/* Density Column Simulation - responsive layout */
.density-sim-page { max-width: 1180px; }
.back-link { color:#3b82f6; font-size:.95rem; font-weight:600; display:inline-block; margin-bottom:12px; }
.back-link:hover,.back-link:focus-visible { text-decoration:underline; }

.sim-wrapper {
  width:100%; max-width:100%; margin:20px auto 0; padding:0; box-sizing:border-box;
  font-family:'Inter',-apple-system,BlinkMacSystemFont,sans-serif; user-select:none;
}
.sim-container {
  display:flex; justify-content:center; align-items:flex-start; gap:24px;
  width:100%; max-width:1100px; margin:0 auto; padding:24px; box-sizing:border-box;
  background:#fff; border:1px solid #e2e8f0; border-radius:14px;
  box-shadow:0 10px 25px -5px rgba(0,0,0,.05);
}
.controls {
  display:flex; flex-direction:column; gap:14px; width:270px; flex:0 0 270px;
  min-width:0; box-sizing:border-box;
}
.control-group {
  background:#fff; padding:14px; border:1px solid #e2e8f0; border-left:4px solid #3b82f6;
  border-radius:10px; box-sizing:border-box;
}
.section-header { display:flex; align-items:center; gap:10px; margin-bottom:12px; padding-bottom:8px; border-bottom:1px solid #f1f5f9; }
.section-header.compact-header { margin-bottom:10px; }
.section-header h2 { margin:0; color:#1e293b; font-size:.95rem; font-weight:600; }
.section-icon { width:20px; height:20px; flex-shrink:0; }
.step-badge {
  display:flex; align-items:center; justify-content:center; width:22px; height:22px; flex-shrink:0;
  border-radius:50%; background:#eff6ff; color:#2563eb; font-size:.78rem; font-weight:700;
}
.control-group label,.field-label { display:block; margin-bottom:6px; color:#475569; font-size:.82rem; font-weight:600; }
.control-group select {
  width:100%; margin-bottom:10px; padding:8px 10px; border:1px solid #cbd5e1; border-radius:6px;
  background:#f8fafc; color:#334155; font:inherit; font-size:.85rem; box-sizing:border-box;
}
.control-group select:focus-visible { border-color:#3b82f6; outline:none; box-shadow:0 0 0 3px rgba(59,130,246,.12); }
.control-group select:disabled { cursor:not-allowed; opacity:.65; }

.segmented-control { display:flex; margin-bottom:12px; padding:3px; border:1px solid #e2e8f0; border-radius:8px; background:#f1f5f9; }
.segment-btn {
  flex:1; min-width:0; min-height:38px; margin:0; padding:6px; border:0; border-radius:6px;
  background:transparent; color:#64748b; cursor:pointer; font:inherit; font-size:.82rem; font-weight:600;
}
.segment-btn.active { background:#fff; color:#1e293b; box-shadow:0 2px 4px rgba(0,0,0,.05); }

.sim-btn {
  display:flex; align-items:center; justify-content:center; gap:4px; width:100%; min-height:42px;
  padding:9px 10px; border:0; border-radius:6px; cursor:pointer; font:inherit; font-size:.88rem;
  font-weight:600; box-sizing:border-box;
}
.sim-btn.action-btn { flex:1; background:#3b82f6; color:#fff; }
.sim-btn.action-btn:hover { background:#2563eb; }
.sim-btn.random-btn { flex:0 0 100px; background:#64748b; color:#fff; }
.sim-btn.random-btn:hover { background:#475569; }
.sim-btn.toggle-btn { margin-bottom:2px; border:1px solid #2563eb; background:#fff; color:#2563eb; font-size:.85rem; }
.sim-btn.toggle-btn:hover { background:#eff6ff; }
.sim-btn.highlight-action { background:#2563eb !important; box-shadow:0 0 0 3px rgba(59,130,246,.3); }
.segment-btn:focus-visible,.sim-btn:focus-visible,.utility-toolbar button:focus-visible { outline:3px solid rgba(59,130,246,.35); outline-offset:2px; }
.sim-btn:disabled,.utility-toolbar button:disabled { cursor:not-allowed; opacity:.45; }

.action-row,.utility-toolbar { display:flex; gap:6px; margin-top:2px; }
.utility-toolbar button {
  flex:1; min-width:0; min-height:40px; padding:8px 5px; border:1px solid #cbd5e1; border-radius:6px;
  background:#f8fafc; color:#475569; cursor:pointer; font:inherit; font-size:.78rem; font-weight:600;
}
.utility-toolbar button:hover:not(:disabled) { background:#f1f5f9; }
.utility-toolbar button.reset-btn { border-color:#fca5a5; color:#dc2626; }
.utility-toolbar button.reset-btn:hover:not(:disabled) { background:#fef2f2; }

.canvas-container {
  display:flex; flex:1 1 750px; flex-direction:column; align-items:center; min-width:0;
  width:100%; max-width:750px; box-sizing:border-box;
}
canvas#simCanvas {
  display:block; width:100%; max-width:750px; height:auto; aspect-ratio:750 / 680;
  border:1px solid #e2e8f0; border-radius:10px; background:#f8fafc;
  cursor:grab; touch-action:none; box-sizing:border-box; -webkit-tap-highlight-color:transparent;
}
canvas#simCanvas:active { cursor:grabbing; }
.info-box {
  width:100%; max-width:750px; margin:10px 0 0; padding:8px 14px; box-sizing:border-box;
  border:1px solid #e2e8f0; border-radius:8px; background:#f1f5f9; color:#475569;
  font-size:.82rem; line-height:1.4; text-align:center;
}
.sr-only { position:absolute; width:1px; height:1px; padding:0; margin:-1px; overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; border:0; }

/* Stack before the original desktop proportions become cramped. */
@media (max-width:1100px) {
  .sim-container { flex-direction:column; align-items:stretch; gap:18px; }
  .controls { width:100%; flex:none; display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); align-items:start; }
  #densityFormatBtn,.utility-toolbar { grid-column:1 / -1; }
  .canvas-container { width:100%; max-width:750px; margin:0 auto; }
}

@media (max-width:700px) {
  .density-sim-page { padding-left:14px; padding-right:14px; }
  .sim-wrapper { margin-top:12px; }
  .sim-container { padding:12px; gap:14px; border-radius:10px; }
  .controls { display:flex; width:100%; gap:12px; }
  .control-group { padding:12px; }
  .action-row { display:grid; grid-template-columns:minmax(0,1fr) 100px; }
  .utility-toolbar { display:grid; grid-template-columns:1fr 1fr; }
  .utility-toolbar .reset-btn { grid-column:1 / -1; }
  .segment-btn,.sim-btn,.utility-toolbar button { min-height:44px; }
  .canvas-container { overflow:hidden; }
  canvas#simCanvas { width:100%; border-radius:8px; }
  .info-box { padding:8px 10px; font-size:.78rem; }
}

@media (max-width:390px) {
  .action-row { grid-template-columns:1fr; }
  .sim-btn.random-btn { width:100%; }
  .segmented-control { flex-direction:column; gap:3px; }
}