:root{
  --navy:#071827;
  --navy2:#0b2941;
  --line:rgba(255,255,255,.16);
  --header-h:72px;
  --footer-h:40px;
}
*{box-sizing:border-box}
html,body{
  margin:0;width:100%;height:100%;overflow:hidden;
  font-family:Arial,Helvetica,sans-serif;
  background:#07131d;color:#fff
}
button,a{font:inherit}
button{cursor:pointer}
.hidden{display:none!important}

.app{
  position:fixed;inset:0;width:100%;height:100%;
  background:#07131d;overflow:hidden
}
.topbar{
  position:absolute;z-index:100;top:0;left:0;right:0;height:var(--header-h);
  display:flex;align-items:center;justify-content:space-between;
  gap:12px;padding:0 18px;
  background:linear-gradient(90deg,var(--navy),var(--navy2));
  border-bottom:1px solid var(--line)
}
.brand{display:flex;align-items:center;gap:12px;min-width:0}
.logo{
  width:44px;height:44px;border:2px solid #fff;border-radius:7px;
  display:grid;place-items:center;font-size:22px;font-weight:700;flex:0 0 auto
}
.brand strong{display:block;letter-spacing:1.5px;white-space:nowrap}
.brand span{display:block;margin-top:4px;font-size:9px;letter-spacing:1.2px;opacity:.66;white-space:nowrap}
.actions{display:flex;align-items:center;gap:8px}
.actions button,.actions a{
  color:#fff;background:rgba(255,255,255,.08);
  border:1px solid var(--line);border-radius:10px;text-decoration:none
}
.actions button{width:38px;height:38px;font-size:24px}
.actions .text-btn{
  width:auto;height:38px;padding:0 13px;
  display:flex;align-items:center;justify-content:center;font-size:12px
}
#pageIndicator{min-width:70px;text-align:center;font-size:13px;opacity:.86}

.viewer{
  position:absolute;z-index:1;
  top:var(--header-h);bottom:var(--footer-h);left:0;right:0;
  overflow:hidden;
  display:flex;align-items:center;justify-content:center;
  background:
    radial-gradient(circle at 50% 35%,rgba(53,114,153,.22),transparent 42%),
    linear-gradient(135deg,#0b1f2e,#07111a)
}

.loading{text-align:center;display:grid;gap:10px;justify-items:center}
.loading span{font-size:12px;opacity:.58}
.spinner{
  width:42px;height:42px;border-radius:50%;
  border:3px solid rgba(255,255,255,.2);
  border-top-color:#fff;animation:spin .9s linear infinite
}
@keyframes spin{to{transform:rotate(360deg)}}
.error{
  max-width:640px;margin:20px;padding:22px;
  border:1px solid rgba(255,100,100,.35);
  background:rgba(125,15,15,.25);
  border-radius:14px;line-height:1.5
}

/* DESKTOP */
.desktop-stage{
  position:absolute;inset:8px 58px;
  display:flex;align-items:center;justify-content:center;
  overflow:visible
}
#desktopBook{
  margin:auto;
  filter:drop-shadow(0 20px 36px rgba(0,0,0,.55));
  transform-origin:center center
}
.desktop-page{
  background:#fff;overflow:hidden
}
.desktop-page canvas{
  width:100%;height:100%;display:block;background:#fff
}

/* MOBILE */
.mobile-stage{
  position:absolute;inset:4px;
  display:flex;align-items:center;justify-content:center;
  overflow:hidden;
  touch-action:none
}
.mobile-canvas-wrap{
  position:relative;
  display:flex;align-items:center;justify-content:center;
  transform-origin:center center;
  transition:transform .18s ease;
  filter:drop-shadow(0 14px 26px rgba(0,0,0,.45))
}
.mobile-canvas-wrap.flip-next{animation:mobileFlipNext .34s ease}
.mobile-canvas-wrap.flip-prev{animation:mobileFlipPrev .34s ease}
@keyframes mobileFlipNext{
  0%{transform:perspective(900px) rotateY(0deg) scale(var(--mobile-scale,1))}
  48%{transform:perspective(900px) rotateY(-16deg) scale(var(--mobile-scale,1));opacity:.55}
  100%{transform:perspective(900px) rotateY(0deg) scale(var(--mobile-scale,1));opacity:1}
}
@keyframes mobileFlipPrev{
  0%{transform:perspective(900px) rotateY(0deg) scale(var(--mobile-scale,1))}
  48%{transform:perspective(900px) rotateY(16deg) scale(var(--mobile-scale,1));opacity:.55}
  100%{transform:perspective(900px) rotateY(0deg) scale(var(--mobile-scale,1));opacity:1}
}
#mobileCanvas{display:block;background:#fff}

/* ONE control bar shared visually, separate engine logic */
.control-bar{
  position:absolute;z-index:500;
  left:50%;bottom:calc(var(--footer-h) + 10px);
  transform:translateX(-50%);
  display:flex;align-items:center;gap:6px;
  padding:6px 8px;border:1px solid rgba(255,255,255,.18);
  border-radius:12px;background:rgba(4,20,32,.94);
  box-shadow:0 12px 28px rgba(0,0,0,.35);
  backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px)
}
.control-bar button{
  min-width:34px;height:34px;padding:0 10px;
  border:1px solid rgba(255,255,255,.16);
  border-radius:9px;color:#fff;background:rgba(255,255,255,.08)
}
.control-bar .wide-btn{font-size:11px}
#zoomLabel{min-width:46px;text-align:center;font-size:11px}

.footer{
  position:absolute;z-index:100;left:0;right:0;bottom:0;height:var(--footer-h);
  display:flex;align-items:center;padding:0 18px;
  background:#06131e;border-top:1px solid var(--line);
  font-size:10px;color:rgba(255,255,255,.62)
}

.app:fullscreen,.app:-webkit-full-screen{
  width:100vw;height:100vh;background:#07131d
}

@media(max-width:700px){
  :root{--header-h:58px;--footer-h:36px}
  .topbar{padding:0 7px}
  .brand-copy{display:none}
  .logo{width:34px;height:34px;font-size:17px}
  .actions{gap:3px}
  .actions button{width:31px;height:31px;font-size:20px;border-radius:8px}
  .actions .text-btn{height:31px;padding:0 7px;font-size:9px;border-radius:8px}
  #pageIndicator{min-width:44px;font-size:10px}
  .control-bar{
    bottom:calc(var(--footer-h) + 6px + env(safe-area-inset-bottom));
    gap:4px;padding:5px 6px;
    max-width:calc(100vw - 12px)
  }
  .control-bar button{height:31px;min-width:31px;padding:0 8px;font-size:15px}
  .control-bar .wide-btn{font-size:9px}
  #zoomLabel{min-width:38px;font-size:9px}
  .footer{padding:0 8px;font-size:8px}
}

@media(max-width:390px){
  .actions a.text-btn{display:none}
}


/* ===== V2 FIXES ===== */

/* Mobile header: controls compact and aligned, no giant white button */
@media(max-width:700px){
  .actions{
    gap:4px!important;
    align-items:center;
  }

  .actions button,
  .actions a{
    background:rgba(255,255,255,.07)!important;
    color:#fff!important;
    border:1px solid rgba(255,255,255,.16)!important;
    box-shadow:none!important;
  }

  .actions button{
    width:32px!important;
    height:32px!important;
    padding:0!important;
    display:grid!important;
    place-items:center!important;
    font-size:18px!important;
    line-height:1!important;
    border-radius:8px!important;
  }

  #pageIndicator{
    min-width:42px!important;
    font-size:10px!important;
    line-height:1!important;
  }

  .actions .text-btn{
    height:32px!important;
    padding:0 8px!important;
    font-size:9px!important;
    border-radius:8px!important;
  }
}

/* Fullscreen desktop: preserve stage dimensions */
.app:fullscreen .viewer,
.app:-webkit-full-screen .viewer{
  top:var(--header-h)!important;
  bottom:var(--footer-h)!important;
  left:0!important;
  right:0!important;
  width:auto!important;
  height:auto!important;
}

.app:fullscreen .desktop-stage,
.app:-webkit-full-screen .desktop-stage{
  inset:8px 58px!important;
  display:flex!important;
  align-items:center!important;
  justify-content:center!important;
}

.app:fullscreen #desktopBook,
.app:-webkit-full-screen #desktopBook{
  margin:auto!important;
}

/* pseudo fullscreen fallback */
.app.pseudo-fullscreen{
  position:fixed!important;
  inset:0!important;
  width:100vw!important;
  height:100dvh!important;
  z-index:99999!important;
  background:#07131d!important;
}

.app.pseudo-fullscreen .topbar,
.app.pseudo-fullscreen .footer,
.app.pseudo-fullscreen .control-bar{
  position:absolute!important;
}
.app.pseudo-fullscreen .viewer{
  position:absolute!important;
}


/* ===== V3: FLEXIBLE FLIP + MOBILE PINCH ZOOM ===== */

/* Desktop: pagina "soft", ombra più naturale durante il trascinamento */
.desktop-page{
  backface-visibility:hidden;
  -webkit-backface-visibility:hidden;
}

/* Mobile: pinch/pan nativo */
.mobile-stage{
  touch-action:none!important;
  overflow:hidden!important;
}

.mobile-canvas-wrap{
  will-change:transform;
  transition:none!important;
  transform-origin:50% 50%;
}

/* su mobile nascondiamo i pulsanti +/-: si usa pinch con due dita */
@media(max-width:700px){
  #zoomOutBtn,
  #zoomInBtn,
  #zoomLabel{
    display:none!important;
  }

  .control-bar{
    gap:5px;
  }

  .control-bar #fitBtn{
    display:none!important;
  }

  .control-bar #fullscreenBtn{
    min-width:78px;
  }
}