:root {
  --bg: #141416;
  --bg-spot: #2e2e34;
  --panel: #1f1f23;
  --fg: #f3f1ee;
  --fg-dim: rgba(243, 241, 238, 0.62);
  --btn: rgba(255, 255, 255, 0.08);
  --btn-hover: rgba(255, 255, 255, 0.16);
  --paper: #ffffff;
  --accent: #c8202a;
  --bar-h: 56px;
  --page-ar: 0.705;
  color-scheme: dark;
  font-family: "Montserrat", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  overflow: hidden;
  overscroll-behavior: none;
  background: var(--bg);
  color: var(--fg);
}

body {
  -webkit-tap-highlight-color: transparent;
  -webkit-text-size-adjust: 100%;
}

.app {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  background: radial-gradient(120% 85% at 50% 45%, var(--bg-spot) 0%, var(--bg) 62%);
  -webkit-user-select: none;
  user-select: none;
  -webkit-touch-callout: none;
}

button { font-family: inherit; touch-action: manipulation; }
:focus-visible { outline: 2px solid var(--fg); outline-offset: 2px; }

svg { fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

/* ---------- lišty ---------- */

.topbar, .bottombar {
  flex: none;
  display: flex;
  align-items: center;
  gap: 12px;
  padding-left: max(14px, env(safe-area-inset-left));
  padding-right: max(14px, env(safe-area-inset-right));
  touch-action: none;
  position: relative;
  z-index: 10;
}

.topbar {
  justify-content: space-between;
  height: calc(var(--bar-h) + env(safe-area-inset-top));
  padding-top: env(safe-area-inset-top);
}

.bottombar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  height: calc(var(--bar-h) + env(safe-area-inset-bottom));
  padding-bottom: env(safe-area-inset-bottom);
}

.bar-left { justify-self: start; display: flex; gap: 8px; }
.bar-right { justify-self: end; display: flex; gap: 8px; }

.brand { display: flex; flex-direction: column; min-width: 0; line-height: 1.2; }
.brand-title {
  font-size: 15px;
  font-weight: 700;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.brand-sub {
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--fg-dim);
}

.actions { display: flex; align-items: center; gap: 8px; flex: none; }

.lang { display: inline-flex; padding: 3px; border-radius: 999px; background: var(--btn); }
.lang button {
  appearance: none;
  border: 0;
  min-width: 44px;
  padding: 9px 12px;
  border-radius: 999px;
  background: transparent;
  color: var(--fg-dim);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}
.lang button:hover { color: var(--fg); }
.lang button[aria-pressed="true"] { background: var(--fg); color: #141416; }

.icon-btn {
  appearance: none;
  flex: none;
  display: inline-grid;
  place-items: center;
  width: 40px;
  height: 40px;
  padding: 0;
  border: 0;
  border-radius: 999px;
  background: var(--btn);
  color: var(--fg);
  cursor: pointer;
  transition: background 0.2s, opacity 0.2s;
}
.icon-btn:hover { background: var(--btn-hover); }
.icon-btn:disabled { opacity: 0.3; cursor: default; background: var(--btn); }
.icon-btn svg { width: 20px; height: 20px; }
.icon-btn[hidden] { display: none; }

#fullscreen .fs-exit { display: none; }
.is-fullscreen #fullscreen .fs-enter { display: none; }
.is-fullscreen #fullscreen .fs-exit { display: block; }

.pager { display: flex; align-items: center; gap: 6px; }
.page-label {
  min-width: 76px;
  text-align: center;
  font-size: 14px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* ---------- plocha s letákem ---------- */

.stage {
  position: relative;
  flex: 1;
  min-height: 0;
  overflow: hidden;
  touch-action: none;
}

.zoom { position: absolute; inset: 0; transform-origin: 0 0; }
.zoom.moving { will-change: transform; }

.book { position: absolute; transition: opacity 0.16s ease; }
.book.fading { opacity: 0; }

.page, .face {
  position: absolute;
  top: 0;
  height: 100%;
  overflow: hidden;
  background: var(--paper);
}
.page { box-shadow: 0 22px 48px -14px rgba(0, 0, 0, 0.6), 0 2px 8px rgba(0, 0, 0, 0.35); z-index: 1; }
.page.empty, .face.empty { visibility: hidden; }

.page img, .face img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  pointer-events: none;
  -webkit-user-drag: none;
}
img.hi:not([src]) { display: none; }

.book.single .page { left: 0; width: 100%; }
.book.single .page.left { display: none; }
.book.spread .page { width: 50%; }
.book.spread .page.left { left: 0; }
.book.spread .page.right { left: 50%; }

/* stín u hřbetu ve dvoustraně */
.book.spread .page::after, .book.spread .face::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.book.spread .page.left::after, .book.spread .face.back::after {
  background: linear-gradient(to left, rgba(0, 0, 0, 0.16), rgba(0, 0, 0, 0) 7%);
}
.book.spread .page.right::after, .book.spread .face.front::after {
  background: linear-gradient(to right, rgba(0, 0, 0, 0.16), rgba(0, 0, 0, 0) 7%);
}

/* otáčený list */
.leaf {
  position: absolute;
  top: 0;
  height: 100%;
  z-index: 3;
  display: none;
  transform-origin: 0 50%;
  transform-style: preserve-3d;
  -webkit-transform-style: preserve-3d;
}
.leaf.on { display: block; will-change: transform; }
.book.single .leaf { left: 0; width: 100%; }
.book.spread .leaf { left: 50%; width: 50%; }

.face {
  left: 0;
  width: 100%;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}
.face.back { transform: rotateY(180deg); }

.shade, .cast { position: absolute; inset: 0; pointer-events: none; opacity: 0; }
.face.front .shade { background: linear-gradient(to right, rgba(0, 0, 0, 0.42), rgba(0, 0, 0, 0.14)); }
.face.back .shade { background: linear-gradient(to left, rgba(0, 0, 0, 0.42), rgba(0, 0, 0, 0.14)); }
.page.right .cast { background: linear-gradient(to right, rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0) 55%); }
.page.left .cast { background: linear-gradient(to left, rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0) 55%); }

/* tlačítko na 23poems.com na poslední straně (velikost a poloha se dopočítá ve skriptu) */
.cta {
  position: absolute;
  left: 50%;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  height: 36px;
  padding: 0 1.3em;
  border-radius: 999px;
  background: #111;
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.02em;
  white-space: nowrap;
  text-decoration: none;
  box-shadow: 0 0.35em 1em rgba(0, 0, 0, 0.2);
  transform: translateX(-50%);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.35s, visibility 0.35s, background 0.2s;
}
.cta::before { content: ""; position: absolute; inset: -8px -10px; } /* větší plocha pro prst */
.cta svg { flex: none; width: 1.15em; height: 1.15em; }
.cta:hover { background: var(--accent); }
.cta.show { opacity: 1; visibility: visible; }
.cta.floating { top: auto; bottom: 16px; height: 44px; font-size: 14px; z-index: 6; }

/* proklikávací místo v textu (např. jméno s odkazem na web) */
.hotspot {
  position: absolute;
  z-index: 2;
  border-radius: 2px;
  box-shadow: 0 2px 0 var(--accent);
  transition: background 0.2s;
}
.hotspot::before { content: ""; position: absolute; inset: -8px -4px; } /* větší plocha pro prst */
.hotspot:hover { background: rgba(200, 32, 42, 0.12); }
.hotspot:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* šipky po stranách (desktop) */
.nav {
  position: absolute;
  top: 50%;
  z-index: 5;
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  margin-top: -26px;
  padding: 0;
  border: 0;
  border-radius: 999px;
  background: var(--btn);
  color: var(--fg);
  cursor: pointer;
  transition: opacity 0.2s, background 0.2s;
}
.nav:hover { background: var(--btn-hover); }
.nav svg { width: 24px; height: 24px; }
.nav.prev { left: max(16px, env(safe-area-inset-left)); }
.nav.next { right: max(16px, env(safe-area-inset-right)); }
.nav:disabled, .stage.zoomed .nav { opacity: 0; pointer-events: none; }

.stage.grabbing { cursor: grabbing !important; }

/* nápověda při první návštěvě */
.hint {
  position: absolute;
  left: 50%;
  bottom: 16px;
  z-index: 6;
  display: flex;
  align-items: center;
  gap: 10px;
  width: max-content;
  max-width: min(520px, calc(100% - 32px));
  padding: 10px 16px;
  border-radius: 16px;
  background: rgba(20, 20, 22, 0.88);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
  font-size: 13px;
  font-weight: 600;
  line-height: 1.35;
  transform: translate(-50%, 8px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.35s, transform 0.35s;
}
.hint svg { flex: none; width: 18px; height: 18px; }
.hint.show { opacity: 1; transform: translate(-50%, 0); }

/* ---------- přehled stran ---------- */

.sheet {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  background: rgba(0, 0, 0, 0.55);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}
.sheet.open { opacity: 1; pointer-events: auto; }

.sheet-panel {
  width: min(760px, 100%);
  max-height: 82%;
  overflow: auto;
  overscroll-behavior: contain;
  touch-action: pan-y;
  padding: 14px max(16px, env(safe-area-inset-right)) calc(22px + env(safe-area-inset-bottom)) max(16px, env(safe-area-inset-left));
  border-radius: 18px 18px 0 0;
  background: var(--panel);
  transform: translateY(24px);
  transition: transform 0.25s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.sheet.open .sheet-panel { transform: none; }

.sheet-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  font-size: 15px;
  font-weight: 700;
}

.thumbs {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(92px, 1fr));
  gap: 16px 14px;
}

.thumb {
  appearance: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 7px;
  padding: 0;
  border: 0;
  background: none;
  color: var(--fg-dim);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}
.thumb img {
  width: 100%;
  aspect-ratio: var(--page-ar);
  object-fit: cover;
  border-radius: 3px;
  background: var(--paper);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.4);
  outline: 2px solid transparent;
  outline-offset: 3px;
  transition: outline-color 0.2s;
}
.thumb:hover img { outline-color: var(--fg-dim); }
.thumb.current { color: var(--fg); }
.thumb.current img { outline-color: var(--fg); }

/* ---------- ostatní ---------- */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
}

.noscript {
  position: absolute;
  inset: auto 0 50% 0;
  padding: 16px;
  text-align: center;
  font-weight: 600;
}
.noscript a { color: var(--fg); }

@media (max-width: 699px) {
  .nav { display: none; }
}

@media (max-width: 380px) {
  :root { --bar-h: 52px; }
  .topbar, .bottombar { gap: 8px; padding-left: max(10px, env(safe-area-inset-left)); padding-right: max(10px, env(safe-area-inset-right)); }
  .brand-title { font-size: 14px; }
  .lang button { min-width: 40px; padding: 9px 10px; }
  .actions, .bar-left, .bar-right { gap: 6px; }
  .pager { gap: 2px; }
  .page-label { min-width: 62px; font-size: 13px; }
}

/* telefon na šířku: co nejvíc místa pro leták */
@media (max-height: 500px) {
  :root { --bar-h: 44px; }
  .brand-sub { display: none; }
  .icon-btn { width: 34px; height: 34px; }
  .icon-btn svg { width: 18px; height: 18px; }
  .lang button { padding: 7px 10px; }
  .nav { width: 44px; height: 44px; margin-top: -22px; }
}

@media (prefers-reduced-motion: reduce) {
  .book, .sheet, .sheet-panel, .hint { transition: none; }
}