.versions-box {
  max-height: 260px;
  overflow: auto;
  border: 1px solid #e5e7eb; /* light grey */
  border-radius: 4px;
}

/* Scope: only inside this popup */
.customer-picker-row .customer-tree-scroll {
  max-height: 250px;      /* < 250px: grow/shrink with content */
  overflow: auto;         /* scrollbar only when needed */
  border: 1px solid #e9ecef;
  border-radius: 0.25rem;
  background: #fff;
  padding: 0.5rem;
  min-height: 0;          /* ensure no unintended minimum */
}

/* keep layout tidy */
.customer-picker-row .col-sm-9 {
  display: flex;
  flex-direction: column;
}

.versions-row .versions-box {
  border: 1px solid #e9ecef;
  border-radius: 0.25rem;
  background: #fff;
}