/* ============ Responsive: narrow window ============ */
  /* Narrow does NOT mean "no right rail". A portrait secondary display is
     under 900px wide and is exactly where the queue matters most; hiding
     .todo-sidebar/.compact-tracker here left the rail rendering as an empty
     column — pinned or peeking, the panel was there but blank. The rail now
     survives, clamped by the shared narrow width in structure.css so it can
     never crowd out the content column. */
  @media (max-width:900px){
    .pb-vol{width:120px;}
    .pb-audio .pb-info{max-width:150px;}
  }
  @media (max-width:680px){
    .pb-vol{display:none;}
    .pb-binaural .pb-timer{display:none;}
    .cb-vol{display:none;}
  }