/* Topic Cards Layout - Visual Content Organization */

/* Topic Cards Grid */
.topic-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

/* Individual Topic Card */
.topic-card {
  background: var(--md-default-bg-color);
  border: 1px solid var(--md-default-fg-color--lightest);
  border-radius: 0.75rem;
  padding: 1.5rem;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.topic-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.1);
  border-color: var(--md-accent-fg-color--transparent);
}

/* Card Header */
.topic-card-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.topic-card-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--md-accent-fg-color) 0%, var(--md-accent-fg-color--light) 100%);
  border-radius: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--md-accent-bg-color);
}

.topic-card-title {
  flex: 1;
}

.topic-card-title h3 {
  margin: 0;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--md-default-fg-color);
}

.topic-card-title .subtitle {
  font-size: 0.9rem;
  color: var(--md-default-fg-color--light);
  margin-top: 0.25rem;
}

/* Card Content */
.topic-card-content {
  margin-bottom: 1rem;
}

.topic-card-content p {
  margin: 0;
  line-height: 1.6;
  color: var(--md-default-fg-color--light);
}

/* Card Tags */
.topic-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.topic-card-tag {
  background: var(--md-accent-fg-color--transparent);
  color: var(--md-accent-fg-color);
  padding: 0.25rem 0.75rem;
  border-radius: 1rem;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* Card Footer */
.topic-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 1rem;
  border-top: 1px solid var(--md-default-fg-color--lightest);
}

.topic-card-stats {
  display: flex;
  gap: 1rem;
  font-size: 0.9rem;
  color: var(--md-default-fg-color--light);
}

.topic-card-action {
  background: var(--md-accent-fg-color);
  color: var(--md-accent-bg-color);
  padding: 0.5rem 1rem;
  border-radius: 0.375rem;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  transition: all 0.2s ease;
}

.topic-card-action:hover {
  background: var(--md-accent-fg-color--dark);
  transform: translateY(-1px);
}

/* Difficulty Indicators */
.topic-card.difficulty-beginner {
  border-left: 4px solid #43e97b;
}

.topic-card.difficulty-intermediate {
  border-left: 4px solid #ff9800;
}

.topic-card.difficulty-advanced {
  border-left: 4px solid #f44336;
}

/* Content Type Indicators */
.topic-card.type-theory .topic-card-icon {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.topic-card.type-practice .topic-card-icon {
  background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.topic-card.type-mixed .topic-card-icon {
  background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

/* Progress Overlay */
.topic-card-progress {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--md-default-fg-color--lightest);
  overflow: hidden;
}

.topic-card-progress-bar {
  height: 100%;
  background: var(--md-accent-fg-color);
  transition: width 0.3s ease;
}

/* Featured Cards */
.topic-card.featured {
  border: 2px solid var(--md-accent-fg-color);
  background: linear-gradient(135deg, var(--md-accent-fg-color--transparent) 0%, transparent 100%);
}

.topic-card.featured::before {
  content: "⭐";
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  font-size: 1.2rem;
}

/* Compact Cards for Mobile */
@media screen and (max-width: 768px) {
  .topic-cards-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  
  .topic-card {
    padding: 1rem;
  }
  
  .topic-card-icon {
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
  }
  
  .topic-card-title h3 {
    font-size: 1.1rem;
  }
  
  .topic-card-footer {
    flex-direction: column;
    gap: 0.75rem;
    align-items: stretch;
  }
  
  .topic-card-action {
    text-align: center;
  }
}

/* List View Alternative */
.topic-cards-list .topic-card {
  display: flex;
  align-items: center;
  padding: 1rem;
  margin-bottom: 1rem;
}

.topic-cards-list .topic-card-icon {
  width: 40px;
  height: 40px;
  font-size: 1.2rem;
  margin-right: 1rem;
  margin-bottom: 0;
}

.topic-cards-list .topic-card-content {
  flex: 1;
  margin-bottom: 0;
}

.topic-cards-list .topic-card-header {
  margin-bottom: 0.5rem;
}

.topic-cards-list .topic-card-footer {
  padding-top: 0;
  border-top: none;
  margin-left: auto;
}

/* Animation for card entrance */
@keyframes cardEntrance {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.topic-card {
  animation: cardEntrance 0.5s ease forwards;
}

.topic-card:nth-child(1) { animation-delay: 0.1s; }
.topic-card:nth-child(2) { animation-delay: 0.2s; }
.topic-card:nth-child(3) { animation-delay: 0.3s; }
.topic-card:nth-child(4) { animation-delay: 0.4s; }
.topic-card:nth-child(5) { animation-delay: 0.5s; }
.topic-card:nth-child(6) { animation-delay: 0.6s; }