/* Base */
:root {
  --primary: #0d6efd;
  --todo: #6c757d;
  --progress: #ffc107;
  --complete: #198754;
  --priority-low: #198754;
  --priority-medium: #fd7e14;
  --priority-high: #dc3545;
  --danger: #dc3545;
  --warning: #fd7e14;
  --surface: #fff;
  --surface-raised: #fffffff0;
  --background: #f4f6fa;
  --overdue-background: #fff5f5;
  --due-soon-background: #fff8f0;
  --muted: #6c757d;
  --timeline: #dee2e6;
  --header-start: #667eea;
  --header-end: #764ba2;
  --shadow-subtle: #00000012;
  --shadow-hover: #0002;
  --shadow-pinned: #ffc10744;
  --shadow-header: #764ba240;
  /* Tint/ink pairs per status: tint backs the count pill, ink keeps text readable on it. */
  --todo-tint: #6c757d1f;
  --todo-ink: #5c636a;
  --progress-tint: #ffc1072e;
  --progress-ink: #7a5c03;
  --complete-tint: #1987541f;
  --complete-ink: #146c43;
  /* Status-agnostic ink for neutral count pills; dark enough to clear AA on --timeline. */
  --count-ink: #495057;
  /* Fallbacks so a .status-column without data-status degrades to neutral instead of
     dropping the declaration entirely at computed-value time. */
  --status-accent: var(--primary);
  --status-tint: var(--todo-tint);
  --status-ink: var(--todo-ink);
}
body {
  background: var(--background);
  font-family: 'Microsoft YaHei', system-ui, sans-serif;
}
.task-header {
  background: linear-gradient(135deg, var(--header-start), var(--header-end));
  color: var(--surface);
  padding: 0.85rem 1rem;
  border-radius: 0.65rem;
  margin-bottom: 0.75rem;
  box-shadow: 0 4px 14px var(--shadow-header);
}
.task-header h1 {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  margin: 0;
}
.toolbar {
  margin-bottom: 0.75rem;
}
.toolbar .btn,
.toolbar .form-control {
  font-size: 0.875rem;
  padding-block: 0.4rem;
}
.toolbar .btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

/* Status columns */
.status-column {
  background: var(--surface);
  border-radius: 1rem;
  padding: 1rem;
  box-shadow: 0 2px 12px var(--shadow-subtle);
  min-height: 12rem;
}
/* Each column publishes its palette so descendants can theme themselves. */
.status-column[data-status='todo'] {
  --status-accent: var(--todo);
  --status-tint: var(--todo-tint);
  --status-ink: var(--todo-ink);
}
.status-column[data-status='inProgress'] {
  --status-accent: var(--progress);
  --status-tint: var(--progress-tint);
  --status-ink: var(--progress-ink);
}
.status-column[data-status='completed'] {
  --status-accent: var(--complete);
  --status-tint: var(--complete-tint);
  --status-ink: var(--complete-ink);
}
.status-column-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 1rem;
}
.status-column-header h4 {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.4rem;
  min-width: 0;
  font-size: 1rem;
  font-weight: 600;
  margin: 0;
}
/* Direct child only, so the visibility toggle's own icon keeps its muted colour. */
.status-column-header h4 > i {
  color: var(--status-ink);
}
.status-count {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.6rem;
  padding: 0.1rem 0.45rem;
  border-radius: 1rem;
  background: var(--status-tint);
  color: var(--status-ink);
  font-size: 0.75rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}
.sort-selector {
  font-size: 0.72rem;
  padding: 0.25rem 0.4rem;
  border: 1px solid var(--timeline);
  border-radius: 0.35rem;
  max-width: 45%;
  background: var(--surface);
  color: var(--muted);
  cursor: pointer;
  transition: border-color 0.15s ease;
}
.sort-selector:hover {
  border-color: var(--status-accent);
}
.sort-selector:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 1px;
}

/* Task cards */
.task-card {
  position: relative;
  border-left: 4px solid var(--primary);
  margin-bottom: 1rem;
  /* Named properties only: `transition: 0.2s` also animated the overdue/due-soon colour flip. */
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}
.task-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 14px var(--shadow-hover);
}
.task-card.todo {
  border-left-color: var(--todo);
}
.task-card.inProgress {
  border-left-color: var(--progress);
}
.task-card.completed {
  border-left-color: var(--complete);
}
.task-card.overdue {
  border-left-color: var(--danger) !important;
  background: var(--overdue-background);
}
.task-card.due-soon {
  border-left-color: var(--warning) !important;
  background: var(--due-soon-background);
}
.task-card.hidden-task {
  opacity: 0.6;
}
.task-card.pinned {
  border-top: 3px solid var(--progress);
  box-shadow: 0 4px 12px var(--shadow-pinned);
}
.task-actions {
  position: absolute;
  right: 0.5rem;
  top: 0.5rem;
  z-index: 10;
  display: flex;
  align-items: center;
  /* flex discards the inter-tag whitespace the original leaned on, so the gap has to be
     declared rather than inherited from the markup's `ms-1` + collapsed space. */
  gap: 0.5rem;
  padding: 0.125rem;
  background: var(--surface-raised);
  border-radius: 0.375rem;
  -webkit-backdrop-filter: blur(5px);
  backdrop-filter: blur(5px);
  opacity: 0;
  transition: opacity 0.15s ease;
}
/* focus-within keeps the buttons reachable by keyboard, which hover alone never allowed. */
.task-card:hover .task-actions,
.task-card:focus-within .task-actions {
  opacity: 1;
}
/* The action bar sits over the title row, so these keep the compact proportions the
   original shipped with: a 0.8rem icon inside 6px/8px of padding. */
.task-actions .btn {
  flex: 0 0 auto;
  font-size: 0.8rem;
}
.task-actions .task-action-button {
  padding: 0.375rem 0.5rem;
}
.pin-button {
  color: var(--muted);
  text-decoration: none;
  cursor: pointer;
  transition: color 0.15s ease;
}
.pin-button:hover,
.pin-button:focus-visible,
.pin-button.pinned {
  color: var(--progress);
}
/* The original tinted this button by letting the card's `.pinned` rule leak onto it, which
   also gave it a 3px top border and left it standing taller than its neighbours. Keeping the
   tint as a background reproduces the look without disturbing the row. */
.pin-button.pinned {
  background: var(--progress-tint);
}
.priority-badge {
  position: relative;
  z-index: 5;
  flex: 0 0 auto;
  font-size: 0.7rem;
  border-radius: 1rem;
  padding: 0.125rem 0.375rem;
  color: var(--surface);
  transition:
    opacity 0.15s ease,
    transform 0.15s ease;
}
/* The action bar overlaps the badge once it fades in, so the badge steps well back
   instead of competing with the buttons stacked on top of it. */
.task-card:hover .priority-badge,
.task-card:focus-within .priority-badge {
  opacity: 0.3;
  transform: translateY(-2px);
}
.priority-low-badge {
  background: var(--priority-low);
}
.priority-medium-badge {
  background: var(--priority-medium);
}
.priority-high-badge {
  background: var(--priority-high);
}
.progress-custom {
  height: 0.45rem;
}
.person-badge {
  font-size: 0.75rem;
  margin: 0.1rem;
}
.task-description-display {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

/* Timeline */
.timeline-toggle {
  cursor: pointer;
  color: var(--muted);
  transition: color 0.15s ease;
}
.timeline-toggle:hover {
  color: var(--primary);
}
.timeline-count {
  display: inline-block;
  min-width: 1.25rem;
  padding: 0 0.35rem;
  border-radius: 1rem;
  background: var(--timeline);
  color: var(--count-ink);
  font-size: 0.7rem;
  font-variant-numeric: tabular-nums;
  text-align: center;
}
.timeline-caret {
  margin-left: 0.15rem;
}
.timeline {
  position: relative;
  padding-left: 1.25rem;
  margin-top: 0.75rem;
}
.timeline:before {
  content: '';
  position: absolute;
  left: 0.5rem;
  inset-block: 0;
  width: 2px;
  background: var(--timeline);
}
.timeline-item {
  position: relative;
  padding-bottom: 0.75rem;
  margin-bottom: 0.5rem;
}
.timeline-item:before {
  content: '';
  position: absolute;
  left: -0.72rem;
  top: 0.35rem;
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: var(--primary);
}
.timeline-content,
.timeline-form,
.timeline-edit-form {
  background: var(--background);
  padding: 0.65rem;
  border-radius: 0.5rem;
  font-size: 0.85rem;
}
.timeline-date {
  font-size: 0.75rem;
  color: var(--muted);
}
.timeline-item-actions {
  float: right;
  opacity: 0;
  transition: opacity 0.15s ease;
}
.timeline-item:hover .timeline-item-actions,
.timeline-item:focus-within .timeline-item-actions {
  opacity: 1;
}

/* Overlays and controls */
.notification {
  position: fixed;
  right: 1rem;
  top: 1rem;
  z-index: 2000;
  max-width: min(28rem, 90vw);
}
.visibility-toggle {
  padding: 0.1rem;
  color: var(--muted);
  text-decoration: none;
}
.visibility-toggle:hover {
  color: var(--status-ink);
}
.empty-state {
  color: var(--muted);
  text-align: center;
  padding: 1rem;
}

/* Responsive */
@media (max-width: 768px) {
  /* Flows inline above the card body, so the raised-surface treatment it needs while
     floating would just paint a white block over overdue/due-soon card tints. */
  .task-actions {
    position: static;
    width: fit-content;
    margin: 0.5rem 0.5rem 0 auto;
    background: transparent;
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
    opacity: 0.9;
  }
  /* Nothing covers the badge once the action bar flows inline, and a sticky touch :hover
     would otherwise leave it stuck at 30% long after the tap. */
  .task-card:hover .priority-badge,
  .task-card:focus-within .priority-badge {
    opacity: 1;
    transform: none;
  }
  .timeline-item-actions {
    opacity: 0.9;
  }
  .toolbar .btn {
    flex: 1;
  }
  .status-column {
    margin-bottom: 0.5rem;
  }
}
@media (max-width: 576px) {
  .task-header h1 {
    font-size: 1.2rem;
  }
  .status-column-header {
    align-items: flex-start;
  }
  .sort-selector {
    max-width: 50%;
  }
  /* Flex centring only here: the enlarged touch target is taller than the icon's line box,
     so normal flow would strand the glyph against the top padding. */
  .task-actions .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 2.25rem;
    min-height: 2.25rem;
  }
  .toolbar .btn {
    position: relative;
    justify-content: center;
  }
  /* Collapse to icon-only, but keep the label readable to screen readers —
     `display: none` would strip these buttons of their accessible name. */
  .toolbar .btn .toolbar-btn-label {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    border: 0;
    overflow: hidden;
    clip-path: inset(50%);
    white-space: nowrap;
  }
}
@media (prefers-reduced-motion: reduce) {
  .task-card,
  .task-actions,
  .timeline-item-actions,
  .priority-badge,
  .pin-button,
  .timeline-toggle,
  .sort-selector {
    transition: none;
  }
  .task-card:hover {
    transform: none;
  }
  .task-card:hover .priority-badge,
  .task-card:focus-within .priority-badge {
    transform: none;
  }
}