@media (max-width: 900px) {
  .workspace, .lower-grid { grid-template-columns: minmax(0, 1fr); }
  .map-panel, .tide-panel, .metrics-panel, .side-panel { min-width: 0; }
}
@media (max-width: 620px) {
  .snapshot-note { min-width: 0; }
  .chart { overflow: hidden; }
  .intro, .workspace, .lower-grid, footer { max-width: 100%; }
}