/* Education Header */
header {
  display: flex;
  align-items: stretch;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 0;
  flex-wrap: wrap;
  padding: 0 2rem;
}

.header-left {
  display: flex;
  gap: 12px;
  align-items: center;
  flex: 1;
  position: relative;
}

.header-text {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.education-logo {
  width: 28px;
  height: 100%;
  color: var(--accent);
  flex-shrink: 0;
  opacity: 0.7;
  filter: drop-shadow(0 0 6px rgba(125, 211, 252, 0.4));
  transition: all 0.8s;
  overflow: visible;
}

.education-logo:hover {
  opacity: 1;
  transform: rotate(360deg) scale(1.1);
}

h1 {
  margin: 0;
  font-size: 1.4rem;
  letter-spacing: -0.02em;
}

.muted {
  color: var(--muted);
  font-size: 0.95rem;
}

/* Controls */
.controls {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
}

/* Control Buttons */
.control-buttons {
  display: flex;
  gap: 8px;
  align-items: center;
}

.control-btn {
  padding: 6px 10px;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.06);
  background: var(--glass);
  color: #e6eef6;
  font-size: 1.4rem;
  cursor: pointer;
  transition: all 0.2s ease;
  min-width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.control-btn:hover {
  border-color: var(--accent);
  background: rgba(125,211,252,0.05);
}

.control-btn:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(125,211,252,0.3);
}

/* Sort Controls */
.sort-controls,
.view-controls,
.filter-controls {
  position: relative;
  display: inline-block;
}

.sort-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 280px;
  background: var(--container);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
  z-index: 100;
  padding: 12px;
}

.sort-section {
  margin-bottom: 0;
}

.sort-section-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.sort-chips-vertical {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.sort-chip {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.15);
  background: var(--glass);
  color: #e6eef6;
  cursor: grab !important;
  transition: all 0.2s ease;
  user-select: none;
  position: relative;
  width: 100%;
}

.sort-chip:active {
  cursor: grabbing !important;
}

.sort-chip.dragging {
  opacity: 0;
  cursor: grabbing !important;
}

.sort-chip.drag-over {
  border-color: var(--accent);
  background: rgba(125,211,252,0.1);
}

.sort-chip.drag-over::before {
  content: '';
  position: absolute;
  left: 0;
  top: -4px;
  right: 0;
  height: 2px;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
}

.sort-chip-placeholder {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 8px;
  border: 2px dashed rgba(125,211,252,0.4);
  background: rgba(125,211,252,0.05);
  color: rgba(230, 238, 246, 0.4);
  opacity: 0.6;
  width: 100%;
}

.drag-handle {
  color: var(--muted);
  font-size: 1rem;
  cursor: grab !important;
}

.sort-chip:active .drag-handle {
  cursor: grabbing !important;
}

.sort-chip:hover {
  border-color: var(--accent);
  background: rgba(125,211,252,0.05);
}

.sort-label {
  font-size: 0.85rem;
  color: var(--muted);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
}

.reverse-btn {
  background: transparent;
  border: 1px solid rgba(255,255,255,0.15);
  color: var(--muted);
  padding: 4px 8px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 1rem;
  transition: all 0.2s ease;
}

.reverse-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(125,211,252,0.05);
}

.reverse-btn.active {
  background: var(--accent);
  color: #000;
  border-color: var(--accent);
}

.sort-chips {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* View Controls */
.view-controls {
  position: relative;
}

.view-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  position: relative;
  justify-content: center;
}

.view-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 200px;
  background: var(--container);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
  z-index: 100;
  padding: 12px;
}

.view-section {
  margin-bottom: 0;
}

.view-section-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 8px;
}

.view-options {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.view-option {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.2s ease;
}

.view-option:hover {
  background: rgba(255,255,255,0.05);
}

.view-option input[type="radio"] {
  width: 16px;
  height: 16px;
  cursor: pointer;
  accent-color: var(--accent);
}

.view-option span {
  flex: 1;
  cursor: pointer;
  color: #e6eef6;
  font-size: 0.9rem;
}

/* Filter Controls */
.filter-controls {
  position: relative;
}

.filter-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  position: relative;
  justify-content: center;
}

.filter-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 320px;
  background: var(--container);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
  z-index: 100;
  padding: 12px;
  max-height: 400px;
  overflow-y: auto;
}

.filter-section {
  margin-bottom: 16px;
}

.filter-section:last-of-type {
  margin-bottom: 12px;
}

.filter-section-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 8px;
}

.filter-options {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.filter-option {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.2s ease;
}

.filter-option:hover {
  background: rgba(255,255,255,0.05);
}

.filter-option input[type="checkbox"] {
  width: 16px;
  height: 16px;
  cursor: pointer;
  accent-color: var(--accent);
}

.filter-option label {
  flex: 1;
  cursor: pointer;
  color: #e6eef6;
  font-size: 0.9rem;
}

.filter-actions {
  display: flex;
  gap: 8px;
  padding-top: 8px;
  border-top: 1px solid rgba(255,255,255,0.1);
}

.filter-action-btn {
  flex: 1;
  padding: 8px 12px;
  border-radius: 6px;
  border: 1px solid rgba(255,255,255,0.15);
  background: transparent;
  color: #e6eef6;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.2s ease;
}

.filter-action-btn:hover {
  background: rgba(255,255,255,0.05);
  border-color: rgba(255,255,255,0.25);
}

.filter-action-btn.primary {
  background: var(--accent);
  color: #000;
  border-color: var(--accent);
}

.filter-action-btn.primary:hover {
  background: rgba(125,211,252,0.8);
}

.search {
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.06);
  background: var(--glass);
  color: inherit;
  min-width: 180px;
  font-size: 1rem;
  height: 44px;
}

input.search::placeholder {
  color: var(--muted);
}

.search option {
  background: var(--card);
  color: #e6eef6;
}

select.search option[disabled][hidden] {
  color: var(--muted);
  opacity: 0.1;
}

select.search:invalid {
  color: var(--muted);
}

.search:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(125,211,252,0.3);
  background: var(--glass);
  color: inherit;
}

.search:active {
  background: var(--glass);
  border-color: var(--accent);
}

/* Education Content */
#education-content {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 0 2rem;
}

#education-content.list-view {
  gap: 0;
}

/* List View */
.course-list-item {
  padding: 8px 12px;
  border-bottom: 1px solid rgba(255,255,255,0.05);
  color: #e6eef6;
  font-size: 0.95rem;
  line-height: 1.5;
}

.course-list-item:hover {
  background: rgba(255,255,255,0.02);
}

.course-list-number {
  color: var(--accent);
  font-weight: 600;
  margin-right: 8px;
}

/* Course Card */
.course-card {
  position: relative;
  background: linear-gradient(180deg, rgba(255,255,255,0.05), transparent);
  border-radius: 12px;
  padding: 12px;
  box-shadow: 0 6px 18px rgba(2,6,23,0.6);
  border: 2px solid rgba(255,255,255,0.15);
  display: flex;
  gap: 12px;
  align-items: flex-start;
  transition: all 0.3s ease;
  opacity: 0;
  transform: translateY(30px);
  animation: fadeInUp 0.6s ease-out forwards;
}

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

.course-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(2,6,23,0.9), 0 0 20px rgba(125,211,252,0.3);
  border-color: rgba(125,211,252,0.6);
}

.course-card .institution-badge {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: #000000;
  background: linear-gradient(135deg, #d1fae5, #bbf7d0);
  padding: 0.15rem 0.4rem;
  border-radius: 0.25rem;
}

/* Thumbnail */
.course-thumb {
  width: 80px;
  height: 80px;
  border-radius: 12%;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, #d1fae5, #bbf7d0);
  font-size: 1.2rem;
  transition: all 0.3s ease;
}

.course-thumb[data-discipline="Physics"] {
  background: linear-gradient(135deg, #dc2626, #991b1b);
  color: #fecaca;
  box-shadow: 0 0 20px rgba(220, 38, 38, 0.5);
}

.course-thumb[data-discipline="Math"],
.course-thumb[data-discipline="Mathematics"] {
  background: linear-gradient(135deg, #3b82f6, #1e40af);
  color: #dbeafe;
  box-shadow: 0 0 20px rgba(59, 130, 246, 0.5);
}

.course-thumb[data-discipline="Computer Science"],
.course-thumb[data-discipline="CS"] {
  background: linear-gradient(135deg, #10b981, #059669);
  color: #d1fae5;
  box-shadow: 0 0 20px rgba(16, 185, 129, 0.5);
}

.course-card:hover .course-thumb[data-discipline="Physics"] {
  box-shadow: 0 0 30px rgba(220, 38, 38, 0.7);
}

.course-card:hover .course-thumb[data-discipline="Math"],
.course-card:hover .course-thumb[data-discipline="Mathematics"] {
  box-shadow: 0 0 30px rgba(59, 130, 246, 0.7);
}

.course-card:hover .course-thumb[data-discipline="Computer Science"],
.course-card:hover .course-thumb[data-discipline="CS"] {
  box-shadow: 0 0 30px rgba(16, 185, 129, 0.7);
}

/* Meta Information */
.course-meta {
  flex: 1;
  min-width: 0;
}

.course-header {
  margin: 0 0 6px 0;
  display: flex;
  align-items: baseline;
  gap: 8px;
  flex-wrap: wrap;
}

.course-number {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  margin: 0;
  opacity: 0.8;
}

.course-title {
  font-size: 1rem;
  font-weight: 600;
  color: #e6eef6;
  margin: 0;
  line-height: 1.3;
  flex: 1;
}

.course-description {
  margin: 6px 0 0 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.3;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  line-clamp: 3;
}

/* Tags */
.course-tags {
  margin-top: 8px;
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.course-tag {
  font-size: 0.78rem;
  padding: 4px 8px;
  border-radius: 999px;
  background: rgba(125,211,252,0.08);
  color: var(--accent);
  border: 1px solid rgba(125,211,252,0.06);
}

/* Status Messages */
.loading, .error, .empty {
  text-align: center;
  padding: 18px 1rem;
  color: var(--muted);
}

button.retry {
  background: transparent;
  color: var(--accent);
  border: 1px solid rgba(125,211,252,0.15);
  padding: 6px 10px;
  border-radius: 8px;
  cursor: pointer;
  margin-top: 8px;
}

button.retry:hover {
  background: rgba(125,211,252,0.1);
  border-color: var(--accent);
}

/* Responsive */
@media (max-width: 768px) {
  header {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .controls {
    width: 100%;
    flex-direction: row;
    align-items: center;
  }
  
  .search {
    flex: 1;
    min-width: 0;
  }
  
  .control-buttons {
    flex-shrink: 0;
  }
  
  .sort-dropdown,
  .view-dropdown,
  .filter-dropdown {
    right: 0;
    left: auto;
  }
}

@media (max-width: 520px) {
  .course-thumb {
    width: 56px;
    height: 56px;
    font-size: 0.9rem;
  }
  
  .control-btn {
    padding: 5px 8px;
    min-width: 38px;
    height: 38px;
    font-size: 1.2rem;
  }
  
  .search {
    font-size: 0.9rem;
    height: 38px;
  }
}