mempool/frontend/src/app/components/block-overview-graph/block-overview-graph.component.html

<div class="block-overview-graph">
  <canvas class="block-overview-canvas" [class.clickable]="!!hoverTx" #blockCanvas></canvas>
  <div class="loader-wrapper" [class.hidden]="(!isLoading || disableSpinner) && !unavailable">
    <div *ngIf="isLoading" class="spinner-border ml-3 loading" role="status"></div>
    <div *ngIf="!isLoading && unavailable" class="ml-3" i18n="block.not-available">not available</div>
  </div>

  <app-block-overview-tooltip
    [tx]="selectedTx || hoverTx"
    [cursorPosition]="tooltipPosition"
    [clickable]="!!selectedTx"
  ></app-block-overview-tooltip>
</div>