app/@overflow/commons/ui/component/window/window-controls.component.html

<div class="window-controls">
  <button aria-label="minimize" tabindex="-1" class="window-control minimize" (click)="onMinimize($event)">
    <svg aria-hidden="true" version="1.1" width="10" height="10">
      <path d="M 0,5 10,5 10,6 0,6 Z" />
    </svg>
  </button>
  <ng-container [ngSwitch]="windowState">
    <button *ngSwitchCase="maximized" aria-label="restore" tabindex="-1" class="window-control restore" (click)="onRestore($event)">
      <svg aria-hidden="true" version="1.1" width="10" height="10">
        <path d="m 2,1e-5 0,2 -2,0 0,8 8,0 0,-2 2,0 0,-8 z m 1,1 6,0 0,6 -1,0 0,-5 -5,0 z m -2,2 6,0 0,6 -6,0 z" />
      </svg>
    </button>
    <button *ngSwitchDefault aria-label="maximize" tabindex="-1" class="window-control maximize" (click)="onMaximize($event)">
      <svg aria-hidden="true" version="1.1" width="10" height="10">
        <path d="M 0,0 0,10 10,10 10,0 Z M 1,1 9,1 9,9 1,9 Z" />
      </svg>
    </button>
  </ng-container>
  <button aria-label="close" tabindex="-1" class="window-control close" (click)="onClose($event)">
    <svg aria-hidden="true" version="1.1" width="10" height="10">
      <path d="M 0,0 0,0.7 4.3,5 0,9.3 0,10 0.7,10 5,5.7 9.3,10 10,10 10,9.3 5.7,5 10,0.7 10,0 9.3,0 5,4.3 0.7,0 Z" />
    </svg>
  </button>
</div>