/* ============================================
   UI COMPONENTS STYLES
   ============================================
   Core UI components: Cards, Buttons, Forms, etc.
   
   IMPORTANT: This is the SINGLE SOURCE OF TRUTH for UI components.
   Do NOT duplicate these styles in other files to avoid conflicts.
   
   Architecture:
   - Cards (basic card structure)
   - Buttons (all button variants)
   - Forms (inputs, textareas, selects)
   ============================================ */

/* ----- Cards ----- */
.card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: all var(--transition-base);
}

.card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-md);
}

.card-title {
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--text-primary);
}

.card-subtitle {
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-top: var(--space-xs);
}

.card-body {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.7;
}


/* ----- Buttons ----- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 10px 20px;
  border: none;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
  text-decoration: none;
}

.btn:disabled {
  background: var(--bg-input) !important;
  color: var(--text-muted) !important;
  border-color: var(--border-color) !important;
  opacity: 0.7;
  cursor: not-allowed;
  box-shadow: none !important;
  transform: none !important;
}

.btn-primary {
  background: var(--accent-gradient);
  color: var(--accent-contrast);
  box-shadow: 0 2px 8px var(--accent-glow);
}

.btn-primary:hover:not(:disabled) {
  box-shadow: 0 4px 16px var(--accent-glow-hover);
  transform: translateY(-1px);
}

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

.btn-secondary:hover:not(:disabled) {
  background: var(--bg-glass-hover);
  color: var(--text-primary);
  border-color: var(--border-hover);
}

.btn-success {
  background: var(--success);
  color: var(--white);
}

.btn-success:hover:not(:disabled) {
  background: var(--success-hover);
}

.btn-danger {
  background: var(--danger);
  color: var(--white);
}

.btn-sm {
  padding: 6px 14px;
  font-size: var(--text-xs);
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 14px 28px;
  font-size: var(--text-base);
  border-radius: var(--radius-md);
}


/* ----- Forms ----- */
.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.form-label {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-secondary);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  color: var(--text-primary);
  transition: all var(--transition-fast);
  outline: none;
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--text-muted);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  background: var(--bg-input-focus);
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.form-textarea {
  min-height: 100px;
  resize: vertical;
}

.form-select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2394a3b8' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

.form-select option {
  background: var(--bg-secondary);
  color: var(--text-primary);
}


/* ----- Badges ----- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-pending {
  background: var(--warning-bg);
  color: var(--warning);
  border: 1px solid rgba(245, 158, 11, 0.2);
}

.badge-graded {
  background: var(--success-bg);
  color: var(--success);
  border: 1px solid rgba(16, 185, 129, 0.2);
}

.badge-teacher {
  background: rgba(139, 92, 246, 0.1);
  color: #a78bfa;
  border: 1px solid rgba(139, 92, 246, 0.2);
}

.badge-student {
  background: var(--info-bg);
  color: var(--info);
  border: 1px solid rgba(59, 130, 246, 0.2);
}

.badge-upload {
  background: rgba(236, 72, 153, 0.1);
  color: #f472b6;
}

.badge-link {
  background: var(--info-bg);
  color: var(--info);
}

.badge-text {
  background: var(--success-bg);
  color: var(--success);
}


/* ----- Module Card ----- */
.module-card {
  cursor: pointer;
  position: relative;
  overflow: hidden;
  padding-bottom: calc(var(--space-lg) + 4px);
}

.module-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.module-card:hover::before {
  opacity: 1;
}

.module-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 10px;
  /*width: 36px;*/
  height: 36px;
  border-radius: var(--radius-sm);
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  font-weight: 700;
  font-size: var(--text-sm);
  color: var(--text-accent);
  margin-bottom: var(--space-md);
}

.module-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-top: var(--space-md);
  font-size: var(--text-xs);
  color: var(--text-muted);
}


/* ----- Assignment Card ----- */
.assignment-card {
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin-top: var(--space-md);
}

.assignment-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}

.assignment-title {
  font-weight: 600;
  font-size: var(--text-base);
  color: var(--text-primary);
}

.assignment-desc {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
  line-height: 1.7;
}

.assignment-meta {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
  font-size: var(--text-xs);
  color: var(--text-muted);
  margin-bottom: var(--space-md);
}


/* ----- Breadcrumbs ----- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-bottom: var(--space-lg);
}

.breadcrumbs span {
  cursor: pointer;
  transition: color var(--transition-fast);
}

.breadcrumbs span:hover {
  color: var(--text-accent);
}

.breadcrumbs .separator {
  cursor: default;
  opacity: 0.4;
}

.breadcrumbs .current {
  color: var(--text-primary);
  cursor: default;
}


/* ----- Toast Notifications ----- */
.toast-container {
  position: fixed;
  top: var(--space-lg);
  right: var(--space-lg);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.toast {
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid;
  animation: slideInRight 0.3s ease;
  max-width: 400px;
  box-shadow: var(--shadow-lg);
}

.toast-success {
  background: var(--success-bg);
  color: var(--success);
  border-color: rgba(16, 185, 129, 0.2);
}

.toast-error {
  background: var(--danger-bg);
  color: var(--danger);
  border-color: rgba(239, 68, 68, 0.2);
}

.toast-info {
  background: var(--info-bg);
  color: var(--info);
  border-color: rgba(59, 130, 246, 0.2);
}


/* ----- Loading Spinner ----- */
.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border-color);
  border-top-color: var(--accent-primary);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

.loading-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-3xl);
  gap: var(--space-md);
  color: var(--text-muted);
  font-size: var(--text-sm);
}

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

.btn-loading {
  position: relative;
  color: transparent !important;
  pointer-events: none;
}

.btn-loading::after {
  content: "";
  position: absolute;
  width: 18px;
  height: 18px;
  top: calc(50% - 9px);
  left: calc(50% - 9px);
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: var(--white);
  animation: spin 0.6s linear infinite;
}