/* ═══════════════════════════════════════════════════════════
   TaskFlow — Design System & Styles
   Mobile-First · Premium SaaS · Accessible
   ═══════════════════════════════════════════════════════════ */

/* ──────────────────────────────────────────
   1. DESIGN TOKENS (Custom Properties)
   ────────────────────────────────────────── */
:root {
  /* HSL Palette — "Electric SaaS" */
  --h-accent: 263; /* Violet-Indigo base */
  
  --color-bg:             hsl(210, 40%, 98%);
  --color-surface:        hsl(0, 0%, 100%);
  --color-surface-hover:  hsl(210, 40%, 96%);
  --color-border:         hsl(214, 32%, 91%);
  --color-border-focus:   hsl(var(--h-accent), 70%, 60%);

  --color-text-primary:   hsl(222, 47%, 11%);
  --color-text-secondary: hsl(215, 25%, 40%);
  --color-text-muted:     hsl(215, 16%, 57%);

  /* Accent — Electric Violet */
  --color-accent:         hsl(var(--h-accent), 80%, 58%);
  --color-accent-hover:   hsl(var(--h-accent), 80%, 50%);
  --color-accent-soft:    hsl(var(--h-accent), 80%, 96%);

  /* Status — Modern Vibrant */
  --color-baja:           hsl(158, 64%, 40%);
  --color-baja-bg:        hsl(158, 64%, 96%);
  --color-media:          hsl(38, 92%, 45%);
  --color-media-bg:       hsl(38, 92%, 96%);
  --color-alta:           hsl(22, 90%, 50%);
  --color-alta-bg:        hsl(22, 90%, 96%);
  --color-urgente:        hsl(350, 89%, 55%);
  --color-urgente-bg:     hsl(350, 89%, 96%);

  --color-done:           hsl(158, 64%, 40%);
  --color-done-bg:        hsl(158, 64%, 97%);

  --color-danger:         hsl(350, 89%, 55%);
  --color-danger-hover:   hsl(350, 89%, 45%);
  --color-danger-soft:    hsl(350, 89%, 97%);

  --header-glass:         hsla(210, 40%, 98%, 0.9);

  /* Sombras — Soft Depth */
  --shadow-sm:   0 1px 2px rgba(0,0,0,0.05);
  --shadow-md:   0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
  --shadow-lg:   0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
  --shadow-xl:   0 20px 25px -5px rgba(0,0,0,0.1), 0 10px 10px -5px rgba(0,0,0,0.04);

  /* Radios — Cohesive system */
  --radius-sm:   8px;
  --radius-md:   12px;
  --radius-lg:   16px;
  --radius-xl:   24px;
  --radius-full: 9999px;

  /* Transiciones */
  --ease-out:    cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration:    0.25s;

  /* Tipografía */
  --font-body:    'Inter', sans-serif;
  --font-heading: 'Outfit', sans-serif;
}

[data-theme="dark"] {
  --color-bg:             hsl(222, 47%, 4%);
  --color-surface:        hsl(222, 47%, 7%);
  --color-surface-hover:  hsl(222, 47%, 10%);
  --color-border:         hsl(222, 47%, 14%);
  --color-border-focus:   hsl(var(--h-accent), 70%, 60%);

  --color-text-primary:   hsl(210, 40%, 98%);
  --color-text-secondary: hsl(215, 20%, 65%);
  --color-text-muted:     hsl(215, 16%, 47%);

  --color-accent:         hsl(var(--h-accent), 70%, 65%);
  --color-accent-hover:   hsl(var(--h-accent), 70%, 75%);
  --color-accent-soft:    hsla(var(--h-accent), 70%, 65%, 0.15);

  --color-baja-bg:        hsla(158, 64%, 40%, 0.15);
  --color-media-bg:       hsla(38, 92%, 45%, 0.15);
  --color-alta-bg:        hsla(22, 90%, 50%, 0.15);
  --color-urgente-bg:     hsla(350, 89%, 55%, 0.15);

  --color-done-bg:        hsla(158, 64%, 40%, 0.12);
  --color-danger-soft:    hsla(350, 89%, 55%, 0.12);

  --header-glass:         hsla(222, 47%, 4%, 0.9);

  --shadow-sm:   0 1px 2px rgba(0,0,0,0.3);
  --shadow-md:   0 4px 6px -1px rgba(0,0,0,0.4);
  --shadow-lg:   0 10px 15px -3px rgba(0,0,0,0.5);
  --shadow-xl:   0 20px 25px -5px rgba(0,0,0,0.6);
}

[data-theme="dark"] .task-item.completed {
  border-color: rgba(5, 150, 105, 0.2);
}


/* ──────────────────────────────────────────
   2. RESET & BASE
   ────────────────────────────────────────── */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--duration) var(--ease-out);
}

a:hover {
  color: var(--color-accent-hover);
}

ul {
  list-style: none;
}

/* ──────────────────────────────────────────
   3. HEADER
   ────────────────────────────────────────── */
.app-header {
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: var(--header-glass);
}

.header-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-mark {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
}

.logo-mark svg,
.logo-mark img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

/* Theme toggle */
.btn-theme-toggle {
  background: var(--color-bg);
  border: 1.5px solid var(--color-border);
  color: var(--color-text-secondary);
  font-size: 1.1rem;
  transition: all var(--duration) var(--ease-out);
}

.btn-theme-toggle:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-soft);
}

.logo h1 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--color-text-primary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Stats bar */
.stats {
  display: flex;
  gap: 16px;
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  font-weight: 500;
}

.stat-item {
  display: flex;
  align-items: center;
  gap: 5px;
}

.stat-item .stat-number {
  font-weight: 700;
  color: var(--color-text-primary);
  font-size: 0.95rem;
}

/* ──────────────────────────────────────────
   4. BUTTONS
   ────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 18px;
  border: none;
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--duration) var(--ease-out);
  white-space: nowrap;
  outline: none;
}

.btn:focus-visible {
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

.btn-primary {
  background: linear-gradient(135deg, #6366f1, #4f46e5);
  color: #fff;
  box-shadow: 0 2px 8px rgba(99, 102, 241, 0.25);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(99, 102, 241, 0.35);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-secondary);
  padding: 8px 12px;
}

.btn-ghost:hover {
  background: var(--color-bg);
  color: var(--color-text-primary);
}

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

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

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

.btn-ghost.btn-danger:hover {
  background: var(--color-danger-soft);
}

.btn-icon {
  width: 34px;
  height: 34px;
  padding: 0;
  display: grid;
  place-items: center;
  border-radius: var(--radius-sm);
  font-size: 1rem;
}

/* ──────────────────────────────────────────
   5. MAIN LAYOUT
   ────────────────────────────────────────── */
.app-main {
  max-width: 900px;
  margin: 0 auto;
  padding: 24px 20px 60px;
  width: 100%;
  flex: 1;
}

/* ──────────────────────────────────────────
   6. FORM SECTION
   ────────────────────────────────────────── */
.form-section {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  padding: 24px;
  margin-bottom: 24px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--duration) var(--ease-out), box-shadow var(--duration) var(--ease-out);
}

.form-section:focus-within {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.section-header h2 {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--color-text-primary);
}

.btn-close-form {
  display: none;
  background: var(--color-surface-hover);
  border: none;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  place-items: center;
  cursor: pointer;
  color: var(--color-text-secondary);
  transition: all var(--duration) var(--ease-out);
}

.btn-close-form:hover {
  background: var(--color-danger-soft);
  color: var(--color-danger);
}

@media (max-width: 640px) {
  .btn-close-form {
    display: grid;
  }
}

.section-header h2 i {
  color: var(--color-accent);
  font-size: 1.2rem;
}

.form-grid {
  display: grid;
  gap: 16px;
  margin-bottom: 20px;
}

/* Form group */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  gap: 5px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.form-group label i {
  font-size: 0.9rem;
}

.form-group input,
.form-group select {
  font-family: var(--font-body);
  font-size: 0.95rem;
  padding: 12px 14px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text-primary);
  transition: all var(--duration) var(--ease-out);
  outline: none;
  width: 100%;
  appearance: none;
  -webkit-appearance: none;
}

.form-group select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16'%3E%3Cpath fill='%236b7280' d='M4.427 6.427l3.396 3.396a.25.25 0 00.354 0l3.396-3.396A.25.25 0 0011.396 6H4.604a.25.25 0 00-.177.427z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

.form-group input:focus,
.form-group select:focus {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

/* Error state */
.form-group.has-error input,
.form-group.has-error select {
  border-color: var(--color-danger);
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

.error-message {
  font-size: 0.78rem;
  color: var(--color-danger);
  font-weight: 500;
  min-height: 18px;
  display: flex;
  align-items: center;
  gap: 4px;
  opacity: 0;
  transform: translateY(-4px);
  transition: all var(--duration) var(--ease-out);
}

.form-group.has-error .error-message {
  opacity: 1;
  transform: translateY(0);
}

.btn-submit {
  width: 100%;
  justify-content: center;
  padding: 14px;
  font-size: 0.95rem;
}

/* ──────────────────────────────────────────
   7. FILTERS
   ────────────────────────────────────────── */
.filters-section {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.filter-chip {
  font-family: var(--font-body);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-full);
  background: var(--color-surface);
  color: var(--color-text-secondary);
  font-size: 0.825rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--duration) var(--ease-out);
  outline: none;
}

.filter-chip:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.filter-chip.active {
  background: var(--color-accent-soft);
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.filter-chip:focus-visible {
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

/* ──────────────────────────────────────────
   8. TASK LIST
   ────────────────────────────────────────── */
.task-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.task-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px;
  display: flex;
  align-items: flex-start;
  gap: 14px;
  transition: all var(--duration) var(--ease-spring);
  box-shadow: var(--shadow-sm);
  animation: slideIn 0.4s var(--ease-spring) both;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.task-item:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-border-focus);
  transform: translateX(4px);
}

.task-item.completed {
  background: var(--color-done-bg);
  border-color: #a7f3d0;
}

.task-item.completed .task-title {
  text-decoration: line-through;
  color: var(--color-text-muted);
}

.task-item.completed .task-email {
  color: var(--color-text-muted);
}

/* Checkbox circular */
.task-check {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 2px solid var(--color-border);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: all var(--duration) var(--ease-out);
  background: transparent;
  margin-top: 2px;
  font-size: 0;
  color: transparent;
}

.task-check:hover {
  border-color: var(--color-done);
  background: var(--color-done-bg);
}

.task-item.completed .task-check {
  background: var(--color-done);
  border-color: var(--color-done);
  color: #fff;
  font-size: 12px;
}

/* Body */
.task-body {
  flex: 1;
  min-width: 0;
}

.task-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 4px;
  word-break: break-word;
}

.task-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.task-email {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  gap: 4px;
}

.task-email i {
  font-size: 0.85rem;
}

/* Priority badge */
.priority-badge {
  font-size: 0.7rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.priority-badge.baja {
  background: var(--color-baja-bg);
  color: var(--color-baja);
}

.priority-badge.media {
  background: var(--color-media-bg);
  color: var(--color-media);
}

.priority-badge.alta {
  background: var(--color-alta-bg);
  color: var(--color-alta);
}

.priority-badge.urgente {
  background: var(--color-urgente-bg);
  color: var(--color-urgente);
}

/* Actions */
.task-actions {
  flex-shrink: 0;
  display: flex;
  gap: 4px;
  opacity: 0;
  transition: opacity var(--duration) var(--ease-out);
}

.task-item:hover .task-actions {
  opacity: 1;
}

/* Siempre visible en mobile */
@media (hover: none) {
  .task-actions {
    opacity: 1;
  }
}

.task-actions .btn-icon {
  color: var(--color-text-muted);
}

.task-actions .btn-icon:hover {
  color: var(--color-danger);
  background: var(--color-danger-soft);
}

/* ──────────────────────────────────────────
   9. EMPTY STATE
   ────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--color-text-muted);
}

.empty-state i {
  font-size: 4rem;
  margin-bottom: 12px;
  display: block;
  /* Shimmer animation applied via Design Spells (section 14) */
}

.empty-state p {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-bottom: 4px;
}

.empty-state span {
  font-size: 0.875rem;
}

.hidden {
  display: none !important;
}

/* ──────────────────────────────────────────
   10. MODAL
   ────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  backdrop-filter: blur(6px);
  display: grid;
  place-items: center;
  z-index: 1000;
  padding: 20px;
  animation: fadeIn 0.2s var(--ease-out);
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.modal {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: 32px;
  max-width: 400px;
  width: 100%;
  text-align: center;
  box-shadow: var(--shadow-xl);
  animation: scaleIn 0.3s var(--ease-out);
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.modal-icon {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--color-danger-soft);
  display: grid;
  place-items: center;
  margin: 0 auto 16px;
  color: var(--color-danger);
  font-size: 28px;
}

.modal h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.modal p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin-bottom: 24px;
}

.modal-actions {
  display: flex;
  gap: 10px;
  justify-content: center;
}

.modal-actions .btn {
  flex: 1;
  justify-content: center;
  padding: 12px;
}

/* ──────────────────────────────────────────
   11. TOASTS
   ────────────────────────────────────────── */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 2000;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}

.toast {
  font-family: var(--font-body);
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 20px;
  border-radius: var(--radius-md);
  background: var(--color-text-primary);
  color: #fff;
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  pointer-events: auto;
  animation: toastIn 0.4s var(--ease-out) both;
}

.toast.toast-success {
  background: var(--color-done);
}

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

.toast i {
  font-size: 1.15rem;
  flex-shrink: 0;
}

@keyframes toastIn {
  from {
    opacity: 0;
    transform: translateY(16px) scale(0.96);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes toastOut {
  to {
    opacity: 0;
    transform: translateY(16px) scale(0.96);
  }
}

/* ──────────────────────────────────────────
   12. MOBILE & FAB (Phase 3)
   ────────────────────────────────────────── */
.btn-fab {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-accent), var(--color-accent-hover));
  color: #fff;
  border: none;
  box-shadow: var(--shadow-lg);
  display: none; /* Only show on mobile */
  place-items: center;
  font-size: 24px;
  cursor: pointer;
  z-index: 900;
  transition: transform var(--duration) var(--ease-spring), box-shadow var(--duration) var(--ease-out);
}

.btn-fab:hover {
  transform: scale(1.1) rotate(90deg);
  box-shadow: var(--shadow-xl);
}

.btn-fab:active {
  transform: scale(0.95);
}

/* ──────────────────────────────────────────
   13. RESPONSIVE REFINEMENTS
   ────────────────────────────────────────── */
@media (max-width: 640px) {
  .btn-fab {
    display: grid;
  }

  .form-section {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    margin-bottom: 0;
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    z-index: 1001;
    transform: translateY(100%);
    transition: transform 0.4s var(--ease-spring);
    box-shadow: 0 -10px 25px rgba(0,0,0,0.1);
  }

  .form-section.show-mobile {
    transform: translateY(0);
  }

  /* Overlay para el bottom sheet */
  .form-overlay-mobile {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    backdrop-filter: blur(4px);
    z-index: 1000;
    display: none;
  }

  .form-overlay-mobile.active {
    display: block;
  }

  .header-inner {
    padding: 10px 16px;
  }

  .logo h1 {
    font-size: 1.1rem;
  }

  .stats {
    display: none; /* Hide stats in header on very small screens to save space */
  }
}

/* ──────────────────────────────────────────
   14. DESIGN SPELLS (Phase 4)
   ────────────────────────────────────────── */
@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

/* Shimmer effect on empty-state icon (merged from duplicate rule) */
.empty-state i {
  background: linear-gradient(90deg, 
    var(--color-text-muted) 25%, 
    var(--color-text-primary) 50%, 
    var(--color-text-muted) 75%
  );
  background-size: 200% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: shimmer 3s infinite linear;
}

.btn-primary {
  overflow: hidden;
  position: relative;
}

.btn-primary::after {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.2) 0%, transparent 70%);
  opacity: 0;
  transition: opacity var(--duration) var(--ease-out);
  pointer-events: none;
}

.btn-primary:hover::after {
  opacity: 1;
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-muted);
}

/* Toast variants and animations moved to section 11 */

/* ──────────────────────────────────────────
   15. FOOTER
   ────────────────────────────────────────── */
.app-footer {
  text-align: center;
  padding: 20px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
}

/* (removed unused .app-footer i — no <i> in footer HTML) */

/* ──────────────────────────────────────────
   16. RESPONSIVE — TABLET (≥ 640px)
   ────────────────────────────────────────── */
@media (min-width: 640px) {
  .form-grid {
    grid-template-columns: 1fr 1fr;
  }

  .form-grid .form-group:first-child {
    grid-column: 1 / -1;
  }

  .btn-submit {
    width: auto;
    align-self: flex-start;
  }

  .toast-container {
    bottom: 32px;
    right: 32px;
  }
}

/* ──────────────────────────────────────────
   17. RESPONSIVE — DESKTOP (≥ 900px)
   ────────────────────────────────────────── */
@media (min-width: 900px) {
  .form-grid {
    grid-template-columns: 1fr 1fr 1fr;
  }

  .form-grid .form-group:first-child {
    grid-column: auto;
  }

  .app-main {
    padding: 32px 20px 80px;
  }
}

/* ──────────────────────────────────────────
   18. RESPONSIVE — MOBILE SMALL (≤ 380px)
   ────────────────────────────────────────── */
@media (max-width: 380px) {
  .header-inner {
    flex-direction: column;
    gap: 10px;
  }

  .stats {
    gap: 10px;
  }

  .stat-label {
    display: none;
  }

  .btn-label {
    display: none;
  }

  .toast-container {
    left: 16px;
    right: 16px;
  }
}

/* ──────────────────────────────────────────
   16. ANIMACIÓN DE ELIMINACIÓN
   ────────────────────────────────────────── */
.task-item.removing {
  animation: slideOut 0.35s var(--ease-out) forwards;
}

@keyframes slideOut {
  to {
    opacity: 0;
    transform: translateX(40px);
    max-height: 0;
    padding: 0;
    margin: 0;
    border: 0;
    overflow: hidden;
  }
}

/* ──────────────────────────────────────────
   17. ACCESIBILIDAD — FOCUS VISIBLE
   ────────────────────────────────────────── */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Eliminar outline en mouse clicks */
:focus:not(:focus-visible) {
  outline: none;
}

/* ──────────────────────────────────────────
   18. SELECCIÓN DE TEXTO
   ────────────────────────────────────────── */
::selection {
  background: var(--color-accent-soft);
  color: var(--color-accent-hover);
}

/* ──────────────────────────────────────────
   19. TOOLBAR — BÚSQUEDA + ORDENAMIENTO
   ────────────────────────────────────────── */
.toolbar-section {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  margin-bottom: 16px;
}

/* Search box */
.search-box {
  position: relative;
  flex: 1;
  min-width: 200px;
}

.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  font-size: 1rem;
  pointer-events: none;
}

#search-input {
  font-family: var(--font-body);
  font-size: 0.9rem;
  width: 100%;
  padding: 10px 14px 10px 38px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text-primary);
  outline: none;
  transition: all var(--duration) var(--ease-out);
}

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

#search-input:focus {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

/* Sort controls */
.sort-controls {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.sort-label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
  white-space: nowrap;
}

.sort-btn {
  font-family: var(--font-body);
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 7px 12px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text-secondary);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--duration) var(--ease-out);
  outline: none;
  white-space: nowrap;
}

.sort-btn:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.sort-btn.active {
  background: var(--color-accent-soft);
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.sort-btn:focus-visible {
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

/* ──────────────────────────────────────────
   20. DUE DATE BADGE en tarjeta de tarea
   ────────────────────────────────────────── */
.task-due {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
}

.task-due i {
  font-size: 0.82rem;
}

/* Fecha vencida */
.task-due.overdue {
  color: var(--color-danger);
  background: var(--color-danger-soft);
  border-color: rgba(220, 38, 38, 0.25);
}

/* ──────────────────────────────────────────
   21. BOTÓN EDITAR en tarjeta
   ────────────────────────────────────────── */
.btn-edit {
  color: var(--color-text-muted);
}

.btn-edit:hover {
  color: var(--color-accent);
  background: var(--color-accent-soft);
}

/* ──────────────────────────────────────────
   22. MODAL DE EDICIÓN
   ────────────────────────────────────────── */
.modal-edit-body {
  text-align: left;
  max-width: 520px;
  padding: 28px;
}

.modal-edit-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.modal-edit-header h3 {
  font-size: 1.1rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--color-text-primary);
}

.modal-edit-header h3 i {
  color: var(--color-accent);
}

/* Responsive: edit modal full-width on small screens */
@media (max-width: 540px) {
  .modal-edit-body {
    padding: 20px 16px;
  }
}

/* ──────────────────────────────────────────
   23. FORM GRID — 4 campos: 2+2 columnas
   ────────────────────────────────────────── */
@media (min-width: 640px) {
  /* El grid del form de creación ya tiene reglas en sección 13.
     Este bloque añade que la fecha límite también ocupe su columna. */
  #task-form .form-grid {
    grid-template-columns: 1fr 1fr;
  }

  /* Nombre ocupa todo el ancho */
  #task-form .form-grid #group-task-name {
    grid-column: 1 / -1;
  }
}

@media (min-width: 900px) {
  #task-form .form-grid {
    grid-template-columns: 1fr 1fr 1fr 1fr;
  }

  #task-form .form-grid #group-task-name {
    grid-column: 1 / 3;
  }
}