/**
 * Chanpaca Education Unity 다중 코스 학습 플랫폼
 * 코스 카드 컴포넌트 스타일
 * 
 * @author Chanpaca Education
 * @version 1.0.0
 */

/* ==========================================================================
   코스 카드 기본 스타일
   ========================================================================== */

.course-card {
  /* 레이아웃 */
  display: flex;
  flex-direction: column;
  position: relative;

  /* 박스 모델 */
  background: var(--card-bg, #ffffff);
  border: 1px solid var(--card-border, #e0e0e0);
  border-radius: var(--card-radius, 12px);
  box-shadow: var(--card-shadow, 0 2px 8px rgba(0, 0, 0, 0.1));

  /* 트랜지션 */
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);

  /* 커서 */
  cursor: pointer;

  /* 접근성 */
  outline: none;
}

.course-card:hover,
.course-card:focus,
.course-card--hovered {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow-hover, 0 8px 25px rgba(0, 0, 0, 0.15));
  border-color: var(--card-border-hover, #007bff);
}

.course-card:focus {
  outline: 2px solid var(--focus-color, #007bff);
  outline-offset: 2px;
}

/* ==========================================================================
   카드 컨테이너
   ========================================================================== */

.course-card__container {
  display: flex;
  flex-direction: column;
  height: 100%;
}

/* ==========================================================================
   썸네일 영역
   ========================================================================== */

.course-card__thumbnail {
  position: relative;
  width: 100%;
  height: 200px;
  overflow: hidden;
  border-radius: var(--card-radius, 12px) var(--card-radius, 12px) 0 0;
  /* 기본 배경 이미지 설정 - Monument Valley */
  background-image: url('../images/default-course-thumbnail.jpg');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

.course-card__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

/* 이미지가 없거나 빈 src일 때 숨김 */
.course-card__image:not([src]),
.course-card__image[src=""] {
  display: none;
}

/* 이미지가 투명하게 설정되어 배경 이미지가 보이도록 */
.course-card__image {
  background: transparent;
}

/* 이미지 컨테이너에 fallback 클래스가 있을 때 이미지 숨김 */
.course-card__thumbnail.fallback .course-card__image {
  display: none;
}

.course-card:hover .course-card__image {
  transform: scale(1.05);
}

/* 배경 이미지에도 호버 효과 적용 */
.course-card:hover .course-card__thumbnail {
  background-size: 110%;
  /* 호버 시 배경 이미지도 확대 */
  transition: background-size 0.3s ease;
}

.course-card__thumbnail {
  transition: background-size 0.3s ease;
}

.course-card__overlay {
  position: absolute;
  top: 12px;
  left: 12px;
  right: 12px;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 8px;
}

.course-card__category,
.course-card__difficulty {
  padding: 4px 8px;
  border-radius: 16px;
  font-size: 0.75rem;
  font-weight: 600;
  color: white;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  white-space: nowrap;
}

.course-card__difficulty {
  margin-left: auto;
}

/* ==========================================================================
   콘텐츠 영역
   ========================================================================== */

.course-card__content {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.course-card__header {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.course-card__title {
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-primary, #1a1a1a);
  margin: 0;
}

.course-card__subtitle {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary, #666666);
  margin: 0;
  line-height: 1.4;
}

.course-card__description {
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--text-secondary, #666666);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ==========================================================================
   메타데이터 영역
   ========================================================================== */

.course-card__metadata {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: auto;
}

.course-card__stats {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.course-card__stat {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  color: var(--text-tertiary, #888888);
  font-weight: 500;
}

.course-card__stat i {
  width: 14px;
  height: 14px;
  opacity: 0.7;
}

/* ==========================================================================
   진행률 영역
   ========================================================================== */

.course-card__progress {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.course-card__progress-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 4px;
}

.course-card__progress-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary, #666666);
}

.course-card__progress-info {
  display: flex;
  align-items: center;
  gap: 8px;
}

.course-card__progress-percentage {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--primary-color, #007bff);
}

.course-card__progress-grade {
  font-size: 0.6875rem;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.05);
  white-space: nowrap;
}

.course-card__progress-bar {
  width: 100%;
  height: 6px;
  background: var(--progress-bg, #f0f0f0);
  border-radius: 3px;
  overflow: hidden;
}

.course-card__progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color, #007bff), var(--primary-color-light, #4dabf7));
  border-radius: 3px;
  transition: width 0.3s ease, background-color 0.3s ease;
}

/* 진행률별 색상 클래스 */
.course-card__progress-fill.progress-none {
  background: #E5E7EB;
}

.course-card__progress-fill.progress-low {
  background: linear-gradient(90deg, #EF4444, #F87171);
}

.course-card__progress-fill.progress-medium-low {
  background: linear-gradient(90deg, #F59E0B, #FBBF24);
}

.course-card__progress-fill.progress-medium-high {
  background: linear-gradient(90deg, #3B82F6, #60A5FA);
}

.course-card__progress-fill.progress-high {
  background: linear-gradient(90deg, #8B5CF6, #A78BFA);
}

.course-card__progress-fill.progress-complete {
  background: linear-gradient(90deg, #10B981, #34D399);
}

.course-card__progress-details {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 4px;
}

.course-card__progress-lectures {
  font-size: 0.6875rem;
  color: var(--text-tertiary, #888888);
}

.course-card__progress-streak {
  font-size: 0.6875rem;
  font-weight: 600;
  color: #F59E0B;
  background: rgba(245, 158, 11, 0.1);
  padding: 2px 6px;
  border-radius: 8px;
}

/* ==========================================================================
   액션 영역
   ========================================================================== */

.course-card__actions {
  padding: 16px 20px 20px;
  display: flex;
  gap: 8px;
  border-top: 1px solid var(--card-border, #e0e0e0);
}

.course-card__button {
  /* 기본 스타일 초기화 */
  border: none;
  background: none;
  font-family: inherit;
  cursor: pointer;

  /* 레이아웃 */
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;

  /* 박스 모델 */
  padding: 10px 16px;
  border-radius: 8px;

  /* 타이포그래피 */
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;

  /* 트랜지션 */
  transition: all 0.2s ease;

  /* 접근성 */
  outline: none;

  /* 플렉스 */
  flex: 1;
}

.course-card__button:focus {
  outline: 2px solid var(--focus-color, #007bff);
  outline-offset: 2px;
}

.course-card__button i {
  width: 16px;
  height: 16px;
}

/* 주요 액션 버튼 (시작하기, 이어보기) */
.course-card__button--start,
.course-card__button--continue {
  background: var(--primary-color, #007bff);
  color: white;
}

.course-card__button--start:hover,
.course-card__button--continue:hover {
  background: var(--primary-color-dark, #0056b3);
  transform: translateY(-1px);
}

/* 보조 액션 버튼 (처음부터, 상세정보) */
.course-card__button--restart,
.course-card__button--info {
  background: var(--secondary-bg, #f8f9fa);
  color: var(--text-secondary, #666666);
  border: 1px solid var(--card-border, #e0e0e0);
}

.course-card__button--restart:hover,
.course-card__button--info:hover {
  background: var(--secondary-bg-hover, #e9ecef);
  color: var(--text-primary, #1a1a1a);
  border-color: var(--card-border-hover, #007bff);
}

/* ==========================================================================
   카드 크기 변형
   ========================================================================== */

/* 소형 카드 */
.course-card.small {
  max-width: 280px;
}

.course-card.small .course-card__thumbnail {
  height: 160px;
}

.course-card.small .course-card__content {
  padding: 16px;
  gap: 12px;
}

.course-card.small .course-card__title {
  font-size: 1.125rem;
}

/* 중형 카드 (기본) */
.course-card.medium {
  max-width: 350px;
}

/* 대형 카드 */
.course-card.large {
  max-width: 450px;
}

.course-card.large .course-card__thumbnail {
  height: 250px;
}

.course-card.large .course-card__content {
  padding: 24px;
  gap: 20px;
}

.course-card.large .course-card__title {
  font-size: 1.5rem;
}

/* ==========================================================================
   테마 변형
   ========================================================================== */

/* 다크 테마 */
.course-card.dark {
  --card-bg: #2d3748;
  --card-border: #4a5568;
  --card-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  --card-shadow-hover: 0 8px 25px rgba(0, 0, 0, 0.4);
  --card-border-hover: #60a5fa;
  --text-primary: #f7fafc;
  --text-secondary: #cbd5e0;
  --text-tertiary: #a0aec0;
  --progress-bg: #4a5568;
  --secondary-bg: #4a5568;
  --secondary-bg-hover: #718096;
}

/* 다크 테마 진행률 바 스타일 */
[data-theme="dark"] .course-card__progress-grade {
  background: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .course-card__progress-streak {
  background: rgba(245, 158, 11, 0.2);
}
}

/* ==========================================================================
   카드 그리드 레이아웃
   ========================================================================== */

.course-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
  padding: 24px;
}

/* 반응형 그리드 */
@media (max-width: 768px) {
  .course-cards-grid {
    grid-template-columns: 1fr;
    gap: 16px;
    padding: 16px;
  }

  .course-card {
    max-width: none;
  }

  .course-card__actions {
    flex-direction: column;
  }

  .course-card__button {
    flex: none;
  }
}

@media (max-width: 480px) {
  .course-card__thumbnail {
    height: 180px !important;
  }

  .course-card__content {
    padding: 16px !important;
    gap: 12px !important;
  }

  .course-card__title {
    font-size: 1.125rem !important;
  }

  .course-card__actions {
    padding: 12px 16px 16px !important;
  }
}

/* ==========================================================================
   아이콘 스타일 (임시 - 실제 아이콘 폰트나 SVG로 교체 예정)
   ========================================================================== */

.icon-lectures::before {
  content: "📚";
}

.icon-time::before {
  content: "⏱️";
}

.icon-play::before {
  content: "▶️";
}

.icon-restart::before {
  content: "🔄";
}

.icon-info::before {
  content: "ℹ️";
}

/* ==========================================================================
   애니메이션
   ========================================================================== */

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.course-card {
  animation: fadeInUp 0.5s ease-out;
}

/* 카드 로딩 상태 */
.course-card--loading {
  pointer-events: none;
  opacity: 0.7;
}

.course-card--loading::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.8);
  border-radius: var(--card-radius, 12px);
}

/* ==========================================================================
   고대비 모드 지원
   ========================================================================== */

@media (prefers-contrast: high) {
  .course-card {
    border-width: 2px;
    border-color: #000000;
  }

  .course-card__button {
    border-width: 2px;
  }

  .course-card__button--start,
  .course-card__button--continue {
    background: #000000;
    color: #ffffff;
  }
}

/* ==========================================================================
   모션 감소 모드 지원
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {

  .course-card,
  .course-card__image,
  .course-card__button,
  .course-card__progress-fill {
    transition: none;
  }

  .course-card:hover {
    transform: none;
  }

  .course-card:hover .course-card__image {
    transform: none;
  }

  .course-card {
    animation: none;
  }
}