/* ── Chapter Nav Bar ── */
#chapterNav {
  position:fixed; bottom:48px; left:27.5%; transform:translateX(-50%);
  z-index:9999; display:flex; gap:8px; align-items:center;
  background:rgba(0,0,0,.85); border-radius:12px;
  padding:10px 20px; backdrop-filter:blur(10px);
  border:1px solid rgba(255,255,255,.2);
  box-shadow:0 0 24px rgba(0,0,0,.6), 0 0 8px rgba(255,255,255,.05);
}
#chapterNav a, #chapterNav button {
  font-family:'Share Tech Mono',monospace; font-size:clamp(11px,1.1vw,14px);
  letter-spacing:2px; text-transform:uppercase; text-decoration:none;
  color:rgba(255,255,255,.9); background:rgba(255,255,255,.08); border:1px solid rgba(255,255,255,.3);
  padding:8px 16px; border-radius:6px; cursor:pointer;
  transition:all .3s ease;
  text-shadow:0 0 10px rgba(255,255,255,.5), 0 0 20px rgba(255,255,255,.2);
}
#chapterNav a:hover, #chapterNav button:hover {
  color:#fff; border-color:rgba(255,255,255,.6);
  background:rgba(255,255,255,.15);
  text-shadow:0 0 14px rgba(255,255,255,.8), 0 0 28px rgba(200,220,255,.4);
  box-shadow:0 0 16px rgba(255,255,255,.25);
}
@media(max-width:600px) {
  #chapterNav { padding:6px 10px; gap:4px; }
  #chapterNav a, #chapterNav button { padding:5px 8px; font-size:8px; letter-spacing:1px; }
}

/* Speed control buttons */
.speed-btn {
  font-size:14px !important;
  padding:4px 8px !important;
  letter-spacing:0 !important;
  border:1px solid rgba(255,255,255,.1) !important;
  opacity:.5;
  transition:all .3s ease;
}
.speed-btn.speed-active {
  opacity:1;
  border-color:rgba(255,255,255,.4) !important;
  box-shadow:0 0 8px rgba(255,255,255,.2);
  text-shadow:0 0 8px rgba(255,255,255,.5);
}
.speed-btn:hover { opacity:.8; }