/*
 * Estilos de la app. Tokens de diseño centralizados en :root para mantener
 * consistencia y permitir dark mode automático según la preferencia del SO.
 * Sin frameworks: CSS plano, alineado con el stack sin build del proyecto.
 */

:root {
  /* Paleta (light) */
  --color-bg: #f4f5f7;
  --color-surface: #ffffff;
  --color-text: #1a1f29;
  --color-text-muted: #5b6472;
  --color-border: #d7dce3;
  --color-border-focus: #2563eb;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-primary-text: #ffffff;
  --color-error: #b91c1c;
  --color-error-bg: #fee2e2;
  --color-error-border: #fca5a5;
  --color-success: #15803d;

  /* Espaciado y formas */
  --radius-sm: 6px;
  --radius-md: 10px;
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --shadow-card: 0 1px 3px rgba(16, 24, 40, 0.1), 0 1px 2px rgba(16, 24, 40, 0.06);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f1419;
    --color-surface: #1a212b;
    --color-text: #e7ebf0;
    --color-text-muted: #98a2b3;
    --color-border: #2d3744;
    --color-border-focus: #60a5fa;
    --color-primary: #3b82f6;
    --color-primary-hover: #60a5fa;
    --color-primary-text: #0f1419;
    --color-error: #fca5a5;
    --color-error-bg: #3a1d1d;
    --color-error-border: #7f1d1d;
    --color-success: #4ade80;
    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.5);
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

.auth-page {
  display: flex;
  min-height: 100vh;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
}

/* --- Tarjeta contenedora --- */
.card {
  width: 100%;
  max-width: 420px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  padding: var(--space-6);
}

.card__header {
  margin-bottom: var(--space-5);
}

.card__title {
  margin: 0 0 var(--space-2);
  font-size: 1.5rem;
  font-weight: 700;
}

.card__subtitle {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* --- Formulario --- */
.form {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.field__label {
  font-size: 0.875rem;
  font-weight: 600;
}

.field__control {
  position: relative;
  display: flex;
  align-items: center;
}

.field__input {
  width: 100%;
  padding: var(--space-3);
  font-size: 1rem;
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.field__control .field__input {
  padding-right: 4.5rem;
}

.field__input::placeholder {
  color: var(--color-text-muted);
  opacity: 0.7;
}

.field__input:focus-visible {
  outline: none;
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.25);
}

/* Estado inválido: marcado vía aria-invalid para no duplicar fuente de verdad. */
.field__input[aria-invalid="true"] {
  border-color: var(--color-error);
}

.field__input[aria-invalid="true"]:focus-visible {
  box-shadow: 0 0 0 3px rgba(185, 28, 28, 0.25);
}

.field__toggle {
  position: absolute;
  right: var(--space-2);
  padding: var(--space-1) var(--space-2);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-primary);
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.field__toggle:hover {
  text-decoration: underline;
}

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

.field__error {
  margin: 0;
  min-height: 1.1em;
  font-size: 0.8rem;
  color: var(--color-error);
}

/* --- Botones --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  font-size: 1rem;
  font-weight: 600;
  font-family: inherit;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background-color 0.15s ease;
}

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

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

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

.btn:disabled {
  opacity: 0.65;
  cursor: progress;
}

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

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

/* Spinner de carga del botón. */
.btn__spinner {
  width: 1em;
  height: 1em;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@media (prefers-reduced-motion: reduce) {
  .btn__spinner {
    animation-duration: 1.6s;
  }
}

/* --- Alertas --- */
.alert {
  padding: var(--space-3);
  margin-bottom: var(--space-4);
  font-size: 0.9rem;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
}

.alert--error {
  color: var(--color-error);
  background: var(--color-error-bg);
  border-color: var(--color-error-border);
}

/* --- Página protegida (post-login) --- */
.app-page {
  max-width: 720px;
  margin: 0 auto;
  padding: var(--space-6) var(--space-4);
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-bottom: var(--space-5);
}

.app-header h1 {
  margin: 0;
  font-size: 1.5rem;
}

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

.user-badge strong {
  color: var(--color-text);
}

/* Oculta visualmente pero mantiene el contenido para lectores de pantalla. */
.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;
}

/* --- Secciones de la app --- */
.section-title {
  margin: 0 0 var(--space-3);
  font-size: 1.05rem;
  font-weight: 700;
}

.field__hint {
  font-weight: 400;
  color: var(--color-text-muted);
}

textarea.field__input {
  resize: vertical;
  min-height: 2.5rem;
  font-family: inherit;
}

.task-create {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  padding: var(--space-5);
  margin-bottom: var(--space-6);
}

.task-list-section {
  margin-bottom: var(--space-6);
}

/* Botón compacto, para acciones por tarea. */
.btn--sm {
  padding: var(--space-1) var(--space-3);
  font-size: 0.85rem;
}

/* --- Estados de la lista --- */
.task-status {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin: var(--space-3) 0;
}

/* --- Lista de tareas --- */
.task-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.task {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
}

.task__main {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  min-width: 0;
  flex: 1;
}

.task__checkbox {
  width: 1.15rem;
  height: 1.15rem;
  margin-top: 0.15rem;
  flex-shrink: 0;
  cursor: pointer;
  accent-color: var(--color-primary);
}

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

.task__body {
  min-width: 0;
}

.task__title {
  display: block;
  font-weight: 600;
  cursor: pointer;
  overflow-wrap: anywhere;
}

.task__description {
  margin: var(--space-1) 0 0;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  overflow-wrap: anywhere;
}

/* Tarea completada: título tachado y atenuado. */
.task--completed .task__title {
  text-decoration: line-through;
  color: var(--color-text-muted);
}

.task__actions {
  display: flex;
  gap: var(--space-2);
  flex-shrink: 0;
}

.task__delete {
  color: var(--color-error);
}

.task__delete:hover:not(:disabled) {
  background: var(--color-error-bg);
}

/* --- Edición inline --- */
.task--editing {
  display: block;
}

.task-edit {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.task-edit__actions {
  display: flex;
  gap: var(--space-2);
}

@media (max-width: 480px) {
  .task {
    flex-direction: column;
  }

  .task__actions {
    align-self: flex-end;
  }
}