:root{
  --bg:#0e0f12;
  --bg-elevated:rgba(22,24,30,0.72);
  --glass:rgba(28,30,38,0.78);
  --glass-border:rgba(255,255,255,0.08);
  --text:#f0f1f4;
  --muted:#8b8f9a;
  --accent:#5b8def;
  --accent-soft:rgba(91,141,239,0.22);
  --danger:#f07178;
  --radius:14px;
  --dock-h:88px;
  --top-h:56px;
  --font:'DM Sans',Segoe UI,system-ui,sans-serif;
}
*{box-sizing:border-box}
html,body{margin:0;height:100%;font-family:var(--font);background:var(--bg);color:var(--text);-webkit-tap-highlight-color:transparent}
body{
  background:
    radial-gradient(1200px 600px at 50% -10%, rgba(91,141,239,0.12), transparent 55%),
    radial-gradient(900px 500px at 80% 100%, rgba(40,48,70,0.45), transparent 50%),
    var(--bg);
}
#app{display:flex;flex-direction:column;height:100%;min-height:100dvh;position:relative}

.top-bar{
  display:flex;align-items:center;gap:12px;
  height:var(--top-h);
  padding:0 16px;
  padding-top:env(safe-area-inset-top);
  padding-left:max(16px,env(safe-area-inset-left));
  padding-right:max(16px,env(safe-area-inset-right));
  flex-shrink:0;z-index:20;
  animation:fadeDown .45s ease both;
}
.brand{flex:1;min-width:0;display:flex;flex-direction:column;gap:1px}
.brand-mark{font-size:10px;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:var(--accent);opacity:.9}
.brand h1{margin:0;font-size:15px;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

.icon-btn{
  width:40px;height:40px;border:0;border-radius:12px;
  background:var(--glass);color:var(--text);
  border:1px solid var(--glass-border);
  backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);
  display:inline-flex;align-items:center;justify-content:center;
  cursor:pointer;flex-shrink:0;transition:background .15s,transform .15s,border-color .15s;
}
.icon-btn:hover{background:rgba(40,44,56,0.9);border-color:rgba(255,255,255,0.14)}
.icon-btn:active{transform:scale(.96)}

#stage{
  flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;
  overflow:hidden;position:relative;
  padding:8px 20px 12px;
  padding-left:max(20px,env(safe-area-inset-left));
  padding-right:max(20px,env(safe-area-inset-right));
  min-height:0;
}
.stage-glow{
  position:absolute;inset:10% 15%;
  background:radial-gradient(ellipse at center, rgba(91,141,239,0.08), transparent 70%);
  pointer-events:none;z-index:0;
}
.book-mount{
  position:relative;z-index:1;
  width:min(980px,100%);
  height:min(calc(100dvh - var(--top-h) - var(--dock-h) - 48px), 78vh);
  min-height:280px;
  animation:fadeUp .55s ease .08s both;
}
#app.fit-width .book-mount{
  width:min(1200px,100%);
  height:min(calc(100dvh - var(--top-h) - var(--dock-h) - 32px), 70vh);
}
#app.fit-page .book-mount{
  width:min(920px,100%);
  height:min(calc(100dvh - var(--top-h) - var(--dock-h) - 48px), 82vh);
}
.stf__parent{margin:0 auto;max-width:100%;max-height:100%}
.hint{
  margin:14px 0 0;font-size:12px;color:var(--muted);text-align:center;z-index:1;
  animation:fadeUp .5s ease .2s both;
}

.hotspot-layer{position:absolute;top:0;left:0;right:0;bottom:0;pointer-events:none;z-index:5}
.hotspot-region{position:absolute;cursor:pointer;pointer-events:auto;border-radius:4px;transition:background .15s,border-color .15s}
.hotspot-region-ellipse{border-radius:50%}
.hotspot-region-rounded{border-radius:12px}
.hotspot-region:hover{background:rgba(91,141,239,0.35)!important;border-color:var(--accent)!important}

.dock{
  flex-shrink:0;z-index:20;
  padding:0 16px max(14px,env(safe-area-inset-bottom));
  padding-left:max(16px,env(safe-area-inset-left));
  padding-right:max(16px,env(safe-area-inset-right));
  animation:fadeUp .5s ease .12s both;
}
.dock-glass{
  max-width:720px;margin:0 auto;
  display:flex;flex-direction:column;gap:10px;
  padding:12px 14px;
  border-radius:var(--radius);
  background:var(--glass);
  border:1px solid var(--glass-border);
  backdrop-filter:blur(18px) saturate(1.2);-webkit-backdrop-filter:blur(18px) saturate(1.2);
  box-shadow:0 12px 40px rgba(0,0,0,0.35), inset 0 1px 0 rgba(255,255,255,0.06);
}
.dock-nav{display:flex;align-items:center;gap:10px}
.nav-btn{
  width:48px;height:48px;border:0;border-radius:14px;
  background:rgba(255,255,255,0.06);color:var(--text);
  border:1px solid var(--glass-border);
  display:inline-flex;align-items:center;justify-content:center;
  cursor:pointer;flex-shrink:0;transition:background .15s,transform .15s,opacity .15s;
}
.nav-btn:hover:not(:disabled){background:var(--accent-soft);border-color:rgba(91,141,239,0.35)}
.nav-btn:active:not(:disabled){transform:scale(.95)}
.nav-btn:disabled{opacity:.32;cursor:default}

.progress-block{flex:1;min-width:0;display:flex;flex-direction:column;align-items:center;gap:6px}
.page-label{font-size:12px;font-weight:500;color:var(--muted);letter-spacing:.02em;font-variant-numeric:tabular-nums}
.scrub{
  width:100%;height:6px;border:0;border-radius:999px;padding:0;
  background:rgba(255,255,255,0.1);cursor:pointer;position:relative;overflow:hidden;
}
.scrub-fill{
  display:block;height:100%;width:0%;border-radius:inherit;
  background:linear-gradient(90deg, #4a7ad9, var(--accent));
  transition:width .2s ease;
}
.scrub:hover{background:rgba(255,255,255,0.14)}

.dock-toggles{display:flex;flex-wrap:wrap;gap:8px;justify-content:center}
.toggle-btn{
  min-height:34px;padding:0 14px;border-radius:999px;
  border:1px solid var(--glass-border);
  background:rgba(255,255,255,0.04);color:var(--muted);
  font-family:inherit;font-size:12px;font-weight:600;letter-spacing:.04em;
  cursor:pointer;transition:background .15s,color .15s,border-color .15s,box-shadow .15s;
}
.toggle-btn:hover{color:var(--text);background:rgba(255,255,255,0.07)}
.toggle-btn[aria-pressed="true"]{
  color:#fff;background:var(--accent-soft);border-color:rgba(91,141,239,0.45);
  box-shadow:0 0 0 1px rgba(91,141,239,0.15);
}

.toc-overlay{position:fixed;inset:0;background:rgba(0,0,0,0.55);opacity:0;pointer-events:none;transition:opacity .22s;z-index:100;backdrop-filter:blur(2px)}
.toc-overlay.open{opacity:1;pointer-events:auto}
.toc-drawer{
  position:fixed;top:0;left:0;bottom:0;width:min(300px,82vw);
  background:rgba(18,20,26,0.96);
  border-right:1px solid var(--glass-border);
  transform:translateX(-100%);transition:transform .28s cubic-bezier(.22,1,.36,1);
  z-index:101;display:flex;flex-direction:column;
  padding-top:env(safe-area-inset-top);padding-left:env(safe-area-inset-left);padding-bottom:env(safe-area-inset-bottom);
  backdrop-filter:blur(20px);
}
.toc-drawer.open{transform:translateX(0)}
.toc-header{display:flex;align-items:center;justify-content:space-between;padding:16px;border-bottom:1px solid var(--glass-border);font-weight:600;font-size:14px}
.toc-list{flex:1;overflow-y:auto;padding:8px 0}
.toc-item{display:block;padding:11px 16px;color:#e0e0e4;text-decoration:none;font-size:13px;border-left:3px solid transparent;transition:background .15s,border-color .15s}
.toc-item:hover{background:rgba(255,255,255,0.05)}
.toc-item.active{border-left-color:var(--accent);background:var(--accent-soft)}
.toc-item[data-indent="1"]{padding-left:32px}
.toc-item[data-indent="2"]{padding-left:48px}
.toc-item[data-indent="3"]{padding-left:64px}
.toc-item[data-indent="4"]{padding-left:80px}
.toc-item[data-indent="5"]{padding-left:96px}

@keyframes fadeDown{from{opacity:0;transform:translateY(-8px)}to{opacity:1;transform:none}}
@keyframes fadeUp{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}

@media(max-width:720px){
  :root{--dock-h:108px;--top-h:52px}
  .hint{display:none}
  .brand-mark{display:none}
  .brand h1{font-size:14px;max-width:52vw}
  .nav-btn{width:44px;height:44px}
  .dock-glass{gap:8px;padding:10px 12px}
  .book-mount,#app.fit-page .book-mount,#app.fit-width .book-mount{
    height:min(calc(100dvh - var(--top-h) - var(--dock-h) - 24px), 68vh);
  }
}
@media(max-width:480px){
  .dock-toggles{gap:6px}
  .toggle-btn{padding:0 11px;font-size:11px;min-height:32px}
  .page-label{font-size:11px}
}