/* ============================================
   CSS 변수 정의 (디자인 시스템)
   ============================================ */
:root {
  /* 배경색 */
  --bg-primary: #0d0d0d;
  --bg-secondary: #1a1a1a;
  --bg-tertiary: #252525;
  --bg-overlay: rgba(0, 0, 0, 0.7);

  /* 텍스트 색상 */
  --text-primary: #ffffff;
  --text-secondary: #888888;
  --text-tertiary: #666666;
  --text-accent: #ff6b6b;

  /* 브랜드 색상 */
  --brand-primary: #ff6b6b;
  --brand-secondary: #ff8e8e;

  /* 기능 색상 */
  --border-color: #333333;
  --divider-color: #2a2a2a;
  --badge-bg: rgba(0, 0, 0, 0.75);

  /* 폰트 */
  --font-primary: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;

  /* 폰트 굵기 */
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;

  /* 줄 높이 */
  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  /* 간격 */
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-5: 1.25rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-10: 2.5rem;
  --spacing-12: 3rem;
  --spacing-16: 4rem;

  /* 모서리 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;

  /* 그림자 */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
}

/* ============================================
   기본 스타일 리셋
   ============================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
}

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

/* ============================================
   컨테이너
   ============================================ */
.container {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding-left: var(--spacing-4);
  padding-right: var(--spacing-4);
}

@media (min-width: 768px) {
  .container {
    padding-left: var(--spacing-6);
    padding-right: var(--spacing-6);
  }
}

@media (min-width: 1200px) {
  .container {
    padding-left: var(--spacing-8);
    padding-right: var(--spacing-8);
  }
}

/* ============================================
   헤더
   ============================================ */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  padding: 0 var(--spacing-4);
}

@media (min-width: 768px) {
  .header-container {
    height: 64px;
    padding: 0 var(--spacing-6);
  }
}

/* 로고 */
.logo {
  display: flex;
  align-items: center;
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  text-decoration: none;
}

.logo-text {
  color: var(--text-primary);
}

.logo-accent {
  color: var(--brand-primary);
}

/* 데스크탑 네비게이션 */
.desktop-nav {
  display: none;
  align-items: center;
  gap: var(--spacing-1);
}

@media (min-width: 1200px) {
  .desktop-nav {
    display: flex;
  }
}

/* 드롭다운 */
.dropdown {
  position: relative;
}

.dropdown-trigger {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
  padding: var(--spacing-2) var(--spacing-3);
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: var(--text-sm);
  cursor: pointer;
  border-radius: var(--radius-md);
  transition: background-color 0.2s ease;
}

.dropdown-trigger:hover {
  background-color: var(--bg-tertiary);
}

.chevron-icon {
  width: 16px;
  height: 16px;
  transition: transform 0.2s ease;
}

.dropdown:hover .chevron-icon {
  transform: rotate(180deg);
}

.dropdown-content {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 200px;
  margin-top: var(--spacing-1);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all 0.2s ease;
}

.dropdown:hover .dropdown-content {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-item {
  display: block;
  padding: var(--spacing-3) var(--spacing-4);
  color: var(--text-primary);
  text-decoration: none;
  font-size: var(--text-sm);
  transition: background-color 0.15s ease;
}

.dropdown-item:hover {
  background-color: var(--bg-tertiary);
}

/* 아이콘 버튼 */
.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  border-radius: var(--radius-full);
  color: var(--text-primary);
  cursor: pointer;
  transition: background-color 0.2s ease;
}

.icon-btn:hover {
  background-color: var(--bg-tertiary);
}

.icon-btn svg {
  width: 24px;
  height: 24px;
}

/* 헤더 우측 액션 그룹 */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
}

/* ============================================
   메인 컨텐츠
   ============================================ */
.main-content {
  min-height: calc(100vh - 200px);
  padding-top: var(--spacing-6);
  padding-bottom: var(--spacing-12);
}

/* ============================================
   비디오 그리드 섹션
   ============================================ */
.video-grid-section {
  padding: var(--spacing-6) 0;
}

/* 섹션 헤더 */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-6);
}

.section-title {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--text-primary);
  margin: 0;
}

.view-all-link {
  font-size: var(--text-sm);
  color: var(--brand-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.view-all-link:hover {
  color: var(--brand-secondary);
}

/* 비디오 그리드 - 핵심 반응형 */
.video-grid {
  display: grid;
  gap: var(--spacing-4);
  grid-template-columns: repeat(2, 1fr); /* 모바일: 2열 */
}

@media (min-width: 640px) {
  .video-grid {
    gap: var(--spacing-5);
    grid-template-columns: repeat(3, 1fr); /* 태블릿 소형: 3열 */
  }
}

@media (min-width: 1024px) {
  .video-grid {
    gap: var(--spacing-6);
    grid-template-columns: repeat(4, 1fr); /* 태블릿 대형/노트북: 4열 */
  }
}

@media (min-width: 1280px) {
  .video-grid {
    grid-template-columns: repeat(5, 1fr); /* 데스크탑: 5열 (최대) */
  }
}

/* ============================================
   비디오 카드 (핵심 컴포넌트)
   ============================================ */
.video-card {
  position: relative;
  background-color: transparent;
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.video-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.4);
}

.video-card-link {
  display: block;
  text-decoration: none;
  color: inherit;
}

/* 썸네일 컨테이너 */
.thumbnail-container {
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 비율 유지 */
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  overflow: hidden;
}

/* 썸네일 이미지 */
.thumbnail-image {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: opacity 0.3s ease, transform 0.4s ease;
  z-index: 1;
}

.thumbnail-image.lazy {
  opacity: 0.7;
  filter: blur(5px);
  transition: opacity 0.3s ease, filter 0.3s ease;
}

.thumbnail-image:not(.lazy) {
  opacity: 1;
  filter: blur(0);
}

.thumbnail-image.hidden {
  opacity: 0;
}

.video-card:hover .thumbnail-image:not(.hidden) {
  transform: scale(1.08);
}

/* 프리뷰 비디오 */
.preview-video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 2;
  transition: opacity 0.3s ease;
}

/* 재생시간 뱃지 */
.duration-badge {
  position: absolute;
  bottom: var(--spacing-2);
  right: var(--spacing-2);
  padding: var(--spacing-1) var(--spacing-2);
  background-color: var(--badge-bg);
  color: var(--text-primary);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  border-radius: var(--radius-sm);
  z-index: 10;
  backdrop-filter: blur(4px);
}

/* 재생 오버레이 (호버 전 표시) */
.play-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgba(0, 0, 0, 0);
  opacity: 0;
  transition: all 0.2s ease;
  z-index: 5;
}

.video-card:hover .play-overlay:not(.hidden) {
  background-color: rgba(0, 0, 0, 0.3);
  opacity: 1;
}

.play-overlay svg {
  width: 48px;
  height: 48px;
  color: var(--text-primary);
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.5));
}

.play-overlay.hidden {
  display: none;
}

/* 로딩 스피너 */
.loading-spinner {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 20;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(255, 255, 255, 0.2);
  border-top-color: var(--text-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* 비디오 정보 */
.video-info {
  padding: var(--spacing-3) var(--spacing-1);
}

.video-title {
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--text-primary);
  line-height: var(--leading-tight);
  margin: 0;
  /* 2줄 말줄임 처리 */
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  text-overflow: ellipsis;
}

.video-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  margin-top: var(--spacing-1);
  font-size: var(--text-xs);
  color: var(--text-secondary);
}

/* 모바일 터치 상태 */
@media (hover: none) and (pointer: coarse) {
  .video-card:hover {
    transform: none;
  }
}

/* ============================================
   더보기 버튼
   ============================================ */
.load-more-container {
  display: flex;
  justify-content: center;
  margin-top: var(--spacing-10);
}

.load-more-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-3) var(--spacing-8);
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  color: var(--text-primary);
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  cursor: pointer;
  transition: all 0.2s ease;
}

.load-more-btn:hover:not(:disabled) {
  background-color: var(--bg-secondary);
  border-color: var(--text-secondary);
  transform: translateY(-1px);
}

.load-more-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-loader {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

.btn-loader .spinner {
  width: 16px;
  height: 16px;
  border-width: 2px;
}

/* ============================================
   푸터
   ============================================ */
.footer {
  background-color: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  padding: var(--spacing-12) 0 var(--spacing-8);
  margin-top: var(--spacing-16);
}

.footer-content {
  display: grid;
  gap: var(--spacing-8);
  grid-template-columns: repeat(2, 1fr); /* 모바일: 2열 */
}

@media (min-width: 768px) {
  .footer-content {
    grid-template-columns: repeat(4, 1fr); /* 태블릿: 4열 */
  }
}

@media (min-width: 1024px) {
  .footer-content {
    grid-template-columns: 1.5fr 1fr 1fr 1fr 1fr; /* 데스크탑: 5열 */
  }
}

/* 브랜드 섹션 */
.footer-brand {
  grid-column: span 2;
}

@media (min-width: 768px) {
  .footer-brand {
    grid-column: span 1;
  }
}

.footer-brand .logo {
  display: inline-flex;
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  text-decoration: none;
  margin-bottom: var(--spacing-4);
}

.footer-description {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  margin: 0;
}

/* 링크 그룹 */
.footer-link-group {
  display: flex;
  flex-direction: column;
}

.footer-link-title {
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  margin: 0 0 var(--spacing-4);
}

.footer-link-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

.footer-link {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-link:hover {
  color: var(--text-primary);
}

/* 저작권 */
.footer-bottom {
  margin-top: var(--spacing-10);
  padding-top: var(--spacing-6);
  border-top: 1px solid var(--divider-color);
  text-align: center;
}

.copyright {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin: 0;
}

.brand-name {
  color: var(--brand-primary);
}

/* ============================================
   상세 페이지 스타일
   ============================================ */
.detail-page {
  padding-top: var(--spacing-4);
  padding-bottom: var(--spacing-12);
}

/* 비디오 플레이어 섹션 */
.video-player-section {
  margin-bottom: var(--spacing-8);
}

.video-player-container {
  width: 100%;
  max-width: 100%;
}

.video-player-wrapper {
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 비율 */
  background-color: var(--bg-secondary);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.main-video-player {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  background-color: #000;
}

/* 플레이 버튼 오버레이 */
.video-play-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgba(0, 0, 0, 0.3);
  z-index: 10;
  cursor: pointer;
  transition: opacity 0.3s ease, background-color 0.3s ease;
}

.video-play-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.play-button {
  width: 80px;
  height: 80px;
  background: transparent;
  border: none;
  cursor: pointer;
  transition: transform 0.2s ease;
  padding: 0;
}

.play-button:hover {
  transform: scale(1.1);
}

.play-button:active {
  transform: scale(0.95);
}

.play-button svg {
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.5));
}

/* 비디오 컨트롤 */
.video-controls {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-3) var(--spacing-4);
  background: linear-gradient(to top, rgba(0, 0, 0, 0.8), transparent);
  z-index: 20;
  opacity: 0;
  transition: opacity 0.3s ease;
}

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

.control-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  border-radius: var(--radius-full);
  transition: background-color 0.2s ease;
}

.control-btn:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

.progress-bar-container {
  flex: 1;
  height: 4px;
  background-color: rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-full);
  cursor: pointer;
  position: relative;
}

.progress-bar {
  width: 100%;
  height: 100%;
  position: relative;
}

.progress-filled {
  height: 100%;
  background-color: var(--brand-primary);
  border-radius: var(--radius-full);
  width: 0%;
  transition: width 0.1s linear;
}

.time-display {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
  font-size: var(--text-xs);
  color: var(--text-primary);
  white-space: nowrap;
}

/* 비디오 정보 섹션 */
.video-info-section {
  margin-top: var(--spacing-8);
}

.video-info-container {
  max-width: 900px;
}

/* 비디오 헤더 */
.video-header {
  margin-bottom: var(--spacing-6);
}

.video-detail-title {
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  color: var(--text-primary);
  margin: 0 0 var(--spacing-4);
  line-height: var(--leading-tight);
}

@media (min-width: 768px) {
  .video-detail-title {
    font-size: var(--text-3xl);
  }
}

.video-meta-info {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  flex-wrap: wrap;
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.meta-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
}

.meta-item svg {
  width: 16px;
  height: 16px;
}

.meta-divider {
  color: var(--text-tertiary);
}

/* 액션 버튼 */
.video-actions {
  display: flex;
  gap: var(--spacing-3);
  margin-bottom: var(--spacing-8);
  flex-wrap: wrap;
}

.action-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-3) var(--spacing-6);
  border-radius: var(--radius-full);
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  cursor: pointer;
  transition: all 0.2s ease;
  border: none;
}

.action-btn.primary {
  background-color: var(--brand-primary);
  color: var(--text-primary);
}

.action-btn.primary:hover {
  background-color: var(--brand-secondary);
  transform: translateY(-1px);
}

.action-btn.secondary {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.action-btn.secondary:hover {
  background-color: var(--bg-secondary);
  border-color: var(--text-secondary);
}

.action-btn svg {
  width: 20px;
  height: 20px;
}

/* 비디오 설명 */
.video-description {
  margin-bottom: var(--spacing-8);
}

.description-title {
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  margin: 0 0 var(--spacing-4);
}

.description-content {
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  color: var(--text-secondary);
  white-space: pre-line;
}

/* 추가 정보 */
.video-additional-info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-4);
  padding-top: var(--spacing-6);
  border-top: 1px solid var(--divider-color);
}

.info-item {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
}

@media (min-width: 640px) {
  .info-item {
    flex-direction: row;
    align-items: center;
  }
}

.info-label {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  min-width: 80px;
}

.info-value {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

/* 태그 컨테이너 */
.tags-container {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-2);
}

.tag {
  display: inline-block;
  padding: var(--spacing-1) var(--spacing-3);
  background-color: var(--bg-tertiary);
  color: var(--text-secondary);
  font-size: var(--text-xs);
  border-radius: var(--radius-full);
  transition: all 0.2s ease;
}

.tag:hover {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
}