:root {
  --bg: #041420;          /* mar profundo */
  --bg-stage: #071f30;
  --surface: #0c2c42;
  --surface-2: #12405e;
  --line: #1c4a68;
  --text: #eaf3fb;
  --text-dim: #8fb0c6;
  --accent: #2e8fd6;      /* azul elétrico da marca */
  --accent-ink: #04202f;
  --spark: #ffa735;       /* faísca laranja */
  --radius: 12px;
  --shadow: 0 22px 60px rgba(1, 12, 22, .6);
  --header-h: 60px;
  --pager-h: 62px;

  /* insets do dispositivo (notch, home indicator); 0 quando não há */
  --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);

  --ui-ease: cubic-bezier(.22, .61, .36, 1);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  height: 100svh;
  background: var(--bg);
  color: var(--text);
  font-family: "Hanken Grotesk", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  overscroll-behavior: none;
  -webkit-tap-highlight-color: transparent;
}

body {
  position: relative;
  height: 100svh;
  overflow: hidden;
}

/* ---------- Topbar (sobreposta) ---------- */
.topbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 5;
  height: calc(var(--header-h) + var(--safe-top));
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: var(--safe-top) calc(18px + var(--safe-right)) 0 calc(18px + var(--safe-left));
  background: rgba(4, 20, 32, .92);
  border-bottom: 1px solid var(--line);
  transition: transform .3s var(--ui-ease);
}

.brand {
  display: inline-flex; align-items: center;
  text-decoration: none;
  opacity: .92;
  transition: opacity .15s;
}
.brand:hover { opacity: 1; }
.brand__logo { height: 26px; width: auto; display: block; }

.controls { display: flex; align-items: center; gap: 12px; }

/* ---------- Segmented control ---------- */
.segmented {
  display: inline-flex;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 3px;
  gap: 2px;
}
.seg {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--text-dim);
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .3px;
  padding: 6px 8px;
  border-radius: 7px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  transition: background .15s, color .15s;
}
.seg .flag {
  display: block;
  width: 25px;
  height: auto;
  border-radius: 3px;
  opacity: .7;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, .2), 0 1px 2px rgba(0, 0, 0, .3);
  transition: opacity .15s;
}
.seg:hover .flag { opacity: 1; }
.seg[aria-pressed="true"] .flag { opacity: 1; }
.seg:hover { color: var(--text); }
.seg[aria-pressed="true"] {
  background: var(--accent);
  color: var(--accent-ink);
}

/* ---------- Botão baixar ---------- */
.download {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .2px;
  text-decoration: none;
  color: var(--text-dim);
  background: transparent;
  border: 0;
  border-radius: 8px;
  padding: 6px 8px;
  cursor: pointer;
  opacity: .8;
  white-space: nowrap;
  transition: color .15s, opacity .15s;
}
.download:hover { color: var(--text); opacity: 1; }
.download__icon { font-size: 14px; line-height: 1; color: var(--spark); }

/* ---------- Stage / viewer ---------- */
.stage {
  position: absolute;
  inset: 0;
  background: var(--bg-stage);
  display: grid;
  place-items: center;
  overflow: hidden; /* página cabe inteira; clipa o deslize do crossfade */
  padding-top: calc(var(--header-h) + var(--safe-top) + 14px);
  padding-bottom: calc(var(--pager-h) + var(--safe-bottom) + 14px);
  padding-left: calc(16px + var(--safe-left));
  padding-right: calc(16px + var(--safe-right));
}

.viewer {
  position: relative;
  display: grid;
  place-items: center;
  max-width: 100%;
  max-height: 100%;
  perspective: 1800px; /* profundidade da virada 3D da folha */
}

.page {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  border-radius: 6px;
  background: #fff;
  box-shadow: var(--shadow);
  display: block;
}

/* Canvas "fantasma": a folha que sai — gira em 3D presa na lombada */
.ghost {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 2;
  display: none;
  box-shadow: none;
  pointer-events: none;
  backface-visibility: hidden; /* some ao passar de 90°, revelando a nova */
  will-change: transform, opacity, filter;
}

/* Sombra que a folha em virada projeta na página revelada (sob o fantasma) */
.fold {
  position: absolute;
  inset: 0;
  z-index: 1;
  display: none;
  border-radius: 6px;
  pointer-events: none;
  will-change: opacity;
}

/* ---------- Loader ---------- */
.loader {
  position: absolute;
  inset: 0;
  z-index: 3; /* acima do fantasma (2): visível durante a troca de idioma */
  display: none;
  place-items: center;
  pointer-events: none;
  background: rgba(12, 12, 12, .34); /* scrim: escurece a página antiga na espera */
  border-radius: 6px;
}
.loader:not([hidden]) { display: grid; }
.loader span {
  width: 34px; height: 34px;
  border-radius: 50%;
  border: 3px solid rgba(255, 255, 255, .18);
  border-top-color: var(--accent);
  animation: spin .8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- Pager (sobreposto) ---------- */
.pager {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  z-index: 5;
  height: calc(var(--pager-h) + var(--safe-bottom));
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding-bottom: var(--safe-bottom);
  padding-left: var(--safe-left);
  padding-right: var(--safe-right);
  background: rgba(4, 20, 32, .94);
  border-top: 1px solid var(--line);
  transition: transform .3s var(--ui-ease);
}
.pager__btn {
  width: 44px; height: 44px;
  display: grid; place-items: center;
  font-size: 22px; line-height: 1;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  cursor: pointer;
  transition: background .15s, transform .08s;
}
.pager__btn:hover { background: var(--surface-2); }
.pager__btn:active { transform: scale(.9); }
.pager__btn:disabled { opacity: .35; cursor: default; }

/* ---------- Modo imersão (auto-ocultar ao ler) ---------- */
body.immersive .topbar { transform: translateY(-100%); }
body.immersive .pager  { transform: translateY(100%); }
/* dica sutil de que a página é tocável pra alternar a interface */
.stage.tappable { cursor: pointer; }

.pager__mid { display: flex; align-items: center; gap: 8px; color: var(--text-dim); font-size: 14px; }
.pager__input {
  width: 58px;
  text-align: center;
  font: inherit;
  font-size: 14px;
  font-variant-numeric: tabular-nums;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 6px 4px;
}
.pager__input::-webkit-outer-spin-button,
.pager__input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.pager__total { font-variant-numeric: tabular-nums; }

@media (max-width: 560px) {
  .topbar {
    gap: 10px;
    padding-right: calc(12px + var(--safe-right));
    padding-left: calc(12px + var(--safe-left));
  }
  .brand__logo { height: 24px; }
  .download__label { display: none; } /* no mobile fica só o ícone ↓ */
  .download { padding: 8px 6px; }
}

/* Ergonomia em telas de toque: alvos generosos + feedback tátil */
@media (pointer: coarse) {
  .seg {
    min-height: 44px;
    padding: 6px 12px;
  }
  .seg:active { transform: scale(.94); }
  .download { min-height: 44px; padding: 8px 10px; }
  .download:active { opacity: .6; }
  .brand { padding: 6px 2px; }
  .pager__btn { width: 46px; height: 46px; }
  .pager__input { min-height: 40px; }
  .seg, .pager__btn, .download, .brand { transition: transform .08s, background .15s, color .15s, opacity .15s; }
}