/* --- Variables y Configuración del Tema --- */
:root {
  /* Fuentes */
  --font-primary: 'Outfit', sans-serif;
  --font-secondary: 'Plus Jakarta Sans', sans-serif;

  /* Colores de Acento por Divisa */
  --color-usd: #22c55e; /* Verde dinero clásico */
  --color-usd-rgb: 34, 197, 94;
  --color-eur: #3b82f6; /* Azul real / Unión Europea */
  --color-eur-rgb: 59, 130, 246;
  --color-usdt: #00b4d8; /* Turquesa / Tether oficial */
  --color-usdt-rgb: 0, 180, 216;

  /* Color Activo Dinámico (Se actualiza con JS según la pestaña activa) */
  --accent-color: var(--color-usd);
  --accent-color-rgb: var(--color-usd-rgb);

  /* --- MODO OSCURO (Predeterminado) --- */
  --bg-dark-1: #030712; /* Fondo espacio profundo */
  --bg-dark-2: #0b0f19; /* Panel superior */
  --card-bg: rgba(15, 23, 42, 0.45); /* Cristal azul noche esmerilado */
  --card-border: rgba(255, 255, 255, 0.05); /* Borde sutil */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --glow-shadow: 0 0 25px rgba(var(--accent-color-rgb), 0.12);
  --card-shadow: 0 20px 40px -15px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(255, 255, 255, 0.05);
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-fast: all 0.15s ease;
}



/* --- Resets & Base --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html, body {
  width: 100%;
  height: 100%;
  overflow-x: hidden;
  background: radial-gradient(circle at top, var(--bg-dark-2) 0%, var(--bg-dark-1) 100%);
  color: var(--text-primary);
  font-family: var(--font-primary);
  font-size: 16px;
  line-height: 1.5;
  transition: background-color 0.3s ease, color 0.3s ease, background-color 0.3s ease;
}

body {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
  position: relative;
}

/* --- Fondos con Gradientes y Brillos (Glows) --- */
.glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(140px);
  z-index: -1;
  pointer-events: none;
  opacity: 0.12;
  transition: var(--transition-smooth);
}



.glow-1 {
  width: 400px;
  height: 400px;
  top: -100px;
  right: -100px;
  background: rgba(var(--accent-color-rgb), 0.5);
}

.glow-2 {
  width: 350px;
  height: 350px;
  bottom: 15%;
  left: -100px;
  background: rgba(var(--accent-color-rgb), 0.3);
}

/* --- Contenedor Principal (App) --- */
.app-container {
  width: 100%;
  max-width: 480px;
  padding: 1.5rem 1rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1.5rem;
}

/* Ajustes para iPhone con barra de inicio inferior (Safe Area) */
@supports (padding-bottom: env(safe-area-inset-bottom)) {
  .app-container {
    padding-top: calc(1.5rem + env(safe-area-inset-top));
    padding-bottom: calc(1.5rem + env(safe-area-inset-bottom));
    min-height: calc(100vh - env(safe-area-inset-top) - env(safe-area-inset-bottom));
  }
}

/* --- Encabezado --- */
.app-header {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.header-main {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-logo {
  width: 2.25rem;
  height: 2.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-color);
  background: rgba(var(--accent-color-rgb), 0.1);
  border: 1px solid rgba(var(--accent-color-rgb), 0.2);
  border-radius: 0.75rem;
  padding: 0.4rem;
  transition: var(--transition-smooth);
  box-shadow: var(--glow-shadow);
}

.brand-logo svg {
  width: 100%;
  height: 100%;
}

.brand h1 {
  font-family: var(--font-secondary);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Header Acciones (Botones lado derecho) */
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}



/* Badge de Conexión */
.connection-badge {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.75rem;
  border-radius: 2rem;
  font-size: 0.75rem;
  font-weight: 600;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.05);
  transition: var(--transition-smooth);
}



.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--text-muted);
  transition: var(--transition-smooth);
}

.connection-badge.online .badge-dot {
  background-color: #10b981;
  box-shadow: 0 0 8px #10b981;
}

.connection-badge.offline .badge-dot {
  background-color: #ef4444;
  box-shadow: 0 0 8px #ef4444;
}

.connection-badge.offline {
  background: rgba(239, 68, 68, 0.05);
  border-color: rgba(239, 68, 68, 0.15);
}

/* Tarjeta de Tasa Destacada */
.rate-display-card {
  background: var(--card-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--card-border);
  border-radius: 1.25rem;
  padding: 1.25rem;
  text-align: center;
  box-shadow: var(--card-shadow);
  position: relative;
  overflow: hidden;
  transition: var(--transition-smooth);
}

.rate-display-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, rgba(var(--accent-color-rgb), 0.5), transparent);
  transition: var(--transition-smooth);
}

.rate-label {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.35rem;
}

.rate-value-container {
  font-size: 2.25rem;
  font-weight: 800;
  font-family: var(--font-secondary);
  color: var(--text-primary);
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.35rem;
  line-height: 1.1;
  position: relative;
}

.rate-value-container span {
  transition: var(--transition-smooth);
}

.rate-currency {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--accent-color);
  transition: var(--transition-smooth);
  margin-right: 0.25rem;
}

/* Botones de acción de la tasa */
.rate-actions {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-left: 0.15rem;
}

.rate-action-btn {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
  color: var(--text-muted);
  width: 1.85rem;
  height: 1.85rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-smooth);
}



.rate-action-btn:hover, .rate-action-btn:focus {
  background: rgba(var(--accent-color-rgb), 0.08);
  border-color: rgba(var(--accent-color-rgb), 0.25);
  color: var(--accent-color);
}

.rate-action-btn.reset:hover, .rate-action-btn.reset:focus {
  background: rgba(245, 158, 11, 0.08);
  border-color: rgba(245, 158, 11, 0.25);
  color: #f59e0b;
}

.rate-action-btn svg {
  width: 0.95rem;
  height: 0.95rem;
}

/* Estado de Tasa Personalizada (Manual) */
.rate-display-card.manual-active::before {
  background: linear-gradient(90deg, transparent, #f59e0b, transparent);
}

.rate-display-card.manual-active .rate-label {
  color: #f59e0b;
}

/* Animación del cursor al editar tasa */
.rate-value-container.editing-rate #rate-value {
  color: var(--accent-color);
  position: relative;
}

.rate-value-container.editing-rate #rate-value::after {
  content: '|';
  color: var(--accent-color);
  animation: blink-cursor 1s step-end infinite;
  margin-left: 2px;
  font-weight: 300;
}

@keyframes blink-cursor {
  from, to { color: transparent }
  50% { color: var(--accent-color) }
}

.rate-date {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.4rem;
}

/* --- Pestañas de Navegación --- */
.currency-tabs-container {
  width: 100%;
}

.currency-tabs {
  display: flex;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 1rem;
  padding: 0.25rem;
  position: relative;
  gap: 0.25rem;
}



.tab-button {
  flex: 1 1 0px;
  min-width: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.75rem 0.5rem;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 0.75rem;
  color: var(--text-secondary);
  font-family: var(--font-primary);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  z-index: 1;
  transition: var(--transition-smooth);
}

/* Iconos de Pestaña SVG */
.tab-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 1.35rem;
  height: 1.35rem;
  border-radius: 50%;
  overflow: hidden;
  transition: var(--transition-smooth);
}

.tab-icon svg {
  width: 100%;
  height: 100%;
}

.tab-button:hover {
  color: var(--text-primary);
}

.tab-button.active {
  color: var(--text-primary);
  background: rgba(var(--accent-color-rgb), 0.08);
  border-color: rgba(var(--accent-color-rgb), 0.18);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15), inset 0 0 8px rgba(var(--accent-color-rgb), 0.05);
}



/* --- Calculadora Container & Inputs --- */
.calculator-container {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.calculator-card {
  background: var(--card-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--card-border);
  border-radius: 1.5rem;
  padding: 1.5rem;
  box-shadow: var(--card-shadow);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  position: relative;
  transition: var(--transition-smooth);
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.03);
  padding: 0.85rem 1.1rem;
  border-radius: 1rem;
  transition: var(--transition-smooth);
}



.input-group:focus-within {
  background: rgba(var(--accent-color-rgb), 0.04);
  border-color: rgba(var(--accent-color-rgb), 0.35);
  box-shadow: 0 0 20px rgba(var(--accent-color-rgb), 0.08), inset 0 0 10px rgba(var(--accent-color-rgb), 0.03);
}



.input-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.input-flag {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 1.35rem;
  height: 1.35rem;
  border-radius: 50%;
  overflow: hidden;
}

.input-flag svg {
  width: 100%;
  height: 100%;
}

.input-code {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
  min-width: 40px;
}

.input-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.input-wrapper input {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-family: var(--font-secondary);
  font-size: 1.75rem;
  font-weight: 700;
  outline: none;
  width: 100%;
  padding-right: 0.5rem;
  caret-color: var(--accent-color);
}

/* Ocultar flechas nativas en inputs tipo número */
.input-wrapper input::-webkit-outer-spin-button,
.input-wrapper input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
.input-wrapper input[type=number] {
  -moz-appearance: textfield;
}

.input-symbol {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-muted);
  transition: var(--transition-smooth);
}

.input-group:focus-within .input-symbol {
  color: var(--accent-color);
}

/* --- Botón Divisor e Intercambio --- */
.divider-container {
  display: flex;
  align-items: center;
  width: 100%;
  position: relative;
  padding: 0.2rem 0;
}

.divider-line {
  flex: 1;
  height: 1px;
  background: rgba(255, 255, 255, 0.06);
}



.swap-button-wrapper {
  padding: 0 0.75rem;
}

.swap-icon {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 50%;
  background: rgba(15, 23, 42, 0.55);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
  outline: none;
  position: relative;
}



.swap-icon::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(var(--accent-color-rgb), 0.25) 0%, transparent 70%);
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: -1;
}

.swap-icon svg {
  width: 1.25rem;
  height: 1.25rem;
  transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.calculator-card.reversed .swap-icon svg {
  transform: rotate(180deg);
}

.swap-icon:hover {
  background: rgba(var(--accent-color-rgb), 0.1);
  border-color: rgba(var(--accent-color-rgb), 0.35);
  color: var(--accent-color);
  transform: scale(1.1);
  box-shadow: 0 6px 16px rgba(var(--accent-color-rgb), 0.18);
}

.swap-icon:hover::after {
  opacity: 1;
}

.swap-icon:active {
  transform: scale(0.93);
}

/* (Sección de conversión rápida eliminada) */

/* --- Footer --- */
.app-footer {
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  padding: 1rem 0;
}

.sources-info {
  font-size: 0.7rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.copyright {
  font-size: 0.65rem;
  color: var(--text-muted);
  opacity: 0.7;
}

/* --- PWA Instalación - Botón Android / Chrome (Flotante Inferior) --- */
.android-install-prompt {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%) translateY(150px);
  width: calc(100% - 2rem);
  max-width: 440px;
  background: rgba(18, 20, 28, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 1.25rem;
  padding: 1rem;
  display: flex;
  align-items: center;
  gap: 0.85rem;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
  z-index: 100;
  transition: transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}



.android-install-prompt.show {
  transform: translateX(-50%) translateY(0);
}

.prompt-icon {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 0.5rem;
  overflow: hidden;
  flex-shrink: 0;
}

.prompt-icon img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.prompt-info {
  flex: 1;
}

.prompt-info h4 {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
}

.prompt-info p {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.prompt-actions {
  display: flex;
  gap: 0.5rem;
}

.btn-text {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-family: var(--font-primary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.5rem;
  cursor: pointer;
}

.btn-primary-install {
  background: var(--accent-color);
  border: none;
  border-radius: 0.5rem;
  color: #ffffff;
  font-family: var(--font-primary);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.5rem 0.85rem;
  cursor: pointer;
  box-shadow: var(--glow-shadow);
  transition: var(--transition-smooth);
}

/* --- PWA Instalación - Bottom Sheet iOS --- */
.ios-install-sheet {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 200;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  transition: opacity 0.3s ease;
}

.ios-install-sheet.hidden {
  opacity: 0;
  pointer-events: none;
}

.sheet-backdrop {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
}

.sheet-content {
  position: relative;
  width: 100%;
  max-width: 480px;
  background: #161822;
  border-top-left-radius: 1.5rem;
  border-top-right-radius: 1.5rem;
  padding: 1.5rem 1.5rem calc(1.5rem + env(safe-area-inset-bottom));
  box-shadow: 0 -10px 40px rgba(0, 0, 0, 0.4);
  transform: translateY(100%);
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  z-index: 2;
}



.ios-install-sheet:not(.hidden) .sheet-content {
  transform: translateY(0);
}

.sheet-handle {
  width: 40px;
  height: 4px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 2px;
  margin: 0 auto 1.25rem;
}



.sheet-header {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 1.5rem;
  position: relative;
}

.app-icon-preview {
  width: 3.5rem;
  height: 3.5rem;
  border-radius: 0.75rem;
  overflow: hidden;
}

.app-icon-preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.app-info-preview h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.15rem;
}

.app-info-preview p {
  font-size: 0.75rem;
  color: var(--text-secondary);
  line-height: 1.3;
}

.close-sheet-btn {
  position: absolute;
  top: -0.25rem;
  right: -0.25rem;
  background: rgba(255, 255, 255, 0.05);
  border: none;
  border-radius: 50%;
  width: 2rem;
  height: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  cursor: pointer;
}



.sheet-steps {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.step-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.04);
  padding: 0.85rem 1rem;
  border-radius: 1rem;
}



.step-number {
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 50%;
  background: rgba(var(--accent-color-rgb), 0.15);
  color: var(--accent-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.85rem;
  flex-shrink: 0;
}

.step-text {
  font-size: 0.8rem;
  color: var(--text-primary);
  flex: 1;
}

.step-icon-visual {
  width: 2.25rem;
  height: 2.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 0.5rem;
  padding: 0.4rem;
}



.safari-share-icon {
  width: 1.5rem;
  height: 1.5rem;
}

.safari-add-icon {
  width: 1.25rem;
  height: 1.25rem;
  color: var(--text-secondary);
}

/* --- Contenedor del Teclado Numérico Flotante / Deslizante --- */
.keypad-container {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%) translateY(100%);
  width: 100%;
  max-width: 480px;
  background: rgba(11, 15, 25, 0.88);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  border-left: 1px solid rgba(255, 255, 255, 0.05);
  border-right: 1px solid rgba(255, 255, 255, 0.05);
  border-top-left-radius: 1.5rem;
  border-top-right-radius: 1.5rem;
  padding: 0.75rem 1rem calc(0.75rem + env(safe-area-inset-bottom)) 1rem;
  box-shadow: 0 -10px 40px rgba(0, 0, 0, 0.45);
  z-index: 150;
  visibility: hidden;
  opacity: 0;
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), 
              opacity 0.3s ease, 
              visibility 0.4s;
  pointer-events: none;
}



.keypad-container.show {
  transform: translateX(-50%) translateY(0);
  visibility: visible;
  opacity: 1;
  pointer-events: auto;
}

/* Barra de Accesorios Superior del Teclado */
.keypad-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.6rem;
  padding: 0 0.25rem;
}

.keypad-indicator {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.indicator-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--accent-color);
  box-shadow: 0 0 8px var(--accent-color);
  transition: var(--transition-smooth);
}

.indicator-text {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  font-family: var(--font-secondary);
  transition: var(--transition-smooth);
}

.close-keypad-btn {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.06);
  color: var(--text-secondary);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-smooth);
}



.close-keypad-btn:hover {
  background: rgba(var(--accent-color-rgb), 0.1);
  border-color: rgba(var(--accent-color-rgb), 0.25);
  color: var(--accent-color);
}

.close-keypad-btn svg {
  width: 1.2rem;
  height: 1.2rem;
  transition: transform 0.2s ease;
}

.close-keypad-btn:active svg {
  transform: translateY(2px);
}

/* Teclas Numéricas */
.numeric-keypad {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
  width: 100%;
}

.keypad-btn {
  height: 3.25rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 0.85rem;
  color: var(--text-primary);
  font-family: var(--font-secondary);
  font-size: 1.35rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
  outline: none;
  user-select: none;
}



.keypad-btn:hover {
  background: rgba(var(--accent-color-rgb), 0.08);
  border-color: rgba(var(--accent-color-rgb), 0.3);
  color: var(--accent-color);
}

/* Respuesta instantánea al tocar */
.keypad-btn:active, .keypad-btn.active-touch {
  transform: scale(0.92);
  background: rgba(var(--accent-color-rgb), 0.2) !important;
  border-color: rgba(var(--accent-color-rgb), 0.5) !important;
  color: var(--accent-color) !important;
  box-shadow: 0 0 12px rgba(var(--accent-color-rgb), 0.25);
  transition: none; /* Sin transiciones para respuesta instantánea */
}

.backspace-key svg {
  width: 1.4rem;
  height: 1.4rem;
}

.backspace-key:hover {
  color: #ef4444;
  border-color: rgba(239, 68, 68, 0.3);
  background: rgba(239, 68, 68, 0.08);
}

.backspace-key:active, .backspace-key.active-touch {
  background: rgba(239, 68, 68, 0.2) !important;
  border-color: rgba(239, 68, 68, 0.5) !important;
  color: #ef4444 !important;
  box-shadow: 0 0 12px rgba(239, 68, 68, 0.25);
  transition: none;
}

/* Padding adaptativo deshabilitado para evitar inestabilidad visual */

/* Clases auxiliares para ocultar elementos */
.hidden {
  display: none !important;
}

/* --- Media Queries para Escritorio --- */
@media (min-width: 480px) {
  body {
    align-items: center;
    background-attachment: fixed;
  }

  .app-container {
    min-height: auto;
    border: 1px solid var(--card-border);
    background: rgba(9, 10, 15, 0.7);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border-radius: 2rem;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6);
    margin: 2rem 0;
    padding: 2rem;
  }


}