/* ==========================================================================
   ToDo Application – Główny arkusz stylów
   Współczesny interfejs, CSS Variables, RWD, Dostępność, Animacje
   ========================================================================== */

:root {
  /* Paleta kolorów */
  --color-primary: #4f46e5;
  --color-primary-hover: #4338ca;
  --color-primary-light: #eef2ff;
  
  --color-success: #10b981;
  --color-success-light: #ecfdf5;

  --color-danger: #ef4444;
  --color-danger-hover: #dc2626;
  --color-danger-light: #fef2f2;

  --color-warning: #f59e0b;

  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-surface-hover: #f1f5f9;

  --color-text-main: #0f172a;
  --color-text-muted: #64748b;
  --color-text-inverse: #ffffff;

  --color-border: #e2e8f0;
  --color-border-focus: #4f46e5;

  /* Typografia i zaokrąglenia */
  --font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  /* Cienie */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
  --shadow-modal: 0 20px 25px -5px rgba(0, 0, 0, 0.15), 0 8px 10px -6px rgba(0, 0, 0, 0.1);

  /* Przejścia */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

/* Reset stylów i bazowe ustawienia */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-family);
  background-color: var(--color-bg);
  color: var(--color-text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* Zapobieganie rozszerzaniu layoutu przez długie słowa */
p, span, h1, h2, h3, h4, label, div {
  overflow-wrap: break-word;
  word-break: break-word;
}

/* Kontener główny aplikacji */
.app-layout {
  max-width: 860px;
  margin: 0 auto;
  padding: 24px 16px 48px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* Nagłówek */
.app-header {
  padding: 12px 0;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 16px;
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--color-primary), #6366f1);
  color: var(--color-text-inverse);
  font-size: 24px;
  font-weight: 700;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
}

.app-title {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--color-text-main);
  letter-spacing: -0.025em;
}

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

/* Karty */
.card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-normal);
}

.section-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 18px;
  color: var(--color-text-main);
}

/* Formularz */
.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--color-text-main);
}

.form-label .required {
  color: var(--color-danger);
}

.form-label .optional {
  font-weight: 400;
  color: var(--color-text-muted);
  font-size: 0.8rem;
}

.form-control {
  width: 100%;
  padding: 10px 14px;
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--color-text-main);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-control:focus {
  outline: none;
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

.form-control.is-invalid {
  border-color: var(--color-danger);
  background-color: #fffbfa;
}

.form-control.is-invalid:focus {
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.15);
}

.form-textarea {
  resize: vertical;
  min-height: 80px;
}

.form-meta {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-top: 4px;
  min-height: 18px;
  gap: 8px;
}

.error-feedback {
  font-size: 0.8rem;
  color: var(--color-danger);
  font-weight: 500;
}

.char-counter {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  white-space: nowrap;
  margin-left: auto;
}

.char-counter.limit-near {
  color: var(--color-warning);
}

.char-counter.limit-reached {
  color: var(--color-danger);
  font-weight: 700;
}

.form-actions {
  display: flex;
  justify-content: flex-end;
  margin-top: 8px;
}

/* Przyciski */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn:focus-visible {
  outline: 2px solid var(--color-border-focus);
  outline-offset: 2px;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-hover);
  box-shadow: var(--shadow-sm);
}

.btn-secondary {
  background-color: #f1f5f9;
  color: var(--color-text-main);
  border-color: var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
  background-color: #e2e8f0;
}

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

.btn-danger:hover:not(:disabled) {
  background-color: var(--color-danger-hover);
}

.btn-outline-danger {
  background-color: transparent;
  color: var(--color-danger);
  border-color: #fca5a5;
}

.btn-outline-danger:hover:not(:disabled) {
  background-color: var(--color-danger-light);
  border-color: var(--color-danger);
}

/* Panel sterowania */
.controls-wrapper {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
}

.filter-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.btn-filter {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  background-color: #f1f5f9;
  border: 1px solid transparent;
  border-radius: var(--radius-full);
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-filter:hover {
  background-color: #e2e8f0;
  color: var(--color-text-main);
}

.btn-filter.active {
  background-color: var(--color-primary-light);
  color: var(--color-primary);
  border-color: rgba(79, 70, 229, 0.2);
}

.badge {
  display: inline-block;
  padding: 2px 7px;
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  background-color: rgba(0, 0, 0, 0.08);
}

.btn-filter.active .badge {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

.tasks-summary {
  margin-top: 14px;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* Lista zadań */
.task-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.task-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
  animation: slideIn 0.25s ease-out;
}

.task-item:hover {
  border-color: #cbd5e1;
  box-shadow: var(--shadow-sm);
}

.task-item.completed {
  background-color: #fafafa;
  border-color: #f1f5f9;
}

/* Checkbox zadania */
.task-checkbox-wrapper {
  padding-top: 2px;
}

.task-checkbox {
  appearance: none;
  -webkit-appearance: none;
  width: 22px;
  height: 22px;
  border: 2px solid #cbd5e1;
  border-radius: 6px;
  cursor: pointer;
  display: grid;
  place-content: center;
  transition: all var(--transition-fast);
  background-color: var(--color-surface);
}

.task-checkbox:hover {
  border-color: var(--color-primary);
}

.task-checkbox:checked {
  background-color: var(--color-success);
  border-color: var(--color-success);
}

.task-checkbox:checked::before {
  content: "✓";
  font-size: 14px;
  font-weight: 800;
  color: var(--color-text-inverse);
}

.task-checkbox:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Treść zadania */
.task-content {
  flex: 1;
  min-width: 0; /* Kluczowe dla flexbox i overflow-wrap */
}

.task-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text-main);
  margin-bottom: 4px;
  transition: color var(--transition-fast);
}

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

.task-desc {
  font-size: 0.88rem;
  color: var(--color-text-muted);
  margin-bottom: 8px;
  white-space: pre-wrap;
}

.task-item.completed .task-desc {
  color: #94a3b8;
}

.task-date {
  font-size: 0.75rem;
  color: #94a3b8;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* Akcje zadania */
.task-item-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn-icon-action {
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 6px 8px;
  color: var(--color-text-muted);
  cursor: pointer;
  font-size: 0.9rem;
  transition: all var(--transition-fast);
}

.btn-icon-action:hover {
  background-color: #f1f5f9;
  color: var(--color-text-main);
}

.btn-icon-action.btn-delete-task:hover {
  background-color: var(--color-danger-light);
  color: var(--color-danger);
}

.btn-icon-action:focus-visible {
  outline: 2px solid var(--color-border-focus);
}

/* Stan pusty */
.empty-state {
  text-align: center;
  padding: 48px 16px;
}

.empty-state[hidden] {
  display: none;
}

.empty-icon {
  font-size: 48px;
  margin-bottom: 12px;
  opacity: 0.7;
}

.empty-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text-main);
  margin-bottom: 6px;
}

.empty-desc {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* Okna modalne (HTML/CSS) */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background-color: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 16px;
  animation: fadeIn 0.2s ease-out;
}

.modal-backdrop[hidden] {
  display: none;
}

.modal-dialog {
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-modal);
  width: 100%;
  max-width: 480px;
  overflow: hidden;
  animation: modalScaleUp 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-header {
  padding: 18px 24px;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text-main);
}

.modal-close-btn {
  background: transparent;
  border: none;
  font-size: 24px;
  line-height: 1;
  color: var(--color-text-muted);
  cursor: pointer;
  padding: 4px;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast);
}

.modal-close-btn:hover {
  color: var(--color-text-main);
}

.modal-body {
  padding: 24px;
}

.modal-message {
  font-size: 0.95rem;
  color: var(--color-text-main);
  line-height: 1.6;
}

.modal-footer {
  padding: 16px 24px;
  background-color: #f8fafc;
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

/* Powiadomienia typu Toast */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 1100;
  pointer-events: none;
  max-width: 360px;
  width: 100%;
}

.toast {
  padding: 12px 18px;
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  border-left: 4px solid var(--color-primary);
  font-size: 0.9rem;
  color: var(--color-text-main);
  pointer-events: auto;
  animation: toastSlideIn 0.3s ease-out forwards;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.toast.toast-success {
  border-left-color: var(--color-success);
}

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

.toast.toast-info {
  border-left-color: var(--color-primary);
}

/* Stopka */
.app-footer {
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  padding: 16px 0;
}

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

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

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes modalScaleUp {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes toastSlideIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Responsywność (RWD) */
@media (max-width: 640px) {
  .app-layout {
    padding: 16px 12px 32px;
  }

  .card {
    padding: 18px 16px;
  }

  .controls-wrapper {
    flex-direction: column;
    align-items: stretch;
  }

  .filter-group {
    justify-content: space-between;
  }

  .btn-filter {
    flex: 1;
    justify-content: center;
  }

  .mass-actions {
    width: 100%;
  }

  .mass-actions .btn {
    width: 100%;
  }

  .modal-dialog {
    width: 100%;
    margin: 12px;
  }

  .toast-container {
    left: 16px;
    right: 16px;
    bottom: 16px;
    max-width: none;
  }
}