/* ==========================================================================
   KIBO Menu Digital — Liquid Glass (iOS 26) + Mobile-first
   Sin dependencias. Requiere HTTPS o localhost para el SW.
   ========================================================================== */

/* --- Tokens de diseño ---------------------------------------------------- */
:root {
  /* Fondo base (visible sólo donde el ambient no llega) */
  --c-base: #0d0d0d;

  /* Texto */
  --c-fg: #ffffff;
  --c-muted: rgba(255, 255, 255, 0.65);

  /* Liquid Glass — material translúcido */
  --glass-bg: rgba(255, 255, 255, 0.10);
  --glass-bg-strong: rgba(255, 255, 255, 0.16);
  --glass-border: rgba(255, 255, 255, 0.22);
  --glass-shine: inset 0 1px 0 rgba(255, 255, 255, 0.35);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.30);
  --glass-blur: blur(24px) saturate(160%);

  /* Acento */
  --c-accent: #ff3b30;   /* iOS red */
  --c-accent-2: #ff9f0a; /* iOS amber */

  /* Error */
  --c-error: #b91c1c;

  /* Tipografía */
  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, sans-serif;

  /* Radios */
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 22px;
  --radius-pill: 999px;

  /* Animación */
  --easing: cubic-bezier(0.22, 1, 0.36, 1);

  /* Layout — alturas fijas para el cálculo de max-height */
  --header-h: 90px;
  --dots-h: 40px;
  --tap: 44px;

  /* Safe areas iOS */
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-left: env(safe-area-inset-left, 0px);
  --safe-right: env(safe-area-inset-right, 0px);
}

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

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--c-base);
  color: var(--c-fg);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow: hidden;
  overscroll-behavior: none;
}

img {
  max-width: 100%;
  display: block;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

button:focus-visible {
  outline: 2px solid var(--c-accent-2);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* --- Fondo Ambient ------------------------------------------------------- */
/*
 * Imagen del menú actual muy ampliada, desenfocada y oscurecida.
 * Se actualiza vía JS al cambiar de página.
 * transform: scale(1.12) evita bordes blancos del blur en los extremos.
 */
#ambient {
  position: fixed;
  inset: 0;
  z-index: 0;
  background-size: cover;
  background-position: center;
  transform: scale(1.12);
  filter: blur(48px) brightness(0.38) saturate(1.6);
  transition: background-image 0ms, opacity 600ms var(--easing);
  will-change: filter, opacity;
}

/* --- Layout principal ---------------------------------------------------- */
.app {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  height: 100dvh;
  padding-top: var(--safe-top);
  padding-bottom: var(--safe-bottom);
  padding-left: var(--safe-left);
  padding-right: var(--safe-right);
}

/* --- Header Liquid Glass ------------------------------------------------- */
.app__header {
  display: flex;
  gap: 10px;
  align-items: center;
  height: var(--header-h);
  padding: 0 16px;
  flex-shrink: 0;

  /* Material glass */
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  box-shadow: var(--glass-shine), 0 4px 24px rgba(0, 0, 0, 0.22);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  flex: 1;
}

.brand__logo {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.40);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shine), 0 2px 10px rgba(0, 0, 0, 0.30);
  display: grid;
  place-items: center;
  flex-shrink: 0;
  overflow: hidden;
}

.brand__logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 6px;
  filter: drop-shadow(0 1px 3px rgba(0, 0, 0, 0.55));
}

.brand__title {
  font-weight: 700;
  font-size: 17px;
  line-height: 1.2;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.brand__sub {
  color: var(--c-muted);
  font-size: 12px;
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Botón de icono en el header */
.icon-btn {
  width: var(--tap);
  height: var(--tap);
  border-radius: var(--radius-pill);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shine), var(--glass-shadow);
  display: grid;
  place-items: center;
  transition: background 150ms var(--easing), transform 120ms var(--easing);
  flex-shrink: 0;
}

.icon-btn:hover {
  background: var(--glass-bg-strong);
}

.icon-btn:active {
  transform: scale(0.92);
}

.icon-btn svg {
  width: 18px;
  height: 18px;
  stroke: var(--c-fg);
  stroke-width: 2;
  fill: none;
}

.icon-btn[hidden] {
  display: none;
}

/* --- Visor principal ----------------------------------------------------- */
.app__main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
  padding: 0;
}

/*
 * .viewer ya no es un contenedor oscuro con padding.
 * Actúa sólo como ancla de posicionamiento relativo para los botones
 * y el indicador de página que flotan sobre la imagen.
 */
.viewer {
  position: relative;
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.book__viewport {
  flex: 1;
  min-height: 0;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
}

/*
 * pageBox: combina aspect-ratio con max-height para que la imagen sea
 * lo más grande posible sin desbordar la pantalla.
 * Si el ancho * ratio > max-height, el navegador reduce el ancho
 * automáticamente manteniendo la proporción.
 */
.pageBox {
  width: 100%;
  aspect-ratio: 0.707 / 1;
  max-height: calc(100dvh - var(--header-h) - var(--dots-h));
  position: relative;
}

.page {
  position: absolute;
  inset: 0;
  background: #fff;
  border-radius: var(--radius-md);
  overflow: hidden;
  display: grid;
  place-items: center;
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.12),
    0 20px 60px rgba(0, 0, 0, 0.55),
    0 4px 16px rgba(0, 0, 0, 0.35);
}

.page img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  pointer-events: none;
  -webkit-user-drag: none;
}

/* Capa que rota durante el flip */
.turn {
  position: absolute;
  inset: 0;
  transform-style: preserve-3d;
  will-change: transform;
  pointer-events: none;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.face {
  position: absolute;
  inset: 0;
  background: #fff;
  border-radius: var(--radius-md);
  display: grid;
  place-items: center;
  overflow: hidden;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.face img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  pointer-events: none;
  -webkit-user-drag: none;
}

.face--back {
  transform: rotateY(180deg);
}

/* Capa que captura gestos — cubre pageBox completo */
.gesture {
  position: absolute;
  inset: 0;
  z-index: 2;
  touch-action: none;
  overscroll-behavior: contain;
}

/* --- Botones laterales de navegación — Liquid Glass Pill ---------------- */
.nav-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 40px;
  height: 40px;
  border-radius: var(--radius-pill);
  background: var(--glass-bg-strong);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shine), var(--glass-shadow);
  color: #fff;
  display: grid;
  place-items: center;
  z-index: 3;
  transition:
    background 150ms var(--easing),
    opacity 200ms var(--easing),
    transform 150ms var(--easing);
}

.nav-btn:hover {
  background: rgba(255, 255, 255, 0.24);
  transform: translateY(-50%) scale(1.06);
}

.nav-btn:active {
  transform: translateY(-50%) scale(0.94);
}

.nav-btn[disabled] {
  opacity: 0.28;
  pointer-events: none;
}

.nav-btn--prev {
  left: 8px;
}

.nav-btn--next {
  right: 8px;
}

.nav-btn svg {
  width: 20px;
  height: 20px;
  stroke: currentColor;
  stroke-width: 2.5;
  fill: none;
}

/* --- Indicador de página — glass pill ----------------------------------- */
.page-indicator {
  position: absolute;
  bottom: 10px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--glass-bg-strong);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shine), var(--glass-shadow);
  padding: 4px 14px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 500;
  z-index: 3;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

/* --- Puntos de progreso -------------------------------------------------- */
.dots {
  height: var(--dots-h);
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
  flex-wrap: wrap;
  padding: 4px 16px;
}

.dot {
  width: 7px;
  height: 7px;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.30);
  border: 1px solid rgba(255, 255, 255, 0.20);
  padding: 0;
  transition:
    transform 220ms var(--easing),
    background 220ms var(--easing),
    width 220ms var(--easing);
}

/* El dot activo se alarga como en iOS */
.dot[aria-current="true"] {
  width: 20px;
  background: #fff;
  border-color: rgba(255, 255, 255, 0.5);
}

/* --- Spinner de carga ---------------------------------------------------- */
.loader {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  z-index: 4;
  background: rgba(0, 0, 0, 0.25);
  border-radius: var(--radius-md);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.loader[hidden] {
  display: none;
}

.spinner {
  width: 34px;
  height: 34px;
  border: 3px solid rgba(255, 255, 255, 0.20);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 700ms linear infinite;
}

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

/* --- Banners (instalar / actualizar) — Liquid Glass --------------------- */
.banner {
  position: fixed;
  left: calc(12px + var(--safe-left));
  right: calc(12px + var(--safe-right));
  bottom: calc(12px + var(--safe-bottom));
  background: var(--glass-bg-strong);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shine), var(--glass-shadow);
  color: var(--c-fg);
  padding: 12px 16px;
  border-radius: var(--radius-lg);
  display: flex;
  gap: 10px;
  align-items: center;
  z-index: 9;
  transform: translateY(130%);
  transition: transform 280ms var(--easing);
  max-width: 560px;
  margin: 0 auto;
}

.banner[data-visible="true"] {
  transform: translateY(0);
}

.banner__msg {
  flex: 1;
  font-size: 13px;
  line-height: 1.35;
}

.banner__btn {
  background: var(--c-accent);
  color: #fff;
  padding: 7px 14px;
  border-radius: var(--radius-pill);
  font-weight: 600;
  font-size: 13px;
  min-height: 34px;
  box-shadow: 0 2px 8px rgba(255, 59, 48, 0.40);
}

.banner__close {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: var(--c-muted);
  font-size: 18px;
  line-height: 1;
}

/* --- Toast de error ----------------------------------------------------- */
.error-toast {
  position: fixed;
  left: calc(12px + var(--safe-left));
  right: calc(12px + var(--safe-right));
  bottom: calc(12px + var(--safe-bottom));
  background: rgba(185, 28, 28, 0.90);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid rgba(255, 100, 100, 0.30);
  color: #fff;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  font-size: 13px;
  z-index: 10;
  box-shadow: var(--glass-shadow);
}

.error-toast[hidden] {
  display: none;
}

/* --- Responsivo ---------------------------------------------------------- */
@media (min-width: 640px) {
  .brand__title { font-size: 19px; }
  .brand__sub   { font-size: 13px; }
  .nav-btn      { width: 46px; height: 46px; }
  .nav-btn--prev { left: 12px; }
  .nav-btn--next { right: 12px; }
}

@media (min-width: 900px) {
  .app__main { padding: 10px 40px 0; }
}

/* --- Accesibilidad: respeta motion reduce ------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  #ambient { transition: none !important; }
  .turn    { transition: none !important; }
}

/* Oculta visualmente pero accesible a lectores de pantalla */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}