/* Flipbook overlay */
.fb-overlay{position:fixed; inset:0;background:rgba(0,0,0,.92);z-index:99999;display:none;color:#fff;font-family:inherit;}
.fb-overlay.is-open{display:block;}
.fb-topbar{position:absolute; top:10px; left:10px; right:10px;display:flex; align-items:center; justify-content:space-between;gap:10px;}
.fb-title{font-size:15px;opacity:.95;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:55vw;}
.fb-actions{display:flex; align-items:center; flex-wrap:wrap;gap:6px;}
.fb-actions .btn{ padding:6px 10px; }
.fb-close{ font-size:18px; }
.fb-layout{position:absolute; top:56px; left:0; right:0; bottom:0;display:flex;}
.fb-sidebar{width:260px;max-width:70vw;background:rgba(0,0,0,.65);border-right:1px solid rgba(255,255,255,.12);overflow:auto;display:none;}
.fb-sidebar.is-open{display:block;}
.fb-thumbs{padding:10px;display:grid;grid-template-columns:repeat(2, 1fr);gap:10px;}
.fb-thumb{cursor:pointer;border:1px solid rgba(255,255,255,.15);border-radius:10px;overflow:hidden;background:#111;}
.fb-thumb img{width:100%;height:auto;display:block;}
.fb-thumb .fb-thumb-label{font-size:12px;padding:6px 8px;opacity:.9;text-align:center;}
.fb-stage-wrap{position:relative;flex:1;overflow:hidden;}
.fb-stage{position:absolute; inset:0;display:flex;align-items:center;justify-content:center;gap:12px;padding:12px;}
.fb-page{max-height:calc(100vh - 96px);max-width:calc(100vw - 40px);box-shadow:0 10px 40px rgba(0,0,0,.4);background:#111;border-radius:10px;}
/* In spread mode, keep same scale as double-page even when only 1 page is displayed */
.fb-overlay.fb-spread .fb-page{max-width:calc((100vw - 80px)/2);}
.fb-hot-left,.fb-hot-right{position:absolute;top:0; bottom:0;width:35%;z-index:2;}
.fb-hot-left{left:0;}
.fb-hot-right{right:0;}
.fb-loader{position:absolute;inset:0;display:none;align-items:center;justify-content:center;z-index:3;background:rgba(0,0,0,.35);backdrop-filter: blur(2px);}
.fb-loader.is-on{display:flex;}
.fb-spinner{width:42px; height:42px;border-radius:50%;border:4px solid rgba(255,255,255,.25);border-top-color:#fff;animation:fbspin .8s linear infinite;}
@keyframes fbspin{to{transform:rotate(360deg)}}
.fb-indicator{position:absolute;right:12px; bottom:12px;background:rgba(0,0,0,.55);border:1px solid rgba(255,255,255,.15);padding:6px 10px;border-radius:999px;font-size:12px;z-index:4;}
.fb-overlay.is-zoom .fb-stage-wrap{ overflow:auto; }
.fb-overlay.is-zoom .fb-stage{align-items:flex-start;justify-content:flex-start;}
.fb-overlay.is-zoom .fb-page{max-height:none;max-width:none;transform:scale(2);transform-origin: top left;}
@media (max-width: 700px){
  .fb-title{max-width:45vw;}
  .fb-actions .btn{ padding:6px 8px; font-size:12px; }
  .fb-sidebar{ width:220px; }
  .fb-thumbs{ grid-template-columns:repeat(2, 1fr); }
}