/**
 * Pomodoro Timer - Estilos principales
 * 
 * Estructura:
 * 1. CSS Custom Properties (temas claro/oscuro)
 * 2. Reset y estilos base
 * 3. Layout principal
 * 4. Componentes
 * 5. Accesibilidad
 */

/* ============================================
   1. CSS Custom Properties - Temas
   ============================================ */

:root {
  /* Tema claro (por defecto) */
  --color-bg: #f5f5f5;
  --color-surface: #ffffff;
  --color-text-primary: #1a1a1a;
  --color-text-secondary: #555555;
  --color-accent: #e63946;
  --color-accent-hover: #c1121f;
  --color-border: #dddddd;
  --color-focus-ring: #0066cc;
  
  /* Tipografía */
  --font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-base: 16px;
  --font-size-display: 48px;
  --font-size-large: 24px;
  --font-size-small: 14px;
  
  /* Espaciado */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  
  /* Transiciones */
  --transition-fast: 100ms ease;
  --transition-normal: 200ms ease;
  
  /* Sombras */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  
  /* Radio de borde */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

/* Tema oscuro */
[data-theme="dark"] {
  --color-bg: #121212;
  --color-surface: #1e1e1e;
  --color-text-primary: #f0f0f0;
  --color-text-secondary: #aaaaaa;
  --color-accent: #ff6b6b;
  --color-accent-hover: #ff4444;
  --color-border: #333333;
  --color-focus-ring: #66aaff;
  
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
}

/* ============================================
   2. Reset y estilos base
   ============================================ */

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: var(--font-size-base);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--spacing-md);
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* ============================================
   3. Layout principal
   ============================================ */

.app {
  width: 100%;
  max-width: 600px;
  min-width: 280px;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.app__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.app__header h1 {
  font-size: var(--font-size-large);
  font-weight: 600;
  color: var(--color-text-primary);
}

/* ============================================
   4. Componentes
   ============================================ */

/* --- Timer --- */
.timer {
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  text-align: center;
  box-shadow: var(--shadow-md);
  min-width: 40vw;
  margin: 0 auto;
}

.timer__session-label {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.timer__display {
  font-size: var(--font-size-display);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--color-text-primary);
  letter-spacing: 0.02em;
  margin-bottom: var(--spacing-md);
}

.timer__cycles {
  font-size: var(--font-size-small);
  color: var(--color-text-secondary);
}

.timer__cycles span {
  font-weight: 600;
  color: var(--color-accent);
}

/* --- Controls --- */
.controls {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.controls button {
  min-width: 120px;
  padding: var(--spacing-md) var(--spacing-lg);
  font-size: var(--font-size-base);
  font-weight: 500;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
  color: var(--color-text-primary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.controls button:hover {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: white;
}

.controls button:active {
  transform: scale(0.98);
}

#btn-play-pause {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: white;
}

#btn-play-pause:hover {
  background-color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
}

#btn-reset {
  background-color: transparent;
}

/* --- Config (hidden section, kept for DOM compatibility) --- */
.config[hidden] {
  display: none;
}

.config__error {
  color: var(--color-accent);
  font-size: var(--font-size-small);
  margin-top: var(--spacing-sm);
}

.config__error[hidden] {
  display: none;
}

/* --- Config Modal --- */
#config-modal {
  border: none;
  border-radius: var(--radius-lg);
  padding: 0;
  background-color: var(--color-surface);
  color: var(--color-text-primary);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
  max-width: 400px;
  width: calc(100% - var(--spacing-xl));
}

#config-modal::backdrop {
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(2px);
}

.config-modal__content {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.config-modal__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--color-border);
}

.config-modal__header h2 {
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-text-primary);
  margin: 0;
}

.config-modal__close {
  padding: var(--spacing-xs);
  border: none;
  background: transparent;
  color: var(--color-text-secondary);
  cursor: pointer;
  font-size: var(--font-size-large);
  line-height: 1;
  border-radius: var(--radius-sm);
  min-width: 32px;
  min-height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.config-modal__close:hover {
  color: var(--color-accent);
  background-color: rgba(230, 57, 70, 0.1);
}

[data-theme="dark"] .config-modal__close:hover {
  background-color: rgba(255, 107, 107, 0.2);
}

.config-modal__body {
  padding: var(--spacing-lg);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.config-modal__body label {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  font-size: var(--font-size-small);
  color: var(--color-text-secondary);
}

.config-modal__body input[type="number"] {
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--font-size-base);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  transition: border-color var(--transition-fast);
}

.config-modal__body input[type="number"]:focus {
  border-color: var(--color-focus-ring);
  outline: none;
}

.config-modal__body input[type="number"]:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.config-modal__footer {
  padding: var(--spacing-md) var(--spacing-lg) var(--spacing-lg);
}

#btn-save-config {
  width: 100%;
  padding: var(--spacing-md);
  font-size: var(--font-size-base);
  font-weight: 500;
  border: none;
  border-radius: var(--radius-md);
  background-color: var(--color-accent);
  color: white;
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

#btn-save-config:hover:not(:disabled) {
  background-color: var(--color-accent-hover);
}

#btn-save-config:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* --- Config Gear Button --- */
#btn-open-config {
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: 18px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background-color: transparent;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  min-height: 36px;
}

#btn-open-config:hover {
  background-color: var(--color-surface);
  border-color: var(--color-accent);
  color: var(--color-text-primary);
}

/* --- Theme Selector (dentro del modal) --- */
.theme-selector {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
}

.theme-selector button {
  flex: 1;
  padding: var(--spacing-sm) var(--spacing-sm);
  font-size: var(--font-size-small);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background-color: transparent;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.theme-selector button:hover {
  background-color: var(--color-bg);
  border-color: var(--color-accent);
  color: var(--color-text-primary);
}

.theme-selector button[aria-pressed="true"] {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: white;
}

/* --- Divider y campo de tema en el modal --- */
.config-modal__divider {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: var(--spacing-xs) 0;
}

.config-modal__field {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.config-modal__field-label {
  font-size: var(--font-size-small);
  color: var(--color-text-secondary);
}

/* --- Notification Banner --- */
.notification-banner {
  position: fixed;
  bottom: var(--spacing-lg);
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--color-surface);
  border: 2px solid var(--color-accent);
  border-radius: var(--radius-md);
  padding: var(--spacing-md) var(--spacing-lg);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  max-width: 90vw;
  z-index: 1000;
}

.notification-banner[hidden] {
  display: none;
}

.notification-banner__message {
  font-size: var(--font-size-base);
  color: var(--color-text-primary);
}

.notification-banner__close {
  padding: var(--spacing-xs);
  border: none;
  background: transparent;
  color: var(--color-text-secondary);
  cursor: pointer;
  font-size: var(--font-size-large);
  line-height: 1;
  transition: color var(--transition-fast), background-color var(--transition-fast);
  border-radius: var(--radius-sm);
  min-width: 32px;
  min-height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.notification-banner__close:hover {
  color: var(--color-accent);
  background-color: rgba(230, 57, 70, 0.1);
}

.notification-banner__close:active {
  transform: scale(0.95);
}

[data-theme="dark"] .notification-banner__close:hover {
  background-color: rgba(255, 107, 107, 0.2);
}

/* --- Header Controls --- */
.header-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
  justify-content: center;
}

/* --- Notification Enable Button --- */
#btn-enable-notifications {
  padding: var(--spacing-xs) var(--spacing-md);
  font-size: var(--font-size-small);
  font-weight: 500;
  border: 2px solid var(--color-accent);
  border-radius: var(--radius-md);
  background-color: transparent;
  color: var(--color-accent);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

#btn-enable-notifications:hover {
  background-color: var(--color-accent);
  color: white;
}

#btn-enable-notifications:active {
  transform: scale(0.98);
}

#btn-enable-notifications[hidden] {
  display: none;
}

/* ============================================
   5. Accesibilidad
   ============================================ */

/* Foco visible para navegación por teclado */
:focus-visible {
  outline: 3px solid var(--color-focus-ring);
  outline-offset: 2px;
}

/* Eliminar outline predeterminado cuando no es necesario */
:focus:not(:focus-visible) {
  outline: none;
}

/* Foco visible específico para elementos interactivos */
button:focus-visible,
input:focus-visible,
.theme-selector button:focus-visible,
.controls button:focus-visible,
#btn-save-config:focus-visible,
#btn-enable-notifications:focus-visible,
.notification-banner__close:focus-visible {
  outline: 3px solid var(--color-focus-ring);
  outline-offset: 2px;
}

/* Estados de focus adicionales para accesibilidad */
button:focus-visible {
  box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.3);
}

[data-theme="dark"] button:focus-visible {
  box-shadow: 0 0 0 3px rgba(102, 170, 255, 0.3);
}

/* Asegurar que los elementos con aria-live sean visibles */
[aria-live="polite"],
[aria-live="assertive"] {
  /* Los lectores de pantalla anunciarán los cambios */
}

/* Skip link para navegación por teclado */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-accent);
  color: white;
  padding: var(--spacing-sm) var(--spacing-md);
  z-index: 100;
}

.skip-link:focus {
  top: 0;
}

/* ============================================
   6. Responsive
   ============================================ */

@media (max-width: 480px) {
  :root {
    --font-size-display: 48px; /* Keep minimum 48px per Requirement 8.2 */
    --font-size-large: 20px;
  }
  
  .app__header {
    flex-direction: column;
    text-align: center;
    gap: var(--spacing-sm);
  }
  
  .app__header h1 {
    margin-bottom: var(--spacing-xs);
  }
  
  .header-controls {
    flex-direction: column;
    width: 100%;
    gap: var(--spacing-sm);
  }
  
  #btn-enable-notifications {
    width: 100%;
    max-width: 280px;
  }
  
  .theme-selector {
    width: 100%;
    justify-content: center;
  }
  
  .timer {
    padding: var(--spacing-lg);
    min-width: auto;
    width: 100%;
  }
  
  .controls button {
    min-width: 100px;
    padding: var(--spacing-sm) var(--spacing-md);
  }
}

@media (min-width: 768px) {
  .timer {
    min-width: 40vw;
  }
}

/* Soporte para pantallas muy pequeñas (320px mínimo) */
@media (max-width: 320px) {
  :root {
    --font-size-display: 48px; /* Keep minimum 48px per Requirement 8.2 */
    --spacing-md: 12px;
    --spacing-lg: 16px;
  }
  
  .controls {
    flex-direction: column;
    align-items: stretch;
  }
  
  .controls button {
    width: 100%;
  }
  
  .notification-banner {
    left: var(--spacing-sm);
    right: var(--spacing-sm);
    transform: none;
    max-width: none;
    width: calc(100% - 16px);
  }
}

/* Preferencia de movimiento reducido */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}