/* ── INFRA LAYER SIDEBAR ── */
  .infra-group { border-bottom: 1px solid var(--border); }
  .infra-group-header {
    display: flex; align-items: center; gap: 8px; padding: 8px 14px;
    cursor: pointer; transition: background .12s; user-select: none;
  }
  .infra-group-header:hover { background: var(--surface2); }
  .infra-group-icon { font-size: 15px; flex-shrink: 0; width: 20px; text-align: center; }
  .infra-group-name { flex: 1; font-size: 11px; font-weight: 600; color: var(--text); }
  .infra-group-arrow { font-size: 10px; color: var(--muted); transition: transform .2s; }
  .infra-group-arrow.open { transform: rotate(90deg); }
  .infra-sublayer-list { display: none; background: rgba(0,0,0,.12); }
  .infra-sublayer-list.open { display: block; }
  .infra-sub-row {
    display: flex; align-items: center; gap: 8px;
    padding: 5px 14px 5px 32px; cursor: pointer; transition: background .1s;
  }
  .infra-sub-row:hover { background: var(--surface2); }
  .infra-sub-row input[type=checkbox] { width: 12px; height: 12px; accent-color: var(--accent); flex-shrink: 0; }
  .infra-sub-symbol {
    width: 22px; height: 22px; border-radius: 50%; flex-shrink: 0;
    display: flex; align-items: center; justify-content: center;
    font-size: 12px; border: 1.5px solid rgba(255,255,255,.25);
  }
  .infra-sub-symbol.line-sym {
    border-radius: 3px; height: 14px; width: 26px;
  }
  .infra-sub-symbol.poly-sym {
    border-radius: 4px; width: 22px; height: 16px;
  }
  .infra-sub-label { font-size: 11px; color: var(--text); flex: 1; }
  .infra-sub-count { font-size: 10px; color: var(--muted); }