }
  
  .youtube-video-card__info {
    padding: var(--space-8);
  }
  
  .youtube-video-card__title {
    font-size: var(--font-size-2xl);
  }
}

/* Large Desktop (1280px 이상) */
@media (min-width: 1280px) {
  .youtube-videos__slider-container {
    max-width: 1000px;
    margin: 0 auto;
  }
}

/* ========================================
   ANIMATIONS - 애니메이션
   ======================================== */

@keyframes fade-in-up {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.youtube-video-card {
  animation: fade-in-up 0.6s ease-out;
}

/* ========================================
   ACCESSIBILITY - 접근성
   ======================================== */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.youtube-video-card:focus-within {
  outline: 2px solid var(--color-accent-500);
  outline-offset: 2px;
}

.youtube-videos__nav:focus {
  outline: 2px solid var(--color-accent-500);
  outline-offset: 2px;
}

.youtube-videos__indicator:focus {
  outline: 2px solid var(--color-accent-500);
  outline-offset: 2px;
}