/* ============================================
   SUBJECT SELECTION PAGE STYLES
   ============================================ */

.subject-selection-main {
  padding: var(--space-8) 0 var(--space-16);
  min-height: calc(100vh - var(--navbar-height));
  background: linear-gradient(to bottom, #f8fafc 0%, #ffffff 100%);
}

/* Page Header */
.page-header {
  text-align: center;
  margin-bottom: var(--space-12);
  animation: fadeInUp 0.6s ease-out;
}

.header-icon {
  font-size: 4rem;
  margin-bottom: var(--space-4);
  animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.page-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: var(--font-bold);
  color: var(--gray-900);
  margin-bottom: var(--space-3);
}

.page-subtitle {
  font-size: var(--text-lg);
  color: var(--gray-600);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.6;
}

/* Subjects Grid */
.subjects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-6);
  margin-bottom: var(--space-12);
}

/* Subject Card */
.subject-card {
  position: relative;
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  text-decoration: none;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  overflow: hidden;
  opacity: 0;
  transform: translateY(30px);
}

.subject-card.fade-in {
  animation: fadeInUp 0.6s ease-out forwards;
}

.subject-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
}

.subject-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  transition: height 0.3s ease;
}

.subject-card:hover::before {
  height: 100%;
  opacity: 0.05;
}

/* Subject Icon */
.subject-icon {
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  border-radius: var(--radius-xl);
  margin-bottom: var(--space-5);
  transition: all 0.3s ease;
}

.subject-card:hover .subject-icon {
  transform: scale(1.1) rotate(5deg);
}

/* Subject Icon Colors */
.subject-icon-blue {
  background: linear-gradient(135deg, #667eea15, #764ba215);
}

.subject-icon-orange {
  background: linear-gradient(135deg, #fa709a15, #fee14015);
}

.subject-icon-green {
  background: linear-gradient(135deg, #43e97b15, #38f9d715);
}

.subject-icon-purple {
  background: linear-gradient(135deg, #a8edea15, #fed6e315);
}

.subject-icon-teal {
  background: linear-gradient(135deg, #30cfd015, #33086715);
}

.subject-icon-indigo {
  background: linear-gradient(135deg, #4facfe15, #00f2fe15);
}

/* Subject Content */
.subject-content {
  position: relative;
  z-index: 1;
}

.subject-name {
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  color: var(--gray-900);
  margin-bottom: var(--space-2);
}

.subject-description {
  font-size: var(--text-base);
  color: var(--gray-600);
  margin-bottom: var(--space-4);
  line-height: 1.6;
}

.subject-meta {
  margin-bottom: var(--space-4);
}

.lesson-count {
  display: inline-block;
  padding: var(--space-2) var(--space-4);
  background: var(--gray-100);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--gray-700);
}

/* Subject Action */
.subject-action {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--primary-blue);
  font-weight: var(--font-semibold);
  font-size: var(--text-base);
}

.action-arrow {
  transition: transform 0.3s ease;
}

.subject-card:hover .action-arrow {
  transform: translateX(5px);
}

/* Available Badge */
.available-badge {
  position: absolute;
  top: var(--space-5);
  right: var(--space-5);
  padding: var(--space-2) var(--space-4);
  background: linear-gradient(135deg, #43e97b, #38f9d7);
  color: var(--white);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  box-shadow: 0 4px 10px rgba(67, 233, 123, 0.3);
}

/* Disabled Subject Card */
.subject-card-disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.subject-card-disabled:hover {
  transform: none;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.subject-card-disabled .subject-icon {
  filter: grayscale(1);
}

.subject-card-disabled:hover .subject-icon {
  transform: none;
}

.subject-badge {
  margin-top: var(--space-3);
}

.badge-coming-soon {
  display: inline-block;
  padding: var(--space-2) var(--space-4);
  background: var(--gray-200);
  color: var(--gray-600);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
}

/* Info Section */
.info-section {
  margin-top: var(--space-12);
  animation: fadeInUp 0.6s ease-out 0.3s backwards;
}

.info-card {
  display: flex;
  align-items: flex-start;
  gap: var(--space-6);
  padding: var(--space-8);
  background: linear-gradient(135deg, #667eea10, #764ba210);
  border-radius: var(--radius-xl);
  border: 2px solid #667eea20;
}

.info-icon {
  font-size: 3rem;
  flex-shrink: 0;
}

.info-content {
  flex: 1;
}

.info-title {
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  color: var(--gray-900);
  margin-bottom: var(--space-2);
}

.info-text {
  font-size: var(--text-base);
  color: var(--gray-700);
  line-height: 1.7;
  margin: 0;
}

/* Loading Container */
.loading-container {
  grid-column: 1 / -1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-16);
  gap: var(--space-4);
}

.loading-container p {
  color: var(--gray-600);
  font-size: var(--text-lg);
}

/* Error Message */
.error-message {
  grid-column: 1 / -1;
  text-align: center;
  padding: var(--space-16);
  color: var(--gray-600);
}

.error-message p:first-child {
  font-size: var(--text-3xl);
  margin-bottom: var(--space-3);
}

/* Footer Simple */
.footer-simple {
  background: var(--gray-900);
  color: var(--white);
  padding: var(--space-6) 0;
  text-align: center;
  font-size: var(--text-sm);
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Mobile Responsive */
@media (max-width: 767px) {
  .subject-selection-main {
    padding: var(--space-6) 0 var(--space-12);
  }

  .page-header {
    margin-bottom: var(--space-8);
  }

  .header-icon {
    font-size: 3rem;
  }

  .subjects-grid {
    grid-template-columns: 1fr;
    gap: var(--space-5);
  }

  .subject-card {
    padding: var(--space-6);
  }

  .subject-icon {
    width: 60px;
    height: 60px;
    font-size: 2rem;
  }

  .subject-name {
    font-size: var(--text-xl);
  }

  .subject-description {
    font-size: var(--text-sm);
  }

  .info-card {
    flex-direction: column;
    padding: var(--space-6);
    gap: var(--space-4);
  }

  .info-icon {
    font-size: 2.5rem;
  }

  .info-title {
    font-size: var(--text-lg);
  }

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

@media (min-width: 768px) and (max-width: 1023px) {
  .subjects-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .subjects-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Smooth scrolling */
html {
  scroll-behavior: smooth;
}