/* HLD/LLD – Kanban board + spring drag */

/* Centered container: match Company Tracking alignment (max-width + side padding). */
.main.main--kanban {
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  padding: 0.75rem 24px 1.5rem;
  width: 100%;
  box-sizing: border-box;
}

.kanban-hero {
  margin-bottom: 1rem;
  padding: 0.5rem 0;
  background: linear-gradient(180deg, var(--color-hero-tint) 0%, transparent 100%);
  border-radius: var(--radius);
}

.kanban-hero__title {
  margin: 0 0 0.5rem;
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.kanban-hero__subtitle {
  margin: 0;
  font-size: 1rem;
  line-height: 1.55;
  color: var(--color-text-muted);
}

.kanban-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.75rem;
  padding: 0.5rem 0;
}

.kanban-toolbar__add-wrap {
  display: flex;
  gap: 0.5rem;
}

.kanban-add-item-btn {
  padding: 0.5rem 1rem;
  border: 1px solid var(--color-accent);
  background: var(--color-accent);
  color: #fff;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
}

.kanban-add-item-btn:hover {
  filter: brightness(1.05);
}

.kanban-add-item-btn--secondary {
  background: var(--color-surface);
  color: var(--color-accent);
}

.kanban-add-item-btn--secondary:hover {
  background: var(--color-hero-tint);
}

.kanban-search {
  flex: 1;
  min-width: 180px;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
}

.kanban-search:focus-visible {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.25);
}

.kanban-difficulty-tabs {
  display: flex;
  gap: 0.25rem;
}

.kanban-difficulty-tabs button {
  padding: 0.4rem 0.75rem;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  color: var(--color-text-muted);
}

.kanban-difficulty-tabs button:hover,
.kanban-difficulty-tabs button.active {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}

.kanban-difficulty-tabs button:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px var(--color-accent);
}

.kanban-tag-filter {
  padding: 0.4rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  background: var(--color-surface);
  color: var(--color-text-muted);
  cursor: pointer;
}

.kanban-tag-filter:focus-visible {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.25);
}

.kanban-progress-summary {
  display: none;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-muted);
  padding: 0.4rem 0;
}

.kanban-board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  height: calc(100vh - 120px);
  min-height: 400px;
  max-height: 85vh;
  min-width: 0;
  padding: 0.5rem 0 1rem;
  background: var(--color-board-bg);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  overflow-x: auto;
}

.kanban-board.kanban-board--four {
  grid-template-columns: repeat(4, 1fr);
}

.kanban-board-hint {
  display: none;
  margin: 0 0 0.5rem;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}
@media (max-width: 900px) {
  .kanban-board-hint {
    display: block;
  }
}

.kanban-column {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
  transition: background 0.2s, box-shadow 0.2s;
}

.kanban-column[data-column="to-study"] {
  border-left: 4px solid var(--color-to-study);
  background: var(--color-to-study-muted);
}

.kanban-column[data-column="in-progress"] {
  border-left: 4px solid var(--color-progress);
  background: var(--color-progress-muted);
}

.kanban-column[data-column="mastered"] {
  border-left: 4px solid var(--color-mastered);
  background: var(--color-mastered-muted);
}

.kanban-column[data-column="revision"] {
  border-left: 4px solid var(--color-revision);
  background: var(--color-revision-muted);
}

.kanban-column.drag-over {
  background: var(--color-card-blue);
  box-shadow: inset 0 0 0 2px var(--color-accent);
}

.kanban-column__header {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-border);
}

.kanban-column[data-column="to-study"] .kanban-column__header { color: var(--color-to-study); }
.kanban-column[data-column="in-progress"] .kanban-column__header { color: var(--color-progress); }
.kanban-column[data-column="mastered"] .kanban-column__header { color: var(--color-mastered); }
.kanban-column[data-column="revision"] .kanban-column__header { color: var(--color-revision); }

.kanban-column__list {
  flex: 1;
  min-height: 0;
  min-width: 0;
  overflow-y: auto;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  padding-right: 2px;
}

.kanban-drop-indicator {
  height: 4px;
  background: var(--color-accent);
  border-radius: 2px;
  margin: 2px 0;
  flex-shrink: 0;
  pointer-events: none;
}

.kanban-card {
  padding: 1rem 1.1rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: grab;
  user-select: none;
  transition: transform 0.2s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.2s;
}

.kanban-card:hover {
  box-shadow: var(--shadow-md);
}

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

.kanban-card.dragging {
  opacity: 0.9;
  transform: scale(1.02);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
  z-index: 10;
}

.kanban-card--hidden {
  display: none !important;
}

.kanban-card__title {
  margin: 0 0 0.25rem;
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.35;
}

.kanban-card__link {
  color: var(--color-text);
  text-decoration: none;
}

.kanban-card__link:hover {
  color: var(--color-accent);
  text-decoration: underline;
}

.kanban-card__link:focus-visible {
  outline: none;
  color: var(--color-accent);
  text-decoration: underline;
  border-radius: 2px;
  box-shadow: 0 0 0 2px var(--color-accent);
}

.kanban-card__type-badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--color-text-muted);
  margin-bottom: 0.25rem;
}

.kanban-card__meta {
  font-size: 0.8125rem;
  line-height: 1.4;
  color: var(--color-text-muted);
}

.kanban-card__delete {
  margin-left: auto;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.2rem 0.4rem;
  border-radius: var(--radius-sm);
}

.kanban-card__delete:hover {
  color: #c00;
  background: rgba(204, 0, 0, 0.08);
}

.hld-loading {
  padding: 1.5rem;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 1rem;
}

.hld-loading.hidden {
  display: none !important;
}

.kanban-card__resources {
  margin-top: 0.5rem;
  font-size: 0.875rem;
}

.kanban-card__resources a {
  color: var(--color-accent);
  text-decoration: none;
}

.kanban-card__resources a:hover {
  text-decoration: underline;
  color: var(--color-accent-hover);
}

.kanban-card__resources a:focus-visible {
  outline: none;
  text-decoration: underline;
  border-radius: 2px;
  box-shadow: 0 0 0 2px var(--color-accent);
}

.kanban-card__notes-toggle {
  margin-top: 0.35rem;
  font-size: 0.875rem;
  color: var(--color-text-muted);
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
  text-align: left;
}

.kanban-card__notes-toggle:hover {
  color: var(--color-accent);
}

.kanban-card__notes-toggle:focus-visible {
  outline: none;
  color: var(--color-accent);
  border-radius: var(--radius-sm);
  box-shadow: 0 0 0 2px var(--color-accent);
}

.kanban-card__notes-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.25rem;
  margin-top: 0.35rem;
}

.kanban-card__delete-progress {
  margin-left: auto;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.25rem 0;
}

.kanban-card__delete-progress:hover {
  color: var(--color-error, #c00);
}

.kanban-card__notes-text {
  margin-top: 0.35rem;
  font-size: 0.875rem;
  line-height: 1.45;
  color: var(--color-text-muted);
  white-space: pre-wrap;
}

.kanban-card__notes-textarea {
  margin-top: 0.35rem;
  width: 100%;
  min-height: 4rem;
  padding: 0.5rem;
  font-size: 0.875rem;
  line-height: 1.45;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  resize: vertical;
  box-sizing: border-box;
}

.kanban-card__notes-textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.2);
}

.kanban-card__notes-actions {
  margin-top: 0.35rem;
  display: flex;
  gap: 0.5rem;
}

.kanban-card__has-notes {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.75rem;
  color: var(--color-accent);
  margin-left: 0.5rem;
}

.kanban-card__content-summary {
  font-size: 0.75rem;
  color: var(--color-accent);
  margin-left: 0.5rem;
}

/* Learning content modal */
.learning-content-modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  pointer-events: none;
  visibility: hidden;
}

.learning-content-modal.learning-content-modal--open {
  pointer-events: auto;
  visibility: visible;
}

.learning-content-modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  cursor: pointer;
}

.learning-content-modal__panel {
  position: relative;
  width: 100%;
  max-width: 520px;
  max-height: 90vh;
  overflow: auto;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  padding: 1.5rem;
  cursor: default;
}

.learning-content-modal__title {
  margin: 0 0 1rem;
  font-size: 1.25rem;
  font-weight: 700;
}

.learning-content-modal__section {
  margin-bottom: 1.25rem;
}

.learning-content-modal__section label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.35rem;
  color: var(--color-text);
}

.learning-content-modal__section-title {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--color-text);
}

.learning-content-modal__notes {
  width: 100%;
  min-height: 5rem;
  padding: 0.5rem;
  font-size: 0.875rem;
  line-height: 1.5;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  resize: vertical;
  box-sizing: border-box;
}

.learning-content-modal__notes:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.2);
}

.learning-content-modal__list {
  list-style: none;
  margin: 0 0 0.5rem;
  padding: 0;
}

.learning-content-modal__list-item {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0.35rem 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.875rem;
}

.learning-content-modal__list-item--image {
  align-items: flex-start;
}

.learning-content-modal__list-link {
  color: var(--color-accent);
  text-decoration: none;
}

.learning-content-modal__list-link:hover {
  text-decoration: underline;
}

.learning-content-modal__list-remove {
  margin-left: auto;
  padding: 0.2rem 0.5rem;
  font-size: 0.75rem;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--color-text-muted);
}

.learning-content-modal__list-remove:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.learning-content-modal__list-caption {
  color: var(--color-text-muted);
  font-size: 0.8125rem;
}

.learning-content-modal__thumb-link {
  display: inline-block;
  cursor: pointer;
  text-decoration: none;
  line-height: 0;
}
.learning-content-modal__thumb-link:hover .learning-content-modal__thumb {
  opacity: 0.9;
}
.learning-content-modal__thumb {
  max-width: 80px;
  max-height: 60px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  display: block;
}

.learning-content-modal__add-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  margin-top: 0.5rem;
}

.learning-content-modal__input {
  padding: 0.4rem 0.6rem;
  font-size: 0.875rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  min-width: 120px;
}

.learning-content-modal__input--wide {
  flex: 1;
  min-width: 160px;
}

.learning-content-modal__input:focus {
  outline: none;
  border-color: var(--color-accent);
}

.learning-content-modal__select {
  padding: 0.4rem 0.6rem;
  font-size: 0.875rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
}

.learning-content-modal__add-btn {
  padding: 0.4rem 0.75rem;
  font-size: 0.875rem;
  border: 1px solid var(--color-accent);
  background: var(--color-accent);
  color: #fff;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.learning-content-modal__add-btn:hover {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
}

.learning-content-modal__add-btn--secondary {
  background: var(--color-surface);
  color: var(--color-accent);
  border: 1px solid var(--color-border);
}

.learning-content-modal__add-btn--secondary:hover {
  background: var(--color-bg);
  border-color: var(--color-accent);
}

.learning-content-modal__upload-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin-top: 0.75rem;
  padding-top: 0.5rem;
  border-top: 1px dashed var(--color-border);
}

.learning-content-modal__upload-label {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  width: 100%;
}

.learning-content-modal__upload-status {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  min-height: 1.25rem;
}

.learning-content-modal__actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
}

.learning-content-modal__btn {
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.learning-content-modal__btn--primary {
  background: var(--color-accent);
  color: #fff;
  border: 1px solid var(--color-accent);
}

.learning-content-modal__btn--primary:hover {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
}

.learning-content-modal__btn--secondary {
  background: var(--color-surface);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
}

.learning-content-modal__btn--secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.learning-content-modal__btn--danger {
  color: var(--color-error, #c00);
  border-color: var(--color-error, #c00);
}

.learning-content-modal__btn--danger:hover {
  background: var(--color-error, #c00);
  color: #fff;
}

.kanban-column__empty {
  padding: 1rem;
  text-align: center;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 4rem;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.kanban-card--highlight {
  animation: kanban-highlight 2s ease-out;
}

@keyframes kanban-highlight {
  0% { box-shadow: 0 0 0 3px var(--color-accent); }
  100% { box-shadow: none; }
}

.kanban-clear-filters {
  padding: 0.35rem 0.6rem;
  font-size: 0.85rem;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--color-text-muted);
}

.kanban-clear-filters:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

@media (max-width: 992px) {
  .kanban-board.kanban-board--four {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .kanban-board {
    grid-template-columns: 1fr;
  }
}