/* ==========================================================================
   Kanban Board Styles (Student Portal)
   ========================================================================== */

.kanban-header-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
  padding: 1.25rem;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.student-info-card {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.student-avatar-lg {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--secondary), var(--primary));
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  font-weight: 700;
  box-shadow: var(--shadow-md);
}

.student-details h2 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}

.student-details p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  display: flex;
  gap: 0.75rem;
  margin-top: 0.2rem;
}

/* Filter Controls */
.kanban-filters {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* Kanban Board Container */
.kanban-board {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
  min-height: calc(100vh - 250px);
  align-items: start;
}

@media (max-width: 1200px) {
  .kanban-board {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .kanban-board {
    grid-template-columns: 1fr;
  }
}

/* Column Container */
.kanban-column {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  max-height: 80vh;
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.kanban-column.drag-over {
  border-color: var(--primary);
  box-shadow: 0 0 0 2px var(--primary-glow);
  background: var(--primary-light);
}

.column-header {
  padding: 1rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 600;
}

.column-title-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.column-title-group .status-dot {
  width: 10px;
  height: 10px;
  border-radius: var(--radius-full);
}

.dot-todo { background: #f97316; }
.dot-progress { background: #3b82f6; }
.dot-submitted { background: #eab308; }
.dot-graded { background: #22c55e; }

.column-count {
  background: var(--bg-primary);
  color: var(--text-secondary);
  padding: 0.15rem 0.6rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
}

.column-body {
  padding: 1rem;
  overflow-y: auto;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  min-height: 180px;
}

/* Empty Column Placeholder */
.kanban-empty {
  border: 2px dashed var(--border-color);
  border-radius: var(--radius-md);
  padding: 2rem 1rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* Kanban Task Card */
.task-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  cursor: grab;
  position: relative;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
  user-select: none;
}

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

.task-card:active {
  cursor: grabbing;
}

.task-subject {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--primary);
  margin-bottom: 0.35rem;
}

.task-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.task-desc-snippet {
  font-size: 0.825rem;
  color: var(--text-secondary);
  margin-bottom: 0.85rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.task-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.task-deadline {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.task-deadline.urgent {
  color: var(--danger);
  font-weight: 600;
}

.task-score-badge {
  background: var(--status-graded-bg);
  color: var(--status-graded-text);
  border: 1px solid var(--status-graded-border);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.85rem;
}

.task-action-btns {
  display: flex;
  gap: 0.35rem;
  margin-top: 0.75rem;
}